Observed temperature changes in the troposphere and stratosphere from 1979 to 2018

Andi K. Steiner (1, 2) , F. Ladstädter (1, 2) , William J. Randel (3) , Amanda C. Maycock (4) , Qinjun Fu (5) , Chantal Claud (6) , H. Gleisner (7) , L. Haimberger (8) , S.-P. Ho , Philippe Keckhut (9) , Thierry Leblanc (10) , C. Mears (11) , L. M. Polvani (12) , B. D. Santer (13) , T. Schmidt (14) , V. Sofieva (15) , Robin Wing (9) , C.-Z. Zou (16)

1 WEGC - Wegener Center for Climate and Global Change
2 IGAM - Institute for Geophysics, Astrophysics and Meteorology [Graz]
3 NCAR - National Center for Atmospheric Research [Boulder]
4 SEE - School of Earth and Environment [Leeds]
5 Department of Atmospheric Sciences [Seattle]
6 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
7 DMI - Danish Meteorological Institute
8 Department of Meteorology and Geophysics [Vienna]
9 STRATO - LATMOS
10 JPL - Jet Propulsion Laboratory
11 RSS - Remote Sensing Systems [Santa Rosa]
12 Department of Applied Physics and Applied Mathematics [New York]
13 LLNL - Lawrence Livermore National Laboratory
14 GFZ - German Research Centre for Geosciences - Helmholtz-Centre Potsdam
15 FMI - Finnish Meteorological Institute
16 STAR - NOAA Center for Satellite Applications and Research

Temperature observations of the upper-air atmosphere are now available for more than 40 years from both ground- and satellite-based observing systems. Recent years have seen substantial improvements in reducing long-standing discrepancies among data sets through major reprocessing efforts. The advent of radio occultation (RO) observations in 2001 has led to further improvements in vertically-resolved temperature measurements, enabling a detailed analysis of upper troposphere/lower stratosphere trends. This paper presents the current state of atmospheric temperature trends from the latest available observational records. We analyze observations from merged operational satellite measurements, radiosondes, lidars, and RO, spanning a vertical range from the lower troposphere to the upper stratosphere. The focus is on assessing climate trends and on identifying the degree of consistency among the observational systems. The results show a robust cooling of the stratosphere of about 1–3 K, and a robust warming of the troposphere of about 0.6–0.8 K over the last four decades (1979–2018). Consistent results are found between the satellite-based layer average temperatures and vertically-resolved radiosonde records. The overall latitude-altitude trend patterns are consistent between RO and radiosonde records. Significant warming of the troposphere is evident in the RO measurements available after 2001, with trends of 0.25–0.35 K per decade. Amplified warming in the tropical upper-troposphere compared to surface trends for 2002–2018 is found based on RO and radiosonde records, in approximate agreement with moist adiabatic lapse rate theory. The consistency of trend results from the latest upper-air data sets will help to improve understanding of climate changes and their drivers.

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]; Climatologie

Andi K. Steiner, F. Ladstädter, William J. Randel, Amanda C. Maycock, Qinjun Fu, et al.. Observed temperature changes in the troposphere and stratosphere from 1979 to 2018. Journal of Climate, 2020, 33 (19), pp.8165-8194. ⟨10.1175/JCLI-D-19-0998.1⟩. ⟨insu-02912462⟩