Surface Solar Irradiance in the Central Pacific during Tropic Heat: Comparisons between in Situ Measurements and Satellite Estimates

Abstract

Abstract We present the first results concerning solar radiation at the ocean surface during the Tropic Heat experiment. Using calibrated GOES visible brightness measurements, a simple radiative transfer model calculates hourly and daily surface solar irradiance values. To validate the satellite-estimated solar irradiance, surface solar irradiance measurements are taken from three sources; the Tropic Heat buoy 3, the R/V Weeama, and the small tropical Pacific island of Hiva Oa. The comparison with the limited set of ocean measurements demonstrates that the method's accuracy is about 12 W m−2 on a daily (for the range of observed values: 240 to 310 W m−2), which meets the requirements of the TOGA program. These results, however, am not yet statistically significant. In comparing model estimates to island data, both satellite observations and measurements indicate that the island's topography influences the oceanic environment by causing local, daily arographic cloud formation over the island's highest moun...