Seasonal shifts in pan-Arctic Ocean downward radiation and key drivers

The Arctic, highly sensitive to climate change, is warming rapidly due to increasing greenhouse gas emissions, resulting in a significant rise in downward radiation over the pan-Arctic Ocean in recent decades. However, the key drivers and their relative contributions remain unclear. This study identifies and quantifies the seasonal impacts of four critical environmental factors-temperature, sea ice concentration (SIC), specific humidity, and latent heat flux-on downward radiation. Results show that temperature dominates during the cold season (October-March), contributing 39.33%, while in the warm season (April-September), temperature and SIC are primary contributors, at 42.18% and -30.57%, respectively. Notably, latent heat flux has a contrasting seasonal effect: it enhances radiation in the cold season but suppresses it in the warm season. These findings reveal the mechanisms underlying Arctic radiative changes and offer valuable insights into the region's climate response under global warming.