Where’s that positive feedback that is supposed to manifest itself in water vapor, the most potent natural greenhouse gas?
Dr. Roger Pielke Sr. writes:
image Figure 4 from Vonder Haar et al 2012
As promised by Tom Vonder Haar; see the posts
The new dataset covering 20+ years will be available to the public in 2012 or 2013.
The initial results are now ready as reported in the paper
Vonder Haar, T. H., J. Bytheway, and J. M. Forsythe (2012), Weather and climate analyses using improved global water vapor observations,
Geophys. Res. Lett.,doi:10.1029/2012GL052094, in press.
Here’s the Abstract:
The NASA Water Vapor Project (NVAP) dataset is a global (land and ocean) water vapor dataset created by merging multiple sources of atmospheric water vapor to form a global data base of total and layered precipitable water vapor. Under the NASA Making Earth Science Data Records for Research Environments (MEaSUREs) program, NVAP is being reprocessed and extended, increasing its 14-year coverage to include 22 years of data. The NVAP-MEaSUREs (NVAP-M) dataset is geared towards varied user needs, and biases in the original dataset caused by algorithm and input changes were removed. This is accomplished by relying on peer reviewed algorithms and producing the data in multiple “streams” to create products geared towards studies of both climate and weather. We briefly discuss the need for reprocessing and extension, steps taken to improve the product, and provide some early science results highlighting the improvements and potential scientific uses of NVAP-M.
Dr. Pielke adds:
The current paper is not the final word on this subject. The end of the paper reads
The results of Figs. 1 and 4 have not been subjected to detailed global or regional trend analyses, which will be a topic for a forthcoming paper. Such analyses must account for the changes in satellite sampling discussed in the supplement. Therefore, at this time, we can neither prove nor disprove a robust trend in the global water vapor data.
However, the figure at the top of this post, if it turns about to be robust, raises fundamental issues with respect to the ability of global climate models to skillfully model the role of humans in altering the climate.
Forrest Mimms III writes via email:
This paper is a bit sketchy and needs filling out. Nevertheless, it’s quite possibly the most significant water vapor paper in a decade.
The key finding of this paper is the time series in Fig. 4(c), which bears a rough resemblance to my time series over nearly the same time.This time series is devastating to the modeler’s assumptions about the positive feedback of water vapor in a world with steadily rising CO2 levels.
The modelers have no explanation for why temperature and PW across the SE USA have actually declined during the last century. The explanation is likely a combination of at least three factors:
1. Global warming is best described as regional warming.
2. ENSO and other natural cycles play a major role.
3. How can we trust the global temperature record when (as shown by you, Watts, et al.) so many stations are improperly situated, especially as urbanization has arrived or surrounded them.
Here’s the full paper http://www.leif.org/EOS/2012GL052094-pip.pdf