MR01-K03

Observational studies on the Material Cycle in the High Latitude Sea.

The northern North Pacific, especially its western part, has been attracting attention of chemical oceanographers because of its importance in global biogeochemical cycles of carbon and its related materials, which have a great impact to the climate change of the earth. In addition, physical oceanographers have been interested in that region with respect to the formation of the North Pacific Intermediate Water. Despite its importance, there has been few systematic survey to cover the temporal and spatial variation of biogeochemical processes in the area. Main goal of this study is to clarify the behavior of carbon and its related materials in the area, and then to estimate the impact of high latitude seas on the global climate change.

Based on the above - mentioned goal, several cruises in the late autumn, the early winter and spring were done in the western northern North Pacific and Okhotsk Sea. In 2001, the cruise will focus on the biogeochemistry in the early summer when the spring bloom is expected to be over and concentrations of nutrients and pCO2 should be reduced. In addition, observation at the Stn. KNOT will be carried out. During the cruise, seawater samples, aerosol, and plankton will be collected. Settling particles will be also collected using floating sediment traps. While the vessel is steaming, CO2, nutrients, Salinity, temperature of the surface water are measured. In the meantime, CO2 in the atmosphere is also measured. Vertical profiles of salinity and temperature will be measured by XBT and XCTD. Bottom sediment will be taken using a multiple corer and piston corer.

The northwestern North Pacific and Okhotsk Sea

Sekinehama - Sekinehama

Masashi KUSAKABE (Chemical Oceanography)