Name
Rich Collins
Geophysical Institute and Department of Atmospheric Sciences, University of Alaska Fairbanks, USA

Title
Waves and the wintertime circulation of the Arctic middle atmosphere

Time and place
Thu 4 April 2013, 15.00
Room C609, Arrhenius Laboratory, 6th floor

(This event has taken place)

 

Abstract

Recent observations have highlighted the variability of the wintertime Arctic middle atmosphere, with Stratospheric Sudden Warmings (SSW) and Elevated Stratopause (ES) Events. These disturbances are associated with major changes in the planetary wave and gravity wave forcing of the circulation. In this paper I will present the use of satellite measurements, lidar measurements, meteorological analyses, and model simulations to understand the wave-driven circulation and variability of the polar atmosphere. The lidar observations yield high-resolution temperature and density measurements that allow characterization of the planetary waves, tides, and gravity waves. The satellite observations yield synoptic-scale temperature measurements of the mesosphere and upper stratosphere. Thee meteorological soundings and analyses provide synoptic-scale measurements of the troposphere and lower stratosphere. The Whole Atmosphere Community Climate Model (WACCM) provides both free-running and specified dynamic simulations that allow investigation of the observed planetary and gravity wave activity in the Arctic atmosphere. I will also discuss how the middle and upper atmosphere circulation modulates the impact of solar processes on the atmosphere through control of transport of thermospheric NOx produced by energetic particle precipitation into the mesosphere and stratosphere.