Microphysical Characteristics of Arctic Summer Sea Fog

The opening of the Arctic Ocean shipping route has significantly benefited the shipping industry. However, low visibility (Vis) in the Arctic Ocean due to fog can lead to a serious challenge during ship navigation. This study proposes a new method for analyzing the ship-based sea fog microphysical observations collected during the ice-breaker Xuelong I expedition to Arctic Ocean in 2016 and 2018, as well as the Xuelong II in 2020. The Vis calculated by droplet size distribution (DSD) using the new method aligns more closely with observed Vis. In the data analysis, both old and new methods are applied to check the droplet size distribution types: (1) double peak DSD model, which influences bulk values of microphysical parameters such as liquid water content (LWC), droplet number concentration (N_d), and effective diameters (D_eff) and (2) a single peak gamma distribution model. Both DSDs obtained by two methods suggested that microphysical characteristics of sea fog adhere more closely to a Gamma-exponential size distribution rather than a Gamma distribution, with double peak values at about 6 and 22 µm. It is concluded that DSD of Arctic fog during summer months have two peak values and can affect fog microphysical properties heavily compared to a single Gamma DSD.