The answer is that this is another well-documented example of cherry picking.
I have posted below my submission to Nature and the subsequent exchange of communications with Nature. David Parker requested that I not post his reply, which I will respect. I invite him, however, to respond to the issues that are raised in my Comment and in the Geophysical Research Letter article.
Pielke Sr., R.A., and T. Matsui, 2005: Should light wind and windy nights have the same temperature trends at individual levels even if the boundary layer averaged heat content change is the same? Geophys. Res. Letts., 32, No. 21, L21813,10.1029/2005GL024407.
resulted from my inability to publish my comment on his paper.
Comment on Parker (2004; âLarge-scale warming is not urbanâ? Nature. Vol. 432 18 Nov 2004).
By Roger A. Pielke Sr. June 7, 2005 Nature
Parker (2004) summarized a very interesting study in which he segmented observed surface temperature data into âcalmâ? (defined as the lower tercile of daily averaged wind speeds) and âwindyâ? (defined as the upper tercile of daily averaged wind speeds) in order to assess whether the reported large-scale global averaged temperature increases are attributable to urban warming. This note, however, questions, whether trends of surface air temperature should even be expected to have the same trends for these different sets of days.
The Parker article focused on nighttime, minimum temperatures. During this time of the day, it is well understood that temperature change with height in the lowest tens of meters can be quite large, particularly in light wind, clear sky conditions (e.g., Stull, 1988; Oke, 1987). For relatively windy nighttime conditions, surface similarity theory has been developed which can be used to describe the vertical temperature lapse rate in the lowest few tens of meters. Pielke (1984; Figure 7-4), for example, illustrates the vertical lapse rate as a function of the intensity of mechanical generation and convective suppression of turbulence. For strong winds, the vertical lapse rate becomes adiabatic (0.1Â°C per 10 meters). For light wind conditions, longwave radiative flux divergence becomes dominant and the lapse rates can become quite large (e.g., 10Â°C per 10 m or even larger).
Thus, if the upper tercile of wind conditions, as defined in the Parker article, is well represented by an adiabatic lapse rate, a temperature trend at 1 m, for instance, would be essentially the same as at 2 m. However, when the large lapse rates typical of lighter wind conditions occur, a trend at 1 m would, in general, be expected to be significantly different at 2 m.
The relative warming of windy nights in the winter in the extratropical Northern Hemisphere that he reports could also, at least partially, be a result of changes in the lapse rate due to trends in surface windiness rather than due to changes in onshore warm advection from the oceans.
If the urban and rural sites have a different aerodynamic roughness, this presents an additional complication by producing greater mechanically-forced turbulent mixing over the rougher surfaces (presumably the urban sites) than for the rural sites. Even with the same trend of temperature when averaged over the lower few tens of meters above the surface, there would be different trends at specific levels within that layer when the aerodynamic roughness effect is included.
This influence of vertical temperature stratification on the temperature trends raises the issue as what is actually meant by the term âsurface temperature trend.â? Along with the issues of surface temperature as contrasted with surface moist enthalpy (Pielke et al. 2004) and microclimate station exposure changes (Davey and Pielke 2005), the reported regionally- and globally-averaged surface temperatures trends have unresolved uncertainties.
The Parker (2004) conclusions, therefore, need further analysis and interpretation before they can be used to conclude whether or not there is an influence of urban warming on the large-scale temperature trends. More broadly, these issues regarding surface temperature trends need investigation to determine whether these effects increase or decrease long-term spatially representative globally-averaged and regionally-averaged surface temperature trends, as well as a clearer definition of what is meant by âsurface temperature.â?
Davey, C.A., and R.A. Pielke Sr., 2005: Microclimate exposures of surface-based weather stations – implications for the assessment of long-term temperature trends. Bull. Amer. Meteor. Soc., 86, No. 4, 497â504.
Oke, T.R., 1987: Boundary layer climates. 2nd Edition. Routledge, London, and John Wiley & Sons, New York, 435 pp.
Parker, D.E., 2004: Large-scale warming is not urban. Nature, November 18, 2004.
Pielke, R.A. Sr., C. Davey, and J. Morgan, 2004: Assessing “global warming” with surface heat content. Eos, 85, No. 21, 210-211.
Stull, R., 1988: An introduction to boundary layer meteorology. Kluwer Academic Pub., 666 pp.
Date: Tue, 21 Jun 2005 13:26:06 UT
Subject: Nature – 2005-06-06864 out to Nature Author
Dear Professor Pielke
Thank you for submitting your Communications Arising entitled “Comment on Parker (2004; “Large-scale warming is not urban” Nature. Vol. 432 18 Nov 2004)” to Nature. This message is to tell you that we are sending your paper out to the Nature authors for their response according to our policy (see our guidelines to authors of Communications Arising on http://nature.com/nature/authors/gta/index.html#a8). Once we have received their reply, we shall decide whether or not to send the exchange out for review.
This decision is reached after discussion with the appropriate specialist editors and depends on a number of factors, including the likely impact of the criticism, the topicality of the discussion, and its interest to the non-specialist readers of this section of the journal (many debates are referred to the specialist literature at this point or the issues are addressed in the form of a published clarification from the criticised authors).
If we have several comments under consideration on one of our published papers, this may introduce delays while we coordinate these steps in the editorial process, so please allow four weeks before sending us any status enquiries.
Please note that consideration of your comment by Nature is contigent on there being no discussion of its content with the media in advance of publication (see http://www.nature.com/nature/authors/policy).
Editor, Brief Communications
Date: Tue, 5 Jul 2005 14:03:24 UT
Subject: Decision on Nature Manuscript 2005-06-06864
5th July 2005
Dear Professor Pielke
Thank you for your comment on the Brief Communication by David Parker, which I am afraid we must decline to publish. As is our policy on these occasions, we showed your comment to the earlier authors, and their response is enclosed. We also sent the exchange to 2 referees, whose comments are attached.
In the light of this advice and of the competition for our space, we have regretfully decided that publication of this debate is not justified as it would not add to our understanding or otherwise clarify this issue in the minds of our readers.
Thank you again, however, for writing to us.
Editor, Brief Communications
Nature Author #1(Remarks to the Author):
Reply by D E Parker to R A Pielke, Sr. s comment on Parker (2004; large-scale warming is not urban Nature. Vol 432 18 Nov 2004).
Prof. Pielke provides no physical hypothesis as to why, in the absence of urban warming, trends of near-surface air temperature on calm nights, when similarity theory is inapplicable and longwave radiative loss dominates, should differ from those on windy nights, when lapse-rate trends are close to adiabatic. In the absence of a known mechanism, Occams razor demands a null hypothesis of equal trends. Parker (2004) found that the temperature trends on calm nights are insensitive to the definition of calm as winds in the lightest decile rather than the lightest terce, so the trends appear to be insensitive to the turbulence-structure of the boundary layer.
Trends in surface windiness will not affect near-surface lapse rates on windy (upper tercile) nights in winter in the extratropical Northern Hemisphere; these lapse-rates will remain close to adiabatic. The temperature trend on windy nights is expected to be least influenced by local effects and microclimate station exposure changes, as horizontal and especially vertical mixing is then strongest. As the global trend of night-time temperature in windy conditions equals that for the whole sample used by Parker (2004), and the global trend for mean temperature based on this sample is similar to the global trend of the Jones and Moberg (2003) dataset, it must be concluded that the Jones and Moberg (2003) global trends are not much biased by urban and other small-scale influences.
Nonetheless, Prof. Pielke is right in stressing the need to analyze enthalpy (i.e. total sensible and latent heat content) for a full understanding of climatic variations and changes.
Jones, P. D., and A. Moberg, 2003: Hemispheric and large-scale surface air temperature variations: an extensive revision and an update to 2001. J. Climate, 16, 206-223.
Parker, D. E., 2004: Large-scale warming is not urban. Nature, 432, 290.
Referee #2(Remarks to the Author):
Pielke has failed to adequately assess whether there are any trends in windiness in the Parker data set. Parker stratified by wind conditions, both at rural and urban sites, so any trends in windiness (even if this were possible in a stratified data set) would occur both at rural and urban sites. To suggest that there would be different turbulent mixing at rural and urban sites would then require differences in trends in temperature to be found, which is exactly what Parker found not to be the case. The logic presented in Pielke’s comment is circular and incorrect.
I cannot recommend publication.
Referee #3(Remarks to the Author):
The key result of the Parker paper that made it worthy of publication in Science is the demonstration that daily minimum temperatures windy nights exhibit an upward trend no less than the trend observed on calm nights. Hence it is unlikely that the observed upward trend in daily minimum temperature during the past few decades could be simply an artifact of the “heat island” effect, as alleged by some global warming skeptics. That the upward trend on windy nights proved to be even larger than the trend observed on calm nights is interesting, but I don’t regard it as central to the paper or of particular interest to Nature’s interdisciplinary reading audience. Parker’s article would have been of no less interest if this material had not been included,
The points raised in this letter address the second, in my view less important result. They have no bearing on the primary result. Hence, I think they would be more appropriately recast as a short article published in a more specialized technical journal. This change of venue would also give the author space to articulate his argument more clearly. As it’s written now I have difficulty getting his point.
Date: Tue, 5 Jul 2005 09:05:08 -0600 (MDT)
From: Roger Pielke
Subject: Re: Decision on Nature Manuscript 2005-06-06864
Dear Dr. Cotter
I am disappointed regarding your choice of reviewers who did not address
the substance of my comment. For the trends to be the same on light and
windy nights violates our understanding of the physics of the surface
As a former Chief Editor of both the American Meteorological Society’s
Monthly Weather Review and the Journal of Atmospheric Science, a
communication such as mine on another paper would never have been
rejected. The community who read the original paper would have been
provided the opportunity to read and, therefore, discuss the issue raised
in my comment.
Unfortunately, the rejection of such a comment perpetuates the impression
that Nature is not permitting a balanced debate on the climate issue.
Roger A. Pielke Sr.
Date: Wed, 20 Jul 2005 15:10:33 +0100
From: “Cotter, Rosalind”
Subject: FW: Decision on Nature Manuscript 2005-06-06864
Dear Professor Pielke
Thank you for your message. Although we appreciate the points you raise, I
am afraid that in view of the severe competition for our space and in the
light of the referees’ recommendations (who are respected experts in the
field), we are unable to offer to reconsider your Communication Arising from
the short paper by Parker.
Thank you, however, for writing to us.
Editor, Brief Communications