Alaska Marine Science Symposium – Final day

 

Anchorage 1/26/17, Hotel Captain Cook

Evening:

It has become more necessary to puzzle out the currents, sea ice behavior and biological systems of the Arctic Ocean. Potential shippers, the U.S. Coast Guard and others join those concerned with ocean acidification, climate warming, food chain and ecosystem considerations and so forth in needing to have better answers…plus, of course, the oil industry.

There has been a lot of progress. Some of this progress is the result of the huge infusion of research money that came with the Chukchi Sea oil lease sale. The Bush administration conducted that sale without really knowing much about those waters, and when Shell decided to drill there, it triggered a truly massive effort to gather baseline about what they soon leaned was a extremely rich bioprovince. In the concluding session of the symposium today, Ken Dunton, the man who led that scientific effort, announced that there was “more chlorophyll on the floor of the Chukchi Sea than anywhere else in the world.” This came offhandedly as he rapidly ran down a bunch of new information from biological sampling done in the muds and waters along the coast of the Beaufort Sea.

The Beaufort and Barrow Canyon got a comprehensive treatment from veteran UAF oceanographer Tom Weingartner, who each year has been revealing another piece of the puzzle of the currents that sweep through the Chukchi after they come through the Bering Strait. There are basically three channels that water can take northward, and the question has been how many Sverdrups go through each. For the past two years, Weingartner has been watching Eddie Carmacks and then Bob Pickart make announcements about how they think those currents work and this year it was finally his turn to take a crack at the big picture, rather than try to correct and adjust the smaller ones.   So here it is. Combining measurements direct from the head of Barrow Canyon with wind data, he has now documented how that current can reverse itself at certain times of year. In the summer is when most of the Bering Strait waters go down the canyon. The rest of the year, most of those waters go up the channel between Herald Shoal and Hanna Shoal and up Herald Channel, between Herald Shoal and Wrangell Island.   From May to September the mean flow is down canyon at a rate of 0.45 Sverdrup, continuing along the shelf of the Beaufort Sea. But from January to April, it equals out, essentially on average not there. And from October to December, the mean flow is actually up canyon, at a rate of about 0.1 Svderdrup.

 

 

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