HR: 16:30h
AN: PP34B-03 INVITED     [Abstracts]
TI: A possible role for North Pacific salinity in stabilizing North Atlantic climate
AU: * Keigwin, L
EM: lkeigwin@whoi.edu
AF: Woods Hole Oceanographic Inst., 360 Woods Hole Rd., Woods Hole, MA 02556
AU: Cook, M
EM: meacook@mit.edu
AF: Woods Hole Oceanographic Inst., 360 Woods Hole Rd., Woods Hole, MA 02556
AB: A simple ocean/atmosphere feedback may reduce the amplitude of climate variability in around the North Atlantic during interglacial compared to glacial states. When climate is warm in the North Atlantic region, the ITCZ has a relatively northward position and moisture is exported from the tropical Atlantic to the tropical Pacific. At the same time, the east Asian summer monsoon is strong, which helps maintain a positive balance of precipitation over evaporation in the subpolar North Pacific. This is thought to account for lower salinity in the North Pacific relative to the North Atlantic, which in turn drives northward flow through the Bering Strait and freshens the northern North Atlantic. Freshening in the North Atlantic tends to suppress the meridional overturning circulation and reduce the North Atlantic heat flux. The opposite situation exists during cold climate: southward movement of the ITCZ in the Atlantic and a weaker east Asian monsoon cause higher salinity in the North Pacific and reduced flow through Bering Strait. Thus, the combination of atmospheric vapor transport and flow through Bering Strait tend to cool the North Atlantic region when warm and warm the region when cool.
DE: 1620 Climate dynamics (0429, 3309)
DE: 1655 Water cycles (1836)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005