Stationary wave biases and their effect on upward troposphere– stratosphere coupling in sub-seasonal prediction models ...

• Main Authors: Schwartz, Chen, Garfinkel, Chaim I., Yadav, Priyanka, Chen, Wen, Domeisen, Daniela
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000554538; http://hdl.handle.net/20.500.11850/554538

The simulated Northern Hemisphere winter stationary wave (SW) field is investigated in 11 Subseasonalto-Seasonal (S2S) prediction project models. It is shown that while most models considered can well simulate the stationary wavenumbers 1 and 2 during the first 2 weeks of integration, they diverge from observations following week 3. Those models with a poor resolution in the stratosphere struggle to simulate the waves, in both the troposphere and the stratosphere, even during the first 2 weeks. Focusing on the tropospheric regions where SWs peak in amplitude reveals that the models generally do a better job in simulating the northwestern Pacific stationary trough, while certain models struggle to simulate the stationary ridges in both western North America and the North Atlantic. In addition, a strong relationship is found between regional biases in the stationary height field and model errors in simulated upward propagation of planetary waves into the stratosphere. In the stratosphere, biases are mostly in ... : Weather and Climate Dynamics, 3 (2) ...