Direct Fluxometer Measurements of the Evaporation from a Bare Soil

Abstract

The accuracy of the fluxometer system, first presented by Sellers and Hodges, is evaluated using data collected with a modification of the original air sampling tunnels. In order to investigate the accuracy of the present system, equations estimating the sensible heat flux are developed for situations for which the evaporation rate is negligible. Two of the investigated gradient forms of the sensible heat flux use the temperature at the earth's surface. A comparison of the latent heat flux, as measured by the fluxometer and as found from the residual of the energy balance equation, shows that the standard error of the fluxometer is about 5 ly hr?1, or 0.08 mm hr?1. It is observed that the fluxometer overestimates the evaporation rate during the afternoon hours.