Construction of Atmospheric Temperature Anomaly Data in the Upper Troposphere and Lower Stratosphere Using Multiple RO Missions from September 2006 to July 2023 at NESDIS/STAR

We develop a new monthly zonal mean temperature anomaly (MMTA) in the upper troposphere and lower stratosphere from September 2006 to July 2023 using the dry temperature profiles from multiple Global Navigation Satellite System (GNSS) Radio Occultation (RO) missions processed by the GNSS RO Science and Data Center (SDC) at the NOAA Center for Satellite Applications and Research (STAR). The multiple RO missions include Formosa Satellite Mission 3/Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC-1), SPIRE, and Meteorological Operational satellite (MetOp)-A, -B, -C. We compare collocated profiles from multiple STAR-processed RO missions to ensure the consistency of the data used in the construction of STAR MMTA. Because the Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) contains a noticeable temperature difference compared with other RO missions, we decided not to include it. We validate the robustness of the sampling error correction method through three reanalyses: ERA-5, MERRA-2, and JRA-55. The result shows the uncertainty caused by using different reanalyses is negligible. This STAR MMTA is then compared with the ROM SAF MMTA and the MMTA derived from these three reanalyses, exhibiting general consistency. Various atmospheric signals, including Quasi-Biennial Oscillation (QBO) and El Niño–Southern Oscillation (ENSO), can be identified from STAR MMTA. The global temperature trends from STAR MMTA show a prominent warming of 0.310 ± 0.128 K/Decade in the upper troposphere and a robust cooling of -0.295 ± 0.145 K/Decade in the mid-stratosphere.