Near Real-Time Earth Radiation Budgets using the FLASH CERES Data

The retrieval of reflected shortwave (RSW) and outgoing longwave radiation (OLR) on a near real-time basis provides a unique perspective for studying the variability of the Earth's current atmospheric radiation budget. The balance between the combined RSW and OLR terms and the total solar irradiance (TSI) defines the energetic state of the Earth-atmosphere system. This balance ultimately constrains not only weather processes but also the climate forcing and feedbacks. For the past 15 years, the Clouds and the Earth's Radiant Energy Systems (CERES) instruments have collected radiometric measurements taken aboard the Terra, Aqua and NPP spacecrafts to derive climate quality Top-of-Atmosphere (TOA) and surface radiative fluxes. The collection and processing of such high quality data products require algorithmic analyses and data input consistency checks that delay release of the CERES data, often by several months. For long-term climate studies such delays are of little consequence, especially after considering the high quality of the released data products. Nevertheless, there are a significant number of near real-time uses for CERES-like data where the requirement for climate-quality results can be relaxed. Thus, the Fast Longwave and SHortwave Radiative Flux (FLASHFlux) initiative was developed within the framework of the CERES project to provide CERES-like results to the data analysis community within a week of the retrieval of the satellite measurements by exchanging some degree of accuracy for speed. Recently, the FLASHFlux data were used to investigate the radiative impacts of the intense 2015–2016 El Nino event, which attained a Multivariate ENSO Index (MEI) exceeding 1.0 in May 2015. Since that time, the MEI has risen to values in excess of 2.0 and has remained above that level, signifying an El Nino event comparable to the strongest of the previously recorded El Nino events. Our study summarizes the variability in the FLASHFlux TOA, surface and implied atmospheric radiative fluxes during the evolution of this latest El Nino event. Where possible, the FLASHFlux data are compared to available surface measurements and CERES EBAF (Energy Balanced and Filled) surface datasets to establish uncertainty estimates.