Emulating lateral gravity wave propagation in a global chemistry–climate model (EMAC v2.55.2) through horizontal flux redistribution ...

• Main Authors: Eichinger, Roland, Rhode, Sebastian, Garny, Hella, Preusse, Peter, Pisoft, Petr, Kuchař, Aleš, Jöckel, Patrick, Kerkweg, Astrid, Kern, Bastian
• Format: Article in Journal/Newspaper
• Language: English
• Published: Forschungzentrum Jülich 2023
• Subjects: 550; Antarctic; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.34734/fzj-2023-03785; https://juser.fz-juelich.de/record/1016801

Geoscientific model development 16(19), 5561 - 5583 (2023). doi:10.5194/gmd-16-5561-2023 ... : The columnar approach of gravity wave (GW) parameterisations in weather and climate models has been identified as a potential reason for dynamical biases in middle-atmospheric dynamics. For example, GW momentum flux (GWMF) discrepancies between models and observations at 60∘ S arising through the lack of horizontal orographic GW propagation are suspected to cause deficiencies in representing the Antarctic polar vortex. However, due to the decomposition of the model domains onto different computing tasks for parallelisation, communication between horizontal grid boxes is computationally extremely expensive, making horizontal propagation of GWs unfeasible for global chemistry–climate simulations.To overcome this issue, we present a simplified solution to approximate horizontal GW propagation through redistribution of the GWMF at one single altitude by means of tailor-made redistribution maps. To generate the global redistribution maps averaged for each grid box, we use a parameterisation describing orography ...