Observed zonally and meridionally resolved trends in lapse rate tropopause temperature and height over the past two decades

The tropopause is a sensitive indicator of both radiative and dynamic changes in the atmospheric climate system. This study presents an analysis of lapse-rate tropopause (LRT) trends using remote-sensing satellite data for the period 2002-2023. The evaluation of trends is performed using GNSS radio occultation satellite measurements, which are particularly well suited for observing the temperature in the tropopause region with high vertical resolution and global coverage. In addition, GNSS radio occultation provides long-term stable measurements that allow robust detection of tropopause trends. Our results indicate pronounced zonal and meridional variations in LRT temperature trends, with  certain regions exhibiting significant warming while others show no substantial trends. In particular, the tropics show LRT warming but no trend in LRT height. Additionally, we observe distinct seasonal patterns of trends in LRT temperature and height, with particularly pronounced trends in the Pacific region in the Northern Hemisphere winter. A spatially and seasonally resolved view of LRT trends is thus required for a complete picture of the changes in the tropopause region.