Summer Pacific Water in the Arctic Ocean: Circulation and Variability
Abstract
What is the fate of summer Pacific water in the Arctic Ocean? Our focus here is on the circulation and variability of the layer containing the slightly warm (usually less than 1 degree above freezing) temperature maximum that resides just below the mixed layer in the western Arctic Ocean. Following recent and much older studies, we separate this layer into 2 salinity ranges which may each contain a temperature maximum. The fresher (shallower) layer is Arctic Coastal Water (ACW), which contains a significant runoff fraction (especially from the Yukon river). The saltier (deeper) layer is Bering Sea Water (BSW), which occupies much of the central Chukchi Sea. A data base of cruise data from the 1990's is used to trace the extent and variability of these water masses. We also include recent data obtained in 2000 and 2001 as part of the North Pole Environmental Observatory. We find that when the Arctic Oscillation (AO) index is low, the Beaufort Gyre contains both ACW and BSW, and the Transpolar Drift Stream (TDS) has a low Pacific water contribution. On the other hand, when the AO index is high, ACW dominates the Beaufort Gyre, while BSW dominates the TDS. This result is used to explain time series data from the Lincoln, Beaufort, and East Siberian Seas. We also speculate on downstream implications for the flow through Fram Strait and the Canadian Archipelago.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFM.U72A0015S
- Keywords:
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- 1620 Climate dynamics (3309);
- 1635 Oceans (4203);
- 4512 Currents;
- 4532 General circulation;
- 4536 Hydrography