Energy and radiation balance components for three grass surfaces near Kursk, Russia

Abstract

The energy and radiation balance components were determined over three grass surfaces, representing different levels of productivity, located on the Streletskaya steppe of the Bio‐spheric Reserve near Kursk, Russia, for 21 days during July 1991. The Bowen ratio energy balance method was used to determine the sensible and latent heat flux densities using six computer controlled systems. A total of 126 variables including global, diffuse and reflected solar radiation, long wave radiation (up and down), net radiation, photosynthetically active radiation above and below the vegetation, infrared surface temperatures, soil temperature and heat flow, air temperature and vapor pressure at two levels, wind speed and direction, and precipitation were sampled at 30 s intervals and averaged for 15 min periods. The day time results from July 20, 1991 (a reasonably clear day) for Site 12 (mowed in 1990), Site 13 (mowed in 1991) and Site 14 (preserve) were: net radiation, 13.50, 12.6, and 13.3MJm−2; soil heat flow, ‐0.11, ‐0.87, and ‐0.09 MJ m−2; latent heat flux density, ‐8.79, ‐7.46 and ‐9.97 MJm−2; and for sensible heat flux density, 4.46, ‐4.26, and ‐3.28 MJm−2, respectively. The ranking of the sites from greatest to smallest for net radiation and latent heat flux density were preserve, mowed in 1990, and mowed in 1991. The ranking of the sites from greatest to smallest for sensible heat flux density were mowed in 1990, mowed in 1991, and preserve.