Description:
The atmospheric longwave radiation is a fundamental quantity in calculating the radiation balance at the surface. Measures of this magnitude in the gaucho Pampas region are scarce. An alternative estimate for this variable is the use of classical equations that use air temperatures and steam pressure. The objective of this study was to evaluate the performance of five equations in the estimation of the long atmospheric wave radiation for a clear day on a Pampa biome located in Santa Maria-RS. Atmospheric longwave radiation measurements taken throughout the year 2014 on the site of Santa Maria / Brazil were used to validate the performance of equations. After the radiation estimates by classical equations, an adjustment by least squares was empegando to calibrate such equations to the biome Pampa. By adjusting it noted that the equation Brutsaert (1975) was best described obsevada long wave radiation in the PAMPA region.