Impact of Land-Atmosphere Interactions on Mesoscale Arctic Forecasts

The impact of mesoscale land-atmosphere interactions on boundary-layer processes in Arctic region is examined using the U.S. Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS^®*) for the period of the ONR Sea State DRI Cruise to the western Arctic Ocean from 1 Oct to 10 Nov 2015. Initial land surface variables in COAMPS are interpolated from the real-time NASA Land Information System (LIS), which provides important land surface characteristics including snow, permafrost, land ice and plant. The model simulations are configured with three nested grids using 45-15-5 km horizontal resolution and consist of a series of 48-h integrations initialized at 0000 and 1200 UTC. Estimation of surface energy fluxes from model simulations for Arctic flora, primarily tundra, shrub and boreal forest, and for the Greenland ice sheet are evaluated with reanalysis. The results showed substantial differences in the vertical transport rate of heat and moisture from the surface into and through the boundary layer when they compared with simulations using land surface force restore (bulk) scheme. Evaluations using all available station data show surface air temperature and relative humidity have smaller biases when these land-surface processes are included in the simulations. The land-surface processes also improve the simulation of the diurnal variation of land surface temperature, which is a key aspect of land-atmosphere interactions in the Arctic.

*COAMPS^® is a registered trademark of the Naval Research Laboratory