[1] Texas A&M Univ, Dept Oceanog, Lab Oceanog & Environm Res, Galveston, TX 77551 USA
[2] Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA
[3] Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA
[4] Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA