Hudson Bay sea ice update: more ice in the east than usual but less in the west

There’s almost more blue in the Canadian Ice Service “departure from normal” charts for this week than red, which means more sea ice than usual, especially in the eastern half of the bay and northern Labrador. Eventually, the melting ice will force polar bears ashore where they will fast for 4-5 months, living off the fat they’ve put on over the spring feeding season.

Hudson Bay weekly departure from normal 2018 June 25

There is less ice than usual in the northwest sector (see chart below for week of 25 June 2018) but that’s been the case for several years now. However, the amount of thick first year ice still present means this won’t be an early breakup year.

Hudson Bay weekly stage of development 2018 June 25

It used to be that ice disappeared first from eastern Hudson Bay (see chart below from 14 June 2010, an early breakup year) but that pattern has recently reversed. We still don’t know really how this change in sea ice melt pattern has affected polar bears because the data that should show the effects have not been published.

Hudson Bay weekly stage of development 2010_June 14

Nevertheless, all of Andrew Derocher’s collared Western Hudson Bay females were still on the ice  as of 25 June, despite the lack of ice in the northwest region, which means they’ll likely come ashore sometime in July:

WHB females with collars_25 June 2018_Derocher lab

CIS charts for 25 June shows there is more low concentration ice close to shore than Derocher’s map indicates:

Hudson Bay North daily concentration 2018 June 25

Hudson Bay South daily concentration 2018 June 25

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