Response By John Christy To A Comment Regarding The Lower Tropospheric Temperature Data At Climate Abyss

John Neilson-Gamon has an interesting post at Climate Abyss titled

About the Lack of Warming…

Using surface temperature data, John concludes that

All else being equal, an El Niño year will average about 0.2 C warmer globally than a La Niña year.  Each new La Niña year will be about as warm as an El Niño year 13 years prior.

In response to his post, I wrote the following

Hi John – I recommend you also perform this analysis on the UAH MSU and RSS MSU lower tropospheric temperatures and on the upper ocean heat content paper. As we have shown in

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2009: An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841 http://pielkeclimatesci.files.wordpress.com/2009/11/r-345.pdf

and

Klotzbach, P.J., R.A. Pielke Sr., R.A. Pielke Jr., J.R. Christy, and R.T. McNider, 2010: Correction to: “An alternative explanation for differential temperature trends at the surface and in the lower troposphere. J. Geophys. Res., 114, D21102, doi:10.1029/2009JD011841″, J. Geophys. Res., 115, D1, doi:10.1029/2009JD013655 http://pielkeclimatesci.files.wordpress.com/2010/03/r-345a.pdf

there is a growing divergence between the surface analyses and the lower tropospheric temperature anomaly data. We attribute a signficant part of the warm surface temperature bias to the land minimum temperatures.

[Roger- I'll run the numbers in a couple of days when I'm back in town.  - John N-G]

One of the commenters responded with

Roger Pielke Sr. “there is a growing divergence between the surface analyses and the lower tropospheric temperature anomaly data. We attribute a signficant part of the warm surface temperature bias to the land minimum temperatures”

I will reserve my judgement until the NOAA analysis of lower troposphere is released (they’re working on it). They’ve identified some biases in the UAH and RSS analysis which have been shown to influence the trends at other altitudes in the atmosphere  meaning that it is probably going to influence the synthetic lower tropospheric altitude.

I sent the above comment to John Christy, who replied with the information below [I also sent to Climate Abyss to post].

We examined the NOAA (STAR) analysis and there is a noticeable problem with their method (attached).  In every comparison with independent data, STAR was the hottest for MT (Table 4) and clearly had more error than UAH for both US and Australian station-by-station comparisons (Table 2 and Table 3).  In the latest STAR TMT, there is also a spurious jump on 1 Jan 2001 that no other dataset has – a processing glitch evidently.

Global LT Trends 1979-2011 C/decade

+0.136 UAH +0.139 RSS +0.121 ERA-I (Reanalysis) +0.169 HadAT2 +0.129 RAOBCORE +0.146 RICH +0.165 RATPAC

That’s a pretty tight grouping (+/- 0.025 from mean) – and if you consider the lack of global coverage on HadAT2 and RATPAC, giving those two a bit more error, you get an even tighter grouping.  So, your inquisitor evidently is not aware of all of this evidence.

STAR’s current TMT trend (1979-2011) is +0.13 C/decade.  To produce a lower tropospheric TLT value consistent with the fact the upper part of TMT is cooling (stratosphere) means the STAR TLT must be warmer than their TMT trend by around +0.07 or so, giving STAR a TLT trend of about +0.20 C/decade – well outside the range of independent observations.

The attachment John refers to is

Christy, J.R., R. W. Spencer, and W. R. Norris, 2011: The role of remote sensing in monitoring global. International Journal of Remote Sensing Vol. 32, No. 3, February 2011, 1–15

The abstract reads

The IPCC AR4 (2007) discussed bulk tropospheric temperatures as an indicator of 5 atmospheric energy content. Here, we examine the latest publications about, and versions of, the AR4 data sets. The metric studied is the trend that represents the average rate atmospheric energy accumulation that relates to increased greenhouse gas forcing. For temperatures from microwave instruments, UAHuntsville’s indicates the lowest trend for 1979–2009 and NOAA-STAR’s the highest, being slightly 10 higher than Remote Sensing Systems’ (RSS). Updated analyses using radiosonde data suggest RSS and STAR experienced spurious warming after the mid-1990s. When satellite and radiosonde data sets are considered, the global trends for 1979–2009 of the lower and mid-troposphere are +0.15 and +0.06◦C decade−1 respectively. Error ranges of these estimates, if we do not apply information that 15 indicates some data sets contain noticeable trend problems, are at least ±0.05◦C decade−1, which needs reduction to characterize forcing and response in the climate system accurately.

source of image

Comments Off

Filed under Climate Change Metrics, Research Papers

Comments are closed.