ABSTRACT
Recent research in the realms of atmospheric sciences has been providing increasing evidence for the role of the stratosphere in the weather and climate of the troposphere. The numerical weather prediction models initialized with a well-resolved stratosphere perform well in predicting the weather at medium-range scales. This phenomenon now is popularly known as ‘raising the lid’, driving many research communities across the globe towards divulging the pathways through which the stratosphere interacts with the troposphere. Among many geographical locations, Southern Hemispheric polar latitude, a critical component of the Earth’s climate system, provides a unique opportunity to study the pathways through which the stratosphere interacts with the troposphere. This opportunity emanates from one of the most significant challenges for the climate change assessment: the formation of the Antarctic ozone hole. This chapter aims at providing a comprehensive view of the state of the Antarctic stratosphere and its role in modulating the Antarctic climate. Using Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) reanalysis data set during 1980–2020, climatologies of three essential climate variables: ozone, temperature, and zonal winds are constructed. Besides discussing the meridional cross-section of these variables in the Southern Hemisphere, their mean annual cycle in the polar cap (60–90°S) region is discussed comprehensively. Forty-one years of deseasonalized perpetrations are obtained. It is employed to estimate the trends in the troposphere and stratosphere. Height-month sections of the annual cycle of trends in ozone, temperature, zonal winds, and the degree of co-variability of trends in these three parameters are discussed in the light of the present understanding of the Antarctic stratospheric ozone depletion. A brief discussion on the role of polar stratospheric clouds and their signatures in the space-based lidar observations are also provided. Finally, a discussion on the potential pathways through which the stratospheric structure and dynamics interact with the troposphere is discussed in detail. The results discussed in this chapter suggest that the stratospheric processes over the Antarctic impact the troposphere through chemical and dynamical processes and play a much more vital role than anticipated.
