TERRAPUB Journal of Oceanography

Journal of Oceanography, Vol. 58 (No. 5), pp. 691-701, 2002

Effects of the Anticyclonic Eddies on Water Masses, Chemical Parameters and Chlorophyll Distributions in the Oyashio Current Region

Masashi Kusakabe1, Andrey Andreev1,2*, Vyacheslav Lobanov2, Igor Zhabin2, Yuichiro Kumamoto1 and Akihiro Murata1

1Japan Marine Science and Technology Center, Natsushima, Yokosuka 237-0061, Japan
2V.I. Il'ichev Pacific Oceanological Institute, 43 Baltiyskaya, Vladivostok 690041, Russia

(Received 15 November 2001; in revised form 22 March 2002; accepted 28 March 2002)

Abstract: Data from the R/V Mirai cruise (May-June 2000) have been examined to discover how mesoscale processes associated with eddy dynamics directly affect the water masses, the distributions and the vertical fluxes of the dissolved oxygen, nutrients and dissolved inorganic carbon in the western subarctic Pacific. Using maps of the temperature, salinity, dissolved oxygen, nutrients, chlorophyll and sea-air pCO2 difference we show that the boundaries of the anticyclone eddies in the study region were composed of high productivity coastal Oyashio water. The coastal waters were wrapped around the anticyclone eddies (thus creating a high productivity belt) and intruded inside of them. Using SeaWifs data we demonstrate that temporal variations in the position and the strength of anticyclone eddies advected the Kuril island coastal high productivity waters to the pelagic part, resulting in temporal variations of the chlorophyll in the Oyashio region. Computed vertical fluxes of the dissolved oxygen (DO), inorganic carbon (DIC) and silicate show that the anticyclonic eddies in the Kuroshio-Oyashio Zone are characterized by enhanced vertical fluxes of the DO and DIC between the upper (sq = 26.7-27.0) and lower (sq = 27.1-27.5) intermediate layer, probably due to the intrusions of the Oyashio waters into the eddies.

*Corresponding author E-mail: andreev@ocean.poi.dvo.ru

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