Climatology and Long-Term Trends in the Stratospheric Temperature and Wind Using ERA5

Michal Kozubek,Jan Laštovička,Radek Zajicek

doi:10.3390/rs13234923

Michal Kozubek, Jan Laštovička + Show 1 more

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https://doi.org/10.3390/rs13234923

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Abstract

This study analyses long-term trends in temperature and wind climatology based on ERA5 data. We study climatology and trends separately for every decade from 1980 to 2020 and their changes during this period. This study is focused on the pressure levels between 100–1 hPa, which essentially covers the whole stratosphere. We also analyze the impact of the sudden stratospheric warmings (SSW), North Atlantic Oscillation (NAO), El Nino Southern Oscillation (ENSO) and Quasi-biennial oscillation (QBO). This helps us to find details of climatology and trend behavior in the stratosphere in connection to these phenomena. ERA5 is one of the newest reanalysis, which is widely used for the middle atmosphere. We identify the largest differences which occur between 1990–2000 and 2000–2010 in both temperature climatology and trends. We suggest that these differences could relate to the different occurrence frequency of SSWs in 1990–2000 versus 2000–2010.

Highlights

This study analyses long-term trends in temperature and wind climatology based on ERA5 data
Temperature climatology and trend from ERA5 reanalysis is compared with MERRA2 for the period 1980–2020
If we look at the trend comparison, the biggest differences can be found for 1 hPa, but for the lower pressure levels the main features are similar even when the amplitude is different

Summary

Introduction

This study analyses long-term trends in temperature and wind climatology based on ERA5 data. We analyze the impact of the sudden stratospheric warmings (SSW), North Atlantic Oscillation (NAO), El Nino Southern Oscillation (ENSO) and Quasibiennial oscillation (QBO). This helps us to find details of climatology and trend behavior in the stratosphere in connection to these phenomena. Temperature trends in the lower stratosphere are affected substantially by the ozone depletion and its potential recovery They may be affected by many phenomena such as NAO (North Atlantic Oscillation), SSW (sudden stratospheric warming) or the presence of aerosols from volcanic activity. The temperature changes in the higher parts of the middle atmosphere are discussed in more detail in many studies, e.g., [4,5], confirming the cooling of the stratosphere and mesosphere. Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

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