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Friday, 30 April 2010 - Sea Ice for Walrus Outlook

Weekly Outlook

30 April 2010
Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus: 

Near Saint Lawrence Island

Persistent northeast winds through April 28th continued to push large floes south into Saint Lawrence Island, especially around and to the east of Savoonga. These winds have also kept concentrations of the large floes 10-25 miles west of Saint Lawrence Island and more than 40 miles to the south of Saint Lawrence Island. The sea ice was generally drifting south through the 28th. Westerly winds on the 29th modified the flow slightly, but this change will be brief. Closer to shore, new ice continued to reform in the polynyas, however, satellite imagery indicates that the concentration of new ice is less than a few days ago.

Wales to Shishmaref

The landfast ice has persisted the last week, with relatively small changes from Wales to Shishmaref. The shorefast ice remains heavily fractured with many leads. Northerly winds had kept pack ice close to the shorefast ice until recently. A reversal of the winds the last few days has caused the pack ice to drift north causing the waters to open up to a few miles in width.

5 and 10 Day Outlook: April 30 through May 10

The overall pattern will be persistent for the 5 and 10 day outlook. A general high pressure is expected to linger to the north. This will maintain east to northeast winds, with perhaps a short-lived reversal to northwest flow. Temperatures will also remain at or slightly below seasonable. As a result, little change is expected in sea ice conditions. Pack ice will continue to push up against the landfast ice between Wales and Shishmaref, with many leads. Temperatures will also likely favor formation of new ice. The polynya around Saint Lawrence Island will be maintained, with the larger flows remaining more than 20 miles south of the island. Ice will push up against the northside of Saint Lawrence Island, and flow around the west and east sides. As a result, the large floes will remain close to Gambell, but will flow away from the west side of Saint Lawrence Island.

Note about the dates of the Remote Sensing Data

There was not a very good recent satellite image available for Bering Strait (Wales), so the bigger view is from April 26th, which shows a nice shot of the sea ice conditions. The more zoomed in view takes a better look at Saint Lawrence Island since it was cloudy up by Wales.

St. Lawrence Island wind direction and speed
Map of 10-day outlook of wind conditions
Bering Strait wind direction and speed

Arrows show wind direction and wind speed in knots

Remote Sensing Images

St. Lawrence Island/Bering Strait: 
Remote sensing data closeup
Bering Sea/Southern Chukchi Sea: 
Remote sensing data overall
Remote sensing data closeup
Remote sensing data overall

Observations and Comments

Observations of Sea Ice Development: 

30 April 2010 - Winton Weyapuk, Jr. - Summary of Ice Development in Wales

Boat crews from Wales have been out hunting successfully for bearded and ringed seal and walrus most of the past week. Beluga and bowhead whales were sighted. On April 26, winds were up to 40 knots at the boat launch site (below 12 knots at the village) preventing boats from going out. A thin ice stable extension that had formed at the launch site broke off on April 27 and the thick extension used for launching boats developed a crack at the ridge, moving a little with the swell.

Between April 28 and 30 a larger lead (with some new ice forming) was present north of Wales and later also extending to south of the village. Larger floes with open water inbetween were drifting towards the SSW. April 29 started out calm with northeasterly winds picking up quickly in early evening; on April 30 winds were at 9 knots at the village and over 15 at the lead edge.

29 April 2010 - Hajo Eicken - Information on Landfast Ice North of Wales and Shishmaref
The radar satellite image (left side of image on right; see also image shown for outlook on 16 April 2010) shows that the landfast ice described by Curtis Nayokpuk on 5 April is still held in place by ridged ice that ran aground. However, the eastern parts of this stretch of shorefast ice are continuing to break out, giving Shishmaref closer access to open water (right side of image on right).