Results are from the global model. Global variation of this parameter will be considered in future versions of the scheme.
Results are from the global model.
The cloud cover predicted by the model is generally underestimated compared to surface observations, and this has worsened in the past 18 months. However, observations gathered by the Met. Based on these observations, a simple modification has been made to the relationship between cloud fraction and grid-box mean RH in the UK mesoscale model. The error allowed non-local mixing to occur in stable conditions. However, the effects were partially compensated for by having a very sharp tail to the atmospheric stability function that determines the local mixing.