Mesoscale Simulation of Open Cellular Convection: Roles of Model Resolutions and Physics Parameterizations

Abstract

The Open Cellular Convection (OCC) associated with cold air outbreaks is a common phenomenon over the North Sea where a large number of wind parks are presented. Thus, reliable numerical simulations of OCC events have great importance for offshore wind energy. We investigate the ability to simulate the OCC events using the Weather Research and Forecast (WRF) model with the ERA5 reanalysis data as initial and lateral boundary conditions and the OSITA data as the sea surface temperature. The domains were nested from 9 km as the outermost domain to 1 km as the innermost domain surrounding the Teesside wind farm located in the North Sea off the northeast coast of England. We simulated an OCC event in 2015 with three series of sensitivity numerical experiments of planetary boundary layer, microphysics, and radiation parameterizations. The model outputs were validated against the wind observation at the Teesside's meteorological mast. The results suggest that the planetary boundary layer schemes are the most sensitive during the events compared to other parameterization schemes. Futher more, a convective-resolved resolution is necessary for simulating the OCC variation properly. The paper also discuss the verification methods for such short time-scale events like the OCC.