Machine Learning Emulation of Subgrid‐Scale Orographic Gravity Wave Drag in a General Circulation Model With Middle Atmosphere Extension

Autor: Yixiong Lu, Xin Xu, Lin Wang, Yiming Liu, Tongwen Wu, Weihua Jie, Jian Sun
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Advances in Modeling Earth Systems, Vol 16, Iss 3, Pp n/a-n/a (2024)
Druh dokumentu: article
ISSN: 1942-2466
DOI: 10.1029/2023MS003611
Popis: Abstract Gravity wave parameterizations contribute to uncertainties in middle atmosphere modeling. To investigate the potential for using machine learning to represent atmospheric gravity waves and the impact of implementing such schemes in a general circulation model (GCM), we train a random forest (RF) emulator on outputs from an existing complex parameterization scheme for orographic gravity wave drag (GWD). The performance of the RF emulator is then evaluated with a focus on stratospheric climatology and variability in climate simulations from the middle atmosphere resolving Beijing Climate Center Atmospheric Circulation Model. In offline tests, the predicted orographic GWD by the RF agrees remarkably well with the target GWD throughout the troposphere and the middle atmosphere. The RF emulator can reproduce the observed climatology of zonal‐mean wind and air temperature in the GCM simulation, as well as its target scheme. Compared to the target orographic GWD parameterization scheme, the RF emulator can reproduce the breakdown of the polar vortex in the Southern Hemisphere stratosphere. This study demonstrates the feasibility of using machine learning to emulate parameterized orographic GWD for modeling the stratosphere with a GCM.
Databáze: Directory of Open Access Journals
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