open access

https://doi.org/10.14943/bull.fish.70.1.41

https://hdl.handle.net/2115/79116

Shelf slope upwelling induced by sea surface heating

日本語

Compensation flow

2020-08-24

北海道大学大学院水産科学研究院

Bulletin of Fisheries Sciences, Hokkaido University

70(1)

41-62

If there is the coastal upwelling, it is common to think that the upward advection of cold deep water will make the coastal side cooler than the offshore side.　Shelf slope upwelling (SSU) presented in this study, however, occurs only when the shallow coastal side is rather warm due to a continuous sea surface heating in summer.　The present study investigated the formation process of such SSU using a numerical model driven by surface heating.　From the results of examining unsteady state of heat budget and dynamic balance, SSU was found to be a kind of compensation flow, not the bottom Ekman flow.　That is, to satisfy continuity in a vertical section, the offshore flow caused by the horizontal density/temperature gradient was supplemented by the shoreward flow strongly confined to the sloping seabed.　This SSU will probably be one of the important flows contributing to material transport, e.g., unused nutrients and anoxic water etc., from deep to near coast in summer, while it is difficult to prove the existence of SSU even indirectly from the observed water temperature.

紀要論文

Version of Record

2435-3353