12-16 May 2025 São Paulo (Brazil)
Third-Order, Adaptively Implicit Time Stepping for Advection Enabling Long Time Steps
Amber Te Winkel  1, *@  , Hilary Weller  2  , Christian Kühnlein  3  , James Kent  4  
1 : University of Reading
2 : University of Reading
3 : European Centre for Medium-Range Weather Forecasts
4 : United Kingdom Met Office
* : Corresponding author

Operational models such as the ECMWFs IFS, UK Met Office's Unified Model, and the NCEP Global Forecast System use a semi-Lagrangian scheme for advection, enabling long, accurate time steps at the expense of conservation. Another option, flux-form semi-Lagrangian schemes, conserve mass but are only efficient for long time steps in one-dimensional sweeps. Therefore, this work focuses on adaptively implicit explicit (AdImEx) schemes that use spatiotemporally variable implicit and explicit Runge-Kutta combinations with the aim to create third-order accuracy in space and time for arbitrary time steps. Combining it with limiting guarantees monotonicity and boundedness. Theory and test cases will be presented.


Loading... Loading...