A method to derive downwelling longwave fluxes at the Arctic surface from TIROS operational vertical sounder data

摘要: The dominant component of the polar surface energy budget during half year is downwelling flux longwave radiation (DLF), yet little known about its spatial and temporal variability except on monthly timescales. As measurements will always be sparse, most promising opportunity for diagnosing DLF provided by satellite data. Estimating this from space, however, presents challenges over all types particularly in environments where cloud detection fraction estimation are less certain. A new method presented to estimate TIROS-N operational vertical sounder (TOVS). Temperature profiles, humidity estimates, cover retrieved TOVS radiances using improved initialization inversion algorithm, which has been modified produce more accurate results snow sea ice. This information combined with brightness temperature differences pairs infrared near-infrared channels. These used infer phase geometric thickness. Longwave fluxes then calculated a forward radiative transfer model. Results winter 1988 spring 1992 compared hourly Coordinated Eastern Arctic Experiment eastern basin Lead Beaufort Sea. Error analyses yield bias approximately 3 W m -2 , standard deviation 23 correlation coefficient 0.75. errors comparable similar studies midlatitude land ocean areas clouds easily identified.