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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 125801 to 125850:

  1. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I assume clouds are water vapor - dense "clouds" of water "molecules". If the atmosphere was completely mixed then "clouds" would appear uniformly in all the sky. And the high concentration of CO2 over the Antarctica is really puzzling - it makes me skeptical when I see data that does not fit one's common sense. I thought all this CO2 was supposed to be coming from blast factories - I doubt penguins have mastered that technology.
  2. Could CFCs be causing global warming?
    Doug Cannon, it's hardly unproven that water vapour content depends on temperature. But you know, scientist always like to go back and check in any different situation. Here you'll find some general discussion on water vapour feedback while here you can find a list of scientific papers.
  3. What ended the Little Ice Age?
    As you are probably already aware, Prof. Svalgaard disputes that the sun actually has "warmed" up in the last few hundred years. http://www.leif.org/research/Seminar-SPRG-2008.pdf Not sure what this means to the early warming from the LIA, but something?
  4. Could CFCs be causing global warming?
    I agree with the concept of looking to the physics of CFC radiation forcing and that concept certainly supports the idea that Lu's conclusion is at least premature if not totally wrong. However, we also have to realize that the physics of CO2 radiation forcing doesn't support the results in the IPCC's models either. The majority of the forcing is due to a presumed, but unproven, amplification from water vapor/clouds. It seems the issue of these secondary effects of CO2 lie at the heart of IPCC model credibility. Other than Spencer's latest, I don't see recent evidence of anyone really getting to the meat of this issue.
  5. It's a 1500 year cycle
    Anyone interested in how a cyclical signal should be detected may want to read this short and nice explanation. And those who think that a natural cycle is superimposed on a linear trend may want to read this.
  6. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, it is not necessary for satellite measurements to be calibrated against a huge number of ground stations, for the same reason that thermometers to stick under human tongues do not need to be calibrated against a huge number of human tongues. The size and type of sample needed for calibration of any instrument is properly determined by combination of observation with statistics about those observations. That's what's done with satellite measurements. An engineer should know that.
  7. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    As for clouds - I think the clouds indicate the LACK of uniformity of density in the atmosphere since they show visually how different the atmosphere can be - regardless of whether you consider water a molecule or not (it is)
    Well, Ralph, a glass of water is not a molecule. A raindrop is not a molecule. The droplets of water or bits of ice that make up a cloud are not molecules. That's just fact, Ralph. As far as the number of sensors needed to accurately sample CO2 in the atmosphere, you flat-out don't know what you're talking about in this case, either.
  8. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Bern - I don't think a satellite actually measures CO2 and certainly not throughout the column. It is more that they measure something else then calibrate those readings with ground station CO2 readings. So if the ground stations are limited so will the satellite data be limited. And the NASA map indicates only some final averaging of data - the highest CO2 values over Antarctica, Peru and Morocco me skeptical. As an Engineer I would like to see widespread, actual measurements throughout the air column around the globe before I make a judgement about the state of CO2. Satellites are cute - but I am not convinced that they are providing sufficient data to base climate models.
  9. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm @ 27: no, we don't need millions of data sensors to get a handle on the total weight of CO2 in the atmosphere. We need millions of measurements by a sensor that moves around and covers the entire globe. Like a satellite in a polar orbit. That's how that NASA map you linked was produced. AIRS returns more than three million measurements per day, according to http://airs.jpl.nasa.gov/story_archive/Measuring_CO2_from_Space/Measurement_to_Science/ There's also a comment on that page: "...carbon dioxide concentrations turn out to vary by two to four parts per million. 'Before AIRS everyone thought carbon dioxide was well mixed above the boundary layer. We found that it is not.' It can vary by nearly a percent." So to you & I, CO2 is pretty evenly distributed. To scientists, a difference of a percent is quite significant - thus the choice of a scale for the graph that *highlights* that small variation. I thought it was interesting to note the comment further down about the coal-fired power plants on the Australian east coast being one of two major CO2 sources in the southern hemisphere, the other being a coal-to-liquids plant in South Africa that is the world's biggest single source of CO2.
  10. Was there a Medieval Warm Period?
    The Wikipedia item gives a link to a pdf of the Science article: http://www.meteo.psu.edu/~mann/shared/articles/MannetalScience09.pdf . The Supplementary Information can be obtained from the Science website for those who want to read the full details and methodology.
    Response: Thanks for the link to the full PDF of the paper - I've updated the link in this blog post as well as in the page addressing the skeptic argument: "Medieval Warm Period was warmer".
  11. What ended the Little Ice Age?
    re From Peru: if there's one thing I've learned in my reading on climate, it's that responses to changes in forcing are very non-uniform across the globe. Ocean currents, in particular, can result in some counter-intuitive results (like some areas actually cooling when everywhere else heats up). Your comment re Black Carbon, though, is interesting (as it's toward the end of the LIA when fossil fuel burning really took off, so it could be a factor). I'm not sure if John has already addressed this anywhere, but I did note that the graphs above start at 1890, though warming began around 1850. It does still help to reinforce the notion of sensitivity to forcing, though.
  12. What ended the Little Ice Age?
    Here something is missing: the 1910s-1940s warming is evident only in the Northern Hemisphere and there the pattern is strongest over the Artic. If the forcing is global, like Volcano+Solar, the pattern should be evident in both Hemispheres. This is not the case, so something else might have done it. I guess that the forcing in question is Antropogenic Aerosols. Important to note that the Meehl 2004 paper ignores Black Carbon forcing. This is an important flaw, as BC is now recognized as the second strongest warming forcing, only superated by CO2.
  13. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I'll certainly take your advice but I will see if there is any one that agrees with my assessment.
  14. Polar bear numbers are increasing
    UNPRECEDENTED LOSS OF SEA ICE RENEW CONCERNS FOR SURVIVAL OF THE WORLD'S POLAR BEARS July6,2009(Copenhagen,Denmark) At the 15th meeting of the IUCN Polar Bear Specialist Group...renewed the conclusions from previous meetings that the greatest challenge to the conservation of polar bears is ecological change in the Arctic, resulting from global warming. "The Western Hudson Bay subpopulation has been on the declilne for almost two decades...the body condition in polar bears is linked to the availibility of sea ice and time of spring break-up; and that when sea ice is available for less time, body condition declines ultimately affecting reproduction in adult female bears..."... ...Reviewing the latest information available, the PBSG concluded that one of 19 subpopulations is currently increasing, three are stable and eight are declining. For the remaining seven subpopulations, available data were insufficielnt to provide an assesment of current trend. The subpopulation increasing is located in Canada's high Arctic, an area that has not seen as much loss of sea ice as others, suppporting the Group's analysis of the critical relationship between the health of polar bears and the amount of sea ice... The IUCN (International Union for the Conservation of Nature and Natural Resouces) Polar Bear Specialist Group...each of the five circumpolar nations that signed the International Agreement for the Conservation of Polar Bears of 1973 - Canada, USA, Greenland(Denmark), Finland and Russia... polarbearsinternational.org Press Release ...(Nov3,2009): For the first time, researchers are studying...the summering ecology of polar bears of the southern Beaufort Sea who choose to migrate north to the sea ice of the polar basin when the winter ice pack melts, rather than return to the shores of Alaska... ...ice breaker expedition... ..."Polar bears need appropriate ice to hunt and survive. Young, thin ice can break up or disappear in a storm and older ice can actually be too thick for the bears to hunt seals..."... Polar Bears International
  15. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    But Ralph, you're just wrong. Factually wrong. Empirically wrong. Seriously wrong. Go read Pierrehumbert's book. It's free. It's online so it's easy to search for key words.
  16. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I look at it this way - the earth surface area is about 200 million square miles. That means each CO2 sensor must account for about the equivalent of one million square miles (I think there are only 200-300 long term datasets). So, this is just one dataset for all of Alaska and California and Texas combined (almost). As for clouds - I think the clouds indicate the LACK of uniformity of density in the atmosphere since they show visually how different the atmosphere can be - regardless of whether you consider water a molecule or not (it is). All I am saying is we would need millions of data sensors to get a handle on the total weight of CO2 in the atmosphere and the data we have is just too weak right now.
  17. CO2 measurements are suspect
    Theo, a "single regime of measurement in the atmosphere (all the way up)" is not needed. Measurements from spacecraft are calibrated against measurements from aircraft and ground stations. Routinely. And different methods of measuring even at ground stations are calibrated against each other. Ditto for aircraft measurements. New spacecraft often are launched while the spacecraft they are replacing are still in service, so that the new spacecraft's measurements can be calibrated against the old spacecraft's measurements. You don't read about such things in the newspaper or even on blogs, because it's part of the mundane, routine, standard, detail of empirical science.
  18. CO2 measurements are suspect
    Theo, see my 13:49 PM on 4 January comment on the Is the airborne fraction of anthropogenic CO2 emissions increasing? thread. See also dhogaza's comments in that thread. "Well mixed" is not an assumption, it is a longstanding observation.
  19. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, you are incorrect that there are "no data on CO2 close to the Earth." Just no data at that level of the atmosphere from AIRS. There are lots of data at that level from ground stations and aircraft, all over the world. The fact that CO2 is well mixed is not an assumption, nor a theoretical prediction. It is an observed fact dating back to at least the U.S. military's measurements in the 1940s. The number of observing stations, and their distribution, have been settled on as a satisfactory sampling, based on those empirical observations. Read dhogaza's comments in this thread; the variation in the mid-troposphere is tiny--less than half of the already-tiny 3% that you claimed. That variation is inconsequential to the big picture of CO2's global warming effects. Climatologists and atmospheric scientists of course got all excited about that tiny variation, because that is their narrow, microscopic specialty. Why do you persist in insisting that clouds are indicators that the atmosphere is uniformly dense? dhogaza already explained to you that clouds are not made of gas molecules, so their distribution and even existence is not evidence of gas molecules being unevenly distributed. If you want more detailed explanations, blogs are not the right place. Go look at Ray Pierrehumbert's book on planetary atmospheres, to which I pointed you earlier.
  20. CO2 measurements are suspect
    Tom Dayton, Thanks much for the reference to Pierrehumbert's book.
  21. CO2 measurements are suspect
    Chris, Mizimi, and Tom Dayton, Thanks for a really interesting discussion of airborne CO2 concentrations. As a philosopher and not a scientist, I am more interested in assumptions that are made when measurements are taken. Chris' remarks seem to assume that CO2 is well-mixed in the atmosphere and that, for that reason, the fact that the measurement stations are located on the surface will provide an accurate picture of airborne CO2 concentrations. Now, I wonder if there are airborne measurement stations and if they are distributed throughout the atmosphere in a way that would make them as effective as the ground based stations. I doubt that they are because they would be very expensive. Satelites are very expensive too and they would use a different technique of measurement. So, my tentative conclusion is this: it seems that there is not a regime of measurement in the atmosphere (all the way up) that could serve to confirm the hypothesis that CO2 is well-mixed throughout the atmosphere. Am I right?
  22. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo, I don't know if there is a single article describing all the methods in detail, because different methods are used by spacecraft versus aircraft versus ground stations. But a description of the collection method on Mauna Loa is on NOAA's site. And on the AIRS site, click on the two links in the section titled "Measuring CO2 from Space with AIRS."
  23. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    There is a 3% variation in the mid-troposhpere (5 miles) and no data on CO2 close to the earth. If the atmosphere is mixed well in that layer it is surely less well mixed at lower levels. If you are seeing a rise in CO2 levels how would you really know whether you were in a density wave or not? And as for clouds which reside at about 2 miles - they are indicators that the atmosphere is not uniformly dense. It appears that real CO2 data would be needed from literally millions of sampling points at varying strata not just the 200 or 300 stations that are used.
  24. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton and cbrock, thank you for answering my question, putting me to materials, and carrying on the conversation. If I may ask another, could you point me to an article on techniques of measuring airborne carbon dioxide concentrations?
  25. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2
    On what did you base your "highly varying" comment? Was it because they used a full spectrum of color (blue to red) to portray the +/- 1.3% variance (with most of the globe falling into a range of < 1.3% variance), or is it because you actually think the +/- 5 PPM range is really "highly variant"? Just curious.
  26. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules.
    Clouds are made up of droplets of water or small bits of ice, not individual molecules of H2O, so your comment regarding clouds is irrelevant.
    Also, the NASA CO2 map belies the idea that CO2 is evenly distributed.
    and
    http://sustainablog.org/files/2008/10/nasa_co2map.jpg
    Depends on your definition of "evenly distributed". The NASA AIRS plot you reference has a scale of 376-386 PPM, or 381 +/- 5 PPM. That's 381 PPM +/- 1.3%. That's extremely close to "evenly distributed". The press release is actually a bit weird, the AIRS data quantifies the "lumpiness". It's always been *known* that it takes time for CO2 (and other gasses) to become distributed by wind etc throughout the atmosphere - if you crack a tank of pure CO2 obviously the CO2 concentration near the tank will be higher than the average in the atmosphere. But once the tank runs out, the CO2 will rapidly disperse and that's it. So this isn't new knowledge at all. It's just quantification of how close to being 100% well-mixed the atmosphere is. We can measure it now, couldn't before, that's all.
  27. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    NASA CO2 graphic http://sustainablog.org/files/2008/10/nasa_co2map.jpg Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2 - if CO2 was diffused evenly the color on the globe would be just one color.
  28. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm, observations trump what you or anyone else "thinks." Also, you are incorrect that all kinds of molecules must be distributed to the same degree; just one example is water vapor's low concentration in the stratosphere versus lower, versus CO2's much more even concentration across those altitudes. Read the above comment by cbrock, and click the links in my above comment.
  29. It's cooling
    John Cook: Comparing the OHC results from the: 1)Upper 700 meters : 0.089 Wm^−2 (data source:http://climexp.knmi.nl/daily2longer.cgi, and the trend obtained in EXCEL) 2)Upper 2000 meters: 0.77 ± 0.11 Wm^−2 It is clear that the heat was sequestered in the Deep Oceans by the Termohaline Circulation, and that explain why the SST warming trend was near zero between 2003 and 2008. From this numbers is clear that if the Termohaline Circulation Shut Down then a BLAST OF HEAT will occur in the Upper Ocean and Atmosphere. Is there any current Climate Model of how much the warming will accelerate if the Termohaline Circulation Shut Down?
  30. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I think the idea that CO2 is diffused evenly througout the atmosphere is bogus. If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules. Also, the NASA CO2 map belies the idea that CO2 is evenly distributed. So the sampling for CO2 must be worldwide - not from few hundred stations.
  31. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: It is sometimes assumed by non-scientists that heavier gas molecules must be found closer to the earth's surface. However, for long-lived species such as CO2, atmospheric mixing (air motions) very effectively stirs up all the gases together so that they are not vertically separated. As one gets in the upper atmosphere (at very low pressures, approaching space), this is no longer true, but this region represents a tiny fraction of the mass of the atmosphere. This does not mean that all gases are perfectly evenly mixed, however. Obviously, near CO2 sources the concentrations will be higher, and near CO2 sinks (such as growing vegetation), the CO2 will be lower. So the end result is a patchiness to atmospheric CO2. There is a seasonality to this, since most vegetation is in the northern hemisphere. This seasonal cycle of CO2 is referred to as the "breathing" of the planet as the vegetation takes up CO2 during the growing season and gives it up during the fall and winter. The CO2 measurements report whatever the CO2 concentration is at a given place and time. Most of these measurements are extremely accurate and precise--a great deal of effort goes into assuring constant calibration standards and reproducibility. One has to average the CO2 measurements over the annual cycle and over the globe to get the global mean value. Hope this helps.
  32. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: CO2 is well mixed throughout the atmosphere--horizontally and (all the way up to the stratosphere). See the Skeptic Argument CO2 Measurements are Suspect. In addition to John's original post there, read the comments by Chris, John's "Response" in the green box within comment 16, and the new comment by me.
  33. CO2 measurements are suspect
    An AIRS press release noted that the AIRS data "complement existing and planned ground and aircraft measurements of carbon dioxide." Complement, not replace, because different tools measure CO2 in different vertical locations. More info on AIRS is available on the AIRS web site. The AIRS data for a recent two weeks can be seen on an interactive, rotating globe on JPL's "Eyes on the Earth 3D" web site. (On my Mac, it works properly in the Safari browser but not in Firefox; but my installation of Firefox doesn't work quite right, so it might be fine on your computer.) At the top left of the page, click the "AQUA" button. Then on the right side of the page, click the "CO2" button to show CO2 levels in the mid-troposphere as colors on the globe. The dates shown are above and to the left of the globe. Now drag the globe to rotate it. Click on the AQUA satellite to see the AIRS instrument. Discussion of CO2 being well mixed is on page 79 of Ray Pierrehumbert's book Principles of Planetary Climate, which is available free on line (and will be published in paper in 2010).
  34. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Could someone please extend some charity to a philosopher and tell me what assumptions are made when direct measurements of carbon dioxide concentrations in Earth's atmosphere are made? For example, is it assumed that CO2 molecules are distributed randomly throughout Earth's atmosphere including the stratosphere? Or is there some reason to believe that CO2 particles collect mostly within the first mile or the first 8 miles or whatever of the Earth's atmosphere?
  35. The physical realities of global warming
    The graph posted in response to #10.WAG (26 November, 2009) is one of the best Global Warming Trend graph I ever seen. Now, how will be the graph INCLUDING 2009, that will surely be warmer than 2007 and 1998? As 2009 data would be the final piece in the grave of the "Global Cooling" nonsense, it should be e-mailed to all deniers inmediately after the December GISS and hadCRU are published. By by, Global Cooling!
  36. Berényi Péter at 09:48 AM on 3 January 2010
    Understanding Trenberth's travesty
    One more thing. If you have a closer look at the figure (Global Ocean Heat Storage 0-2000 m) you have shown us from von Schuckmann 2009, you may notice a considerable jump at the turn of 2006/2007. In just two months OHC went up by 8x10^7 J/m^2. It is huge. It requires some 15 W/m^2 surplus heat flux for an extended period (9 weeks). Even taking into account the error bars, it's 15 ± 6.5 W/m^2. It is 6% of the heat flux coming from the sun to the surface. If this much heat is transferred to the ocean, it would cool down the ENTIRE atmosphere by 8°C. In midwinter. And he says most of the marine heat gain occurred in the North Atlantic. If I had three legs it would not pass unnoticed.
  37. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    sorry... Probably there are other causes of greater relevance than are being systematically ignored, not only by the scientific community, but by the IPCC, for example, rapidly growing trend of forest fires directly proportional to the exorbitant growth population in the world. Read news about a few months ago published: + http://www.cubanuestra.nu/web/article.asp?Artid=15784 More information on this site (by autor): + http://calentamientoglobalacelerado.net/alerta.htm
  38. Models are unreliable
    "If this is the case, then the temperature record shown is a slight underestimate of actual warming..." Are you implying that IPCC uses temperature records that aren't published and we don't have access to? None of the surface air temperatures or the satellite temperature records that I'm aware of come close to showing the temperature increases in figure 1. Certainly HadCRUT reflects less than half the increase in figure 1.
    Response: "Are you implying that IPCC uses temperature records that aren't published?"

    Not at all. The IPCC TAR use the HadCRUT record, NCDC and NASA GISS. They just don't indicate which of these records are used in Figure 1 above. As for the trends in Figure 1, just eyeballing the graph, it looks like the trend in the last few decades is 0.2°C which is consistent with all three temperature records.
  39. Models are unreliable
    The IPCC curves that you reproduce in figure 1 always looked wrong to me. Granted they're hard to read, but they show "observed" temperatures increasing much more than actual measurements from Hadcrut3, GISS,etc.....by a factor of 2-3 in some periods. e.g. 1975-2000. I think these were published in "Nature" years ago and I recall there was controversy about them then.
    Response: I'm having trouble determining which is the observed temperature record in Figure 1 as the IPCC TAR doesn't say which explicitly for that particular graph. I'm guessing it's the HadCRUT3 record as that seems to be the favoured record used throughout TAR. If this is the case, then the temperature record shown is a slight underestimate of actual warming as the HadCRUT record excludes some of the regions on earth that are warming the most.
  40. Arctic sea ice melt - natural or man-made?
    The RV anomaly doesn't cause anticyclonic circulation (in the totality of the flow anomaly of the PV anomaly) about the cyclonic PV anomaly but to some degree it spatially restricts the strength of the cyclonic circulation.
  41. Arctic sea ice melt - natural or man-made?
    NOTE I'm now using @ as a substitute partial derivative symbol for ease of typing and readability. Correction/clarification: For a reference frame that rotates with the planet (or star, etc.) u = x component of velocity v = y component of velocity For flow patterns along surfaces (in x,y,z coordinates, surfaces of constant z; otherwise, for x,y,p coordinates, surfaces of constant p (isobaric surfaces), or for x,y,q coordinates, where q is potential temperature, using surfaces of constant q (isentropic surfaces), and where 'vorticity' refers to the vertical component of the vorticity vector, the vorticity is equal to the sum (two horizontal dimensions) of variations over horizontal distances of the horizontal component of flow perpendicular to those direction; RV (relative vorticity) = @v/@x - @u/@y, f = planetary vorticity = the coriolis parameter = the vertical component of vorticity associated with planetary rotation, AV = absolute vorticity = RV + f where horizontal distances x and y are the horizontal components of distances along the surfaces within which the vorticity is being determined; when x and y are rotated so that the x direction is locally aligned with the flow, @v/@x becomes the orbital (curvature) vorticity (the vorticity associated with curvature of streamlines), and - @u/@y becomes the shear vorticity (the vorticity associated with changing the wind speed or direction across streamlines) For a pattern of flow that is like rigid solid-body rotation, @v/@x = - @u/@y = 1/2 * vorticity = shear vorticity = orbital (curvature) vorticity = angular velocity of rotation = angular frequency The circulation* (*not to be confused with the more general usage of the term) along a closed perimeter (the integral over length along the perimeter of the component of velocity locally parallel to the contour, taken to be positive in the counterclockwise direction) is equal to the integral of vorticity over the area enclosed. Circulation = line integral of (component of velocity parallel to the line in the counterclockwise direction) area-average vorticity = circulation/(area enclosed) If the perimeter follows a closed loop streamline (streamlines are parallel to the wind velocity), then the average of the counterclockwise speed over the length of the streamline is equal to the area-average of vorticity within the streamline multiplied by the area and divided by the length of the streamline. Circular streamlines will be centered on a circularly-symmetric vorticity field (which maintains symmetry out to infinitiy) if the flow is nondivergent (streamlines can only be assigned to a nondivergent component of the flow). For a circular streamline of radius r: Circulation = 2*pi*r * (circumference-average speed) = pi*r^2 * (area-average vorticity) (average speed) = r/2 * (average vorticity) Note that for two different closed-loops that completely envelope a region of nonzero vorticity which is surrounded by a zero vorticity field, the circulation about each loop is the same and hence the average speed (component along the loop) will vary among the loops in inverse proportion to loop length. Hence, the average speed about such loops which are circular is inversely proportional to the radii. If such circular loops are centered about a circularly-symmetricy vorticity field which goes to zero within a radius smaller than the loop radii (and remains at zero to infinity), then the loops are streamlines and the average speed on each loop is the speed at all points on each loop. Outside a circularly-symmetric region of nonzero vorticity, the orbital (curvature) vorticity and shear vorticity cancel each other. (There is a planetary circulation for planetary vorticiy, relative circulation ('circulation' by default) for RV, etc.) Linearly-superpositional vorticity fields and circulation values are associated with linearly-superpositional wind fields. Thus, if the total wind velocity = V1 + V2 ..., then the total RV = RV1 + RV2 ..., etc. Hence, any circularly-symmetric vorticity field has a set of concentric circular streamlines that are contours of that vorticity field's streamfunction (whether or not there are other nonzero vorticity fields at any location); the streamfunctions of multiple vorticity fields can be summed to find the total streamfunction. A particular component of a vorticity field can be called a vorticity anomaly, and a vorticity anomaly has a flow-pattern anomaly (streamfunction anomaly). Within a circular homogeneous RV anomaly, the anomaly flow pattern acts like rigid-body rotation. True that: 1. a point or homogeneous circular RV anomaly is mathematically associated with a wind anomaly which forms circular streamlines centered on the RV anomaly with wind speed being proportional to 1/r outside the RV anomaly, where r is the distance from the center (such a relationship has curvature/orbital vorticity same sign as the RV anomaly which is equal and opposite to the shear vorticity). AND for a homogenous RV anomaly along a line or constatn-wideth band, the velocity anomaly outside the line or band does not vary with distance from the line or band and is everywhere parallel to the line/band. HOWEVER (and this is where I may have made a mistake earlier): For a barotropic PV anomaly (with flat bottom topography) that is either a point-anomaly or has a 'hard edge' (as opposed to a sinusoidal or sufficiently-gradually tapered distribution (?), etc.), assuming geostrophic balance, the velocity field will generally have to decay in magnitude more rapidly with horizontal distance. This is because, for example, a cyclonic PV anomaly must have a low pressure anomaly associated with it. The pressure can't have a sharp jump within infinite geostrophic winds; thus, the pressure must decline gradually going towards the PV anomaly, even in the region of zero PV anomaly; this requires a RV anomaly of opposite sign to surround the PV anomaly (there will still generally be an RV anomaly of the same sign within the PV anomaly, and the circulation along closed loops (closure at infinity for infinite band/line PV anomaly) will still be cyclonic at any distance from the PV anomaly, but will decrease in strength outward from the PV anomaly due to the oppositely-signed RV anomaly required by geostrophic balance and a continuous pressure distribution. In the case of a baroclinic PV anomaly that is either a point or otherwise 'hard-edged' or not-sufficiently tapered, with limited extent vertically and horizontally, similar arguments apply. Along the isentropic surfaces that intersect the PV anomaly, for a cyclonic anomaly in geostrophic balance, the spacing between isentropes must decrease approaching the anomaly even outside the anomaly, so that there is a positive stability anomaly, which requires an anticyclonic RV anomaly outside a cyclonic PV anomaly in order for the PV anomaly to be zero outside the nonzero PV anomaly. Above and below a cyclonic PV anomaly in geostrophic balance, the isentrope spacing anomaly must be negative, requiring a cyclonic RV anomaly, as previously described. Qualitative arguments suggest a pattern with something like a conical shape with upper and lower cones that have vertices at/within the PV anomaly; outside the region of nonzero PV anomaly, for a cyclonic PV anomaly: within the cones, the stability anomaly is negative and the RV anomaly is cyclonic (as is generally the RV anomaly within the PV anomaly), while outside the cones, a ring of anticyclonic RV anomaly surrounds the PV anomaly along with a positive stability anomaly that generally extends through the PV anomaly. The RV anomaly doesn't cause anticyclonic circulation about the cyclonic PV anomaly but to some degree it spatially restricts the strength of the cyclonic circulation.
  42. Measuring Earth's energy imbalance
    I said: "this levels of C02-equivalent" with "this" I refer to the current ones, now near 450 ppm.
  43. Measuring Earth's energy imbalance
    What is dirturbing is that more than half of the greenhouse warming is masked by aerosols. This doesn't imply: 1) A climate sensitivity much bigger than the commonly assumed value of 3ºC per doubling of CO2, maybe 6-7ºC per doubling of CO2? 2)There is a lot of forcing (I said forcing,not warming) "in the pipeline" from the greenhouse gases, that will emerge as the aerosol emissions drop(these will be regulated before CO2 because them are highly toxic)? I suspect that the "Dangerous Antropogenic Influence" treshold was passed long ago, because according to paleoclimate studies, this levels of C02-equivalent are more than enough to melt away ALL GREENLAND, ALL THE MOUNTAIN GLACIERS AND THE WEST ANTARCTIC ICE SHEET.
  44. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Humanity rules wrote: "It's hard for me to understand how the rate of absorption can become reduced or the system become saturated. Common sense would say if you were looking at the movement of a substance from one fluid to another (atmosphere to ocean) then the larger the gradient (in this case caused by higher CO2 conc in the atmosphere) then the faster the diffusion of material." You're right about the second paragraph there but you just might be missing one important point. In order for the airborne factor to increase, the flux of CO2 to oceans etc. does not need to decrease. In order for AF to stay constant, the flux needs to increase at the same rate as emissions. Therefore, even if the flux of CO2 from atmosphere to the oceans etc. increases, but slower than the emissions, the AF will increase. Actually, mathematically a constant AF is exactly what you would expect, if you had exponentially growing emissions combined with sinks, whose rate is linearly proportional to the concentration.
  45. A visual deconstruction of a skeptic argument
    What about the CO2 reaching it's greenhouse saturation effect at a much lower level, and that much of the "worrying" is by taking into consideration amplification by high level water vapor? Many skeptics completely agree about the increased 20th century CO2 levels likely to be anthropogenic, but it is the "complete theory" of amplification which is hard for many to swallow? The increased heat will cause evaporation and increased water vapor, but the vapor will be high cirrus clouds resulting in greenhouse effect, and not low typical clouds which result in overall cooling.
    Response: Obviously, I can't hit all skeptic arguments in the one page (or can I?). This article is addressing the specific argument that humans aren't causing the rise of CO2 levels in the atmosphere. Those other arguments are addressed elsewhere:
  46. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    John, maybe you should say something about the IPCC model forecasts re fraction of CO2 in atmosphere? It would also be interesting to learn more about the reason for the different estimated trends (1.2 vs 3 %/decade). Is it only because of Knorr using a longer time series for his modeling?
  47. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    FF, it's not necessary to measure emissions to know how much CO2 is produced by burning fossil fuels, we only need to look at the accounting of fuel production. For example, we know that global oil production is about 31e9 bbl/year. From that we can calculate the amount of CO2, after taking into account the fraction of the oil going toward non-fuel purposes ( http://numero57.net/?p=255 ). It comes out to about 10e12 kg of CO2 per year produced by burning petroleum. Similar calculations can be made for coal and natural gas.
  48. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Wrong isotope, nfw, try 12C to 13C.
  49. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Yes, there is another twist to this tale. Without looking into to too much right now, C14 which is created from fossil burning. Apparently it is able to be measured. I think I remember reading an article by Roy Spencer(big, important skeptic) questioning that research too! LOL. But that should be the next topic to explore. Back to the topic above. The Knorr paper concludes with "The hypothesis of a recent or secular trend in the AF cannot be supported on the basis of the available data and its accuracy." Doesn't this mean they don't understand what is going on. It continues that they need to know more about land use, well I say what about CO2 changes in the ocean, which hold many times over the CO2 of the ocean. They can likely fairly estimate the man-made CO2, and then they just work backwards to fill n the number.
  50. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    FF, have you never heard of carbon isotope ratios? This allows for identification of sources of CO2.

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