Climate change deniers do like to use a graph of surface temperatures showing a recent temporary slowdown in statistically significant warming, to insinuate that global warming has stopped. Of course this begs the question as to whether or not data representing less than 5% of the global system can be used to extrapolate to the remaining 95%? Ummmmm, NO! The climate system comprises the Earth’s surface, all of the atmosphere and the oceans and there is a whole lot of atmosphere and oceans.
The evidence that ocean warming continues unabated is conclusive and now there is another line of evidence to that shows that the top of the troposphere is still warming and much faster than the lower troposphere.
30-Year atmospheric temperature record derived by one-dimensional variational data assimilation of MSU/AMSU-A observations
Fuzhong Weng & Xiaolei Zou
In the past, satellite observations of the microwave radiation emitted from the atmosphere have been directly utilized for deriving the climate tends of vertical-layer-averaged atmospheric temperatures. This study presents the 30-year atmospheric temperature trend derived by one-dimensional variational (1D-Var) data assimilation of Microwave Sounding Unit/Advanced Microwave Sounding Unit-A (MSU/AMSU-A) observations. Firstly, the radiance measurements from MSU on board the early National Oceanic and Atmospheric Administration (NOAA)-6 to NOAA-14 and AMSU-A on board NOAA-15 to -19 have been inter-calibrated to form a fundamental climate data record. A 1D-Var method is then employed to establish the thematic climate data record of atmospheric temperature profiles that are appropriate for climate change study. Verification of the MSU/AMSU-A derived temperature profiles with collocated Global Positioning System radio occultation data confirms a reasonable good accuracy of the derived atmospheric temperature profiles in the troposphere and low stratosphere. Finally, the global climate trend of the atmospheric temperature in clear-sky conditions is deduced, showing not only a global warming in the troposphere and a cooling in the stratosphere, but also a stronger warming in the upper troposphere than in the low troposphere.