Changes in Clear?Sky Shortwave Aerosol Direct Radiative Effects Since 2002

A new method for determining clear-sky shortwave aerosol direct radiative effects (ADRE) from the Clouds and Earth's Radiant Energy System is used to examine changes in ADRE since 2002 alongside optical depth (AOD) Moderate Resolution Spectroradiometer. At global scales, neither nor AOD show a significant trend. Over northern hemisphere (NH), increases by 0.18 ± 0.17 Wm?2 per decade (less reflection space) but shows no change over southern hemisphere. The increase NH primarily due emission reductions China, United States, Europe. COVID-19 shutdown noticeable impact on either or AOD, there substantial influence northeastern China March 2020. In contrast, February 2020 anomalies are within natural variability even though of industry was more pronounced than March. reason because exceptionally hot humid which compensated reduced emissions. After accounting meteorology normalizing incident solar flux, substantially, exceeding climatological mean 23%. correspond only period adjusted exceed 95% confidence interval 2 consecutive months. Distinct water-land differences observed not AOD. This likely surface albedo presence absorbing aerosols.