High Horizontal and Vertical Resolution Limited-Area Model: Near-Surface and Wind Energy Forecast Applications

Abstract

s harvesting of wind energy grows, so does the need for improved forecasts from the surface to the top of wind turbines. To improve mesoscale forecasts of wind, temperature, and dewpoint temperature in this layer, two different approaches are examined. In the first experiment, the vertical resolution of a limited-area model with 2.5-km grid spacing (LAM-2.5 km) is significantly increased near the surface to better represent profiles in that layer. In the second experiment, prognostic variables for land and ocean surfaces are initialized using results from an external land surface model system [the Global Environmental Multiscale Surface system (GEM-Surf)] and from a regional ocean model. Results show that increasing the vertical resolution near the surface leads to improved temperature and dewpoint temperature forecasts at the surface and in the wind turbine layer. For winds, improvements are more modest, because they are limited to the gradient measured across the span of the vertical wind turbine blades. On the other hand, the replacement of operational surface analyses with high-resolution analyses obtained from GEM-Surf is found to improve summer dewpoint temperature forecasts. It is shown that changes in soil moisture analyses explain the bulk of the improved dewpoint forecasts.