Freeze-up and break-up with two summer ice events.
Calculated dates of freeze-up (open blue squares) and break-up (open red squares) from 1982 through 1986 over daily sea-ice concentration (blue line) and the 34-year climatology (black line). Dates for end of break-up could not be calculated for 1983 and 1985 when significant ice (red arrows) remained in the region or was advected into the region during summer.