Climatology of Total Cloudiness in the Arctic: An Intercomparison of Observations and Reanalyses

摘要: Total cloud fraction over the Arctic (north of 60°N) has been evaluated and intercompared based on 16 climatologies from different satellite surface observations reanalyses. The annual-mean total is about 0.70±0.03 according to observational data. It greater ocean (0.74±0.04) less land (0.67±0.03). Different for are in a better agreement summer than winter land. An interannual variability higher all observations. prominent annual cycle most time its maximum concurs with sea ice extent minimum (early summer–late autumn) vice versa (late spring). main reason discrepancies among difference cloud-detection algorithms, especially when clouds detected ice/snow (during whole year) or regions presence strong low-tropospheric temperature inversions (mostly winter). Generally, reanalyses not close cloudiness Arctic.