Browse

You are looking at 1 - 1 of 1 items for :

  • Multi-Scale Dynamics of Gravity Waves (MS-GWaves) x
  • Pictures of the Month in Monthly Weather Review x
  • Monthly Weather Review x
  • Refine by Access: Content accessible to me x
Clear All
Andreas Dörnbrack, Sonja Gisinger, Michael C. Pitts, Lamont R. Poole, and Marion Maturilli

Abstract

The presented picture of the month is a superposition of spaceborne lidar observations and high-resolution temperature fields of the ECMWF Integrated Forecast System (IFS). It displays complex tropospheric and stratospheric clouds in the Arctic winter of 2015/16. Near the end of December 2015, the unusual northeastward propagation of warm and humid subtropical air masses as far north as 80°N lifted the tropopause by more than 3 km in 24 h and cooled the stratosphere on a large scale. A widespread formation of thick cirrus clouds near the tropopause and of synoptic-scale polar stratospheric clouds (PSCs) occurred as the temperature dropped below the thresholds for the existence of cloud particles. Additionally, mountain waves were excited by the strong flow at the western edge of the ridge across Svalbard, leading to the formation of mesoscale ice PSCs. The most recent IFS cycle using a horizontal resolution of 8 km globally reproduces the large-scale and mesoscale flow features and leads to a remarkable agreement with the wave structure revealed by the spaceborne observations.

Full access