Objective tracking of African Easterly Waves in Met Office models

摘要: A simple and computationally efficient objective tracking technique is used to assess the representation of African Easterly Waves (AEWs) in Met Office Unified Model (MetUM). The algorithm takes Hovmoller diagrams curvature vorticity at 700 hPa uses object-orientated image processing identify propagating waves. We use evaluate how well AEWs are captured by MetUM comparison ERA-Interim reanalysis GPCP rainfall data. waves inspected from a dynamical perspective also rainfall-coupling perspective. results show that able capture AEW features weather forecasting climate time-scales has reasonable large-scale dynamics. Some coupling forecasts. However, it found enhancement due wave passage underestimated models, as strength frequency AEWs. Potential causes forecast deficiency investigated both resolution changes convective parametrisation have impacts on model performance. implications for future development over Africa discussed suggested good convection within models key importance realistic simulations their West rainfall.