Análise de componentes da radiação solar observados por um avião laboratório.

Abstract

The present thesis deals with the shortwave radiative properties of cumulus clouds and is based on data collected from flights over the state of Ceara conducted by FUNCEME in the months of April 1992 and June 1993. The aircraft was equipped to collect radiation and thermodynamic information and also microphysical data of clouds. Vertical profiles of precipitable water, relative humidity, temperature, dew point temperature and shortwave heating rates are analysed. The variation in downward radiant flux due to the aircraft passing beneath the clouds was used to determine the horizontal extent of the cloud layers. The equivalent depth of cloud was estimated using two flux method. Radiation measurements at the cloud top were not collected during the experiment. A two flux method was used to estimate shortwave radiation at the cloud top and to evaluate the transmittance of a cloudy atmosphere in the visible wavelegth range. Absorption of solar radiation within clouds was estimated using an empirical relation suggested by Rawlins (1989). The values obtained are in good agreement with those reported by Rawlins.