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Comments 129801 to 129850:

129801. Patrick 027 at 09:11 AM on 21 April 2009
        It's the sun
        “The Geography of Poverty and Wealth” by Jeffrey D. Sachs, Andrew D. Mellinger, and John L. Gallup, Scientific American, March 2001, pp.70-75, http://www.earth.columbia.edu/sitefiles/File/about/director/documents/SCIAM032001_000.pdf p.74: "Winter could be considered the world’s most effective public health intervention."
129802. Patrick 027 at 06:42 AM on 21 April 2009
        It's the sun
        ... and the albedos of snow, ice, and clouds are much higher for solar radiation than for terrestrial radiation. The terms 'albedo' and 'albedo feedback' are generally assumed to refer to SW (shortwave; solar radiation) effects; for Earthly conditions, LW (longwave; terrestrial) radiation processes are dominated by emission and absorption with reflection/scattering playing only a minor role.
129803. Patrick 027 at 05:18 AM on 21 April 2009
        It's the sun
        "It's average albedo has no effect . See http://cosy.com/Science/TemperatureOfGrayBalls.htm . The implementation there needs to be extended to colored spectra ," Earth's albedo at solar-dominated wavelengths is about 0.3. At wavelengths dominated by terrestrial emissions, it is closer to zero.
129804. Patrick 027 at 04:59 AM on 21 April 2009
        It's the sun
        Gord - so you aren't going to talk to a physics professor? Too bad for you. Bob Armstrong - skinny spectral lines? Have you ever seen the CO2 spectrum? Satellites can and have measured the spectrum of radiation emitted by the Earth to space and both water vapor and CO2 take significant chunks out of the total energy from the surface (by hiding it underneath the cooler atmosphere, which radiates to space but with less power). CO2 does this significantly between about 12 and 18 microns; the effect at the tropopause is saturated near the center of this band but not at the edges; the tendency is for each doubling of CO2 (within a range that we are currently in) to reduce net outgoing radiation at the tropopause by nearly 4 W/m2; the climatic response to this forcing is for the troposphere and surface temperature to increase until the radiative balance is restored; feedbacks occur that make the process a bit complicated. The band of absorption by a gas consists of some or many absorption lines; in the absence of line spreading mechanisms, these would have little width and not have much effect over the whole spectrum; however, random molecular motions and collisions broaden each contributing line so that they can form an absorption spectrum with peaks and valleys, but with significant absorption occuring even in the valleys. Unless the total C content of the biosphere and ocean are changing, the large C fluxes between those and the atmosphere must be balanced. The very small geologic outgassing rate also tends to be balanced by C sequestration by chemical weathering and organic C burial. There is a negative feedback that acts significantly over very long periods of time (generally longer than glacial-interglacial time scales), changes in the sun, geological outgassing, and forced changes in chemical weathering and organic carbon burial caused by continental drift and the raising of mountain ranges, etc, cause climate changes that tend to (depending on geography) change the chemical weathering rate in a compensating way (it may also change the organic carbon burial rate, though not necessarily in a compensating way (?), and also depending on geography); a long-term equilibrium climate occurs when the chemical weathering rate and organic carbon burial rate together balance the geologic outgassing rate. The biologic portion of the C cycle (any portion of it) will also be affected over many millions of years by biological evolution. The glacial-interglacial variability on the 20,000 to 100,000 year time scale is likely caused by Milankovitch cycles; not so much by changes in global annual average radiative forcing, but by large latitudinal and seasonal redistributions of solar heating, which, when certain thresholds are exceeded in one or the other directions (won't be the same value in both directions), can favor ice sheet formation and growth, or ice sheet decay and disintegration. The climatic response involves globally-averaged positive feedbacks - in particular, the positive albedo feedbacks of snow and ice, with some contribution from vegetation and aerosol changes, and also a positive greenhouse gas feedback from changes in CO2 and a couple other gases (and of course the faster-acting feedbacks that are involved in all climate changes, including water vapor). The precise mechanisms of the greenhouse feedbacks is not fully understood, but is understood to exist based on the robust correlation between greenhouse gas concentrations and climate on the glacial-interglacial time scale. Changes in atmospheric CO2 on this time scale can be caused by redistribution of C among the atmosphere, biomass, soil, upper ocean, and deep ocean; one potential factor is an increase in biological C sequestration from the upper ocean (which will then take CO2 from the atmosphere); this doesn't necessarily involve a large increase in geological sequestration because organic C precipitating from the upper ocean may be oxidized in the deep ocean; however, it will then be stored in the deep ocean until currents transport it upward - thus C storage in the ocean depends on the locations of biological C uptake relative to oceanic circulation patterns, and both can change in response to climate. Changes in oceanic pH caused by changing CO2 concentration can be buffered by dissolution of carbonate minerals and, generally over longer time periods, by the supply of dissolved elements by chemical weathering. Human activity has caused most if not all of the increase in CO2, CH4, CFCs, and if I'm not mistaken, N2O, over the last couple centuries. A majority, especially recently, is from the burning of fossil fuels - effectively an artificial acceleration (by well-over an order of magnitude) of geological outgassing. Some is also from cement production, and some (especially farther back in time) is from deforestation. This has occured significantly faster than glacial-interglacial changes in atmospheric composition and has gone outside the range of the variations over at least the last several hundred thousand years. The CO2 increase has been too rapid for oceanic pH buffering. There have been and are still some addtional uptakes, by oceans and biomass, of CO2 in response to the anthropogenic emissions; however, they are only a portion of the anthropogenic flux, so atmospheric CO2 has and is still increasing. There are limitations to how much more CO2 can be taken up from the atmosphere over a given time scale (limits to much more can the mass of C in biomass and soil increase, and limits on oceanic uptake because of oceanic chemistry and the limited rate of water exchanged between the upper and deep ocean), and climate change itself has the potential to reduce if not reverse these additional uptakes of CO2 from the atmosphere (as well as adding more CH4). Rapid and large changes into relatively unfamiliar conditions (unfamiliar as gauged by how long ago such conditions last occured) put stresses on ecosystems (even when species migrate or adapt, they may do so at different rates or in different ways - for example, the change in the activity of pollinators may not match the change in the plants whey would pollinate; also, different plant species will not respond the same way to CO2 changes and their response can be limited by other conditions - this is of relevance to agriculture) and can cause extinctions over and above the background level, up to the point of mass extinctions. Ecosystems are even more vulnerable if they are already under other stresses - such as habitat destruction and disintegration. If ecosystem stresses cause deforestation faster than aforestation (which is likely for a rapid climate change), then this could be an additional CO2 feedback. A CO2 sink will eventually materialize when boreal forests advance northward to replace tundra, although that will also be a positive albedo feedback. Human culture, including the economy, including infrastructure and farming, constitute an ecosystem - certainly one which can evolve in at least some ways much faster than any 'natural' ecosystem. However, an imposed change that requires adaptation will not be without costs. Soil does not migrate very fast. As with plants in general, some crops are photoperiod sensitive and so cannot simply be moved to follow temperature and moisture without additional breeding or loss of productivity. Temperature in not the only limiting factor in the growing season, and tropical conditions are not kind to many valued food crops. While some regions may experience increased agricultural productivity at first, this is only up to a point beyond which further climate change will reduce productivity, and this also tends to apply more to regions which already have enough food (for now). There are also biological ecosystem services, such as free pollination, that must be acknowledged (as well as natural pest control - biotic and abiotic factors apply). It is naive to expect global warming and CO2 increases to result in dependable bumper crops world-wide. The regular availability of fresh water resources - not just for agriculture - is of great concern in some regions. Warming also increases risk for some tropical diseases. It has been said that winter is our most effective public health program (see later comment for reference**). Our buildings and other infrastructure are designed for conditions - when those conditions change, infrastructure will require remodeling. Of course, the full cost is reduced when accounting for maintenance that must be done anyway (and that infrastructure yet to be developed). But it will cost when people must migrate upward from sea level (a large fraction of the world's people have settled near sea level) and away from newly arid regions, and perhaps abandon an even larger fraction of homes in some places than would be otherwise justified to reduce river and urban flooding costs. There are concerns about severe weather (not just tropical cyclones - extreme precipitation events in general, perhaps among other things; although in some places, winter headaches (land and air travel problems and costs) will be reduced - but not when and where snow is replaced by ice). There is confidence that a doubling of CO2 will increase global average surface temperature by about 3 +/- 1 degree C or so. Some regional effects, including general poleward shifts in midlatitude storm tracks, with associated drying on the low-latitude edge of storm tracks and increasing precipitation at high latitudes, as well as a sea level increase (which will not stop at 2100 - there are long term effects), are expected with confidence. But some uncertainty remains in the global average changes and especially with associated regional effects. This uncertainty imposes some adaptation costs by reducing the ability to plan - although it may also have a benifit in discouraging use of climate as a weapon.
129805. XPLAlN at 03:18 AM on 21 April 2009
        Is the climate warming or cooling?
        I woke up today feeling great - like I was 10 years younger. So I cross referenced my birth certificate with the calender and was upset to discover that I am in fact continuing to age. Bummer, but good job I checked.
        Response: I on the other hand tend to feel older than I really am. Dang natural variability!
129806. Gord at 16:46 PM on 20 April 2009
        It's the sun
        AGW Theory: 1. VIOLATES the 2nd Law of Thermodynamics. 2. VIOLATES the Law of Conservation of Energy. 3. VIOLATES Electromagnetic Physics. 4. VIOLATES the Stefan-Boltzmann Law 5. VIOLATES Heat Radiation Physics. 6. VIOLATES Vector Mathematics. 7. VIOLATES Actual Measurements. 8. VIOLATES Cause and Effect logic. Further, despite over $50 Billion having been spent on AGW "research" and literally thousands of papers produced on the subject: - There is not even ONE Law of Science that supports AGW. - There is not even ONE measurement that shows that atmospheric CO2 can heat the Earth. ----------- "In academia and science, fraud can refer to academic fraud – the falsifying of research findings which is a form of scientific misconduct – and in common use intellectual fraud signifies falsification of a position taken or implied by an author or speaker, within a book, controversy or debate, or an idea deceptively presented to hide known logical weaknesses." http://en.wikipedia.org/wiki/Fraud Forms of scientific misconduct include: fabrication – the publication of deliberately false or misleading research, often subdivided into: - fabrication – the actual making up of research data and (the intent of) publishing them - falsification – manipulation of research data and processes or omitting critical data or results Another form of fabrication is where references are included to give arguments the appearance of widespread acceptance, but are actually fake, and/or do not support the argument" http://en.wikipedia.org/wiki/Scientific_misconduct ------------- I think AGW Theory is fraudulent and the people who claim that AGW is factual are guilty of fraud and scientific misconduct because: 1. AGW is deceptively presented to hide known logical weaknesses. 2. AGW omitts critical data or results.
129807. Bob Armstrong at 10:31 AM on 20 April 2009
        It's the sun
        Scanning the above , a lot is excessively complex . Simple application of Stefan-Boltzmann and Kirchhoff shows the mean temperature of the earth will inevitably be about 1/21st the effective surface temperature of the sun . It's average albedo has no effect . See http://cosy.com/Science/TemperatureOfGrayBalls.htm . The implementation there needs to be extended to colored spectra , but its highly unlikely the couple of skinny spectral lines of CO2 , particularly when multiplied by the small portion released by man , relative to the already highly saturated base , has virtually any detectable effect . In any case , this analysis produces experimentally falsifiable numbers . I have never found an experimental demonstration of the purported "greenhouse" effect . Of course , plants being almost totally CO2 + H2O love that extra 3% man released from that sequestered in geologically lush ages . There is no question the planet is greener for the CO2 we are returning to the atmosphere .
129808. Quietman at 03:30 AM on 20 April 2009
        There is no consensus
        HealthySkeptic My point was less the conversion than the words that he used. "There is no real substitute, except the get the real science right"
129809. Quietman at 03:27 AM on 20 April 2009
        It's the sun
        Patrick My point is simply that it is yet another variable that was not accounted for in the models. There are just too many factors ignored for the models to work.
129810. GFW at 18:36 PM on 19 April 2009
        Arctic icemelt is a natural cycle
        What jecht8 either doesn't know or acknowledge is that it took Amundsen 3 years to make the trip because only bits opened up at a time. Also, he took an extremely shallow water route sticking close to the mainland shore. When we speak of the NW passage opening now, we're talking about being able to go pretty much full speed, just steering around a few bergs - and it's the more northern, deep water route.
129811. Patrick 027 at 13:59 PM on 18 April 2009
        It's the sun
        Re Quietman - My earlier use of a ratio of 30,000,000,000,000,000 for the heat capacity of the climate system to the heat capacity of the solar wind may have been a bit off. If the solar wind plasma has a specific heat comparable to air, the heat capacity per square meter of the faster-reacting portion of the climate system (including the top 100 m of the ocean) is about 100,000,000,000 times that of the solar wind passing through a square meter in about 20 years. 150,000 K / 100 billion = 0.0000015 K. That doesn't include the factor of 4 for spherical geometry, although it also doesn't include the ratio of the effective capturing area to the area of the Earth.
129812. Patrick 027 at 13:29 PM on 18 April 2009
        It's the sun
        Clarification end of my comment 254: ..."much much greater forces (Winds, climate-driven buoyancy variations, tides) shape the ocean's conditions and dynamics and variability in these dwarf any short-term volcanic effects (Panama wasn't built in a single millenium). " I was refering in that context to just the direct geothermal heating effects, and not the radiative forcing of volcanic aerosols. ---- Other notes (with no significant climatological implications) Relativistic effects - if two blackbodies are moving toward each other, their radiation will be blueshifted upon absorption relative to the energy it had upon emission. The blackbodies would appear to be hotter to each other than they actually are. Where does the energy come from? For simplicity, consider two blackbody surfaces sliding toward each other like pistons in mirrored tube, so they only see each other and nothing else. 1. As the pistons move toward each other, the volume in between decreases. At thermodynamic equilibrium, the volume between bodies with nonzero emissivity will be filled with radiation with some energy density that depends on the temperature of those bodies. Even outside of equilibrium, the volume between the two blackbody pistons will contain photons being exchanged. As that volume shrinks, the energy density of that space will tend to increase due to the blue-shift that causes (if the blackbody pistons are insulated on their opposited sides) the temperature of the pistons to rise, but not enough to maintain the same total energy of the photons in the space between the pistons. Thus, the decreasing total energy of the radiation contained between the pistons is due to a net transfer of energy to the pistons. 2. Energy is also added to the system by the work that must be done against radiation pressure to push the pistons together.
129813. Patrick 027 at 13:05 PM on 18 April 2009
        It's the sun
        Gord - You might want to actually talk to a physics professor sometime.
129814. Gord at 08:27 AM on 18 April 2009
        It's the sun
        Patrick - You are entitled to your "opinions". It appears that is all you have posted. Laws of Science are generally accepted as being fundamental truths in any scientific endeavor or discussion. I do accept attempted re-writes, attempted dis-proofs or use of analogies that violate these fundamental laws to be a valid basis for any scientific debate. My posts are based on established Laws of Science and actual physical measurements that have been duplicated and verified. Third-party readers, who accept these Laws of Science as being valid, are my target audience.
129815. HealthySkeptic at 15:30 PM on 17 April 2009
        There is no consensus
        Yes Quietman, And David Evans is just one of a growing number of scientists who work or have worked in AGW-related fields to finally 'see the light' as it were.
129816. HealthySkeptic at 15:21 PM on 17 April 2009
        Misinterpreting a retraction of rising sea level predictions
        Thanks Mizimi, I can't wait for Chris' creative interpretation of this new data. When reading the protestations of fervent AGW proponents I am constantly reminded of creationist leader Henry Morris who decreed that any scientific evidence that did not support a 'young earth' was to be "explained away".
129817. Patrick 027 at 14:47 PM on 17 April 2009
        Why is Antarctic sea ice increasing?
        Timothy Chase - I have actually tracked down some articles on the subject, though haven't actually gotten to reading most of them yet. I may post the websites sometime... I have a long-running series of comments at: http://www.skepticalscience.com/Arctic-sea-ice-melt-natural-or-man-made.html (Starting at comment ~272) about atmospheric circulation, eventually focussing on wave-mean interactions, in particular Rossby waves. By the time of my last comments on that matter so far (~ 491 - 496), I had only just established the basic concepts that may be necessary for understanding storm track variability and troposphere-stratosphere interactions...(I was figuring some of it out as I explained it).
129818. Patrick 027 at 10:19 AM on 17 April 2009
        It's the sun
        "If this were not true, then I could build a perpetual motion machine. If an orange hot object can emit red photons " Later in that paragraph I accidentally switched "orange hot" for "white hot" - out of habit. Either would work in this example. Sorry for the confusion (Don't think you've gotten me to waste my time writing stuff you don't care about, Gord - I wrote this for the benifit of third-party readers).
129819. Patrick 027 at 10:13 AM on 17 April 2009
        It's the sun
        corrections/clarification: Another reason objects in the solar oven may reach lower temperatures at night than the surrounding land surface is that they are not connected to the heat capacity of the land surface (bearing in mind that the later is effectively limited for any heating cycle by the time it takes for heat to diffuse over distance; I think for the diurnal cycle, the surface can store and draw heat to and from depths of maybe 20 cm ?). Depending on local weather conditions, Brigham Young University may be a better site to use the solar oven for cooling purposes than other places - places with higher humidity and lower elevation. An object being heated by 168 W/m2 solar radiation and 324 W/m2 from the atmosphere will warm up or cool off until it loses, by convection and radiation emission, 168 + 324 = 492 W/m2. Even with a majority of the 324 W/m2 of atmospheric radiation remaining, removal of the 168 W/m2 of solar heating will cause that object to cool to a lower temperature until it only loses by convection and emission 324 or less W/m2. ----- Locally, the average Poynting vector of diffuse solar radiation, from blue sky or clouds, may tend to be nearly straight downward, but obviously the Poynting vector of the direct (beam) solar radiation will vary, being nearly horizontal (and per unit area horizontal surface, nearly zero) close to sunrise and sunset. ________________________________ Gord: "Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics." I, and many others, have been over that piece of trash before - see this selection of comments (all of mine and a few of some others, but feel free to see all responses by others, of course): http://www.realclimate.org/index.php/archives/2009/03/olympian-efforts-to-control-pollution/langswitch_lang/in (*** indicates comment by another person) Radiation in the atmosphere: 131 - 17 March 2009 at 11:40 PM 132 - 17 March 2009 at 11:50 PM 133 - 17 March 2009 at 11:55 PM 144 - 18 March 2009 at 1:32 PM *** 145 - 18 March 2009 at 1:44 PM 149 - 18 March 2009 at 11:29 PM 150 - 18 March 2009 at 11:42 PM 186 - 19 March 2009 at 11:00 PM 188 - 19 March 2009 at 11:28 PM Responses to G&T: *** 163 - 19 March 2009 at 11:21 AM (note link!) 189 - 19 March 2009 at 11:37 PM - http://www.realclimate.org/index.php/archives/2009/03/olympian-efforts-to-control-pollution/langswitch_lang/in#comment-115353 *** 194 - 20 March 2009 at 7:59 AM 210 - 20 March 2009 at 5:58 PM 211 - 20 March 2009 at 6:08 PM 231 - 21 March 2009 at 2:12 PM 232 - 21 March 2009 at 4:05 PM 254 - 23 March 2009 at 1:35 PM 267 - 23 March 2009 at 8:16 PM 268 - 23 March 2009 at 8:24 PM 269 - 23 March 2009 at 8:29 PM *** 271 - 23 March 2009 at 11:17 PM 274 - 23 March 2009 at 11:48 PM *** see link in response to 297, 24 March 2009 at 12:40 PM 308 - 24 March 2009 at 11:13 PM (note links!) 309 - 24 March 2009 at 11:43 PM 310 - 24 March 2009 at 11:52 PM *** 314 - 25 March 2009 at 7:18 AM 323 - 25 March 2009 at 6:07 PM *** 337 - 28 March 2009 at 9:03 AM - http://www.realclimate.org/index.php/archives/2009/03/olympian-efforts-to-control-pollution/langswitch_lang/in#comment-116369 not dealing specifically with radiation: 148 - 18 March 2009 at 11:11 PM 230 - 21 March 2009 at 2:05 PM ________________ "I am really amused when I read "science" like this:"... "The Greenhouse Effect" http://www.physicalgeography.net/fundamentals/7h.html "Tutorial on the Greenhouse Effect- University of Arizona" http://www.lpl.arizona.edu/~showman/greenhouse.html The first one states that 90 % of atmospheric radiation is to the surface; I think the actual value is different (and it could be described more clearly, though I am only going by the excerpt you provide). The second implies that none of the radiation directly from the surface reaches space, and that the atmosphere emits equally upward and downward; these are not true, but the excerpt refers to a 'simple' model; often when a concept is introduced it is introduced with a very simple model that illustrates a process qualitatively but cannot readily be applied to actual situations. "Somehow, they must have missed the fact that the Sun is the only energy source and what they describe is really a perpetual motion machine in a positive feed-back loop." Somehow, amazingly (to the point that I have wondered if you are being honest in your demonstration of apparent inability to understand physics and also perhaps lack of basic arithmetic skills - or perhaps you are not even trying to understand anything), you have missed the fact that they, Kiehl and Trenberth, climatologists in general, and myself, all realize that the sun is the only significant energy source (tides, geothermal heat fluxes being tiny) in the energy budget of the climate system. You also seem to have little understanding of what a perpetual motion machine actually would do. ---- "No matter how much you want to believe that there is a way around the 2nd Law of Thermodynamics and the Law of Conservation, there is none." Same to you. With variation over wavelengths, overall the atmosphere looks cooler from above than from below because of the general temperature decrease with height in the troposphere; it radiates more downward than upward. (The atmosphere recieves more heat (from convection and radiation) from below from the solar-heated surface than it does directly from radiation; convection can reduce the temperature decrease with height only to a moist-adiabatic limit (where it occurs - within the troposphere).) Whereever there is radiative energy exchanged by thermal emission and absorption between bodies which are themselves in local thermodynamic equilbrium, the net flow of energy is from warmer to cooler, because for two objects, at any given wavelength, each of any emissivity (with absorptivity = emissivity) as any function of wavelength, for each line of sight (whatever turns it may take by scattering, refraction, or reflection) that connects the two, of the radiation emitted and absorbed by the objects being considered, there will be greater radiant intensity in the direction toward the cooler object than in the reverse. You can add the two sets of electromagnetic waves and find an average Poynting vector that goes from warmer to cooler, if you prefer that. But at any given wavelength (and direction, polarization, etc., for local thermodynamic equilibrium), an object has to have the same absorptivity as emissivity - for reasons stated in the "hyperphysics" website that you trust for your information about the second law of thermodynamics. If this were not true, then I could build a perpetual motion machine. If an orange hot object can emit red photons to a red hot object that absorbs them, and yet not absorb any red photons from that red hot object, then its optical properties are such that I could substitute a blue hot object for the red hot object, use an optical filter so that only red photons can go between the objects (other photons being reflected back to the objects), and have the white hot object spontaneously lose heat to the blue hot object. Using spontaneously heat flow from the blue hot object to the white hot object along a different path, I could run a heat engine. This set-up would convert heat energy to work energy in a manner that decreases the entropy of a closed isolated system; it would draw in heat energy at high entropy (low temperature) to run a perpetual motion machine. That would violate the second law of thermodynamics. And I AM TELLING YOU that this will not happen in physical reality. (In case you need another analogy, in thermodynamic equilibrium in a chemical reaction, the forward and reverse reactions are happening at the same rate; it does not mean activity on the molecular level has ceased.) The optical properties will not spontaneously change just by moving external objects around. Have you ever had your stovetop heating elements on? Did you notice them glowing red? Did you turn on an incandescent light bulb (filament hotter than red-hot) while the heating element was on? If so, did the heating element suddenly stop glowing in order to avoid radiating millions of photons toward the bulb, to avoid one of those photons being scattered into the bulb (as the light from a frosted light bulb is scattered on the way out) at the right direction to hit the filament and be absorbed? That's not how physical reality works. "On that note, I will no longer respond to any of your posts where you have used repeated violations of these basic Laws of Science to make your points." Those violations are a figment of your lack of understanding. Anyway, I ought to be saying that to you.
129820. chris at 07:33 AM on 17 April 2009
        Comparing IPCC projections to observations
        Not really Mizimi. If one compares the Mauna Loa data with the CO2 data averaged over the marine surface sites, it's pretty clear that we have a pretty reliable measure of monthly averaged, and especially yearly averaged atmospheric CO2 data: both data sets here: http://www.esrl.noaa.gov/gmd/ccgg/trends/ Apart from the the contrived "fishing" for problems that don't exist, are you at some point going to indicate in what respect the Mauna Loa data is inadequate for a specific purpose? and what is the "ARES satellite data"? Link please. and can you give an example of what you mean by "...projections using that data..."? An example of your "projections" please. rather than just saying stuff, why not show us the evidence. Where is the "red blob", and on what satellite data? argumentation by vagueness and insinuation isn't very scientific Mizimi. Be specific. Show us the data ("ARES" ??....."red blobs on the left of the picture" ??).
129821. Mizimi at 04:31 AM on 17 April 2009
        Comparing IPCC projections to observations
        Chris: take a look at the latest ARES satellite data on CO2 levels. Mauna Loa stands out as a small red blob on the left of the picture; in other words as an anomaly - high compared to other sea level measurements. Mauna Loa may well be a reliable measure of levels, AT THAT SITE ( your words) but that is not the same as accurate. The satellite data shows ML to be high compared to the global condition and thus any projections using that data are suspect.
129822. Mizimi at 04:12 AM on 17 April 2009
        Misinterpreting a retraction of rising sea level predictions
        Have a look at this: http://www.friendsofscience.org/assets/documents/FOS%20Essay/GlobalTroposphereTemperaturesAverage.jpg which shows a linearised temp trend downwards since 2002, an actual decrease of 0.2C in 6 years. Yes, 1998 was an anomaly, but the cooling trend is continuing.
129823. Mizimi at 03:49 AM on 17 April 2009
        The link between hurricanes and global warming
        #24 The graphs at the website QM points to in #23 show a steep decline in cyclone activity in both hemispheres ( if you go to the bottom of the page both hemispheres are shown over a time series from 1970 to 2009). This suggests that there is decreasing overall energy in the climate system as both the frequency and intensity have fallen to historic lows. This correlates ( at face value) with satellite data showing a cooling trend over the last decade. So one might argue that weather is becoming less dynamic...but the sensitivity of our instrumentation has improved and the sensitivity of our societies to weather based disruption has increased..so it 'seems' the weather is more dynamic. One possibility that may give some further insight is to access a meteorological database that logs windspeed and use that as an indicator.
129824. Mizimi at 03:27 AM on 17 April 2009
        Does Urban Heat Island effect add to the global warming trend?
        One issue about UHI seems to be swept under the carpet...namely they affect weather - not just locally but over quite large distances. Warm air plumes,wind shadows,water vapour additions all serve to change the local microclimate which in turn affects the general conditions. Whilst the thermal data may be adequately corrected for UHI effects, how do you factor in the physical changes caused by the very existence of cities?
129825. Mizimi at 03:16 AM on 17 April 2009
        Temp record is unreliable
        #45 Unfortunately most of the weather stations in Siberia have been shut down and if you look up the current distribution of weather stations globally they are distributed very unevenly...the highest density being in the USA. Many other parts of the world are not 'thermally' represented so any global mathematical average (however it is derived) is going to be wrong. Satellite measurement has been around now for only 30 years so whilst we have a more even distribution of data (not necessarily more accurate) the data series is too short for any predictive climate modelling. Interestingly, the current series of satellite temperature data shows a clear cooling trend since 2002 despite increasing CO2 levels.
129826. Gord at 18:25 PM on 16 April 2009
        It's the sun
        I am really amused when I read "science" like this: ---- The Greenhouse Effect "Absorption of longwave radiation by the atmosphere causes additional heat energy to be added to the Earth's atmospheric system. The now warmer atmospheric greenhouse gas molecules begin radiating longwave energy in all directions. Over 90% of this emission of longwave energy is directed back to the Earth's surface where it once again is absorbed by the surface. The heating of the ground by the longwave radiation causes the ground surface to once again radiate, repeating the cycle described above, again and again, until no more longwave is available for absorption." http://www.physicalgeography.net/fundamentals/7h.html ---- Tutorial on the Greenhouse Effect- University of Arizona "In this case, the Earth still gains 240 Watts/meter2 from the sun. It still loses 240 Watts/meter2 to space. However, because the atmosphere is opaque to infrared light, the surface cannot radiate directly to space as it can on a planet without greenhouse gases. Instead, this radiation to space comes from the atmosphere. However, atmospheres radiate both up and down (just like a fire radiates heat in all directions). So although the atmosphere radiates 240 Watts/meter2 to space, it also radiates 240 Watts/meter2 toward the ground! Therefore, the surface receives more energy than it would without an atmosphere: it gets 240 Watts/meter2 from sunlight and it gets another 240 Watts/meter2 from the atmosphere -- for a total of 480 Watts/meter2 in this simple model." http://www.lpl.arizona.edu/~showman/greenhouse.html ----- Somehow, they must have missed the fact that the Sun is the only energy source and what they describe is really a perpetual motion machine in a positive feed-back loop.
129827. Gord at 18:01 PM on 16 April 2009
        It's the sun
        Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics. International Journal of Modern Physics B, Vol. 23, No. 3 (30 January 2009), 275-364 Notice what is said in the Abstract: "The atmospheric greenhouse effect, an idea that authors trace back to the traditional works of Fourier 1824, Tyndall 1861, and Arrhenius 1896, and which is still supported in global climatology, essentially describes a fictitious mechanism, in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system." AND... "According to the second law of thermodynamics such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature it is taken for granted that such mechanism is real and stands on a firm scientific foundation." http://arxiv.org/abs/0707.1161
129828. Gord at 17:40 PM on 16 April 2009
        It's the sun
        Patrick - Re: Your Posts #281, #282, #283, #284 etc. Again, I disagree with all these Posts. I really think that the Law of Conservation of Energy, the 2nd Law of Thermodynamics are beyond dispute. The Trenberth Energy Budget diagrams show the Earth radiating 390 w/m^2 and the in-comming Solar radiation (the only energy source) is only 342 w/m^2. This is a clear violation of the Law of Conservation Energy and is not disputable. The colder atmosphere Back Radiation of 324 w/m^2 is also shown to be absorbed by the much warmer Earth surface. This violates the 2nd Law of Thermodynamics and is proven to do so by actual measurements done by Physics Dept.of Brigham Young University, Utah. These same results have been verified by previous tests at Brigham Young University. The Back Radiation of 324 w/m^2 is also greater than the 198 w/m^2 Solar radiation reaching the Earth's surface (as shown in Trenberth's Energy Budget diagram). Another clear violation of the Law of Conservation Energy and is not disputable. Remember this Back Radiation is supposed to have caused the entire Earth to increase in temperature from -18 deg C to +15 deg C, according to the AGW'ers. But, obviously, it can't even prevent water from freezing when the Back Radiation is concentrated at the focal point of a Solar Oven, as proven in the Brigham Young University experiments. If the 324 w/m^2 Back Radiation actually reached the Earth's surface it should produce more heating than Solar radiation, even at night. There are probably over a million Solar Ovens on the planet and none will produce heating at night. If they did, the worlds energy problems would be solved. There is no "refigerator in the sky". No matter how much you want to believe that there is a way around the 2nd Law of Thermodynamics and the Law of Conservation, there is none. On that note, I will no longer respond to any of your posts where you have used repeated violations of these basic Laws of Science to make your points.
129829. Patrick 027 at 12:29 PM on 16 April 2009
        It's the sun
        "This is closely related to inverse square laws." The relationship between the solid angle filled by an object from a point to the distance between that point and the object is such that the same inverse square laws for point masses and charges (gravitational force due to a point mass and electric force due to a point charge being inversely proportional to the square of the distance from that mass or charge) are analogous to the way radiant flux per unit area facing a point source of radiation varies with distance, and also, the analogy extends to distributions of masses, charges, and radiation sources - that outside of a spherically symmetrical distribution of such things, that force (equal to field line density - the gravitational or electric field flux per unit area) or radiant flux per unit area due to the distribution is inversely proportional to the square of the distance from the center; for a infinite straight line radiator, mass, charge, or current, or outside a cylindrically symmetrical distribution about the center of such a straigth line, the radiant flux per unit area, the gravitational field, the electric field, or the magnetic field will be in proportion to the inverse of the distance from the line; for an infinite flat surface or sheet with even distribution in directions parallel to the surface or sheet of radiation source, mass, charge, or current, the radiant flux per unit area, gravitational field, electric field, or magnetic field, due to that surface or sheet distribution, will be constant across all space on one side of the sheet. (An infinite sheet will fill a full hemisphere of solid angle as seen from any location).
129830. Lee Grable at 08:59 AM on 16 April 2009
        Why is Antarctic sea ice increasing?
        I saw a sattelite photo of Antarctica and noticed a band of icebergs right off and all along the coast. Now it seems to me, with all those icebergs melting that the water along the coast would be less salty, and colder than would otherwise be the case,and thus would freeze at a higher tempurature. I know it sounds simple, but sometimes the simple explanation is the right one.
129831. chris at 01:54 AM on 16 April 2009
        Comparing IPCC projections to observations
        Re #38 It's not obvious what your real point is concerning Mauna Loa CO2 measurements. It looks a bit like "error insinuation" to me, in which one thinks of all the possible things that might be a problem and insinuates that these are a problem! Let's look at some of your insinuations: ONE: CO2 isn't measured....it's a voltage that is measured. Welcome to the modern world Mizimi. In my research I use UV, IR (like the Mauna Loa one most likely), fluorescence.... etc. spectrophotometers. The absorption or emission of a substance (e.g. CO2) at a particular wavelength affects the flux of photons that reach a detector (photomultiplier most likely) and this signal is converted into a voltage. Since the relationship between the voltage and the concentration of the substance is known, the concentration of the substance can be determined rather accurately. Mauna Loa supplement their CO2 measurements with a rigorous calibration protocol in which air containing gases (CO2) at known mole fractions is used to continuously re-establish the quantitative relationship between voltage and CO2 concentration. What specifically about these procedures do you consider to be suspect Mizimi? TWO: "MLO is at around 3200m altitude, so there has to be a correction for PT no?" No that's incorrect. You should read the README file at the NOAA site: http://www.esrl.noaa.gov/gmd/ccgg/about/co2_measurements.html You'll see that one of the reasons for using their calibration protocol is that this obviates the need for very careful control of temperature and pressure. So long as the IR spectrophotometer is continuously calibrated with air containing CO2 at a known conentration/mole fraction, any variations in temperature and pressure are internally corrected for. THREE: "The tables contain blanks where there are no readings". Yes data for 5 months out of the past 50 years is missing (Oct 1958, Feb 1964, March 1964, April 1964, April 1984): ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt Please tell us specifically why you consider that this casts doubt on the reliability of Mauna Loa measurements. FOUR: General insinuation of inaccuracy: The Scripps group determine an independent analysis of atmospheric CO2 concentration at Mauna Loa. This group uses a different method of air collection, analysis and calibration. The Scripps and NOAA atmospheric CO2 data sets for Mauna Loa have an average difference of 0.04 ppm and an annual SD of 0.12 ppm. The Scripps data can be accessed here for comparison with the NOAA data set urled above: http://cdiac.ornl.gov/trends/co2/sio-mlo.html That seems rather good evidence that the Mauna Loa data is a reliable measure of atmospheric CO2 at that site. The fact that the yearly averaged Mauna Loa data is rather similar to the yearly averaged CO2 measures from all of the marine surface sites also indicates that the data from Mauna Loa is a reliable measure of atmospheric CO2. http://www.esrl.noaa.gov/gmd/ccgg/trends/ If you've got some specific evidence of inaccuracy why not show us? Likewise if you consider that the Mauna Loa (and by extension all the other CO2 atmospheric CO2 analysis data) is inadequate for a specific purpose, then that would be interesting.
129832. chris at 00:55 AM on 16 April 2009
        CO2 measurements are suspect
        re #12 For anyone that is interested in knowing what Mizimi's picture actually means, it is Figure 3 of: M. T. Chahine et al. (2008) Satellite remote sounding of mid-tropospheric CO2 Geophys. Res. Lett. 35, L17807, doi:10.1029/2008GL035022. The figure compares the July 2003 satellite-determined CO2 distribution (top panel) with a particular model for CO2 circulation (bottom panel). Not surprisingly there are variations in CO2 concentrations in different regions of the world on a monthly time scale, and this is the reason that the measures of atmospheric CO2 concentrations used to assess the relationshps between emissions and atmospheric concentrations, or atmospheric concentrations and temperature trends, and so on, are yearly-averaged. With respect to the odd attempts to insinuate significant problems with the Mauna Loa data, it's worth pointing out that the July 2003 atmospheric CO2 concentration measured at Mauna Loa was 376.7 ppm: ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt and although the position of the Hawaiian islands are not easy to identify on the map Mizimi linked to (see top map showing the mid-tropospheric satellite-determined (AIRS) atmospheric CO2 for July 2003), the region of the Hawaiian islands has a CO2 concentration in the range >373 and <377.5. So the evidence that Mizimi presents us with (it's not clear what his point was) rather supports the large amount of independent evidence that the Mauna Loa CO2 measurements are reliable determinations of regional atmospheric CO2 concetrations, and when yearly averaged, are reliable measures of globally averaged atmospheric CO2 concentrations. If you want to try to pinpoint the location of the Hawaiian islands and Maun Loa on the AIRS satellite CO2 map for July 2003, here's a picture of a world "globe" with Mauna Loa highlighted: http://www.eoearth.org/article/Mauna_Loa_curve
129833. chris at 00:20 AM on 16 April 2009
        CO2 measurements are suspect
        re #11, Well yes, we can either establish the accuracy and precision of atmospheric CO2 measurements by careful calibrations, duplicate independent determinations at specific sites (as is the case with Mauna Loa), comparison with a multitude of monitoring sites all around the world...... ..or we can throw out the science and fall back on arch insinuations (as in your post #11).
129834. Mizimi at 19:37 PM on 15 April 2009
        Models are unreliable
        QM: Got it, thanks.
129835. Timothy Chase at 16:07 PM on 15 April 2009
        Why is Antarctic sea ice increasing?
        Patrick 027 wrote, "Very informative, Thanks! "From the little bit I've pieced together, I would have thought that the ozone hole - via SAM - would also tend to make the storm tracks shift poleward ?? - but maybe only in winter ????" I am no expert. However, I understand that both the Arctic and Antarctic Polar Vortices are essentially persistent cyclones. The eye of the cyclone will become smaller and more well-defined as the cyclone strengthens and larger and less well-defined as the cyclone weakens. But as I understand it, the cyclone itself should become larger as it strengthens and smaller as it weakens. Thus as the Antarctic Polar Cyclone weakens as the result of the ozone hole repairing itself and reducing the temperature differential between the stratosphere and the troposphere, I would expect it to become smaller, resulting in the Antarctic Polar Vortex and its domain of influence giving way to the moist maritime climate to the north. And as it does so, I would expect the storm tracks in the southern hemisphere to move further southward. Likewise, as the Hadley Cells weaken they tend to expand, and this will shift storm tracks poleward. But as I have said, I am no expert, and if someone knows better I would be interested in learning. In the meantime I will do some digging.
129836. Patrick 027 at 14:45 PM on 15 April 2009
        Why is Antarctic sea ice increasing?
        Very informative, Thanks! From the little bit I've pieced together, I would have thought that the ozone hole - via SAM - would also tend to make the storm tracks shift poleward ?? - but maybe only in winter ????
129837. Patrick 027 at 12:42 PM on 15 April 2009
        It's the sun
        It will help you a lot in understanding radiative energy transfer if you can visualize how things would look at different wavelengths.
129838. Patrick 027 at 12:42 PM on 15 April 2009
        It's the sun
        "LW glow of the atmosphere generally appears hotter near the horizon than straight upward when there are not clouds that are too close to the ground or the water vapor concentration is not too high, etc." Of course, this varies by wavelength. I think it would make the greatest difference generally between about 8 and 12 microns. It might not make any appreciable difference near 15 microns, or longer than ~ 20 microns, or around 6 to 7 microns, etc. - or at such wavelengths where the atmosphere is sufficiently opaque, a thin nighttime inversion would actually make the atmosphere glow brighter closer to the zenith.
129839. HealthySkeptic at 09:59 AM on 15 April 2009
        Did global warming cause Hurricane Katrina?
        Chris, Again you seem to be implying that Prof. Gray's scientific opinion is somehow diminished, simply by having it reported in a media article rather than a scientific journal. If that is indeed the case, then you are more naiive than I thought you were. I think you are just clutching at straws here in trying to explain away the fact that a respected atmospheric scientist simply does not agree with your apparently 'inerrant' scientific paradigm. This trend is growing stronger and stronger in scientific circles... get over it and move on. It's how science works.
129840. Patrick 027 at 09:52 AM on 15 April 2009
        It's the sun
        "It seems that your posts are really about trying to dis-prove the 2nd Law of Thermodynamics and the Law of Conservation of Energy." That's because you're confused. "I don't understand your logic." Then you probably won't understand any of this: ----- In the following and previously I have mentioned that radiant intensity is conserved along any path radiation propagates if there is no emission, absorption, scattering, or partial reflection along that path (perfect reflection without scattering - as with a perfect mirror surface - will conserve intensity, even if the mirror is curved on a macroscopic scale). There is an exception: when radiation propagates through materials, in the absence of reflection, scattering, absorption, or emission, the intensity is proportional to the square of the real component of the index of refraction. This can be proven with geometric optics. It is related to 'total internal reflection'. Assuming the second law of thermodynamics remains true, then it must be concluded that blackbody radiation intensity is also proportional to the square of the real component of the index of refraction of the medium in which the blackbody radiation is being considered. The index of refraction is of little importance to the macroscopic patterns of radiation transfer in the atmosphere when optical properties are stated as bulk properties of macroscopic parcels of air (obviously those properties arise in part from microscopic processes which may require taken into account the index of refraction - for example, in the evaluation of how cloud droplets scatter radiation). ----- "These objects [trees,buildings] have thermal radiation and will reduce the cooling effects." How could they? By your own logic, if the object being cooled just happened to be a slight bit warmer than those trees and buildings, the radiation from the trees and buildings must never ever ever reach the object that one is trying to cool. Isn't that a strange notion? ---- "If there really was a "refigerator in the sky"...The water at the focal point would NOT freeze, it would HEAT UP.....even MORE than it does with Solar Energy!" Are there refrigerators on airplanes? If an airplane with a refrigerator flew over, I don't think it's having a refrigerator would have much effect on radiation reaching the ground. There are heat engines in the atmosphere powered ultimately by the sun (via convection allowed by the distribution of solar heating and radiant cooling). If this were not true, there would not be much wind. Air accelerates when flowing from higher to lower pressure (horizontally - otherwise, gravity + pressure gradients affect acceleration), thus gaining kinetic energy - this process tends to be associated with warmer air rising and cooler air sinking - the warmer air's temperature drops more than the cooler air's temperature rises, so the average temperature drops, because heat energy has been converted to kinetic energy. Much kinetic energy is converted back to thermal energy by frictional dissipation, but at lower entropy so that it cannot be recycled very much into the atmospheric heat engine. But sometimes the reverse of the heat engine process does happen, and kinetic energy does work on the air, lifting cooler air up (and lowering its temperature) while warmer air sinks (and increases its temperature). This can be observed, most obviously in the global-scale overturning of the mesosphere, wherein the upper mesosphere over the summer polar region is refrigerated. All of which can adjust regional radiation patterns, but none of which is THE cause of backradiation from the atmosphere (the mesosphere in particular has very little effect on the radiant fluxes). The atmosphere radiates downward and upward because it is not perfectly transparent (emissivity is not 0) and it is not at absolute zero temperature - this would be qualitatively true even if there were no motions in the atmosphere. "Further, "a refigerator in the sky" still would need energy to operate and it would have to come from the SUN!" Yes, the vast majority of the energy does ultimately come from the sun. "All the energy radiated by the Earth and the atmosphere could still NEVER EXCEED the 342 w/m^2 Solar Energy!"" Then why is the Earth not frozen over? (think - how cold would the surface have to get to only radiate at the 168 W/m2 that it recieves directly from the sun?) Set aside the second law of thermodynamics for a moment; having radiant fluxes greater than 342 W/m2 does not violate the conservation of energy. If I started throwing balls to you, and you didn't start throwing them back until you had ten of them, mass is still conserved; you would just happen to have a reservoir of ten balls. Suppose three people, you, I and a third person (let's say Bob) have buckets of balls. Suppose every minute, I throw 10 balls into your bucket and 5 balls into Bob's bucket, and every minute, you throw 2 balls into the lake and Bob throws 13 balls into the lake. And every minute, you throw 20 balls into Bob's bucket and Bob throws 12 balls into your bucket. By how many does the number of balls in your bucket and Bob's bucket change in each minute? Answer: Zero. And that's true without needing either you or Bob to manufacture your own balls or destroy them. So you can throw 20 balls to Bob for every 10 balls I throw to you because Bob is throwing you 12 balls. How can Bob afford to throw you 12 balls when I only throw him 5? Because you are throwing him 20 balls. And in the back-and-forth of balls between you and Bob, you are not creating or destroying balls; nor are you constantly increasing your buckets' quantities of balls. -- "Any energy that would be absorbed by the Sun from the Earth would CAUSE the SUN TO INCREASE IN TEMPERATURE!"..."A very, very obvious violation of the Law of Conservation of Energy!"..."Further, if the Sun actually increased in temperature, the Earth would receive this energy and increase in temperature."..."The Earth would radiate MORE energy to the Sun, causing the Sun to increase in temperature, causing the Earth to heat up even more....etc."..."What you describes is a Perpetual Motion machine in a positive feed-back loop that will increase it's temperature to INFINITY!"..."An IMPOSSIBILITY." Have you forgotten what the law of conservation of energy is? It is actually separate from the second law of thermodynamics; the later could be violated without violated the first (though nothing I've suggested as being physically possible violates either one). The conservation of energy implies that if an object absorbs more energy than it emits, it will have a net energy gain. If it absorbs less than it emits, it will have a net energy loss. If it absorbs and emits the same amount, it neither gains nor loses energy (or gains and loses the same amount so that their is no net change in the total energy it has). In the buckets of balls illustration above, you and bob throwing balls to each other from those that you have does not create or destroy balls; you throw balls that you TAKE from your bucket. Likewise, if you picked up a ball from your bucket and bounced it off a wall and it landed in your bucket, your bucket will have only the same number of balls that it initially had. If you and I each had 100 dollars, and then I gave you ten dollars, and then you gave me ten dollars, and we repeated this all day long, by your logic, we'd be millionaires soon. But this is not what would happen; together we'd have the same total amount of money as when we started, because each time you get money from me, your gain is MY LOSS, and vice versa. If you have a heating element (the range on top of your oven - if you have an electric oven) that is glowing red (because it is hot), and you have a mirror, can you not see the heating element in the mirror if you angle the mirror just so? Do you not think that the heating element could 'see' itself in the mirror if you held the mirror up to it? ***And remember, it must be able to absorb the same photons that it could emit, or else you actually could construct a perpetual motion machine (as is the case if radiant intensity were not conserved in the absence of partial reflection, scattering, emission, and absorption). Therefore it could absorb photons from another object at the same temperature, or at any temperature sufficient to emit at least a few photons at the same wavelengths that the heating element is emitting.*** Mutual exchange of radiant energy could not be used to drive a perpetual motion machine by breaking the conservation of energy because it does not break that law. The radiant energy exchange between two objects at different temperatures cannot be used to construct a perpetual motion machine if the net heat flow is from hot to cold, and with radiant energy transfers behaving as I have described them, there is no way to get the net flow of heat to go from cold to hot spontaneously (without work input), so there is no way to run a perpetual motion machine that way. -- "A refigerator transfers heat from objects inside to the Radiating Tubes at the back. The Radiating Tubes are warmer than the surrounding air....so heat is transfered to the air. The atmosphere is, obviously, cooler than the Earth.....therefore...there IS NO REFIGERATOR IN THE SKY!"" That is like saying that your house is cooler than the outside air; therefore there is no refrigerator in your house. "There is no evidence, at all, of there being a "refigerator in the sky"."..."There is however, conclusive evidence that a "refigerator in the sky" does NOT EXIST!" On the contrary, it is known that there is such a refrigerator, most obviously in the summer high-latitude mesosphere; but that has little to do with the basic principles of the greenhouse effect, back radiation from the atmosphere, or how a solar oven works either as a oven or as a cooler. ------ "All radiation from the Spherical Earth and Spherical Atmosphere will occur normal to the surface."..."The Back Radiation from the Atmosphere will flow directly along lines to the center of the Earth."... What ever gave you that impression? Radiation emitted thermally is not a laser beam. It is not coherent (the phases of individual photons are not aligned). It is not all parallel rays. If all radiation from the surface were precisely vertical, then how could it be that radiation from trees and buildings could affect the radiative cooling of any object on the surface? If you take a flat surface and heat it up so it glows red hot, you can generally see that red glow even if you are looking at the surface obliquely; if the optical properties do not vary over angle - for example, if the surface is a perfect blackbody - then the intensity of the radiation will be the same as viewed in all directions that enter the surface from the front, whether head on or slantwise; the radiant flux per unit area normal to the direction of view will be proportional to the cosine of the angle from perpendicular to the surface, as is the projected area of that surface onto the plane perpendicular to the direction being considered. --- More precisely, that is the case for the radiant flux per unit area normal to the direction that comes from a particular unit area of the radiating surface, at a given distance from that unit surface. If the radiating surface covers a large area in comparison to the distance from the surface where the measurement is made, if one moves the measuring location around in any direction, the radiant fluxe per unit area in each direction from the measurement point will stay the same (assuming intervening space is transparent), because if one gets farther away from the emitting surface, the radiant flux per unit area from each unit area of the emitting surface decreases but the amount of emitting surface contained within a given range of directions (a solid angle) increases so that the total radiant flux per unit area for any direction stays the same; if one slides around parallel to the emitting surface, any particular area of emitting surface in some direction will shift to a different direction but will be replaced as another equal area of emitting surface comes into view along the same direction. Furthermore, if one is close enough to the emitting surface relative to the emitting surface's expanse, one will find same radiant flux per unit area for any direction that approaches the surface from any angle, because the more slanted angles will have a view of a greater amount of emitting surface per unit solid angle, in inverse proportion to the decrease in radiant flux per unit area from each unit area of emitting surface with more slanted angles, due to both the unit surfaces being farther away and to the cosine of the angle for the projection of a unit area at a given distance. --- A much simpler way to explain this is that contributions to total radiant flux per unit area of a surface with some set orientation come from each direction with nonzero radiant intensity, in proportion to the intensity, the cosing of the angle of the direction from the normal of the surface, and the solid angle that the intensity covers. A solid angle is analogous to a field of view. As seen from the center of a sphere with a radius of 1, the entire sphere encompasses a solid angle of 4*pi; a hemisphere (such a the sky as seen from a flat plain with no hills, buildings, etc., interfering) has a solid angle of 2*pi; the solid angle covered by any object is proportional to the portion of the surface area of that sphere covered by the object's projection onto that sphere (by rays emanating or going toward the sphere's center). An object will appear bigger when it is closer because it makes a larger projection onto such a sphere; it fills a larger solid angle - hence, if it is emitting radiation, it will make a larger contribution to radiant flux per unit area when it is closer, while it's radiant intensity (flux per unit solid angle) remains constant if the space between is transparent. This is closely related to inverse square laws. ..."The max effect will occur if the Solar Oven is pointed at the Zenith....straight up!....day or night!" That's because that's the direction in which backradiation is generally the least. It is the shortest distance through any layer of the atmosphere, so one can see farther into the atmosphere, less of the warmer lower air and more of the colder layers of the upper troposphere and lower stratosphere, and also more of space itself. If you look closer to the horizon, the atmosphere appears more opaque, and individual layers appear more opaque, because the line of sight goes over a longer distance to get through each layer at such an angle. (If you cut a slice of apple thin enough, you can almost see through it. You can see more of an object through a fog if it is closer to you. Imagine a fog that is glowing incandescently - this is how the atmosphere (and surface) appears in the LW portion of the spectrum. But using visible light to illustrate the point, imagine a fog that is glowing white hot. A very thin layer of it won't appear as bright as a sufficiently thick layer that blocks almost all radiation from behind it. The totality of what you see will appear hotter if you are looking through the fog toward a blue-hot object, more so if the blue-hot object is closer or the fog is optically thinner. It would appear cooler if you are looking in the direction of a red-hot object, more so through an optically-thinner white-hot object. This assuming the red-hot and blue-hot objects have nonzero emissivities.) "In fact, this is exactly what the The ACTUAL MEASUREMENTS conducted at the Physics Dept.of Brigham Young University, Utah clearly states:" ...""At night the solar cooker needs to also be aimed straight up towards the cold sky."..."During the day the solar cooker needs to be turned so that it does not face the Sun and also points towards the sky."" That makes perfect sense given everything I've said. ------------- "The only time I have heard of heat flowing from cold to hot is at the Quantum Level and was resticted to system masses of no more than a few "picograms"....obviously, not applicable to the Earth, Atmosphere and Sun system." The entire mass of the known universe consists of many quadrillions of quadrillions of quadrillions of quadrillions ... of picograms. The second law of thermodynamics arises from the statistics of microscopic processes. Keep that in mind when discussing the Poynting vector ... ------------- "This is clearly a subtraction of propogating Electromagnetic Fields." ... "Propogating Electomagnetic fields are Vector fields and obey Vector mathematics."... "P/A = e*BC*T^4 - e*BC*Tc^4 (Watts/m^2) is the Resultant Vector Electromagnetic Field after subtraction."..."There can ONLY be ONE Resultant Vector Electromagnetic Field, having only ONE magnitude and only ONE direction." From: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html "P = net radiated power" NET! NET! NET! PS: See also: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/raddens.html#c1 -- http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/radpow.html#c1 (the later mentions radiation from multiple directions). The vector that describes the energy transport by electromagnetic waves is called the Poynting vector: http://hyperphysics.phy-astr.gsu.edu/hbase/waves/emwavecon.html#c1 Yes, at any given time and place, the total poynting vector has a single vector value - but that value may be a vector sum of contributing sets of electromagnetic waves. And on a microscopic level, it will fluctuate as individual photons pass by in various directions and at various energies. The average over a surface parallel to the Earth's surface will tend to point up or down, in the direction of the resultant (if you prefer that term to net) energy transport. But this has contributing components. The radiation from the surface is a large upward component. The radiation downward from the atmosphere is a smaller downward component. The average of the resultant is upward. So if that's what you go by, use the resultant. That combined with convection will just balance the solar heat absorption by the surface, in agreement with what you've been insisting. Why not just accept that Kiehl and Trenberth's energy budget diagram was showing contributing components, not the total. From a climatologist's point of view, those contributing components are useful to know. Actually, though, if you insist on only considering the total, the average resultant from all electromagnetic waves, then you must also include solar radiation. In that case, the global average at the top of the atmosphere and in the stratosphere is nearly zero. In the troposphere it must be downward in order to balance the upward heat transport of convection. And do not think that just because the average of the resultant tends to be vertical, that photons are not going in many directions. For example, the resultant of solar radiation may be downward, but you can see blue sky all over the sky - in fact, it generally appears brighter near the horizon (for the same geometrical reasons that make the LW glow of the atmosphere generally appears hotter near the horizon than straight upward when there are not clouds that are too close to the ground or the water vapor concentration is not too high, etc.
129841. HealthySkeptic at 09:45 AM on 15 April 2009
        Misinterpreting a retraction of rising sea level predictions
        Like I said...talk about creative interpretation of the data!
129842. dchristie64 at 09:29 AM on 15 April 2009
        It's satellite microwave transmissions
        Dear sir, I worked as an electronic technician for goverment high-tech radar jamming systems back in the 80'. We tested these RF radar jamming sytems with typical RF generators at minimul power between .25 and 2 watts ranging from 2GHZ to 250 GHZ or so. If you left the generator on and pointing at you for a few days you's feel the effect on your heart and skin. It was reminded to us not to due that unless you want to have cancer. Since satelites have been put into space, the worlds cancer rate continues to climb. Do not try to deny people from real fact. Ever since we went into outer space, using the discovery, and sending rocketts and satelites remote areas in desserts and in the poles, polar caps have been effected, changes in our seasons, weather patterns and disease. So don't tell me that a dam aerisol can or a crushed styrophome cup is destroying the world. Wake up!..oh ..and find out a better calculation. To penetrate a 4 mile thick ozone layer takes more than 1.6 watts /m2...not to forget the refraction values as well to re-enter into the earth.
129843. Gord at 22:57 PM on 14 April 2009
        It's the sun
        Patrick - Re: Your Posts #282...etc --- Heat Radiation Radiation is heat transfer by the emission of electromagnetic waves which carry energy away from the emitting object. For ordinary temperatures (less than red hot"), the radiation is in the infrared region of the electromagnetic spectrum. The relationship governing radiation from hot objects is called the Stefan-Boltzmann law: P = e*BC*A(T^4 - Tc^4) Where P = net radiated power (Watts), e = emissivity, BC = Stefan's constant, A = area, T = temperature of radiator and Tc = temperature of the surroundings or another body. ..when rearranged gives P/A = e*BC*T^4 - e*BC*Tc^4 (Watts/m^2) This is clearly a subtraction of propogating Electromagnetic Fields. http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html --- Propogating Electomagnetic fields are Vector fields and obey Vector mathematics. P/A = e*BC*T^4 - e*BC*Tc^4 (Watts/m^2) is the Resultant Vector Electromagnetic Field after subtraction. There can ONLY be ONE Resultant Vector Electromagnetic Field, having only ONE magnitude and only ONE direction. If T > Tc the direction is ONLY from T toward Tc and the magnitude is P/A. This complies with the 2nd Law of Thermodynamics. "Energy will not flow spontaneously from a low temperature object to a higher temperature object." If there were ANY flow from Tc to T (cold to hot) it would VIOLATE Electromagnetic Vector Field physics as well as the 2nd Law of Thermodynamics and Conservation of Energy. --------------- Regarding your discussion of emissivity and absorbtion being different, it does not apply to Trenberth's paper. He assumes that emissivity applies equally to absorbtion and emission. The only time I have heard of heat flowing from cold to hot is at the Quantum Level and was resticted to system masses of no more than a few "picograms"....obviously, not applicable to the Earth, Atmosphere and Sun system. --------------- You said.... "My pointing out that there is/are refrigerators in the sky was to correct your statement that their are none...." I have already posted a response to this before: --- My Post #264: The Trenberth Energy Budget shows that the Back Radiation flowing from the colder atmosphere and absorbed by the Earth's surface to be 324 Watts/m^2. (The Back Radiation ABSORBED by the Earth is, supposed, to Heat the Earth according to the AGW theory) Notice that the Back Radiation EXCEEDS the Solar Radiation (the only energy source)! Solar ovens (parabolic mirrors) have no problem concentrating the Solar radiation at it's focal point producing very high temperatures. Parabolic mirrors will concentrate IR energy (Back Radiation) the same way. Notice the authors of the paper state: "During both times, the solar cooker needs to be aimed away from buildings, and trees. These objects have thermal radiation and will reduce the cooling effects. At night the solar cooker needs to also be aimed straight up towards the cold sky. During the day the solar cooker needs to be turned so that it does not face the Sun and also points towards the sky." If there were a "refigerator in the sky" heat would flow from the colder atmosphere to the Solar Oven's focal point where this energy would be concentrated. In Fact, according to Trenberth, the Back Radiation exceeds the Solar Radiation and is 163% GREATER THAN THE SOLAR RADIATION. If there really was a "refigerator in the sky"...The water at the focal point would NOT freeze, it would HEAT UP.....even MORE than it does with Solar Energy! Further, "a refigerator in the sky" still would need energy to operate and it would have to come from the SUN! All the energy radiated by the Earth and the atmosphere could still NEVER EXCEED the 342 w/m^2 Solar Energy!" --- My Post #265 "If there were "a refigerator in the sky" the atmosphere would have to be warmer than the Earth. A refigerator transfers heat from objects inside to the Radiating Tubes at the back. The Radiating Tubes are warmer than the surrounding air....so heat is transfered to the air. The atmosphere is, obviously, cooler than the Earth.....therefore...there IS NO REFIGERATOR IN THE SKY!" --- The POINT being: There is no evidence, at all, of there being a "refigerator in the sky". There is however, conclusive evidence that a "refigerator in the sky" does NOT EXIST! --------------------- You said... "The solar oven works by concentrating sunlight to work as an oven, and by allowing radiative energy transfer between the sky and an object while blocking such heat transfers between the object and heat from trees, buildings, and perhaps also the sky near the horizon - which will tend to appear warmer because the rays in near horizontal directions pass through longer distances through the warmer lower atmosphere, so that it is nearly opaque in that direction, whereas, under clear skies (or only high clouds) with sufficiently low humidity, the warmer lower atmosphere exceeds some level of partial transparency over a greater range of wavelengths when looking more straight upwards. I mention this last point because it helps explain how the solar oven used as a radiant cooler (not a refrigerator) can achieve temperatures (in the object being cooled) lower than the surrounding surface temperature, which cools at night by radiation upward to space and the cooler atmosphere, but over all directions (radiant intensity weighted by the cosine of the zenith angle for a horizontal surface, for geometrical reasons)." --- All radiation from the Spherical Earth and Spherical Atmosphere will occur normal to the surface. The Back Radiation from the Atmosphere will flow directly along lines to the center of the Earth. The max effect will occur if the Solar Oven is pointed at the Zenith....straight up!....day or night! In fact, this is exactly what the The ACTUAL MEASUREMENTS conducted at the Physics Dept.of Brigham Young University, Utah clearly states: "At night the solar cooker needs to also be aimed straight up towards the cold sky. During the day the solar cooker needs to be turned so that it does not face the Sun and also points towards the sky." ----------------------- You said.... "When the sun radiates energy to the Earth it is losing that energy; if it got any back, it gains that energy. Nowhere in that statement is energy being created or destroyed; it is conserved all the way. The vast majority of what the sun loses will not come back, but the sun maintains its temperature because mass is being converted to energy in its core." --- Again, I strongly disagree! The Sun is a constant energy source. It provides all the Energy to the Earth. The Earth IS NOT AN ENERGY SOURCE! Any energy that would be absorbed by the Sun from the Earth would CAUSE the SUN TO INCREASE IN TEMPERATURE! A very, very obvious violation of the Law of Conservation of Energy! Further, if the Sun actually increased in temperature, the Earth would receive this energy and increase in temperature. The Earth would radiate MORE energy to the Sun, causing the Sun to increase in temperature, causing the Earth to heat up even more....etc. What you describes is a Perpetual Motion machine in a positive feed-back loop that will increase it's temperature to INFINITY! An IMPOSSIBILITY. ----------------------- You said.... "That analogy doesn't work very well; if it were truly the net law of gravity, some of the rest of the people who are not blasted into space would have to sink down into the Earth." --- You did not understand my point. I said... "It is equivalent to saying that the Universal Law of Gravitation is really the "NET Law of Gravitation" and that some people could be blasted into space by gravity as long as most people remained Earth bound!....Producing a violation of the Law of Conservation of Energy!" What I am referring to is the DIRECTION of Gravity changing. As long as the NET direction of Gravity was "downward" most people would remain Earth bound. Those few people who had Gravity spontaneously change direction to "up" would be blasted into space. This also would violate the Law of Conservation of Energy. The 2nd Law of Thermodynamics has everything to do with DIRECTION of energy flow.....warm to colder bodies. "Second Law of Thermodynamics: It is not possible for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. Energy will not flow spontaneously from a low temperature object to a higher temperature object." http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html#c3 In your case, you think that there can be a spontaneous change so that heat can flow cold to hot as long as the NET (most) of the energy flows from warm to cold. This also would violate the Law of Conservation of Energy. Both the 2nd Law of Thermodynamics and the Universal Law of Gravitation do NOT deal with NET effects....for a very good reason....the Law of Conservation of Energy! -------------------------- It seems that your posts are really about trying to dis-prove the 2nd Law of Thermodynamics and the Law of Conservation of Energy. I don't understand your logic.
129844. Timothy Chase at 15:27 PM on 14 April 2009
        Why is Antarctic sea ice increasing?
        Over at the thread on Real Climate that is devoted to the collapse of the ice bridge that helped support the Wilkins Ice Shelf, someone asked, "How does the collapse square with the latest NSIDC data which shows an increasing Antartic ice coverage?" Gavin responded, "Look in the region where this is happening." There is the warm West Wind Drift which is resulting in ice melt in along the West Antarctic Peninsula and in the nearby ocean, particularly the Bellingshausen Sea -- where sea ice is declining at -5.3% per decade. This is leading to additional fresh water at the surface which is no doubt leading to some of the stratification suggested in the model. However, if this fresh water gets caught up in the inner cold East Wind Drift, it will be carried to the West Pacific Ocean, where sea ice is growing at 1.2% per decade. That is essentially along the coast of continental West Antarctica. And some will be carried further east where the Ross Sea forms a harbor between West Antarctica and East Antarctica. This is where sea ice is growing at 4.8% per decade. No other place rivals it. In fact, the closest you get is the West Pacific Ocean at 1.2%. So part of what explains the growth in sea ice may be stratification due to fresh water, but also I would suggest the fresh water itself -- which freezes at a higher temperature than saltier seawater. However, with respect to the future, the ozone hole was increasing the strength of the Antarctic Polar Vortex, and now that the ozone hole is being repaired the Antarctic Polar Vortex is weakening, and the cold dry Antarctic climate is giving way to the moist maritime air of the north. Of course with global warming we would expect a poleward shift of storm tracks in any case, but in this case the effects would appear to be mutually reinforcing. In any case, here is a link to my comment where I followed up Gavin's suggestion -- by I would also recommend checking out the comment below it: 8 April 2009 at 8:19 PM http://www.realclimate.org/index.php?p=667#comment-119074
129845. Patrick 027 at 11:19 AM on 14 April 2009
        It's the sun
        2 more things: "Any, radiation absorbed by a body will increase it's temperature."..."The Sun cannot absorb (and increase in temperature)energy radiated from the Earth because the only energy that caused the Earth's radiation came from the SUN!"..."That is the same as saying that the SUN can heat itself....a violation of the Law of Conservation of Energy!" When the sun radiates energy to the Earth it is losing that energy; if it got any back, it gains that energy. Nowhere in that statement is energy being created or destroyed; it is conserved all the way. The vast majority of what the sun loses will not come back, but the sun maintains its temperature because mass is being converted to energy in its core. It does not violate the conservation of energy to wrap a hot brick in aluminum foil. If the sun were surrounded by mirrors, would not the sun get back it's light? If not, why can you see yourself in the mirror? How could a mirror even exist without breaking physical laws? --------- "It is equivalent to saying that the Universal Law of Gravitation is really the "NET Law of Gravitation" and that some people could be blasted into space by gravity as long as most people remained Earth bound!....Producing a violation of the Law of Conservation of Energy!" That analogy doesn't work very well; if it were truly the net law of gravity, some of the rest of the people who are not blasted into space would have to sink down into the Earth. For example, if one person were at the long end of a very lopsided teeter-totter and a whole crowd of other people jumped off a tall cliff and landed on the short end, then the first person could be expected to fly upward. The potential energy of some large mass would be converted into kinetic energy that would be converted into the kinetic energy of a much smaller mass moving at faster speed, which will ultimately change into potential energy as the person slows down, being accelerated toward the Earth by gravity; if the person has enough energy to never completely stop than s/he has reached escape velocity, etc. Hey, that's what would happen (setting aside air drag, etc.)! Of course, it is not a net law of gravitation, but simply the conservation of energy, work, energy = force times distance, and a lever, etc.
129846. Patrick 027 at 10:16 AM on 14 April 2009
        It's the sun
        It is obvious to me that the second law of thermodynamics and the conservation of energy do appear to be correct, no violation has yet been discovered and no one expects such a violation to be found (within this universe, etc.); provided that one considers mass to be a form of energy. It is also obvious to me that you have misinterpreted what these things mean. Since you take "hyperphysics" at it's word without qualification (PS that's no knock on the website; I think it's pretty good!), consider: ------------------------------ HEAT: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heat.html#c1 "Heat may be defined as energy in transit from a high temperature object to a lower temperature object. An object does not possess "heat"; the appropriate term for the microscopic energy in an object is internal energy. The internal energy may be increased by transferring energy to the object from a higher temperature (hotter) object - this is properly called heating. " If that is true, I've been a bit careless in terminology, but a few word substitutions would correct that in what I've written thus far - and in what I shall write, as I might slip up again... However, if it is the transfer of energy ... maybe the 390 W/m2 emission upward from the surface + 102 W/m2 convection and the 324 W/m2 downward from the atmosphere are not in themselves heat flows; it may just be the net flow of this energy that is the heat flow. Or maybe not... Anyway, consider this: ------------------------------ RADIATION: http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html#c2 "The energy radiated by a blackbody radiator per second per unit area is proportional to the fourth power of the absolute temperature"... (see website for equation) "For hot objects other than ideal radiators, the law is expressed in the form:" ... (see website for equation) ... "where e is the emissivity of the object (e = 1 for ideal radiator). If the hot object is radiating energy to its cooler surroundings at temperature Tc, the net radiation loss rate takes the form" (see website for equation) I'll rewrite the equations here but replacing some variables and symbols with names: Ideal blackbody radiation: Power/area = sigma*T^4 where sigma = 5.6703*10^-8 W/(m^2 K^4) So that the radiant power is proportional to the fourth power of absolute temperature, and a 1000 K blackbody radiates with a power of 56,703 W/m2. And a 288 K blackbody (about the average surface temperature of the Earth) radiates with a power of about 390.1 W/m2. Sound familiar? For a nonideal radiator, the emission is a fraction of blackbody radiation is called emissivity, so that: Power/area = emissivity * sigma * T^4. And for a hot object at temperature T radiatively cooling to it's surroundings at temperature Tc, assuming the surroundings are effectively an ideal blackbody, the "net radiation loss" is Power/area = emissivity(of hot object) * sigma * (T^4 - Tc^4) A little math shows this is equal to: emissivity(of hot object) * (blackbody Power/area at T - blackbody Power/area at Tc) Nowhere does it say that the emissivity of the hot object must decrease to zero if it's surroundings are not at absolute zero. For clarification (you might find this if you follow links from http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/stefan.html#c2 ), emissivity is a material property that can vary as a function of wavelength and this wavelength dependent emissivity can vary as a function of temperature OF the emitting surface (but not simply as a function of it's surroundings). Because the temperature of surroundings affects the wavelength distribution of their emitted radiation, this can affect the effective absorptivity of a recieving surface - for example, clouds have higher absorptivity for the radiation as a whole emitted from the surface and atmosphere (including other clouds) than they do for the radiation from the sun - but this is because clouds have generally greater absorptivity in the wavelengths dominated by terrestrial emission (longer than about 4 microns) than those dominated by solar radiation (shorter than about 4 microns). BUT at any particular wavelength, the net radiative loss is from a hotter object to a colder object - for perfect blackbodies, power/area for any wavelength interval is greater at higher temperature; the emissivity is equal to absorptivity for each object (at local thermodynamic equilibrium) or layer or surface, etc, at each wavelength, and so when optical properties are varied, the absorption and emission change in proportion, so that a hot object cannot absorb more radiation emitted from a cold object than the same cold object can absorb from emission from the same hot object. Thus at every wavelength, the net radiation loss is from hot to cold. However, this can pass through a partially transparent layer of any temperature, as I explained previously. See: http://hyperphysics.phy-astr.gsu.edu/hbase/bbcon.html#c1 Blackbody radiation spectrum: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/radfrac.html#c1 Examples: http://hyperphysics.phy-astr.gsu.edu/hbase/bbrc.html#c1 AND for emissivity = absorptivity (why the surface does absorb radiation from the atmosphere, as they emit in some of the same wavelengths): "A Good Absorber is a Good Emitter" http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/absrad.html#c1 This section continues from the formula for net radiation loss, of a hot object at temperature T to surroundings at temperature Tc: QUOTE: "In this relationship the term with Tc represents the energy absorbed from the environment." Energy from the cooler environment is absorbed by the hot object! "This expression explicitly assumes that the same coefficient e [emissivity] applies to both the emission into the environment and the absorption from the environment. That is, a good emitter is a good absorber and vice versa; the same coefficient can be used to characterize both processes. Why is that true?" next paragraph - note the reference to the second law of thermodynamics: "Perhaps the most fundamental conceptual way to approach this question is to observe that a hot object placed in a room must ultimately come to thermal equilibrium with the room. The hot object will initially emit more energy into the room than it absorbs from the room, but that will cause the temperature of the room to rise and the temperature of the object to drop. But when they reach the same temperature, we can conclude that the amount of energy absorbed on average is exactly the same as the energy emitted. That is, the expression above for net energy radiated to the environment must give us zero when T=Tc." Their words, not mine. But I agree. "The above argument is based upon the Second Law of Thermodynamics in the form that states that heat will not spontaneously flow from a cold object to a hot object. If the absorption coefficient were higher than the emission coefficient for the object, then it could absorb net energy from the room even when its temperature were higher than the room." "But suppose you wanted to argue that a good absorber must be a good emitter based on the microscopic processes involving the atoms in the surface of an object. Then it becomes quantum question and involves the following ideas: " (see website for more). ---------------------------------------- I haven't found it in the "hyperphysics" website yet (but - please realize this - just because it is not explicitly mentioned in one website does not mean it is not true), but blackbody radiation is isotropic - the intensity (power per area per solid angle) does not vary over directions. Real materials can have direction-dependent optical properties. For an ideal blackbody at temperature T shaped as a thin plate with area A, the radiant energy flux per unit area from the plate's surface is the blackbody radiation at temperature T; the radiation has the same intensity in all directions but the projection of the area of the plate varies - just as one would recieve less radiant power per unit area from farther away, one would recieve less radiant power per unit area if viewing the plate slantwise instead of face-on. Either way, it is because the plate occupies a smaller solid angle from the viewing position. Conservation of radiant intensity in the absence of scattering, partial reflection, absorption, and emission is required by the second law of thermodynamics, because along every ray path in which object A can see object B, object B can also see object A, so both can exchange radiation along all such paths - at any wavelength and along any line of sight (even if bent at a perfect mirror or perfectly transparent lens), a hot object will have net radiation loss to a cold object if there is any thermally-emitted radiation exchanged. Hence, the highest temperature that can be achieved by focusing the sun's radiation on an object to heat it up is the temperature of the sun (if in space; othewise a bit less because of atmospheric scattering, even without clouds or much haze), in agreement with the second law of thermodynamics. Radiation at any wavelength and polarization (blackbody radiation is evenly distributed among polarizations) can be assigned a temperature based on the blackbody that would emit radiation at that wavelength and polarization with that intensity. This assigned temperature is reduced when radiation confined to nearly parallel rays are scattered (as sunlight is scattered to produce the blue sky and the light seen from clouds - sunlight is initially nearly parallel at great distances from the sun because the sun can only be seen within a small solid angle of directions) - this increase the radiation's entropy, and entropy = heat/temperature for heat flow. One other thing that can be mentioned, pertaining to lasers: entropy is reduced if some intensity of radiation is packed into a smaller interval of phase shifts relative to each other - coherent radiation has very low entropy, corresponding to the entropy of radiation from a blackbody at a sufficient temperature to produce such a concentrated radiant intensity per unit phase shift. Another reason to believe that some radiant energy can flow from colder to warmer: The blackbody radiation spectrums at different temperatures overlap - a white hot object emits more red light than a red-hot object of the same size and optical properties. Both red-hot objects and white-hot objects emit red photons. A red-hot object can even emit a few blue photons, though not many; a white hot object will emit many more blue photons. A violet-hot object emits even more blue photons, etc. The point is that, while temperature can be assigned to a population of photons (radiation intensity over a given wavelength interval, interval of polarizations, interval of phase shifts), a temperature cannot be assigned to an individual photon (just as it cannot be assinged to an individual molecule, atom, or electron, etc. - see: http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/ktcon.html#c1 ). So if a white hot object can absorb a yellow photon from a violet hot oject, why not absorb an identical photon from a red hot object. (PS for that matter, some optical manipulation could be used to make a white hot object appear to be a violet hot object with lower emissivity - by partially blocking lower-energy photons. This radiation could be absorbed by a blue hot object. However, this will not reverse the net radiation loss between the two objects; it will still be from blue-hot to white-hot. ------------------------------- "So, I take it that you now agree that there is no "refigerator in the sky" and Solar Ovens are not "heat engines" or "refrigerators in the sky"?" My pointing out that there is/are refrigerators in the sky was to correct your statement that their are none, but it has nothing to due with how the solar oven works. The solar oven itself is not a refrigerator or a heat engine; this has nothing to do with whether or not the atmosphere contains refrigerators and heat engines - it does; the heat engines are driven by the convective portion of heat flow from the surface to the various levels of the cooler troposphere, and the refrigerators-heat pumps are driven by a portion of the kinetic energy produced by those heat engines (but most, as I understand it, of the kinetic energy is lost to friction before it can drive any such refrigerator). The solar oven works by concentrating sunlight to work as an oven, and by allowing radiative energy transfer between the sky and an object while blocking such heat transfers between the object and heat from trees, buildings, and perhaps also the sky near the horizon - which will tend to appear warmer because the rays in near horizontal directions pass through longer distances through the warmer lower atmosphere, so that it is nearly opaque in that direction, whereas, under clear skies (or only high clouds) with sufficiently low humidity, the warmer lower atmosphere exceeds some level of partial transparency over a greater range of wavelengths when looking more straight upwards. I mention this last point because it helps explain how the solar oven used as a radiant cooler (not a refrigerator) can achieve temperatures (in the object being cooled) lower than the surrounding surface temperature, which cools at night by radiation upward to space and the cooler atmosphere, but over all directions (radiant intensity weighted by the cosine of the zenith angle for a horizontal surface, for geometrical reasons).
129847. Philippe Chantreau at 01:47 AM on 14 April 2009
        Arctic sea ice melt - natural or man-made?
        Quietman you're misunderestimating the skill of the conspirators. They're really really smart. Therefore, they know that the best way to destroy capitalism is to have capitalism destroy itself, by letting it go unchecked. The "green socialist threat" is nothing but a decoy. The real conspirators have been sitting in Wall Street and K Street (and the SEC?), encouraging always more deregulation, less regulation and weak enforcement of what little exists. Their plan is working like a (swiss) watch. It has already produced socialized banking. Not only the helicopters are black, after all, but they're also coporate...
129848. Philippe Chantreau at 01:34 AM on 14 April 2009
        Why is Antarctic sea ice increasing?
        Lee, I guess that's what David was asking in post #8 and I must say I have no idea. One would think that satellites are blind to the real origin of the ice. Hence, some glacial ice is bound to be part of the extent and area. I don't know how significant that is.
129849. Gord at 19:25 PM on 13 April 2009
        It's the sun
        Patrick - Re: Your Posts #273 etc. You said... "Gord - I know how a solar oven works. I don't disagree with your description of it. I looked over parts of http://solarcooking.org/research/McGuire-Jones.mht and do not see any errors there. It does not disagree with what I've been saying. That heat flows from hot to cold is just a useful simplication of the complete picture, which is that heat often flows in both directions but the net heat flow is from hot to cold." First, you have peviously stated that: Your Post #259 "THERE IS a refrigerator in the sky..." And, with reference to Solar Ovens: Your Post #267 "That's only true with some additional specifications. There are both heat engines and refrigerators in the sky." So, I take it that you now agree that there is no "refigerator in the sky" and Solar Ovens are not "heat engines" or "refrigerators in the sky"? --- With regard to: "That heat flows from hot to cold is just a useful simplication of the complete picture, which is that heat often flows in both directions but the net heat flow is from hot to cold." I TOTALLY DISAGREE as the 2nd Law of Thermodynamics is VERY CLEAR on this: "Second Law of Thermodynamics: It is not possible for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. Energy will not flow spontaneously from a low temperature object to a higher temperature object." http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/seclaw.html#c3 There is no mention of "net" anywhere! In fact, the 2nd Law specifically states that it is "NOT POSSIBLE" for heat to flow from a colder body to a warmer body without any work having been done to accomplish this flow. This, OBVIOUSLY, does NOT allow ANY heat flow from cold to hot UNLESS work is done to accomplish this flow...and for a good reason!! The reason is that ANY HEAT flow from cold to hot objects without work being done to accomplish this flow will VIOLATE the Law of Conservation of Energy. Example: Your claim that the Earth's radiation can be absorbed by Sun. I repeat what I have already posted: "Any, radiation absorbed by a body will increase it's temperature. The Sun cannot absorb (and increase in temperature)energy radiated from the Earth because the only energy that caused the Earth's radiation came from the SUN! That is the same as saying that the SUN can heat itself....a violation of the Law of Conservation of Energy!" --- It should be obvious to you that both the 2nd Law of Thermodynamics and the Law of Conservation of Energy are BOTH correct and BOTH SUPPORT each other! Patrick, these are basic fundamental Laws of Science and saying that "it is the net heat flow that is being discussed" in 2nd Law is, obviously, not true. It is equivalent to saying that the Universal Law of Gravitation is really the "NET Law of Gravitation" and that some people could be blasted into space by gravity as long as most people remained Earth bound!....Producing a violation of the Law of Conservation of Energy! --- It seems that your posts are really about trying to dis-prove the 2nd Law of Thermodynamics and the Law of Conservation of Energy. In fact, your posts contain numerous examples of violations of these Laws of Science in an attempt to prove that these same violations comply with these Laws of Science. I don't understand your logic.
129850. Lee Grable at 07:00 AM on 13 April 2009
        Why is Antarctic sea ice increasing?
        Given the breaking away of several major ice shelves in the recent past, the Wilkens shelf being the latest, are'nt there more icebergs floating around the continent now?

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