HOURLY AND SEASONAL VARIATION OF INCIDENT AND REFLECTED SOLAR RADIATION AND THEIR RELATIONS WITH MICROMETEOROLOGICAL VARIABLES IN NORTH PANTANAL OF MATO GROSSO, BRAZIL

Abstract

The study has analyzed the hourly and seasonal variation of incident solar radiation and the radiation reflected by the ground and albedo, in a woodland area with dominance of Vochysia divergens Pohl in the Pantanal of Mato Grosso, Brazil, in 2012. The studied area presented particular seasonal differences in soil cover: in the flooded period the soil is saturated with moisture, and during the dry period the soil is covered with litter pool. The highest albedo coefficient (0.39) was observed in September, during the dry season. This value contrasts the average for the flooded period (0.09). The Spearman correlation method was employed in order to understand the degree of dependence between variables, and a high positive correlation was seen between albedo and reflected global radiation, whereas a moderate negative correlation was observed between the zenith angle and the global radiation. A moderate negative correlation was also observed between ground water level and reflected solar radiation and albedo.