Heat or Temperature?

Another interesting entry on the often-provoking RP Sr site. This time a guest post by McNider, who I don’t know. He indulges in some giveaway ranting: Climate change alarmists have used the global surface temperature record as evidence of man’s impact on climate being “real” yet, as discussed below, most of the warming in this record is at night and probably has little to do with the accumulation of heat in the atmosphere which is foolish, unless you want to dismiss the IPCC as alarmists, which leaves you amongst the wild-eyed Lubos fringe. And requires you to believe some strange things about the SST record.

But leaving that regrettable stuff aside, there is some interesting substance, about the effects of radiative forcing on boundary layer stability and the diurnal temperature range (DTR). I don’t vouch for the statments about DTR in general there; for the official view there is stuff about DTR if you care to read it from IPCC chapter 3 (scroll down to p251 and above).

So their thesis is that there is a regime in which increasing radiative forcing will warm the surface somewhat; this in turns reduced the atmospheric stability somewhat; which allows more vertical mixing and pulls down warmer air for above, leading to more surface warming. This seems quite plausible and quite interesting. Their comments on this being a process missing (or poorly represented) in GCMs is also quite possibly correct, since GCMs tend to use adjusted stability functions (which are nominally to represent inhomogeneous terrain, but are probably in there because the std theoretical functions are thought to lead to “runaway stability” under certain conditions (the idea being that on cold nights the sfc cools by radiation, cooling the air just above; this increases the stability and since heat transfer reduces with stability, the heat flow to the sfc reduces, leading to further cooling, until heat transfer shuts off entirely and the sfc sits there cooling radiatively. Only my experiments with HadCM3 says this doesn’t actually happen. But thats another story)). Are we out of the brackets yet?

But the bit they seem to care most about, and which I think is wrong, is about heat accumulation: The essay ends with a plea to discard nighttime temperatures as a means to track heat accumulation in the atmosphere from greenhouse gases or other positive radiative forcing. Since no-one (except them) are proposing to use heat accumulation as a measure of warming, who cares? What people use is temperature, which is the thing people care about. If this is a feedback that increases surface warming then… thats what it is. But it isn’t a problem with GW in general. And saying the minimum temperatures measured in the nocturnal boundary layer represent only a very shallow layer of the atmosphere which is usually only a few hundred meters thick doesn’t make much sense: its the bit people live in; its the bit plants grow in; its the bit that governs (sensible) heat transfer into the oceans and ice sheets.

Comments

  1. #1 Alexander Ac
    2007/07/03

    I guess there would be people doubting (anthro) climate change and it’s effects, even it there is 1000 ppm of CO2 in the air, glaciers, arctic ice and west-antarctic ice-sheet are gone and sea level is up 4 meters…

  2. #2 Adam
    2007/07/03

    I thought that the idea that increased greenhouse gases would show a distinct warming at night went right back to Arrhenius, so saying that this was the main effect measured is backing it up? Or have I misunderstood their article?

    I know there’s been stratopsheric temp studies, but has anyone seen how middle trop temps (say 850hpa, 500hpa etc.) temps have varied over time (from ascent data)? Does it fit the theories?

  3. #3 Eli Rabett
    2007/07/03

    [Unnecessary bit removed -W]

    McNider’s is another version of the let us ignore the elephant in the room argument. Yes, there are things that are not in GCMs, the nature of the beast is that some things will increase surface warming, others will decrease it and on balance you are left, pretty much, with the huge heating effect of greenhouse gas warming. It is the same thing with the surface temperature anomaly record.

  4. #4 Raymond Arritt
    2007/07/03

    Eli, it’s not necessary to smear people in order to argue their ideas. McNider is a good and decent person who knows more than a thing or two about nocturnal boundary-layer meteorology. He makes a number of valid points though I don’t agree with his bottom line about only using daytime temperatures.

  5. Hmm. To respond intelligently I really should read the article on RP Sr’s site and that I am loath to do because I find it…provoking.

    I do know (of) Dick McNider, though I don’t believe I ever met him. He has collaborated with Roger in the past and was (I think) a student of his, as was I.

    They do have a point: one of the things that the instrumental surface temperature (HadCRU etc) time series are used for is as a general indicator of “global warmth” (heat accumulation if you will, though it’s not a term I like) and in that application night-time, near-surface temperatures over land have their limitations, as they are affected by very local phenomena. It’s conceivable that night-time temperatures could increase without the rest of the climate system warming up. We know, that hasn’t happened, or at least it’s not the whole story, because of the various other indicators of increasing “global warmth” (SST, tropospheric temperatures, glaciers, sea ice, etc).

    There now, having got that off my chest and once the v a l i u m tablets have taken effect, I’ll read Dick McNider’s article.

    [Note: it turns out that you can’t say Vali um -W]

  6. #6 SomeBeans
    2007/07/03

    Who’s MH? He must be really important if he gets the blogmaster to make his comments for him…

  7. #7 Eli Rabett
    2007/07/03

    Although I don’t really remember what I wrote that Wm pushed down the memory hole, or that Raymond Arritt saw, let me make a general point. For many years now I have watched people make excuses for the likes of Fred Singer, Pat Michaels, and Richard Lindzen while in public these worthies tossed very hot words at climate science (indeed also other areas) accusing others of dishonesty, double dealing, ignorance and more. They may have been perfectly nice folk in seminars, department meetings and other places, but their public words showed that they are neither friends nor colleagues.

    So yes, the McNider’s of the world need to be called on their behavior, rather strongly, but that is only my humble opinion. Tutting does not appear to have had much effect if the last twenty years (almost enough for a climate record) tells us anything. If McNider wants to discuss this as science, let him. If he wants to wave the red flag let him. In either case he should expect the response that he seeks. It is time for his colleagues to offer him the choice. He cannot expect to play both sides of the street.

    Finally, let me make a related point. RP has been going on about how the various things he has published have been ignored, and indeed they appear to have been so. Very often the response to things that the field thinks are uninteresting, or off the wall is to ignore them. That may no longer be a viable option in a field that intersects policy such as climate science. Pielke appears to be collecting a crowd of others who feel dissed. Tellingly they appear to be mostly (caution here) among those whose areas of interest have gone out of fashion and are neither strongly funded nor of interest to young students (some connection there). The more they are ignored, the more that they radicalize.

  8. #8 Steve Bloom
    2007/07/04

    I assume everyone recalls in vivid detail RP Sr.’s experience as lead author of a chapter of the recent-ish CCSP report dealing with temp record reliability. For those who don’t, Roger decided that it was acceptable behavior for him to simply sit on his chapter until all his co-authors came around to his, um, eccentric views. After a while Steps Were Taken to alleviate the constipation. To his credit, Roger did display much of the dirty laundry on his then-new blog, starting here. AFAICT the events leading up to his resignation are what motivated him to enter the blogosphere.

    MH, I don’t think anyone especially disagrees with Roger on the defects of the land surface record or even that absent those defects it would still be an imperfect proxy for heat content. It’s just that his crusade to convince people to abandon the land surface RIGHT NOW causes him to grasp at some pretty ludicrous straws. Add to that his pathological unwillingness to admit error and the welcome mat he’s put out for the denialist wingnuts. I just don’t understand what he hopes to accomplish.

    Having gone back and reviewed the early history of Roger’s blog to locate the link above, I found this interesting series of events:

    This is the second of two posts from the first day (July 11, 2005). In it, he makes it very clear that he’s engaged in an organized attack to destroy the credibility of the surface record and replace it with… well, recalling Tom Lehrer: “I just send them up, who knows where they come down, that’s not my department, says Werner von Braun.”

    Two weeks later, this post appears, in which we see (in reference to an important U.S. Senate hearing):

    “I am particularly interested in learning what testimony was given since I was called on July 11 and invited to present testimony at this Hearing. However, on July 13, I was e-mailed

    “‘Dr. Pielke: we have had a change in plans. We have decided to ask NCAR to provide a senior scientist from that organization for the hearing.

    “‘As a result we won’t be asking you to drop everything and appear at our hearing. My apologies for the confusion.’

    “When I read the testimony that was presented, Dr. Jim Hurrell of NCAR was my ‘replacement.’ He provided a much different perspective on the science issue than I would have given”

    Well, somebody was paying attention! Later on in the same post Roger executed this little drive-by:

    “Indeed, other testimony similarly cherrypicked information. For instance, while Dr. Ralph Cicerone in this testimony (http://energy.senate.gov/public/index.cfm?FuseAction=Hearings.Testimony&Hearing_ID=1484&Witness_ID=4225) included some information from the National Research Council report , he missed the opportunity to educate the Committee on the spectrum of newly recognized human climate forcings, as reported in the NRC (2005) report, and how this complicates our ability to achieve skillful climate forecasts. He should have summarized the findings of that report in his testimony. As President of the National Academy of Science, it is particularly important that he provide a balanced presentation of climate science. He did not do so.”

    Talk about getting off to a fast start.

  9. #9 tourettist
    2007/07/05

    From strictly a layman’s point of view, warmer nights are a beyotch. A night-time drop in (Farenheit) temperature to the 70’s makes a day in the 90’s or 100’s much more bearable for the un-air-conditioned.

    I can’t help but believe that humans’ evolved responses coincide with the responses of other systems in the environment, like ecosystem health. Given that these living systems are physically based, I also have to believe they are picking up a signal the same as or similar to what is happening the big physical systems, like oceans, glaciers, atmospheric layers. I.e. night-time temperatures are part of the conditions under which these physical systems function, and a break from the heat of the day matters, so if they get less of a break, like in the upper 80’s, various systemic functions won’t “recover” as well.

    Again, a layman speaking here, so if you gotta’ shoot down my reasoning, no problem but try to make it painless.

  10. #10 Carl Christensen
    2007/07/05

    old met & climate scientists never die; they just bitch & bitch!

  11. #11 rda
    2007/07/05

    Nighttime temperatures play a huge role in determining the length of the growing season. The last frost of the spring and the first of the fall define the extent of this period. If night temperatures increase, especially in the spring and fall, then growing seasons increase.

    Winter fronts typically move through at 7-10 day intervals. Raising night temperatures by a degree or so can thus quickly increase the growing season by 1-2 weeks. Many areas around the US are seeing growing seasons starting 1-3 weeks earlier than 30 years ago!

    Depending on the type of vegetation, this can give advantages to weeds or to natives. (Your result may vary, depending, in part, on how limiting water supplies are for plant growth in native ecosystems.)

    Insects are also very sensitive to accumulated heat units and insect populations respond more rapidly than plant populations to increased temperatures. With longer growing seasons, insects can produce more than one generation per year in temperate zones — re: bark beetle outbreaks in North America.

    Note also that night temperatures during the summer lead to increased electrical demand. In 1998, Denver experienced brownouts because of higher than expected night temperatures leading to extreme electrical demand for air conditioners.

    We live in exciting times!

  12. #12 Mark Hadfield
    2007/07/08

    RA: “He makes a number of valid points though I don’t agree with his bottom line about only using daytime temperatures.”

    Would you like to expand on that, Ray? Here or elsewhere.

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