Datensatz

Zusammenfassung

The NASA GEWEX Surface Radiation Budget (SRB) project announced its Release 4 integrated products (Rel. 4.0-IP) in 2019. The parameters include TOA and surface shortwave and longwave fluxes for all-sky, clear-sky and pristine-sky conditions on a 1°x1° quasi-equal-area grid system. The dataset spans continuously for 34 years from 1983-07 to 2017-06, and the data are available as 3-hourly, daily, 3-hourly-monthly and monthly means. The shortwave algorithm is based on the Pinker-Laszlo algorithm and the longwave on Fu-Liou algorithm. The inputs are primarily from the ISCCP. Other inputs include the MAC-v1 aerosol, SORCE/TIM solar irradiance, and the blend of TOMS, TOVS, OMI and SMOBA ozone. The fluxes have been extensively validated against the BSRN, ARM, PMEL, GEBA and WRDC data, and all these surface-based datasets are quality-checked. The results show appreciable improvement over Rel. 3.0. The availability of the RadFlux data, which are the clear-sky radiative fluxes at the BSRN sites empirically inferred through regression analyses of actually observed clear-sky fluxes, also makes it possible for us to validate the clear-sky and pristine-sky fluxes. The spatiotemporal continuity of the dataset gives us an opportunity to study the effects of clouds and aerosols on radiative fluxes, in context of long-term variability and regional dimming/brightening. In this presentation, we will examine how the cloud, aerosol and radiation change in time and space, while noting how clouds and aerosols pose challenges to validation of the satellite-based data against ground-based observations.