Simulated and Observed Surface Energy Fluxes and Resulting Playa Breezes during the MATERHORN Field Campaigns

• Published in: Journal of applied meteorology and climatology Vol. 56; no. 4; pp. 915 - 935
• Main Authors: Massey, Jeffrey D., Steenburgh, W. James, Hoch, Sebastian W., Jensen, Derek D.
• Format: Journal Article
• Language: English
• Published: Boston American Meteorological Society 01-04-2017
• Subjects: Albedo; Albedo (solar); Arid zones; Aridity; Atmospheric models; Atmospheric sciences; Autumn; Breezes; Climatology; Components; Computer simulation; Daytime; Deserts; Energy; Energy balance; Enthalpy; Errors; Fluctuations; Heat; Heat conductivity; Heat flux; Heat transfer; In situ measurement; Latent heat; Latent heat flux; Loam soils; Mathematical models; Modelling; Parameterization; Playas; Satellites; Saturation vapor pressure; Sensible heat; Sensible heat flux; Sensible heat transfer; Soil; Soil analysis; Soil conductivity; Soil moisture; Soils; SPECIAL MATERHORN COLLECTION; Studies; Surface energy; Surface energy balance; Surface properties; Temperature; Temperature differences; Temperature effects; Terrain; Thermal conductivity; Vapor pressure; Vapour pressure; Vegetation; Weather; Weather forecasting; Wind speed
• ISSN: 1558-8424; 1558-8432
• DOI: 10.1175/JAMC-D-16-0161.1

Weather Research and Forecasting (WRF) Model simulations of the autumn 2012 and spring 2013 Mountain Terrain Atmospheric Modeling and Observations Program (MATERHORN) field campaigns are validated against observations of components of the surface energy balance (SEB) collected over contrasting desert-shrub and playa land surfaces of the Great Salt Lake Desert in northwestern Utah. Over the desert shrub, a large underprediction of sensible heat flux and an overprediction of ground heat flux occurred during the autumn campaign when the model-analyzed soil moisture was considerably higher than the measured soil moisture. Simulations that incorporate in situ measurements of soil moisture into the land surface analyses and use a modified parameterization for soil thermal conductivity greatly reduce these errors over the desert shrub but exacerbate the overprediction of latent heat flux over the playa. The Noah land surface model coupled to WRF does not capture the many unusual playa land surface processes, and simulations that incorporate satellite-derived albedo and reduce the saturation vapor pressure over the playa only marginally improve the forecasts of the SEB components. Nevertheless, the forecast of the 2-m temperature difference between the playa and desert shrub improves, which increases the strength of the daytime off-playa breeze. The stronger off-playa breeze, however, does not substantially reduce the mean absolute errors in overall 10-m wind speed and direction. This work highlights some deficiencies of the Noah land surface model over two common arid land surfaces and demonstrates the importance of accurate land surface analyses over a dryland region.