We analyzed the Arctic atmosphere – sea ice – ocean relationships to reveal their intrinsic connections and the roles of the sea surface temperature (SST) and surface air temperature (SAT) on the interannual variations and trends of Arctic sea ice concentration (SIC) in July to October during 1951 to 2021. Both SST and SIC have significant impacts on Arctic SIC. SST affects both interannual variations and decadal trends of SIC, whereas SAT has more significant effects on interannual variations of SIC. In addition, SAT affects SIC trends with a seven-month lead time, which is due to the much stronger warming trend in winter than summer. Statistically SST explained 53 % and SAT 35 % of the detrended interannual variance of SIC. SIC trends will continue to decline in the future as SAT and SST continue to rise.