Mid‐Tropospheric Layer Temperature Record Derived From Satellite Microwave Sounder Observations With Backward Merging Approach

Abstract We present a new version (v5.0) of the NOAA Center for Satellite Applications and Research (STAR) mid‐tropospheric temperature (TMT) time series. This data set uses backward‐merging approach to intercalibrate 16 satellite‐based microwave sounding records. The instrument observations included those from Microwave Sounding Unit (MSU) during 1979–2004, Advanced Unit‐A (AMSU‐A) 1998–2017, Technology Sounder (ATMS) 2011 present. A TMT series 2002–present based on satellite in stable sun‐synchronous orbits was used as reference backward merging process which earlier satellites were adjusted merged reference. Observations recalibrated remove their calibration drifting errors relative using sequential overlapping observations. removal spurious warming drifts MSU onboard NOAA‐11, NOAA‐12, NOAA‐14 cooling drift NOAA‐15 AMSU‐A Temperature changes resulting diurnal sampling corrected an observation‐based semi‐physical model developed this study. Other adjustments channel frequency differences between companion channels blackbody warm target effect observed radiances. These resulted inter‐consistent records spanning MSU, AMSU‐A, ATMS. produced global mean trend 0.092 ± 0.043 K/decade 1979–2021 total tropospheric 0.142 0.045 after stratospheric TMT. Remarkably, trends latest half period nearly doubled over ocean.