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Byline: Masashi Kusakabe (1), Andrey Andreev (1,2), Vyacheslav Lobanov (2), Igor Zhabin (2), Yuichiro Kumamoto (1), Akihiro Murata (1) Keywords: Eddy; Oyashio; Kuril Islands; North Pacific; chemical parameters Abstract: Data from the R/V Mirai cruise (May--June 2000) have been examined to discover how mesoscale processes associated with eddy dynamics direct 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 pCO.sub.2 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 anticylonic eddies in the Kuroshio-Oyashio Zone are characterized by enhanced vertical fluxes of the DO and DIC between the upper ([sigma].sub.I, = 26.7--27.0) and lower ([sigma].sub.I, = 27.1--27.5) intermediate layer, probably due to the intrusions of the Oyashio waters into the eddies. Author Affiliation: (1) Japan Marine Science and Technology Center, Natsushima, Yokosuka, 237-0061, Japan (2) V.I. Il'ichev Pacific Oceanological Institute, 43 Baltiyskaya, Vladivostok, 690041, Russia Article History: Registration Date: 12/10/2004

Byline: Andrey Andreev (1), Makio Honda (1), Yuichiro Kumamoto (1), Masashi Kusakabe (1), Akihiko Murata (1) Keywords: Carbon cycle; antropogenic CO.sub.2; North Pacific Abstract: Excess CO.sub.2 and pH.sub.excess showing an increase in dissolved inorganic carbon and a decrease in pH from the beginning of the industrial epoch (middle of the 19th century) until the present time have been calculated in the intermediate water layer of the northwestern Pacific and the Okhotsk Sea. It is concluded that: (1) The Kuril Basin (Okhotsk Sea) and the Bussol' Strait areas are characterized by the greatest concentrations of excess CO.sub.2 at isopycnal surfaces due to the processes of formation and transformation of intermediate water mass. (2) The largest difference in excess CO.sub.2 concentration between the Okhotsk Sea and the western subarctic Pacific (about 8 Aumol/kg) is found at the [sigma].sub.I, = 27.0. (3) The difference in excess CO.sub.2 between the western subarctic Pacific and subtropical regions is significant only in the upper part of the intermediate water layer ([sigma].sub.I, = 26.7--27.0). (4) About 10% of the excess CO.sub.2 accumulation in the subtropical north Pacific is determined by water exchange with the subarctic Pacific and the Okhotsk Sea. Author Affiliation: (1) Japan Marine Science and Technology Center, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan Article History: Registration Date: 08/10/2004

Byline: Dong-Chan Oh (1), Mi-Kyung Park (1), Sang-Hwa Choi (2), Dong-Jin Kang (1), Sun Young Park (1), Jeom Shik Hwang (1), Andrey Andreev (3), Gi Hoon Hong (2), Kyung-Ryul Kim (1) Keywords: Surface fCO.sub.2 in the East (Japan) Sea; air-sea CO.sub.2 flux; seasonal variability of fCO.sub.2; solubility pump; gas-exchange model Abstract: During CREAMS expeditions, fCO.sub.2 for surface waters was measured continuously along the cruise tracks. The fCO.sub.2 in surface waters in summer varied in the range 320--440 Auatm, showing moderate supersaturation with respect to atmospheric CO.sub.2. In winter, however, fCO.sub.2 showed under-saturation of CO.sub.2 in most of the area, while varying in a much wider range from 180 to 520 Auatm. Some very high fCO.sub.2 values observed in the northern East Sea (Japan Sea) appeared to be associated with the intensive convection system developed in the area. A gas-exchange model was developed for describing the annual variation of fCO.sub.2 and for estimating the annual flux of CO.sub.2 at the air-sea interface. The model incorporated annual variations in SST, the thickness of the mixed layer, gas exchange associated with wind velocity, biological activity and atmospheric concentration of CO.sub.2. The model shows that the East Sea releases CO.sub.2 into the atmosphere from June to September, and absorbs CO.sub.2 during the rest of the year, from October through May. The net annual CO.sub.2 flux at the air-sea interface was estimated to be 0.032 (+-0.012) Gt-C per year from the atmosphere into the East Sea. Water column chemistry shows penetration of CO.sub.2 into the whole water column, supporting a short turnover time for deep waters in the East Sea. Author Affiliation: (1) Department of Oceanography and Research Institute of Oceanography, Seoul National University, Seoul, 151-742, Korea (2) Korea Ocean Research &amp Development Institute, Ansan, P.O. Box 29, Seoul, 425-600, Korea (3) Russian Academy of Science, Pacific Oceanological Institute, Vladivostok, Russia Article History: Registration Date: 01/10/2004

Excess CO2 and pHexcess showing an increase in dissolved inorganic carbon and a decrease in pH from the beginning of the industrial epoch (middle of the 19th century) until the present time have been calculated in the intermediate water layer of the northwestern Pacific and the Okhotsk Sea. It is concluded that: (1) The Kuril Basin (Okhotsk Sea) and the Bussol' Strait areas are characterized by the greatest concentrations of excess CO2 at isopycnal surfaces due to the processes of formation and transformation of intermediate water mass. (2) The largest difference in excess CO2 concentration between the Okhotsk Sea and the western subarctic Pacific (about 8 µmol/kg) is found at the σθ = 27.0. (3) The difference in excess CO2 between the western subarctic Pacific and subtropical regions is significant only in the upper part of the intermediate water layer (σθ = 26.7–27.0). (4) About 10% of the excess CO2 accumulation in the subtropical north Pacific is determined by water exchange with the subarctic Pacific and the Okhotsk Sea. [ABSTRACT FROM AUTHOR]