2014 summer Arctic sea ice thickness and concentration from shipborne observations

Abstract

A series of shipborne sea ice observations were performed during the Chinese National Arctic Research Expedition in the Pacific Arctic sector between 2 August 2014 and 1 September 2014. Undeformed sea ice thickness (SIT) as well as area fractions of open water, melt pond, and sea ice (Aw, Ap, and Ai) were monitored using downward-oriented and oblique-oriented cameras. The results show that SIT varied between 20 and 220 cm throughout the whole cruise, with the average and standard deviation equaling 104.9 and 29.1 cm, respectively. Mean Aw and Ai were 0.52 and 0.44 in the marginal ice zone, respectively, while mean Aw decreased to 0.23 and mean Ai increased to 0.73 in the pack ice zone. Limited variation between 0 and 0.32 in Ap was seen throughout the whole cruise. Shipborne sea ice concentration was then rectified and mapped across a large transect to validate estimates derived from the satellite sensors Special Sensor Microwave Imager/Sounder (SSMIS) (25 km) and AMSR2 (25 km). Overestimations were 9.5% and 9.9% for SSMIS and AMSR2 compared with measurements, respectively. The mean areal broadband surface albedo based on shipborne survey increased from 0.07 to 0.66 along the transect between 72°N and 81°N.

Keywords

• arctic sea ice
• shipborne photography
• remote sensing
• surface albedo
• summer melt