In this paper, based on the current data since 1996 to 2015 obtained by the FVCOM ocean model, the design surface current speed of three selected sites in the Barents Sea is studied. Four types of probability distributions are applied to fit omnidirectional or directional annual extreme current speed, then corresponding return values are estimated. The results show that the return values of omnidirectional current speed are generally larger than those of directional, but there are exceptions, which should be taken into account when estimating and using the design parameters of ocean current speed.
In recent years, the ice cover of Arctic sea is declining. Bader et al. (2011) reviewed the research on the sea ice of Northern Hemisphere, and they concluded that the sea ice in the Arctic Ocean has decreased significantly in all seasons, with the fastest decline in summer, and probably will even be completely ice-free by the summer of 2040. Ross and Fissel (2018) reviewed recent findings of sea-ice research, they concluded that Arctic sea ice has changed a lot in the past 30 years, and its coverage has been greatly reduced especially in the summer and early fall, people are expected to have more Arctic commercial transportation and offshore oil and gas exploration in this century.
The Barents Sea is a marginal sea of the Arctic Ocean, with the Norwegian Seas to the west and the Kara Sea to the east. The Barents Sea has a maximum depth of 600m, and in its southeast near the Svalbard Archipelago, there is a wide continental shelf with a depth of less than 100m (ISO, 2010). This sea area is rich in oil and gas resources (U.S. Geological Survey, 2008). Herbaut et al. (2015) found that, the average area of sea ice in the Barents Sea has decreased rapidly since 2005, Specifically from 670 000 km2 in 2005 to 400,000 km2 in 2012. Duan et al (2018) found that the sea ice in the Barents Sea is experiencing a decreasing process with oscillations in some periods due to unsteady and extreme synoptic process.
