Global warming is in the air, in the UAH lower troposphere

The UAH data for October is out. John Christy and Roy Spencer from the University of Arizona Huntsville have a contract with NOAA to analyse temperature changes in the atmosphere. Each month they publish the latest data.

Deniers dislike it less than other data sets, especially since John and Roy revised the latest version considerably downwards, making their data an anomaly!

I came across a chart I prepared a few years ago and thought I'd do it over again using the latest UAH data.

101 conspiracy theories about troposphere temperature: the RSS love affair is over

Over at WUWT there have been three articles about the lower troposphere temperatures. The first (archived here) was a Guest Post by Werner Brozek and Nick Stokes, Edited by Just The Facts with the title: "Long Satellite Pauses Ending (Now Includes January Data)".  The second article was about the February data for UAH (archived here, latest here). It had the wistful wishful title: "Global Temperature Report: Warmest Ever February 2016 driven by El Niño". The third article is the real doozy (archived here). It's by Anthony Watts so could well have some awful blunders in it. He's called his article: "The ‘Karlization’ of global temperature continues – this time RSS makes a massive upwards adjustment."

This article is a few hours late, and I'm not satisfied that I've got everything right because this is a subject on which I am feeling distinctly out of depth. Science deniers will try to tell you that there are little thermometers on satellites sending raw data to Earth and miraculously drawing temperature charts - or something like that. That's a pile of hogwash. The real story is much more complicated. Satellites come and go. Instruments change. Orbits decay. Temperature isn't measured directly, it's estimated from measurements from microwave sounding instruments (MSUs). What's reported is the result of complex calculations after adjustments and conversion to temperature. What we get are temperature trends in very thick layers in the atmosphere (kilometers thick, looking upwards into space), not the temperature of a particular spot or distinct level in the sky. Then there is "diurnal drift" - which is largely what the new paper by Carl Mears and Frank J. Wentz is all about.

Warning: this article is rather long. It explains the new RSS paper in more detail than I did in the previous article.

The mid-troposphere has been warming faster than you thought

A new version of the RSS dataset has been announced in a paper in the AMS Journal of Climate. The paper, by Carl Mears and Frank J. Wentz, was published before the new version has appeared. This is in contrast to UAH, where the paper hasn't yet appeared but version 6.0 beta came out in April last year, and is now at beta 5.

The paper is about middle troposphere measurements, not lower troposphere which is what is usually discussed here. However, it's about the same instruments that are used to estimate lower troposphere temperatures: Microwave Sounding Unit (MSU) channel 2, and the Advanced Microwave Sounding Unit (AMSU) channel 5.