Contrasting spectral changes limit albedo impact on land-atmosphere coupling during the 2003 European heat wave

Abstract

Soil moisture related changes in the Earth's reflectance have been suggested to impact warm season climate variability through their direct impact on surface shortwave radiative forcing. Here we investigate the potential contribution of albedo to land-atmosphere coupling during the 2003 European heat wave. MODIS land surface albedo data for the years 2000-2004 are utilized to identify visible, near-infrared, and total shortwave anomalies for 2003. Changes in vegetation structure result in significant but contrasting albedo anomalies in the visible and near-infrared broadbands for most ecosystem types. Although locally the associated total shortwave radiative forcing can be significant (-10 W m-2) especially over cropland areas, the effects almost cancel out at the sub-continental scale (-1 W m-2). The net effect is too small to support the hypothesis that albedo impacts large-scale land-atmosphere coupling. Copyright 2008 by the American Geophysical Union.