Past and future wind climates over the contiguous USA based on the North American Regional Climate Change Assessment Program model suite

Abstract

Multiple descriptors of wind climates over the contiguous USA from a suite of thirteen simulations conducted with five Regional Climate Models (RCMs) nested within reanalysis data and four Global Climate Models are evaluated relative to the North American Regional Reanalysis (NARR) and independent observations. Application of the RCMs improves forecasts of wind climates during 1979-2000 relative to the driving reanalysis, and the RCMs exhibit some skill in depicting historical wind regimes. However, the relative paucity of reference data sets for wind climates represents a significant challenge to evaluation of the modeled wind climates. Simulation of intense and extreme wind speeds by the RCMs are, to some degree, independent of the lateral boundary conditions, and instead exhibit greater dependence on the RCM architecture. RCMs that do not employ a hydrostatic formulation have higher skill in manifesting the macro-scale variability of extreme (20 and 50 year return period) wind speeds even when the RCM are applied at the spatial resolution of 50 km. Output from RCM simulations conducted for the middle of the current century (2041-2062) indicate some evidence of lower intense wind speeds particularly in the western U.S., but no difference in extreme wind speeds, relative to 1979-2000. © 2012. American Geophysical Union. All Rights Reserved.