Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  Next

Comments 101 to 125 out of 308:

101. Patrick 027 at 13:13 PM on 19 October, 2008
     ... or 5. internal variability greater than thought __________ About efficacy of forcings: I haven't actually read much about that but here's what I would expect: Consider a forcing by Solar TSI LW (greenhouse) forcing volcanic stratospheric aerosols tropospheric aerosols surface albedo For any given forcing - let's start with radiative forcing - there is: 1. a global average TOA (top of atmosphere) value, R-TOA. 2. a global average tropopause value, R-tp 3. a global average surface value, R-sfc. 4. Some spatial-temporal (seasonal, perhaps interannual) variation in either of R-TOA, R-tp, R-sfc, which I will simply refer to here as R-var. 5. Some climatic response which results from the effect of R and feedbacks. - To start with, we might assume an approximation that the climatic response in so far as global average is concerned, is similar to any R-tp or R-TOA for any forcing. Then we might look for deviations from that. Differences: R-TOA is the forced net change in downward minus outgoing radiation 'at' the top of the atmosphere. R-tp is different then R-TOA; both are different from R-sfc - First: 1. An increase in solar TSI - if the same % increase at all wavelengths - the forcing is a heating distributed (unevenly) through the atmosphere and surface. R-TOA is the sum of all of this heating; R-tp is only the heating below the tropopause and is therefore somewhat less than R-TOA; R-sfc is only surface heating and is therefore less than R-tp. Typically changes in solar TSI are greater in UV in particular, so a larger fraction than otherwise of solar forcing goes into heating the upper atmosphere, thus decreasing R-tp even further. 2. Greenhouse forcing is a reduced cooling to space, which is a heating of the surface and/or lower atmosphere. The cooling to space of the stratosphere and above, however, increases, while the heating of higher atmospheric layers by the surface and/or lower troposphere decreases. Thus for greenhouse forcing, R-TOA will be a little less then R-tp. Starting at minimal LW opacity, R-sfc might be greater than R-tp (?), but at least for CO2, my impression is increases from the current amount result in greater R-tp than R-sfc. Water vapor is a feedback, but applying the same concepts to water vapor, I think, at least under some conditions, R-sfc is greater than R-tp for water vapor. This is at least in part due to water vapor's increasing concentration toward the surface. Ozone concentration is also variable so greenhouse effects of ozone changes may be a bit different than the 'typical' well-mixed greenhouse gas. The exact relationship between R-tp, R-sfc, and R-TOA for even well-mixed greenhouse gases (like CO2, CH4, N2O, CFCs) (they have some spatial and seasonal variations but not to the degree of ozone or water vapor) could vary because they have different spectrums, and temperature (and water vapor, ozone, cloud content) varies with height (and other dimensions), they may overlap with each other and other things in different ways due to the above differences, and they have different initial amounts before changes occur. 3. a decrease (to keep the same sign of forcings for more straightforward comparison) in volcanic stratospheric aerosols - this would reduce albedo. The aerosols reflect SW (solar) radiation back up from the stratosphere, thus cooling the troposphere and surface but possibly heating the air above; and perhaps heating the stratosphere a little bit (? I think the stratosphere or some part of it actually warms up after relevant eruptions - this might be due to the nonzero absorption of solar radiation by the aerosols themselves) (some of the solar radiation is scattered downward or sideways - for a near-overhead sun (middle of day, summer midlatitude, or at low latitude), this can increase the path length before reaching the surface, thus increasing the portion absorbed in the air...) ... SO scattering of radiation is complicated (but not so much that it isn't understood), but reducing volcanic aerosols results in an R-sfc and R-tp greater than R-TOA, and I suspect R-sfc would be greater than R-tp. 4. tropospheric aerosols 4a. A decrease in the albedo from reduced scattering by aerosols: R-sfc will be greater than R-tp and R-TOA as some of the reflected and scattered radiation had been absorbed by air and clouds. 4b. An increase in the atmospheric heating by increased absorption of aerosols: R-TOA and R-tp will be positive while R-sfc is negative. 4c. scattered radiation can be subsequently absorbed in the air; the total effect of aerosols is not simple, but again, it isn't an impossible riddle either. 5. Decrease in albedo due to surface conditions: The change in albedo actually at the surface may have to be greater than that which results at TOA, due to clouds, but also time of day and year issues, and latitude. Anyway, reflected solar radiation has a second chance to be absorbed by the air, so the decrease in albedo because of surface conditions may result in R-sfc greater than R-tp and R-tp greater than R-TOA (but perhaps only slightly). HOWEVER: R-tp may be (as it is in IPCC work) defined as that which occurs after the stratosphere and above have reached thermal equilibrium with the forced heating or cooling (R-TOA - R-tp) which occurs there (PS notice this is not the same as that equilibrium which would result after the climate response including the tropsophere and surface). If R-TOA is greater than R-tp, then the stratosphere, etc, will have warmed, so R-tp will be a little higher as a result due to increased downward LW radiation (or a decrease in net upward LW radiation). If R-TOA is less than R-tp, the opposite will be true. In other words, R-tp will get closer to the original R-TOA (But I don't think it would be equal to the original R-TOA - I expect it to still be less or greater than R-TOA, whichever was the case to begin with). R-sfc might also shift in the same direction but not as much so long as there are any greenhouse agents within the troposphere. Of course, in the full climatic response, however tropospheric heating (R-tp - R-sfc) is distributed within the troposphere, or however much it is, as an upper layer warms up, it reduces convective heat transport from below, thus the tendency is for the full effect of R-tp to propogate by convection to the surface, whatever R-sfc was. However, a larger R-tp - R-sfc and/or smaller or negative R-sfc value will tend to reduce convection from the surface - HOWEVER, after all feedbacks have occured, the radiative heating/cooling distribution may be different again. ***I think this would be less true for regionally-concentrated forcings (pockets of high aerosol concentrations, for example), because advection into and out of the area would prevent a radiative convective equilibrium on the regional scale, so perhaps this is partly why I hear of atmospheric brown clouds (dark absorbing aerosols) in particular reducing vertical motion by increasing stability. So a global average R-tp will tend to result in some global average tropospheric and surface temperature increase. Some other effects due to the vertical distribution may change the feedbacks that occur and thus the resulting temperature changes in the surface and troposphere - but to my knowledge that is not a big effect (?). The horizontal (and seasonal, if and when it matters (ozone)) variations could also affect the actual global average results. For example - the R-tp and R-TOA of albedo reduction from BC landing on snow/ice will likely be a little smaller than the R-sfc value (some radiation reflected from the surface can be reflected back to the surface by clouds, aerosols, and air molecules); furthermore and perhaps much more importantly, the effect is concentrated where a positive feedback is also concentrated (snow-ice albedo feedback). Thus the climate sensitivity could be expected to be larger to BC on snow/ice forcing than to some other forcings, to the extent that the forced heating is not entirely advected away from similar locations. As far as anthropogenic well mixed greenhouse gases (WMGHG - to adopt the acronymn I saw in a paper - this includes CO2, CH4, N2O, CFCs - well, at least a couple CFCs) compare to solar radiative forcing - the geographic distribution of R-tp is going to be at least a little similar on a broad scale - the LW forcing is highest in the subtropics because of the relatively dry cloud-free air and higher lapse rates; high cloud tops in the tropics prevent greenhouse gases below them from having any direct effect on R-tp; lower tropospheric and surface temperatures in general and smaller lapse rates at higher latitudes reduce the difference in outgoing LW radiation (at least at tropopause level - and the tropopause is lower there, too) that would result from changing greenhouse gas concentrations (and the lower surface temperatures. Solar forcing will generally be greatest at low latitudes, during the day, and/or in summer, where there are fewer clouds, reflective aerosols, darker surfaces (ocean, forests), etc. For example, the dry subtropics (but unlike WMGHGs, solar forcing would not be as large over dry light-colored landscapes as it would be over dark oceans). Etc. R-tp will be higher than otherwise when there is less stratospheric ozone. There is a latitudinal and seasonal ozone variation - there tends to be more ozone at higher latitudes in winter/spring, I think - because while stratospheric ozone is produced more at low latitudes, winter stratospheric circulation brings it into high latitudes, and actually 'piles it up' there, in part (if not in whole) because the stratosphere is thicker at higher latitudes (lower tropopause)... ---- Of course anthropogentic GHG forcing is expected to result in a cooler stratosphere (observed - although stratospheric ozone depletion also has a similar effect - but each can be calculated so it should be possible to attribute portions of cooling), and greater warming at nights during days near and at the surface over land (not much diurnal cycle to begin with over oceans because of heat capacity) - (also observed, at least somewhat). Positive solar forcing that would warm the surface and troposphere would also warm the stratosphere (not observed). However, because of this, there could be effects on atmospheric circulation that are different than for GHGs, which might affect climate sensitivity (but how much and in what direction?).*** (Quietman - if you want to show a reduced climate sensitivity by way of greater total forcing, you might try looking into how solar forcing, including non-TSI or non-UV effects, affect not only the stratosphere, but also the ionosphere, and for example the E-region dynamo, and how geomagnetic effects also affec the E-region dynamo and solar-magnetospheric-ionospheric interactions, and what any resulting circulation pattern changes would be, and if and how that propogates downward. I am not saying that I expect you to be successful, but it's a thought - while I have my doubts, I think it's got a lot more potential than submarine volcanism, solar jerk, tides on sun, Spencer's PDO+ENSO work, Spencer's cloud forcing work, urban heat island dominance, or the idea that there hasn't been a recent spurt of global warming above and beyond internal variability.)
102. Patrick 027 at 14:04 PM on 19 October, 2008
     "so perhaps this is partly why I hear of atmospheric brown clouds (dark absorbing aerosols) in particular reducing vertical motion by increasing stability." Actually, the full effect may be an increase in stability to moist convection by reduction in evaporation; in so far as dry convection is concerned, while the heating has been moved upward from the surface, it won't generally be all the way up to the tropopause; while there will tend to be increased stability beneath such a brown cloud, there will tend to be reduced stability above it. The heating of the brown cloud itself will tend to cause a low pressure beneath it and a high pressure above it, and the brown cloud itself will tend to rise.
103. Patrick 027 at 14:13 PM on 19 October, 2008
     ... of course, I've never been quite clear on 'global dimming - H2O evaporation' - of course if water is being heated to higher temperature, the tendency is for faster evaporation under the same wind and relative humidity. But there has been global warming along with 'global dimming' (? - according to some comments at "Arctic sea ice..."), so how does decreased solar radiation reaching the surface affect evaporation independently of temperature? Is it analogous to the photoelectric effect - in this case, individual higher energy photons are able to kick off H2O molecules into the air even if the temperature is low (but not too low)? Sounds conceivable, but then again, the absorption of solar radiation is distributed within a depth of water from the surface downward; less so for the shortest wavelengths, red light and solar IR, but I suspect it's a tiny tiny fraction that would be absorbed within a 'molecular layer' or two from the surface.
104. Patrick 027 at 14:17 PM on 19 October, 2008
     Since much of what I am about to say applies to the "Arctic sea ice"... , I'm going to post a few comments there now. If after that I haven't covered some of what was brought up here in comments 87-95, I'll come back here.
105. Quietman at 03:21 AM on 20 October, 2008
     Patrick Your explanations and willingness to look at both sides is exactly why I asked you to come to this site. In most cases I can see your logic and find it convincing. Keep in mind that this type of science is new to me. I have a beckground in engineering research (product developement) and bench testing emissions but I have never done well with theoretical math only logic and applied math, so keep it simple. Trust me, it is just as frustrating for me when someone points to a paper and claims it as fact without a logical explanation as it is when I get quoted from a bible passage. The fact that you don't resort to that is quite refreshing.
106. Quietman at 04:55 AM on 24 October, 2008
     Patrick In a new article at MSNBC titled ‘Dead’ planets might be livable after all they explain planetary tidal forces in the manner that I see them (inferring from the Solar Jerk) but carried to more of an extreme than we experience. The hypothesis is the same however, it's only a matter of degree.
107. Quietman at 11:34 AM on 26 October, 2008
     Patrick I found a little more background data: Evidence Mounts For Arctic Oscillation's Impact On Northern Climate: ScienceDaily (Dec. 20, 1999)- A growing body of evidence indicates that a climate phenomenon called the Arctic Oscillation has wide-ranging effects in the Northern Hemisphere and operates differently from other known climate cycles. Arctic Oscillation Has Moderated Northern Winters Of 1980s And '90s: ScienceDaily (July 10, 2001) - The Arctic Oscillation has been linked to wide-ranging climate effects in the Northern Hemisphere, but new evidence shows that in recent decades it has been the key in preventing freezing temperatures from extending as far south as they had previously. Synchronized Chaos: Mechanisms For Major Climate Shifts: ScienceDaily (Aug. 2, 2007) — In the mid-1970s, a climate shift cooled sea surface temperatures in the central Pacific Ocean and warmed the coast of western North America, bringing long-range changes to the northern hemisphere. It seems that someone has been ignoring this data for quite a few years now. I wonder why.
108. Patrick 027 at 13:20 PM on 26 October, 2008
     That was interesting. One important point is that the heat would take time to build up from such a process. In spite of all the Earth's internal heat, it counts little for regional or global scale climate (directly), because the heat flux is very small. For internal heat to make a difference to surface temperatures on a large scale, the heat flux has to be significant compared to the heating by radiation from the planet's star. Assuming a rocky crust as on Earth, the thermal gradient must then be that much greater, which means perhaps a thin crust on a molten mantle.
109. Patrick 027 at 13:23 PM on 26 October, 2008
     That last comment was about "'Dead' planets might be livable after all". hope to get back to AO discussion within a few days...
110. Quietman at 14:54 PM on 28 October, 2008
     Patrick Re: 108 Maybe not global, I was thinking on a much more localized scale (as in the cause of El Nino) that has wide effects (as in El Nino).
111. Quietman at 15:43 PM on 7 November, 2008
     2004 Indian Ocean Tsunami Biggest in 600 Years turns out to be more evidence of tectonic upset.
112. Quietman at 15:32 PM on 10 November, 2008
     Mystery Wave Strikes Maine Harbor By Robert Roy Britt, LiveScience Managing Editor, 04 November 2008: "A series of large, unexpected tsunami-like waves as high as 12 feet struck Maine's Boothbay Harbor on Oct. 28, and there's still no explanation for what caused them."
113. Patrick 027 at 15:35 PM on 11 November, 2008
     "Mystery Wave Strikes Maine Harbor" - interesting, yes. Likely related to climate change, or a multidecadal scale geological variance - the later seems unlikely, the former could be true in the sense that this may happen more often due to storm waves or whatever, but considering the (apparently) sparse number of such events, it's hard to find a trend, so unless this kind of thing could be expected as a result of something else, there isn't much to go on. "2004 Indian Ocean Tsunami Biggest in 600 Years" - "turns out to be more evidence of tectonic upset." - it was a tectonic upset, but not the kind for which a correlation to multidecadal climate trends would be expected. On the Arctic Oscillation - "Synchronized Chaos: Mechanisms For Major Climate Shifts" - I will have to read the paper referenced by the article. I suspect though that more is understood about how CO2 would affect climate than is about these kinds of things. The other two: they suggested global warming could be behind the trend in the AO, or at least some portion of it. Of course there is internal variability, and some unforced variation in AO will occur. (?) AO itself doesn't seem to cause much of a global average temperature change (? - if the change in temperature at midlatitudes is balanced by that in the polar region).
114. Quietman at 04:20 AM on 25 November, 2008
     More on Tectonic activity and poor instruments: "On May 12, 2008, at 2:28 p.m., China's Szechwan province changed forever. In the space of 90 seconds, an earthquake equivalent to 1,200 H-bombs pulverized the earth's crust for more than 280 kilometers. Entire cities disappeared and eight million homes were swallowed up. This resulted in 70,000 deaths and 20,000 missing." "According to ShaoCheng this tragedy could have been avoided. "There hasn't been one earthquake in Szechwan province for 300 years. Chinese authorities thought the fault was dead," he says. The problem is that China relied on GPS data, which showed movements of 2 mm per year in certain areas when in reality the shifts were much bigger. "GPS is high-tech, but do we really know how to interpret its data?," he questions." Ref: Can China's Future Earthquakes Be Predicted? ScienceDaily (Nov. 24, 2008)
115. Quietman at 05:28 AM on 26 November, 2008
     This article Prehistoric Climate Can Help Forecast Future Changes ScienceDaily (Nov. 25, 2008, includes an interesting graphic. The "hot spot" anomalies in ocean temperatures are all very geologically active areas of volcanism/plate tectonics. While the article itself is worth reading, it's the illustration that stands out.
116. Arkadiusz Semczyszak at 01:07 AM on 28 November, 2008
     John Cook said: “There are two skeptic approachs to volcanoes: high volcanic activity causes global warming and/or low volcanic activity causes global warming” - I say: “two skeptic approachs to volcanoes”, don’t excluded… „On the contrary, relatively frequent volcanic activity in the late 20th century may have masked some of the warming caused by CO2.” - I think - it’s not “all” right… 1.In IV report IPCC, chapter 2, p. 194, is Fig. 2.18 - distinctly differ from John’s Fig whit volcanic - optical depth… 2. In this IV report on p. 195-6 is writing about “chemical destruction of stratospheric ozone”. Here is, in references, one interesting position: Tabazadeh at al, 2002… I remind You, what Tabazadeh was said then - in 2002 y: "Both the 1982 El Chichon and 1991 Mt. Pinatubo eruptions were sulfur-rich [not only S, but else Cl2 ,B(OH)3,NH3,CH4, Cl, F by metals compounds] , producing volcanic clouds that lasted a number of years in the stratosphere," "A 'volcanic ozone hole' is likely to occur over the Arctic within the next 30 years, [!!!]" “Between about 15 and 25 kilometers (9 to 16 miles) in altitude, volcanic Arctic clouds could increase springtime ozone loss over the Arctic by as much as 70 percent, according to Drdla” (http://www.spaceflightnow.com/news/n0203/05volcano/ and http://www.gsfc.nasa.gov/topstory/2002/20020304volcano.html) The annually production anthropogenic CFC = 750,000 T pure Cl, = one week by Mount Erebus productions…, at the all a World volcanoes, have a annually production 36,000,000 T Cl… Results about It , is visible here http://www.esrl.noaa.gov/gmd/dv/spo_oz/SP_Dobson_Oct15-31_2007_mod1.gif, and of stratosphere temperature in: http://www.atmosphere.mpg.de/media/archive/1385.jpg, Robert A. Ashworth in papers: CFC Destruction of Ozone - Major Cause of Recent Global Warming! (2008; http://omsriram.com/GlobalWarming.htm - all paper is very interesting) say: “The loss of ozone allowed more UV light to pass through the stratosphere at a sufficient rate to warm the lower troposphere plus 8-3/4" of the earth by 0.48 o C (1966 to 1998).” IPCC said: global anthropogenic GHG effects in this period = ~ 0,5 dg. C, Ashworth said: “anthropogenic emissions of chlorofluorocarbons”, it’s the reason it… …I say: volcanic S, Cl, F - emissions, dear Mrs. Ashworth… I propose else this image: http://www.leif.org/research/Erl70.png. It’s worth seeing.
117. Patrick 027 at 06:55 AM on 28 November, 2008
     Arkadiusz Semczyszak - "The annually production anthropogenic CFC = 750,000 T pure Cl, = one week by Mount Erebus productions…, at the all a World volcanoes, have a annually production 36,000,000 T Cl" CFCs are generally very unreactive until they reach the stratosphere and are broken down by UV, releasing Cl, etc. Volcanic Cl is probably much more reactive, and more likely to be rained out before reaching the stratosphere. I don't have time to read those papers right now, but I'll just note that the stratospheric cooling associated with AGW, (and also polar stratospheric cooling associated with increasing AO, which may or may not be a seperate matter, depending...) will make polar ozone holes more likely to result from any given ozone-depleting emission. Ozone depletion itself, while warming the troposphere below, cools the stratosphere by reduced UV absorption there, and also lets more longwave radiation from the surface escape to space, reducing any tropospheric warming that would result.
118. Patrick 027 at 06:09 AM on 29 November, 2008
     A few of the problems with this: http://omsriram.com/GlobalWarming.htm 1. (at least one of) the IPCC figures are incorrectly interpreted - tropospheric ozone is increasing, NOT decreasing - this is also an anthropogenic effect. 2. some temperature graphs are off. 3. CO2 graph is off (though not as far off as another one I've seen). 4. The evidence really does justify a conclusion that significant CO2 increases cause significant global (tropospheric and surface) warming.
119. Patrick 027 at 11:58 AM on 29 November, 2008
     " “The loss of ozone allowed more UV light to pass through the stratosphere at a sufficient rate to warm the lower troposphere plus 8-3/4" of the earth by 0.48 o C (1966 to 1998).” " Now spread that heat out over the top 100 m of ocean and see what happens. ( 100 m * 70 % of area + 10/4 m** / (8.75 in* 2.54 cm/in + 10/4 m** (**water depth equivalent to atmospheric heat capacity)) = 72.5 m / 2.72225 m = 26.6 0.48 deg C / 26.6 = 0.018 deg C. But the quote refers to the lower troposphere, in which case the result is less; if the lower troposphere is the air below about the 500 mb level, for example, then I get 0.48 deg C/ 48.4 = 0.0099 deg C. )
120. Quietman at 11:15 AM on 2 January, 2009
     Patrick I do see what you are saying but is it in fact catastrophic or just minor warming? Click Here for a recent article at Live Science : Earth's Atmosphere "Breathes" More Rapidly Than Thought By Andrea Thompson, Senior Writer, 2008-12-16 "Earth’s atmosphere was known to "breathe" in a cycle lasting nearly a month. Now scientists say the planet takes a quick breath every few days."
121. Patrick 027 at 06:56 AM on 5 January, 2009
     Concerning the breathing of the Atmosphere - (mostly the Magnetosphere) http://www.livescience.com/space/081216-agu-breathing-atmosphere.html If there is a significant impact on surface+tropospheric climate, it would have to be either 1. changes in magnetosphere, ionosphere, or sun itself directly causing changes in radiative forcing via a supposed change in albedo such as by cloud particle nuclei or clear air transmissivity changes ... (how much of that happens and is there any multidecadal trend?) 2. via interaction with the E-region dynamo, driving circulation changes in the ionosphere, which somehow changes circulation in lower layers, perhaps in the way the stratospheric conditions affect the EP flux from waves in the troposphere ... (how much EP flux is way up there and what does it do? ? ?) Because the ionosphere and magnetospere are extremely thin, just too optically thin (except at shortest wavelengths - UV, etc.) to have significant direct effect on the overall energy budget of the atmosphere by changes in infrared radiation.
122. Patrick 027 at 11:31 AM on 5 January, 2009
     ...(And the amount of energy in those shortest wavelengths is a very small fraction of the total radiant energy flux up or down)
123. Quietman at 09:07 AM on 9 January, 2009
     Patrick My point from the very befinning is that the atmosphere does not play as large a role in temperature as the IPCC and the alarmists claim. Every new article I read only confirms that our models are wrong. They just figured out, after 30 years of AGW hype, that the NE part of the US (and eastern Canada) has not warmed and in fact has gotten colder while the west coast warmed. I have come to the conclusion that it's the west coast alarmists hot air that caused the warming effect in the first place. :)
124. Patrick 027 at 10:35 AM on 11 January, 2009
     "They just figured out, after 30 years of AGW hype, that the NE part of the US (and eastern Canada) has not warmed and in fact has gotten colder while the west coast warmed." And the interior of the continent? And Europe? And Asia? And Africa? And South America? And Australia? And Antarctica? And the oceans? And the glaciers? The tropical mountain glaciers? And the forests, and the birds, and the plants?...
125. Quietman at 08:35 AM on 16 January, 2009
     Patrick You may recall that when we started talking about Bertha we took note that tropical storms had been forming farther east, meaning a change in air currents. Eastern Canada and the N.E. U,S, are not the only places on earth that have cooled while population centers warmed and it is from population centers that most data comes from. Why was this cooling ignored? South America, Antarctica and Africa have not experienced the same changes as Europe and PARTS of Asia. In fact, it has been noted that most warming has been on the western coasts of the Americas and Europe. If you check the ocean threads here you will see that overall the oceans have not warmed but there ate definate warm currents and hot spots. South Atlantic and Antarctic deep water is notably getting colder. Referring to this as "climate change" is quite accurate, but it is by no means "global warming".

Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  Next

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.