DRAFT!! DRAFT!! DRAFT!!
Posted September 10, 2014
By Elizabeth Dobbins, Research Scientist, UAF
At the beginning of September, a vigorous low in the Beaufort Sea brought significant snowfall to Barrow, AK. Winds there were strong and from the north, and waves caused a lot of erosion along the shoreline. In the Chukchi, winds were consistently 20 knots (see figure). It didn't decrease water temperatures much in Burger, but the more southerly Klondike area experienced a decrease of several degress in water temperature.
By the way, notice how the winds have been edging back up again recently.
It is not immediately clear from the surface HFR maps how the currents were affected by this weather system. Perhaps, the Alaskan Coastal Current is pushed closer to shore and weakened. However, the drifters were obviously affected, as decribed below.Drifters
When we last checked in with the drifters, it looked as though the ones in the western Chukchi were moving northward over Herald Valley and the Central Channel. However, then the winds strengthed and shifted, and things changed.
Instead of heading north through the Central Channel, the drifters that had been deployed off Pt. Lay were swept toward the coastline. Their velocity increased quite a bit - they moved farther in a couple days than they had in the previous weeks. As they entered the ACC, what had been a tight pack of drifters sheared along the coast, until they were dispersed almost to Barrow.
Then the wind shifted again, and the drifters sort of stopped. The drifters that had reached the southern rim of Barrow Canyon continued to move toward the Beaufort Sea. Those that had trailed behind went southwest, confirming the divergent flow pattern off Wainwright that was seen during that time in the HFR current maps (not shown).
The drifters that had been released off Point Hope were previously moving northward into Herald Valley. By Sept. 4, these had broken into groups. Of the original 27 drifters, ~4 went up the valley, ~5 moved onto Herald Shoal and remain there, while the rest hover sourtheast of Wrangel Island.
Meanwhile, the drifters released at Wainwright had been amongst the sea ice along the shelf-break. They are slowly dispersing as the ice breaks up. Some have moved into the basin, but there haven't been any large shelf-basin exchange events like we have seen in other years (for example in late August, 2012).
With the scattering of all these drifters, we are putting together a nice picture of Sea Surface Temperature (SST) along the edges of the Chukchi Sea:
- Three Metbuoys have been deployed. However, the UAF Metbuoy is not sending data in real-time because of an instrument malfunction.
- 104 drifters have been deployed in 4 locations as part of the CBCS program.
- 16 drifters have been deployed in Burger prospect as part of the ARCTREX program.
- All 4 HFR sites are operational.
- 3 gliders have been deployed:
- g159 will hover near the ARCTREX dye release site
- g191 will do a larger scale hydrographic over Hanna Shoal and the mooring array
- we04 will survey along the coast and listen for whales
- The ARCTREX cruise is ongoing and includes hydrographic transects using the towed Acrobat instrument, and vertical microstructure profiles.
- Arctic Revelry Blog: a blog by a group of UAF graduate students who were recently cruising in the Beaufort Sea as part of the US-Canada Transboundary Fish and Lower Trophic Communities program.
- Study: Sparser, thinner Arctic Ocean ice enabling new phytoplankton blooms: story in the Alaska Dispatch about a study of sea ice and phytoplankton. A recent expedition included a dance inspired by sea ice.
- Kaktovik brings in first whales of fall season: Whaling season will be moving to Barrow soon.