Size-resolved dust direct radiative effect efficiency derived from satellite observations

Abstract. The role of mineral dust aerosol in the global radiative energy budget is often quantified by direct effect (DRE). DRE strongly depends on optical depth (DAOD), therefore, efficiency (DREE = / DAOD) widely compared across different studies to eliminate differences due various loads. Nevertheless, DREE still influenced uncertainties associated with particle size distribution (PSD) and properties. In this study, we derive a clear-sky size-resolved dataset both shortwave (SW) longwave (LW) at top atmosphere (TOA) surface based satellite observations (i.e., satellite-retrieved extinction spatial vertical distributions). dataset, geometric diameter from 0.1 100 µm divided into 10 bins corresponding monthly mean (with respect DAOD 532 nm) for each bin derived using Rapid Radiative Transfer Model (RRTM). Three sets state art refractive indices (RI) two shape models (sphere vs. spheroid) are adopted investigate sensitivity absorption shape. As result, contains globally distributed TOA 5? (longitude) ×2? (latitude) resolution as well RI combination. can be used readily calculate any PSD, including uncertainty induced microphysical properties, (e.g., shape). By calculating climatology retrieved sensors find that pattern induces more than % SW TOA. observation-based PSD around 15–20 atmosphere. assessments further suggest nonsphericity negligible estimations, while turns out most important factor determining DRE, particularly SW.