The CERES Flux by Cloud Type Product: Algorithm and Validation

The Clouds and the Earth's Radiant Energy System (CERES) project now has over 16 years of an accurately observed top-of-the-atmosphere (TOA) flux record for climate monitoring and diagnostic studies. CERES provides the climate community the following parameters: coincident instantaneous 1° gridded CERES observed TOA fluxes, computed profile and surface fluxes, as well as MODIS cloud and aerosol retrievals. As part of its suite of products, CERES has packaged its MODIS derived cloud properties in the ISCCP-D2 monthly format that can be compared against climate model diagnostics with ISCCP simulators. There are four instantaneous gridded CERES ISCCP-D2 like products: ISCCP-D2like-MODIS, ISCCP-D2like-geo, ISCCP-D2like-merge, and flux-by-cloud-type product. The flux product combines for the first time CERES measured TOA fluxes along with the associated MODIS cloud properties, which links radiative flux directly to a specific cloud type. This was achieved by computing sub-footprint fluxes for the clear-sky and cloudy portions of the CERES footprint. The spatially distributed cloud properties within the CERES footprint were retrieved from 2-km MODIS pixels, that were stratified by cloud type. The sub-footprint fluxes were estimated from MODIS radiances based on empirically derived narrowband to broadband coefficients. The combined sub-footprint fluxes can then be validated with the observed footprint flux. This presentation will focus on the algorithm development of the flux-by-cloud-type product and its validation.