Abstract:

Based on the OSI-SAF daily Arctic sea ice type and concentration data from October 2005 to April 2017, the spatial-temporal characteristics of the changes in first-year ice (FYI) and multi-year ice (MYI) in the Arctic were analyzed. A result of this research was that the multi-year mean sea ice growth rate of FYI was faster during October to December of each growth period, with a mean rate of 1.87?106 and 1.77?106 km2·month–1, for sea ice extent and area, respectively. The growth rate was slower from January to March of each growth period, with a mean growth rate of 0.50?106 and 0.43?106 km2·month-1, respectively. The FYI decreased from March to April, with a mean rate of –0.38?106 and –0.24?106 km2·month-1, respectively. The extent/area of the MYI varied during the different growth periods, with no identical pattern observed in the MYI extent/area time series. The variation characteristics of the sea ice extent in eight sea areas were different, and the Arctic Ocean core region played a leading role in the change in the Arctic MYI. During the growth period, the FYI grew to the south of the Arctic Ocean, and the MYI was mostly distributed in the center of the Arctic. The overall sea ice extent in October and November had significant negative correlations (significance level at 0.05) with the average Arctic air temperature of the last six months. The FYI extent in March and April also had significant negative correlations with the average temperature of the last six months (significance level at 0.05). There were no significant correlations between the MYI extent and monthly mean air temperature in the Arctic.

Key words: Arctic, first-year ice, multi-year ice, sea ice extent, sea ice area