Comparison of the long-term trends in stratospheric dynamics of four reanalyses

Abstract

Abstract. Since the long-term trends of different atmospheric parameters have been already studied separately in many papers, this study is focused on the stratospheric wind (zonal and meridional components) and temperature over the whole globe at 10 hPa during 1979–2015. We present the trends for the whole winter (October–March), for each individual month of winter and separately for the period before and after the ozone trend turnaround during the mid-1990s. The change of ozone trends has a clear impact on trends in other investigated stratospheric parameters. Four reanalyses (MERRA, ERA-Interim, JRA-55 and NCEP-DOE) are used for comparison. Every grid point is analysed, not zonal averages. The comparison of trends in meridional wind, which is closely connected with Brewer–Dobson circulation, shows a good agreement for all four reanalyses (main features and amplitudes of the trends) in terms of winter averages, but there are some differences in individual months, particularly in trend amplitude. These results could be important for studying dynamics (transport) in the whole stratosphere.