Offshore transport of dense shelf water to the Arctic basin across a shelf break region
Takashi Kikuchi
Japan Marine Science and Technology Center
2-15
Natsushima, Yokosuka, 237-0061 JAPAN
Tel.: 81-468-67-3468
Fax: 81-468-65-3202
takashik@jamstec.go.jp
Dense shelf water which is formed and modified over a continental shelf is transported across a shelf break to an intermediate or deep layer in the Arctic Ocean. Several researchers have investigated the transport process of dense shelf water using a hydrographic observation and/or a numerical experiment. These results show that eddy flux is important to the offshore transport of dense shelf water over a continental shelf and that the transport by a bottom dense plume is important in aslope region. Also, it is well known that the shelf break dynamics, i.e., an effect of shelf break topography and frontal instability over a shelf break and so on, plays an important role in the water exchange between the continental shelf and basin. One of my interests is how the dense shelf water behaves on a shelf break and a slope regions. Results of numerical simulation and data analysis are shown for the purpose. The results of numerical experiments show that eddy flux of dense shelf water makes a shelf break front. The location of shelf break front corresponds to the boundary that shows which process, eddy flux or bottom dense plume, is dominant on the transport of dense shelf water. Other results show that the outflow of dense shelf water from a continental shelf produces subsurface eddies at the mouth of a canyon. The results correspond to earlier insight that subsurface eddies are probably generated on the periphery of the basin. JAMSTEC has carried out hydrographic and mooring observations in the Chukchi Sea and Beaufort
