Stratospheric Circulation Modeling with the SL-AV Semi-Lagrangian Atmospheric Model

V. V. Shashkin, M. A. Tolstykh, and E. M. Volodin

The article describes the development of the version of the SL-AV global semi-Lagrangian atmospheric model with high spatial resolution in the stratosphere. The new model version uses the vertical grid of 100 levels, grid spacing of 500 m in the layer between 100 and 10 hPa, and the upper lid at 0.04 hPa. The parameterization of the non-orographic gravity wave drag is implemented. Numerous modifications are introduced in the block for the numerical solution of dynamical equations to enhance model stability. The experiment on atmospheric dynamics modeling for 28 years is carried out. It is shown that the SL-AV model reproduces the main features of stratospheric circulation, such as the polar night stratospheric jet formation and sudden stratospheric warming. The quasi-biennial oscillation of equatorial wind is reproduced with realistic period and amplitude.