Abstract
Hereby is presented a methodology to correct observations of Downwelling Longwave Radiation (DLR) generated by surface stations. It consists in the application of the least squares method to find coefficients (ks) of PIR Eppley (EP) and CGR4 Kipp & Zonen (KZ) sensors, and reprocessing of time series. The evaluation of the methodology used data obtained in an experiment conducted in the Meteorological Instrumentation Laboratory - CPTEC / INPE. The application of statistical tests in the data series, with and without correction shows a significant reduction of the Root Mean Square Error, which went from 9,02 to 0,43 W/m2 for the EP sensor and 4,11 to 1,21 W / m2 for KZ; bias decreased from 0,50 to −7,99 W/m2 (EP) and 3,53 to 0,27 W/m2 (KZ). A CG4 sensor (KZ) of the calibrated reference Physikalisch-Meteorologiches Observatorium Davos (PMOD) with traceability was used.
Keywords:
longwave radiation; pyrgeometer
