Impacts of tides and atmospheric forcing ... - Wiley Online Library

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, C07S10, doi:10.1029/2005JC003103, 2006

Impacts of tides and atmospheric forcing variability on dissolved oxygen in the subarctic North Pacific Andrey G. Andreev1 and Victoria I. Baturina1 Received 14 June 2005; revised 30 March 2006; accepted 10 April 2006; published 4 July 2006.

[1] The impacts of variations in wind-forcing and the 18.6-year period tidal cycle on the

concentration of dissolved oxygen (DO) in the intermediate waters of the subarctic North Pacific were analyzed. Our results demonstrate that the interannual changes of DO on isopycnal surfaces in the intermediate waters of the western subarctic Pacific can be described very accurately by a linear combination of the intensity of the Aleutian Low pressure system (North Pacific Index), the zonal wind stress (45
N–52
N, 165
E– 170
W) in winter, and an annually averaged cubic of tidal amplitude for the central Aleutian and northern Kuril regions. The residual signal shows a good correlation with the temporal variations of DO in the Alaska Gyre. Citation: Andreev, A. G., and V. I. Baturina (2006), Impacts of tides and atmospheric forcing variability on dissolved oxygen in the subarctic North Pacific, J. Geophys. Res., 111, C07S10, doi:10.1029/2005JC003103.

1. Introduction [2] The identification of natural climate variability can significantly improve confidence in the detection of the anthropogenic climate change. Dissolved oxygen (DO) is one of the best candidates for study of the climatic changes in the oceans due its coupling with the carbon cycling and the existence of long period (>60 years), relatively high accuracy (error 200 mmol kg
1) are observed in the Bering and Okhotsk Seas, and they are stretched northeastward from the Kuroshio-Oyashio Mixed Water Region (35
N–42
N, 155
E– 160
E). In the eastern North Pacific, the California Undercurrent transports low-oxygen (