Abstract
The NASA Clouds and the Earth’s Radiant Energy System (CERES) project provides globally observed fluxes and clouds to monitor the Earth’s energy imbalance and to validate climate model energetics. The CERES data products consist of overlapping Terra, Aqua, SNPP, and NOAA-20 CERES instrument records. The CERES SSF1deg single satellite products utilize MODIS and VIIRS cloud properties for scene identification to convert the CERES observed radiances into fluxes using angular directional models. Consistent MODIS and VIIRS cloud properties are crucial to retrieve uniform CERES fluxes across satellite platforms.
The NASA CERES project is preparing for the Edition 5 reprocessing of the data products by incorporating the latest MODIS C7 L1b imager visible radiances and radiometrically scaling MODIS and VIIRS to the Aqua-MODIS C7 calibration reference. The MODIS C7 and VIIRS C2.1 L1b radiance stability assessment is based on Libya-4, Dome-C and deep convective cloud (DCC) Earth invariant targets. The MODIS C7 stability was found to be within ±0.5% and is an improvement over C6.1. Terra-MODIS is scaled to Aqua-MODIS using polar simultaneous nadir overpass radiance pairs. The MODIS SNOs are based on 100-km calibration footprints designed to mitigate the 16-minute time mismatched induced radiance disparities. The SNPP and NOAA20 orbits intersect with Aqua over the tropics every 64 hours with little time difference. The spectral band adjustments are based on hyperspectral SCIAMACHY radiances. The MODIS and VIIRS scaling factors are also compared with the MAIAC scalings.
MODIS and VIIRS Invariant Target Stability Assessment and Radiometric Scaling for the NASA CERES Edition 5 Products
The NASA Clouds and the Earth’s Radiant Energy System (CERES) project provides globally observed fluxes and clouds to monitor the Earth’s energy imbalance and to validate climate model energetics. The CERES data products consist of overlapping Terra, Aqua, SNPP, and NOAA-20 CERES instrument records. The CERES SSF1deg single satellite products utilize MODIS and VIIRS cloud properties for scene identification to convert the CERES observed radiances into fluxes using angular directional models. Consistent MODIS and VIIRS cloud properties are crucial to retrieve uniform CERES fluxes across satellite platforms.
The NASA CERES project is preparing for the Edition 5 reprocessing of the data products by incorporating the latest MODIS C7 L1b imager visible radiances and radiometrically scaling MODIS and VIIRS to the Aqua-MODIS C7 calibration reference. The MODIS C7 and VIIRS C2.1 L1b radiance stability assessment is based on Libya-4, Dome-C and deep convective cloud (DCC) Earth invariant targets. The MODIS C7 stability was found to be within ±0.5% and is an improvement over C6.1. Terra-MODIS is scaled to Aqua-MODIS using polar simultaneous nadir overpass radiance pairs. The MODIS SNOs are based on 100-km calibration footprints designed to mitigate the 16-minute time mismatched induced radiance disparities. The SNPP and NOAA20 orbits intersect with Aqua over the tropics every 64 hours with little time difference. The spectral band adjustments are based on hyperspectral SCIAMACHY radiances. The MODIS and VIIRS scaling factors are also compared with the MAIAC scalings.