Cloud-Dependent Surface Energy Budgets over the Ocean: Observation-Based and Reanalysis Estimates

Abstract:

Regional balance of the atmospheric energy budget provides a stringent constraint to evaluate datasets of global energy budgets. Previous studies indicated that satellite-based and reanalysis estimates describe different heating rates in the atmosphere. Compared to the satellite-based heating rates, reanalyses (European Center for Medium Range Weather Forecast Interim, ERA-Interim, and Modern-Era Retrospective Analysis for Research and Applications, MERRA) have larger heating in the tropical convective regimes and smaller cooling in the subtropical subsidence regimes. Many of these discrepancies originate in cloudy regions where different estimation methods give different energy budgets. In this study, we investigate how different components of the surface energy budget depend on cloud properties in the atmosphere. We will also examine the dependence of discrepancies between reanalysis and the satellite-based surface energy budgets on cloud properties. Different satellite-based estimates, including Tropical Rainfall Measuring Mission (TRMM)-based surface shortwave and longwave heat fluxes, NASA Global Energy and Water Cycle Experiment surface energy budget (SRB) shortwave and longwave radiative heat fluxes, Goddard Satellite-based Surface Turbulent Flux (GSSTF)’s sensible and latent heat fluxes, and the objectively-analyzed air-sea fluxes (OAFlux), are collocated with cloud property measurements of Moderate Resolution Imaging Spectroradiometer (MODIS). MODIS cloud optical depth (COD) and cloud top pressure (CTP) are used to identify cloud types. Different components of surface energy budgets from the satellite-based estimates and the discrepancies from their reanalysis counterparts will be presented as functions of COD and CTP for selected regions that represent tropical convective and subtropical subsidence regimes.