Improving NWP forecasts of mountain wave induced CAT using objective observations

The Global Atmopsheric DataSet (GADS) dataset from the British Airways 747-400 fleet is used to calculate the Derived Equivalent Vertical Gust (DEVG) - an objective aircraft independent measurement of turbulence - every 4 seconds. This dataset has been used to generate a climatology of turbulence events over Greenland based on objective observations which will be compared to the climatology of Lane et al. (2009) which was derived from subjective observations.

Initial results will also be presented from numerical model simulations of case studies of turbulent mountain wave events. These simulations will be undertaken using the Met Office Unified Model with a new version of the dynamical core: ENDGame. ENDGame provides improvements in accuracy and model stability, as well as a significantly better representation of gravity wave motion. It is hoped that, in the future, this will allow automated forecasts of mountain wave turbulence to based on the resolved model flow, rather than relying on sub-grid-scale mountain wave parametrization schemes.