Climate model biases in jet streams, blocking and storm tracks resulting from missing orographic drag

Extension of an orographic - drag parametrization scheme to incorporate orographic anisotropy and flow blocking

The Kim–Arakawa orographic gravity-wave drag parametrization scheme, which is a component of the US Navy’s NOGAPS ALPHA (Navy Operational Global Atmospheric Prediction System, Advanced-Level Physics and High Altitude), is extended to include the effects of orographic anisotropy and low-level flow blocking. The algorithms to calculate the orographic statistics needed for the parametrization are ...

Orographic wave drag modelling

The main topic of this article is wave propagation in disordered media. Of particular interest is the long wave regime where an arbitrary rapidly varying orography is modelled as a (stochastic) disordered medium. A brief description of mathematical theory and results is presented. The apparent diffusive behaviour, predicted in the theory for the wave-orography interaction, is confirmed through ...

Atmospheric Blocking and Mean Biases in Climate Models

Models often underestimate blocking in the Atlantic and Pacific basins and this can lead to errors in both weather and climate predictions. Horizontal resolution is often cited as the main culprit for blocking errors due to poorly resolved small-scale variability, the upscale effects of which help to maintain blocks. Although these processes are important for blocking, the authors show that muc...

The physics of orographic gravity wave drag

*Correspondence: Miguel A. C. Teixeira, Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK e-mail: [email protected] The drag and momentum fluxes produced by gravity waves generated in flow over orography are reviewed, focusing on adiabatic conditions without phase transitions or radiation effects, and steady mean incoming flow. The orographi...

Turbulent transport and interactions with the surface Chapter 4 Subgrid - scale orographic drag Chapter 5 Non - orographic gravity wave drag