Changes in mesospheric dynamics at 78°N, 16°E and 70°N, 19°E: 2001-2012

Abstract

Mesospheric wind data from meteor wind radars situated on Svalbard (78°N, 16°E) and the Norwegian mainland (70°N, 19°E) are examined for evidence of systematic change during the interval 2001-2012. For both locations, we find changes that suggest a strengthening of the summer westward jet, a weakening of the local winter eastward flow and, yet at the same time, weak evidence for any significant corresponding trend in the winter poleward flow. There is also a suggestion of an increase in the altitude of the summer polar jet, but more data will be required to confirm this. The main finding of a strengthening zonal flow is consistent with earlier studies and also with a contemporary scenario of progressive strengthening of the Brewer-Dobson circulation. We show that inclusion of sudden stratospheric warmings strongly influences trends. There is no obvious causality between the changes detected over the 2001-2012 time interval and the solar cycle parameterized by total solar irradiance. © 2013. American Geophysical Union. All Rights Reserved.