Stratosphere, Stratopause, and Lower Mesosphere in the JRA-55and JRA-3Q reanalyses: Insights and Discrepancies

The representation of the stratosphere in reanalyses is crucial for various issues such as atmospheric transport, sudden stratospheric warmings, the polar vortex, and studying the impact of climate change. High-top and latest reanalyses are designed with the aim of being able to reproduce the high stratosphere better than previous generation of low-top reanalyses, thus being better equipped to capture issues such as elevated stratopause events.

In this study, we examine how various variables behave in both reanalyses, JRA-55 and JRA-3Q, showing notable differences when comparing various parameters such as correlations and trends. We show that JRA3Q exhibit substantial differences in their representation of the middle and upper stratosphere compared to its predecessors or ERA5.1. Different latitudinal bands have been compared for this purpose. For instance, negative correlations in stratopause height have been observed in the subtropical zone between both reanalyses. Moreover, negative correlations with JRA-3Q and high correlations with JRA-55 have been observed when compared with observational data from MLS (Microwave Limb Sounder), on board of AURA satellite. Also, we compare our results with SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) data, allocated in TIMED (Thermosphere Ionosphere Mesosphere Energetics Dynamics) satellite.