Causes of the drastic change in sea ice on the southern northwind ridge in July 2019 and July 2020: From a perspective from atmospheric forcing

Arctic sea ice is a key factor in high–latitude air–sea–ocean interactions. In recent decades, its extent has been decreasing all seasons with large interannual variability, especially for the Northwind Ridge. After removing trend changes during July 1979 to 2020, 2019 had an abnormally low value, while following year, high value. The underlying processes driving this variability near southern Ridge, which one of areas most drastic Arctic, are not well understood. There, we demonstrated that shortwave radiation anomaly direct reason and 2020. Importantly, total energy surplus spring (enough melt ∼18 cm ice) 2020 (potentially melting ∼11 indirectly influenced ice. abnormal change moisture convergence mainly caused by atmospheric circulation were main reasons longwave latent flux anomalies. Cloud water affected radiation, including positive net May 2019.