Spatial-Temporal Variation of Surface Radiation Budget over the Arctic Sea Ice Region from 1981 to 2020

Objectives The Arctic sea ice region is rapidly decline, and the surface net radiation and cloud radiative forcing are of great importance to understand global climate and environment change.

Methods A long-term dataset of 40 years (1981—2020) from the European centre for medium-range weather forecasting reanalysis v5 is adopted to investigate the seasonal, annual and decadal variations in surface net shortwave radiation, surface net longwave radiation, surface net all-wave radiation, shortwave cloud radiative forcing, longwave cloud radiation forcing, and all-wave cloud radiative forcing.

Results The results show that the surface net all-wave radiation exhibited a warming effect in summer over the Arctic sea ice region from 1981 to 2020 and the average value was 84.16 W/m². In contrast, the all-wave cloud radiative forcing caused -16.78 W/m² of cooling in summer.

Conclusions Shortwave radiation contributed most to the surface net radiation and cloud radiative forcing. The shortwave net radiation showed a significant increasing trend from 1981 to 2020 with decadal change rate of 2.22 W/m², while declined at a decadal change rate of -6.58 W/m² from 2011 to 2020. The summer average of shortwave cloud radiative forcing was -67.91 W/m², and it decreased deeply at a decadal rate of change of -2.75 W/m², indicating that the cooling effect of cloud on the surface was enhanced. The spatial distribution of summer trends showed that the highest changing rate of surface radiation fluxes existed in the Arctic marginal sea area, especially in the Barents-Kara Sea, where the surface net all-wave radiation and all-wave cloud radiation forcing changed fastest in summer.