Predicted satellite based sampling errors of the SW and LW spectra in support of CLARREO

The NRC Decadal Survey has called for SI traceability of long-term hyper-spectral flux measurements in order to monitor climate variability. The proposed Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission is currently in Extended Pre-Phase A (EPPA) status. Until mission funding is fully restored, several proof of concept platforms have been proposed. Although the main objective is the CLARREO instrument absolute calibration accuracy, can these venture class missions obtain sufficient sampling for climate benchmarking? These platforms include the International Space Station (ISS) and Iridium constellation. The CLARREO proposed orbits repeat annually, however this is not the case with the ISS and Iridium, where natural variability, manifested in the seasonal and diurnal cycles, may alias into the inter-annual variability signal. The study will incorporate Clouds and the Earth's Radiant Energy System (CERES) SYN1deg 10-year product TOA LW and SW climate quality fluxes. The flux dataset derived by combining Terra and Aqua CERES fluxes with the 3-hourly 5-geostationary satellite estimated broadband fluxes, which are carefully normalized using the CERES fluxes, to complete the diurnal cycle. These regional fluxes were saved hourly during processing and considered the truth dataset. The 90°, 83° and 74° inclination precessionary, sun-synchronous as well as ISS and Iridium orbits will be evaluated. The inter-annual variability SW and LW sampling error will be stratified globally/zonally and annually/seasonally and compared with the corresponding truth anomalies.