Select A Date:

Current Synopsis:

DRAFT!!      DRAFT!!      DRAFT!!

Posted August 23, 2014

By Elizabeth Dobbins, Research Scientist, UAF

 

Ice Retreat

According to the August 19, 2014 edition of The National Snow and Ice Data Center's Sea Ice News, warm air was advected from the south over the Chukchi Sea in August, which led to rapid melting there. There is certainly a reduction of ice coverage in our study area compared to 2012 and 2013 (see figures below). Whereas in previous years we worried that ice would affect our cruise plans, this year it isn't a concern. However, while NSIDC does predict sea ice extent this year to be among the 10 lowest years, they do not expect a record setting low at the end of the melt season.

Ice Edge, Aug 21, 2012.

Map of 2012's National Weather Service sea ice prediction, Aug. 21, 2012, with some drifters.

Ice Edge, Aug 21, 2013.

Map of last years's NWS's sea ice prediction, Aug. 21, 2013. Note the very different ice category described in the info box and is primarily first year ice.

Ice Edge, Aug 21, 2014.

Map of this years's NWS's sea ice prediction, Aug. 21, 2014. Ice is far removed from the study area.

 

Drifters
Drifters and HFR, Aug 13, 2014

Easterly winds and blocked drifters, Aug. 13, 2014

 

In early August, winds were generally strong and from the east, which opposes the usual current direction of the ACC along the Chukchi coast. The Wainwright drifters sped northwest for a day (as described in the Aug. 5 synopsis), but then loitered north of Point Barrow for at least a week. Some of them even re-entered the Chukchi Shelf area. The HFR data also show a current reversal over much of the shelf.

Drifters, Aug 23, 2014

By Au., 22, winds relaxed and currents going to the northwest.

 

On approximately Aug. 18, the winds shifted and now orient toward the northwest. The ACC is now stronger, and drifters are resuming their trip north along the shelf break. The Point Hope drifter pack was traveling westward toward Russia, but now seems also to be going north into Herald Valley The Point Lay drifters are the least dispersed, and are now in the Central Channel. These two deployments seem poised to explore the pathways illustrated by our canonical figure of Chukchi Sea circulation

 

High Frequency Radar Activation Barrow RPM and Team

Much of August was spent setting-up the HFR systems and the Remote Power Modules (RPM) that power them. (photo by Hank Statscewich)

HFR currents, Aug 23, 2014

Surface currents measured by the HFRs, Aug 23, 2014.

 

One of the benefits of maintaining the HFR installation at Cape Simpson is the ability to measure currents all around Point Barrow - an especially complex place because of the convergence of current systems there. For instance, on Aug. 23, there was an eddy over the shallow water of the western Beaufort Sea. This area has been described as a hotspot of bowhead whale feeding, and is of particular interest because of that.

 

Field Ops

 

News

 


Last modified: August 25 2014 11:23:40.