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Comments 106351 to 106400:

  1. DMI and GISS Arctic Temperatures: Hide the Increase?
    And again about UHI: Im sorry to say it, but one of the WORST arguments I have seen against UHI is here from Skeptical science, im sorry. I saw an article where they have chosen a little area where the whole area is a UHI area, and then compared the data! In places like southern california, Rhein Ruhr in Germany, and central England, there are so many big cities, that these regions as a whole are affected but the UHI from the cities. There fore the WORST place to make a comparison between "rural" and city is in such an area. But this is im afraid what skeptical science did, they used south central England. And worse: UHI shows up because cities normaly changes size radically from 1900 till today. And there is very very few cities in the world that where already multi million cities in year 1900, and a such is London... Skeptical science shows a "Non-UHI" argument by comparing London temperatures with its sorrounding subburbs to London in the southern England. I simply dont know why anyone with an wish to study UHI would do like this. K.R. Frank Lansner
    Response: You are probably looking at the Basic Version of the UHI page. That's the problem when you try to explain things simply - there's always the danger of oversimplification (which I was warned about when we embarked on the basic rebuttals). In the Intermediate Version of the UHI page, we begin by looking at the London area but then point out, just as you do, that we need to look at developing areas. So we compare rural to urban trends in China which has shown much economic growth over the last 30 years with a dramatic increase in its city areas. And what we find is, well, I don't want to spoil the ending, check it out for yourself...
  2. DMI and GISS Arctic Temperatures: Hide the Increase?
    Hi Bibliovermis. For all subjects in the climate debate one can find a link with any viewpoint. But you just bring the links and I have to figure out myself WHY you think that this link has the best answers, WHAT arguments you where thinking of when bringing the links. So for now, I will just bring you a short description of why i believe that UHI is a very important part of the rising "global" temperature measured mostly from cities and airports. In my viewpoint, the best and biggest UHI research was made by Thomas Carl in 1984. Like it or not, but there are different opinions on the temperature adjustments done after 1984, and therefore the early dating of Thomas Carls work - 1984 - simply omits the claimed problem of temperature adjustments that makes UHI harder to see in data. Thomas Carl used 4-500 pairs from USA of rural vs. city measurements, and since USA holds around half(?) of the worlds temperature series all the way back from year 1900, then a total USA study is a very good approach. Thomas Carl Finds a systematic strong relation ship between city size and artificial UHI heat in data: http://hidethedecline.eu/media/city%20heat%20IPCC/aau.jpg What could Thomas Carl have done wrong?? Its so simple, compare rural with not rural. I have to trust these results. Many other results suggests UHI, here from all over the world, this list isnt even updated: http://hidethedecline.eu/pages/posts/urban-heat-island---world-tour-155.php Then, the global warming side came up with Petersons results. He found just 0,05 K UHI, but when finally Steve McIntyre got his hands on Petersons data to see how on Earth Peterson could get this result, something quite else turned up. When Steve did a simple check of Petersons calculations, he found 0,7 K... and not 0,05K And worse: It turned out, that Peterson had put city stations in the rural category and vice versa. In another study - pro global warming - a guy (parker??) had NOT done the obvious and simply compared the temperatures of city vs. rural. For some unexplained reason, this guy had chosen not to do the obvious. This lack of explanation itself casts a shadow over the study. In stead he had done some rules of what he expected to find when looking at winds from cities. And then a team (wang ??) had examined UHI in China, getting again practically no UHI, but when they where asked to deliver their data, they failed to fully explain how they got their result. As far as I know they are actually under official accusation for faul play. Then later a new team including P.Jones came with the result that UHI in China actually accounts for 0,5 K of the warming. Then the CRU approach to UHI: As we saw in Carls data, practically all cities show UHI warming polution in data. But to come around this, CRU has simply omitted i think 30 - 35 cities in the world, and used the rest without any UHI correction. Again, there is not much in the warmists approach to UHI that gives me the impression that they treat UHI as it should be treated. ANd then i showed you guys, that UAH satellite measurements fully agree with conventional SST, but do NOT match temperatures from land, that is, temperatures from cities: http://hidethedecline.eu/media/PERPLEX/fig78.jpg I think this last argument is very strong. Unless of course UAH satellite temperatures only work over the oceans :-) K.R. Frank
  3. Waste heat vs greenhouse warming
    RSVP #238: "So instead of the effect you describe, as seen from a map, there is typically a large smudge or plume that emerges around an urban center that tapers eastward... heat that is gradually dispersed but never lost" Great. Show me such a map. I had always been under the impression that UHI effects were extremely localized, hence the term 'island', and disappeared within just a few miles outside the city limits. It will be fascinating to see the long trails of increased temperatures stretching out from urban centers. Of course, that still wouldn't explain your claims about the Arctic... where there are no major cities. Do all the 'heat trails' (in the map you are going to show any time now) collect in the Arctic for some reason?
  4. Waste heat vs greenhouse warming
    CBDunkerson "the area in and around New York City should show tremendous temperature anomalies with decreasing amounts radiating out from there and other industrial centers" Here is a link I recommend you visit... http://www.epa.gov/heatisld/ In North America winds predominate from the west in a continuous fashion with the notorious "jet stream" where the flow is most accentuated. So instead of the effect you describe, as seen from a map, there is typically a large smudge or plume that emerges around an urban center that tapers eastward... heat that is gradually dispersed but never lost, as per RSVPs theory, which I will describe once more in my next post.
  5. DMI and GISS Arctic Temperatures: Hide the Increase?
    Hi all: Thankyou for very good argumenting. My problem is that "there are too many of you" :-) so it will take time to answer all. So far, its my impression that Peter Hogarth himself actually sees where im getting at at some points. If you have the patience, i will answer you all, so please keep coming back to this discussion later. Many of you gives many opinions of which I totally disagree and I will take it in the order they came in. I wish i was full time oil payed to have all the time in the world :-). But I think that your tone and seemingly wish to make honest debate is SUPER, and that why I will answer all. Coming soon :-) K.R. Frank
  6. Climate cherry pickers: Falling humidity
    Thanks for the new article, John. It's an interesting read. I caught that Q and A show earlier in the week, too, and was surprised by Marohasy's statement about humidity - it appeared Tim Flannery was too, although it was almost amusing to watch him twitch at some of the more outrageous statements she was making. He displayed admirable restraint, though - keeping it polite even when giving her a dressing down for interrupting! I note she also quoted Roy Spencer, but more than a few of her talking points might have been easily rebutted by a reference to this website...
  7. Increasing southern sea ice: a basic rebuttal
    Much appreciated :-)
  8. Do 500 scientists refute anthropogenic global warming?
    @oxymoron: what Ned said. In one word: aerosols.
  9. Climate cherry pickers: Falling humidity
    By the way, there's also a new paper out from Dai et al. who make an effort to homogenize the radiosonde humidity records: http://journals.ametsoc.org/doi/abs/10.1175/2010JCLI3816.1 (I haven't found full text, sorry.) Their conclusion: "The DPD adjustment yields a different pattern of change in humidity parameters compared to the apparent trends from the raw data. The adjusted estimates show an increase in tropospheric water vapor globally."
  10. Increasing southern sea ice: a basic rebuttal
    chris, Not sure about anything later but the figure here runs up to 2007.
  11. Increasing southern sea ice: a basic rebuttal
    E @ 15: I'm happy to stand corrected. However, I'd be interested if you have any data for 2004 -> roughly now.
  12. Do critics of the hockey stick realise what they're arguing for?
    I guess we should leave it alone, Ned - sometimes communication fails with the best will in the world. I supect the fault (for want of a better word) lies much more with me than with you. The AR4 graphic in your comment @ 8 refers to forcings only seemingly including cloud albedo under that rubric. Maybe that has contributed to the confusion. Thanks for trying :-).
  13. Stephen Baines at 14:47 PM on 21 October 2010
    Climate cherry pickers: Falling humidity
    BTW. This is a nice summary by John. I learn something again. I also want to agree with Ned. This discussion of insolation and skin temperatures is a distraction. All other things being equal (insolation included), evaporation and water vapor should increase if the earth and atmosphere warm.
  14. Climate cherry pickers: Falling humidity
    JohnD - how can wind be a forcing?
  15. Throwing Stones at the Greenhouse Effect
    RSVP at 20:30 PM on 20 October, 2010 says "IR travels at the "speed of light", some 3 x 10E8 meter per second. Maybe you can explain where the delay is coming from?" Ok... all matter radiates, a rock dosnt just radiate at its surface, it is radiating according to its temperature all the way through its center, but rocks are extremely opaque to both LW and SW. So what this means, is that the energy transfer through radiation, through its center, is indistinguishable from conduction, its a differential in T that allows a flow of heat, if something is extremely opaque to LW radiation, the difference in T between molecules will be very similiar, limiting the amount of energy able to be transmitted, which will be a result of its boundary conditions, at what rate it is absorbing, or emitting energy. With a temperature gradient necessary to allow a flow of energy through radiation (or conduction, or convection, but rocks dont convect very well at normal terrestrial T's). The reason is simple, if its neighboring molecule is at the same T, it will be emitting the same as it is absorbing. Essentially meaning no change in energy. Or local thermal equilibrium LTE. So by increasing the opacity of a gas, you are essentially restricting the distance energy can travel via radiation. Making it behave more like a solid, in regards to the passing of energy through LW radiation. The temperature gradient, will restrict the flow of energy out of the system, because it is only the net difference between layers that is being transmitted. And the more opaque a gas is, the shorter the distance between the emitting and absorbing molecule will be, the smaller the difference in T will be between molecules, the smaller the amount of net energy flow will be. And thats why.
  16. Increasing southern sea ice: a basic rebuttal
    chriscanaris, The figure you just cited does not plot SST temperatures directly, please read more carefully. It is plotting the variability of SST's, which is a measure of how "spread out" the data is. A plot of variability is not going to tell you whether the data was going up or down, just that it was changing. Ironically, that paper is using the same raw SST data series (NCEP–NCAR reanalysis data) as the Zhang paper that scaddenp referred you to. If you are interested in actual SST trends in the antarctic, take a look at that paper. It is linked in the intermediate version of this post (or just look at the figures duplicated from that paper in the intermediate post).
  17. Stephen Baines at 14:14 PM on 21 October 2010
    Climate cherry pickers: Falling humidity
    Johnd, are you suggesting that the most solar radiation is absorbed by the skin of the ocean, rather than by layers beneathe the surface? The citation you refer to is for calculating evapotranspiration on land, where light does not penetrate beneathe the "skin", at least not far. Water is actually fairly transparent to light so the very thin "skin" accounts for little of the absorbance, although eventually most incoming light is absorbed at depth. The skin temperature of the ocean (where the vast majority of evaporation on earth happens) is largely a function of mixed water column temperature as a whole, which reflects the balance between inputs (solar radiation, incoming IR radiation) and outputs (outgoing IR radiation, evaporation, convection, mixing)of heat energy. As the earth's temperature increases that heat balance results in higher mixed layer temps, which leads to high skin temps and greater evaporation.
  18. Climate cherry pickers: Falling humidity
    Ned, I feel it is both relevant and important enough to clarify given the statement in the article "Water vapor provides the most powerful feedback in the climate system. When surface temperature warms, this leads to an increase in atmospheric humidity." I feel that is not conveying a sense of the correct drivers that are most relevant to how water vapour enters the atmosphere in the first place. There is a need to be sure that the foundations any discussion is built upon are fully understood and solid.
  19. Climate cherry pickers: Falling humidity
    This doesn't seem like a particularly relevant or useful start to the discussion of this topic. John's done some nice work looking at humidity trends wrt the water vapor feedback, and it would be a shame to divert the discussion right from the start into a lot of wrangling over minutia.
  20. Do 500 scientists refute anthropogenic global warming?
    You also might want to consider whether CO2 or "the Sun" is a better fit for the temperature trend, especially post-1970s: Ignore the PDO line for now, and just focus on temperatures (RSS, GISS), CO2, and TSI (solar). ------------- PDO data from University of Washington. Surface temperatures from GISS land+ocean. Satellite temperatures from RSS. Law Dome CO2 from NOAA NCDC. Mauna Loa CO2 from NOAA ESRL. PDO and temperature data shown in monthly and 120-month LOESS smoothed versions. Law Dome CO2 dating based on "air age" with 20-year smoothing. Mauna Loa CO2 (monthly) are seasonally adjusted. Both CO2 data sets were log-transformed (base 2). Data sets with differing units (PDO, temperature, log[CO2]) have been scaled to fit on the same graph. Solar irradiance data from University of Colorado, shown annually and with a 22-year LOESS smoothing function.
  21. Climate cherry pickers: Falling humidity
    Ned, for solar radiation to manifest itself as a forcing it must first be absorbed. In this case I am referring to that portion of the solar energy that is absorbed at the skin of the water and is immediately transferred to the water vapour so transformed and becomes part of the atmosphere. The solar radiation that is not absorbed at the skin, but progressively at further depths then goes on to manifest itself, and be measured, in different ways.
  22. Do 500 scientists refute anthropogenic global warming?
    oxymoron, you might want to look at the following: CO2 is not the only driver of climate What happened to greenhouse warming during mid-century cooling?
  23. Climate cherry pickers: Falling humidity
    Does he have a point about wind though? If warming temperatures caused less mixing, the absolute humidity at the surface could rise, while falling at greater altitudes, thus introducing a negative feedback. I suspect that warming temperature _won't_ cause less mixing, and there's probably already data on whether it will/does, but at least it seems like there's a scientific possibility in there. (Not that anything really defeats the paleo evidence for a sensitivity around 3, so any discovery of previously overlooked feedbacks is like showing your work when the answer is known.)
  24. Do 500 scientists refute anthropogenic global warming?
    archiesteel: CO2 concentrations began rising significantly around 1940, but temperatures dropped from 1940 to 1970, so it definitely is not CO2.
  25. Increasing southern sea ice: a basic rebuttal
    Philippe @ 12 Figure 7 in Verdy, Marshall, & Czaja suggests overall cooling since the 1980s. However, ice loss is ice loss until proven otherwise.
  26. Do 500 scientists refute anthropogenic global warming?
    @oxymoron: sorry, but it's definitely not the sun. Arctic air temperatures have been going up in the past decades, like CO2 concentration, while TSI has been going down.
  27. Do critics of the hockey stick realise what they're arguing for?
    chriscanaris, what am I supposed to be seeing in that quote? I'm afraid I'm not getting it. Volcanic aerosols are a forcing. Anthropogenic aerosols are also a forcing, but cloud albedo is a feedback. The terminology is important, but even with that aside I'm still not quite following what you're trying to say. Maybe if I sign off for the night and get some sleep it will be obvious in the morning...
  28. Do critics of the hockey stick realise what they're arguing for?
    Ned @ 69: Take a look at this excerpt on climate impact of volcanoes. 'Volcanic aerosol particles scatter and absorb a fraction of incoming solar radiation, as well as absorbing a fraction of outgoing terrestrial radiation. The change in global temperatures caused by the aerosols from El Chichon and Mt Pinatubo is estimated to be 0.2¡C and 0.5¡C. However both these values lie within the natural variability of temperature.' Volcanic forcings don't seem to behave differently from aerosol and cloud albedo forcings though undoubtedly they are presumably nearly entirely independent of temperature whereas the relationship between aerosols, clouds, and temperature eventually becomes very complex and, somewhat to my regret, confusing partly because of the uncertainties around the feedbacks.
  29. Climate cherry pickers: Falling humidity
    No, johnd. If increasing solar radiation were warming the planet, then solar radiation would be the forcing and increasing humidity would be one among several feedbacks. Likewise, if increasing CO2 leads to an increase in humidity, CO2 is the forcing and water vapor is the feedback. On Earth, water vapor is basically never seen acting as a forcing.
  30. Do 500 scientists refute anthropogenic global warming?
    Sorry, it's the sun. Arctic air temperature is strongly correlated with total solar irradiance over the period 1880 to 2000 [Soon, W. (2005) Geophysical Research Letters 32, 2005GL023429, and Hoyt, D. V. and Schatten, K. H. (1993) J. Geophvsical Res. 98, 18895-18906]. What is NOT correlated with arctic air temperature is hydrocarbon use [Marland, G., Boden, T. A., and Andres, Ri J. (2007) Global, Regional, and National CO2 Emissions. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, TN, USA]
  31. DMI and GISS Arctic Temperatures: Hide the Increase?
    Your [Peter's] carefully researched postings really raise the level of discussion. Yes. This is a really nicely done post. Like michael sweet, I really look forward to new comments or posts by Peter Hogarth.
  32. Do critics of the hockey stick realise what they're arguing for?
    chriscanaris writes: Moreover, I did *not* at any time suggest that 'one creates policy based on assuming that the true value of an estimate is at the extreme negative value of a very wide error bar.' I agree, you didn't suggest that. This is a busy site and when the comments get flying it's easy for us all to misinterpret each other. I know it's very annoying when people misunderstand me, or attribute someone else's views to me, or whatever. In kdkd's defense it gets a bit tiresome being repeatedly confronted with an argument that appears to be, in essence, "Well, there is a large uncertainty band around the best estimate for [whatever], so maybe things won't be as bad as those doomsayers claim." Your comments have much more nuance than that, and all of us should probably do a better job of being alert to nuances in others' comments. It's difficult when one's patience is worn down by some of the more unreasonable and unhelpful commenters here. More chriscanarises among our SkS "sceptic" contingent would be a distinct improvement, IMHO.
  33. DMI and GISS Arctic Temperatures: Hide the Increase?
    Peter Hogarth: I was linking to Dr. Hansens' web site to defend the GISS data. My position is that both DMI and GISS are good records and can be used for the purpose you use them in this article. I dislike people who choose one record and distort another, especially since they cite blogs (or personal opinion) and not peer reviewed papers. I am glad to see you back. Your carefully researched postings really raise the level of discussion.
  34. DMI and GISS Arctic Temperatures: Hide the Increase?
    archiesteel writes: You seem to be missing the obvious: the DMI data shows a dramatic warming trend. In fact, as I indicated at the beginning of this comment trend, the DMI agrees with the dramatic warming of the arctic over the last decades. To be precise, the 50-year trend in DMI's temperature is just slightly higher than the trend in GISS (0.37C/decade vs 0.35C/decade), though this difference may be accounted for by the slightly different areas included in the two. See Peter Hogarth's excellent Figure 3 from the top of this thread.
  35. Do critics of the hockey stick realise what they're arguing for?
    Goddard is just trying to get attention, and should probably be ignored. The comment here by Albatross is just great. I too had read through the van Hoof 2005 paper but didn't get around to commenting, and I'm glad I didn't waste my time because Albatross's response is better than mine would have been. Once again BP is making strong claims that don't really stand up under close examination. This is IMHO unfortunate because many of the papers or sources that BP cites in his comments on this site are very interesting and could probably lead to some good discussions if he could just stop making these exaggerated claims that every one of them conclusively disproves AGW. A more modest approach to interpreting the evidence would probably do wonders for BP's credibility on this site, IMHO.
  36. Do critics of the hockey stick realise what they're arguing for?
    chriscanaris #75 Can you please point out where you perceive my language was incautious? If you're not advocating policy based on assuming that the true value of an estimate is at the extreme negative value of a very wide error bar, then that's fine. However you haven't made this clear. What would climate sensitivity be with strong negative feedback from clouds assumed by the way?
  37. Climate cherry pickers: Falling humidity
    The article seems to overlook the relative importance of solar radiation and wind as being the two main drivers of evaporation, translating as the skin temperature of the evaporating surface rather than ambient temperature, and the airflow over it, which in the case of solar radiation would make water vapour more of a forcing than a feedback. This paper details the calculations and the various inputs that are involved BUREAU OF METEOROLOGY REFERENCE EVAPOTRANSPIRATION CALCULATIONS
  38. DMI and GISS Arctic Temperatures: Hide the Increase?
    @FLansner: "We have only the choice between data measured in the area (DMI) or data projected from land far away. I think you need biiiig globalwarming glasses not to see what data source is most reliable." You seem to be missing the obvious: the DMI data shows a dramatic warming trend. In fact, as I indicated at the beginning of this comment trend, the DMI agrees with the dramatic warming of the arctic over the last decades. Who should I trust on what the DMI data says? Web contrarians or the DMI itself?
  39. DMI and GISS Arctic Temperatures: Hide the Increase?
    Can someone fill me in on a question that bothers me about air temperatures above ice/snow? The heating of surface is radiative and from AGW point of view the interest is LW radiation. For ice-free land/sea then I would expect the air temperature 2m above ground to reflect this warming of the ground surface. But above ice/snow? Unless there was evaporation/sublimation going on, how much heat transfer is there into the air above? If surface warms from say -20 to -10, is that going to be reflected in the cold dry air above it?
  40. Do critics of the hockey stick realise what they're arguing for?
    Phila @ 70 What may be confusing people is the apparent implication that this somehow makes you different from anyone else, or that this view is some sort of alternative or corrective to what the what of us think. Sorry to confuse :-) I've long shed any pretensions to any unique status. KDKD: With respect, your language was certainly neither conservative nor cautious. I've been reading scientific literature principally in my field for as long time - I do have some passing familiarity with academic writing. Moreover, I did *not* at any time suggest that 'one creates policy based on assuming that the true value of an estimate is at the extreme negative value of a very wide error bar.' Ned: You're right - I genuinely do find the notion of the apparent mutual exclusivity of high climate sensitivity and negative feedback from clouds difficult to grasp. Give me time - and I'll certainly go hunting around the Internet for ideas.
  41. DMI and GISS Arctic Temperatures: Hide the Increase?
    Something else to consider. Here are surface temperatures (not air temperatures) for northern high latitudes derived from satellite data between 1981 and 2003. Sourced here.
  42. It's the sun
    KL #705 "Hence rising temperatures with 'flat' non-zero forcing are quite consistent with the 'Temperature vs. Solar Activity chart on the Basic version of this thread'" That may be the case, if we didn't have additional data showing that the role of CO2 has been strong for the past 60 years. However we do. If you omit key information, then your hypothesis would appear credible. However omitting key information is not justified, so your hypotheis is not credible.
  43. DMI and GISS Arctic Temperatures: Hide the Increase?
    Frank, The impacts of the UHI are taken into consideration, see Tamino's recent post on Tokyo's temperatures. Anyhow, I am not sure what your argument is. Is it that the warming may be less than observed b/c of the alleged impact of the UHI? If so, then that can be discussed on the appropriate thread. There are very few skeptics even who consider the various SAT records and satellite records to be compromised-- that argument is usually made by "conspiracy" theorists. Anyhow, the Arctic is warming. ERA-interim data show warming, GISS shows that, and satellite data to 82.5 N show that. There is no reason to believe that there would be some rapid change or discontinuity in the temperature anomalies north of 82.5 N-- especially give that we know the correlation length-scale of anomalies is on the order of hundreds of km. I have a huge issue with people (including you) claiming that the "Arctic" is not warming when they are not even talking about temperatures north of the Arctic circle, but rather north of 80 N. The Arctic, of course, starts at the Arctic circle, which is much further south than 80 N, and that is an important difference. Do you disagree with the excellent agreement between GISS and DMI shown in Ned's post @31? So I'm not sure what kind of glasses you are wearing when you look at that graph. I also find it odd that "skeptics" ridicule the models, except that is when they think the output supports their point of view. Well, in this case the ECWMF reanalysis data do not support the claim that the Arctic has been cooling since 1958. Increase in mean near-surface temperature (°C) from (1989-98) to (1999-2008) "The lower figure is the ECMWF analysis which uses all available observations, including satellite and weather balloon records, synthesised in a physically- and meteorologically-consistent way, and the upper figure represents the same period from our HadCRUT record. The ECMWF analysis shows that in data-sparse regions such as Russia, Africa and Canada, warming over land is more extreme than in regions sampled by HadCRUT. If we take this into account, the last decade shows a global-mean trend of 0.1 °C to 0.2 °C per decade. We therefore infer with high confidence that the HadCRUT record is at the lower end of likely warming." DMI really needs to generate a product that is representative of the Arctic circle, not just north of 80 North.
  44. DMI and GISS Arctic Temperatures: Hide the Increase?
    FLanser, Are surface temperature records reliable? (argument #6)
    The warming trend is the same in rural and urban areas, measured by thermometers and satellites.
    Does Urban Heat Island effect exaggerate global warming trends? (argument #21)
    Urban and rural regions show the same warming trend.
  45. DMI and GISS Arctic Temperatures: Hide the Increase?
    Hi Peter! Its true, GISS has mostly 2 "products", its only in one they use the projections. Non the less, these projections are seen not rarely when argumenting for global warming, for instance in this NASA graphic used to show that the Arctic is going crazy: http://hidethedecline.eu/media/arctic%20temperatures/nasa2005.jpg But to make the Arctic look Sooooo dark red as on the NASA site here, they used start year 1955. But as you see in comment 46 above, start year 1937 would have shown something else. And using DMI/ERA-40 data would have shown a more nuanced picture. If you say that both GISS and DMI is only so-so useful, then i think they should make the area grey. K.R. Frank
  46. DMI and GISS Arctic Temperatures: Hide the Increase?
    Hi Albatross, The resemblance or lack of same between different sources of temperature data i have written a lot about: http://hidethedecline.eu/pages/posts/the-perplexing-temperature-data-published-1974-84-and-recent-temperature-data-180.php Here i would focus on PART 4, where for example this graphic appears: http://hidethedecline.eu/media/PERPLEX/fig78.jpg Here, notice how UAH OCEAN temperatures rather nicely follow the SST (called CSST, an average of different hadley and NOAA sources to SST). But the UAH LAND temperatures does not match the different sources of land temperatures, being GISS, GRUTEM3, Vinnikov and NCDC. The overall difference between UAH and the land based readings are not so easy to see when land and ocean are combined, but difference for land is clear. This indicates that something makes land temperatures (mostly taken from cities) are too hot, and this could be explained by UHI. But this general idea you have that all the different sources just shows the same is very wrong. Even the individual balloon sources dissagre (!) RATPAC has one story, ERA-40 another for example. But to get back to the Arctic area near the North pole 80-90N: We have only the choice between data measured in the area (DMI) or data projected from land far away. I think you need biiiig globalwarming glasses not to see what data source is most reliable. K.R. Frank Lansner
  47. DMI and GISS Arctic Temperatures: Hide the Increase?
    FLansner at 08:28 AM on 21 October, 2010 As I understand it, GISS has access to relatively high spatial resolution land and ocean measurements over most of the globe, and they have no need to extrapolate unless station data is actually not available (as over much of the very high Arctic) or SST data and local air temperature are very different (as near the "boundaries" of the high Arctic sea ice).
  48. DMI and GISS Arctic Temperatures: Hide the Increase?
    Berényi Péter at 01:53 AM on 21 October, 2010 The first data you cite is ocean flux buoy data (ocean temperature data) which is not quite relevant to surface temperature, but the second linked data set is recent and pertinent. The snippet of data in the link very nicely shows the Summer 0 degrees C clipping effect. I will try to get the complete high resolution time series updated (given time) as I have the earlier buoy data. If we look at slightly less up to date buoy data as in Polyakov 2002, where: “The datasets of monthly surface air temperature and sea level pressure used in this study contain data from land stations, Russian NP stations, and drifting buoys operated by the International Arctic Buoy Programme (IABP)”. We see again GISS correlates well over the buoy data period. Below I have plotted the Polyakov Arctic annual values with publicly available GISS annual Arctic zonal values. The buoy data is used from around 1950 onwards in Polyakov.
  49. Throwing Stones at the Greenhouse Effect
    RSVP, Any object with a temperature above 0K never stops radiating - ever. Finding an object that does not radiate, or a process to make any object not radiate, would unsettle our most basic understandings of the physical universe. DSL, RSVP is trying. He's trying to force the accumulated scientific knowledge to conform to his preconceived notions.
  50. DMI and GISS Arctic Temperatures: Hide the Increase?
    Hi Frank (re #44), Could you please explain to us why then there is such excellent agreement between the surface temperature data and those from the satellite MSU data, not to mention the balloon data and OHC data? And note that the MSU satellite data are not calibrated against the surface temperatures. Your concerns have been addressed on this very site and elsewhere. The surface SAT records (GISTEMP, HadCRUT, JAMA, NOAA-NCDC), despite their known limitations, are robust. The Arctic is warming at twice the rate of the rest of the globe-- that has been determined from multiple, independent data sets, and is explained by a phenomenon called "polar amplification". It is no artifact.

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