The Global Environmental and Climate Change Centre (GEC3) 2008-09 Seminar Speaker Series presents:
Dr. Robert Newton
Lamont Doherty Earth Observatory
The Earth Institute at Columbia University
“Deconstructing Water in the Canadian Basin: Not as easy as it looks”
Thursday, April 23, 2009
Room 426, Burnside Hall
805 Sherbrooke St. West
Montreal, QC H3A 2K6
Abstract: There is a cottage industry in using suites of tracers to deconvolve water samples from the Arctic and sub-Arctic region into their components: Atlantic Water, Pacific Water (a.k.a.: Bering Strait Inflow), Sea-Ice Melt, and Meteoric Water (composed of river runoff and precipitation). Those of us who play this trade typically cite errors on the order of 5 to 10 percent on individual mass fractions. However, estimates of the Pacific and Atlantic fractions can differ by nearly a factor of two for samples from the same water types.
The contradiction apparently revolves around exactly how one chooses end members. Digging deeply into these choices offers some insight into water transformations on the Arctic shelves and, more generally, into how subtle this process of water mass decomposition can be if one pays attention to the details.