Relation of material exchange between sea ice and water to a coupled ice-ocean ecosystem at the Hokkaido coastal region of the Okhotsk Sea

摘要

In this paper, the material exchange between the sea ice and the water just below the ice, and its relation to the lower trophic ice system are examined using field observations in the Hokkaido coastal region of the Okhotsk Sea and a coupled ice-ocean ecosystem model which in detail formulates the material exchange between the ice and the water. The accuracy of the model is confirmed by a comparison of the results of the numerical computation with the observations. The estimation of the transport of the organic carbon and nutrients based on the computation demonstrates that the physical coupling effect between the ice and water plays a prominent role in supplying the nutrients from the water to the ice ecosystem and in efficiently releasing the organic matter produced by the primary producer in the ice (ice algae). As a result, this study quantitatively clarifies that the physical coupling effect, tidal mixing, and biological activity in the ice drive the material cycle in the ice and water under the ice.