Validation of explicitly resolved orographic gravity waves in ICON simulations

• Main Authors: Meyer, Catrin, Hoffmann, Lars, Stein, Olaf
• Format: Conference Object
• Language: English
• Published: 2020
• Subjects: Antarctic; Antarctic Peninsula; Antarc*
• Online Access: https://juser.fz-juelich.de/record/888752; https://juser.fz-juelich.de/search?p=id:%22FZJ-2020-05181%22

Orographic gravity wave (OGW) drag is one of the fundamental physics parameterizations employed in global prediction models across timescales from weather to climate. Orographic waves are part of the complex dynamical interaction of winds with topography, and one piece in the puzzle that is topography's effect on global circulation. Parameterized OGW drag provides an important control on model wind biases at levels from the surface through the middle atmosphere, and these alterations in winds in turn affect stationary and synoptic Rossby wave propagation and dissipation. Thus, properly tuned OGW drag parameterizations can improve weather model prediction skill from synoptic to seasonal timescales.Despite its importance for global models, OGW parameterization tuning is still only weakly constrained by observations in today's models, while new issues related to shortcomings in OGW parameterization are arising. Recent advances in high-resolution numerical modeling and satellite data analysis open up the possibility of a new global approach to validation of OGW parameterizations. Hyper-spectral infrared nadir sounding instruments with cross-orbital scan patterns like the Atmospheric Infrared Sounder (AIRS) can provide information on the 3D structure of OGWs. In this study, high-resolution simulations of stratospheric gravity waves using the ICON model are conducted and compared to AIRS. The study focuses on simulations and observations for OGW hotspots in the southern hemisphere, in particular for the Southern Andes and Antarctic Peninsula and the time period of the Concordiasi field campaign from September 2010 to January 2011.The research activities are directly linked to the International Space Science Institute's project 'New Quantitative Constraints on Orographic Gravity Wave Stress and Drag: Satisfying Emerging Needs in Seasonal-to-Subseasonal and Climate Prediction' (see http://www.issibern.ch/teams/consonorogravity/). The study is conducted by an international team of experts on modeling and observations of ...