Micrometeorological measurements during the total solar eclipse of August 11, 1999

Abstract

Micrometeorological measurements of radiation, atmospheric and soil parameters, and turbulent energy and momentum fluxes, ozone and carbon dioxide fluxes have been conducted over a maize field at Freising-Weihenstephan in Southern Germany during the total solar eclipse on August 11, 1999. For the period 30 minutes before and after the totality the weather conditions at the location where the micrometeorological measurements were made was satisfactory. Several connections between the irradiation and other meteorological parameters over a maize field have been found. The time response between irradiation and the long-wave upward radiation was only a few minutes, whereas almost all parameters caused by the turbulent transport had a time shift of up to 30 minutes. A period of nearly 30 minutes with reduced turbulence regime after the totality was found. Using a wavelet transformation for the time series, a change of time scales from longer to shorter ones was observed before the totality, and after the turbulence increased in the short time scales. The investigation of the residuum of the closure of the energy balance showed that with a time shift for the latent heat flux (unlike the net radiation) after the totality, a better energy budget closure was obtained.