Upwelling and ocean structures off Algoa Bay and the south-east coast of South Africa
Upwelling and ocean structures off Algoa Bay and the south-east coast of South Africa
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阿尔戈亚湾和南非东南海岸的上升流和海洋结构
DOI：
10.2989/1814232x.2012.749810
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发表时间：
2012
影响因子：
1.2
通讯作者：
S. Deyzel
中科院分区：
文献类型：
--
作者：
W. Goschen;E. Schumann;KS Bernard;S. Bailey;S. Deyzel
当厄古拉斯洋流沿着南非东南海岸流动时，一些过程将寒冷的深水带到狭窄的大陆架上。因此，上升流沿着海岸线增强进一步向南和下游。这种情况进行了调查关闭Algoa湾和沿着东南海岸阿尔弗雷德港，测量表明，显着的温度变化发生在海岸线上，特别是在夏季时，温度结构更强烈，东风分量风更常见。没有迹象表明阿尔弗雷德港的上升流更为普遍;在伍迪角/帕德龙角（英语：Woody Cape/Cape Padrone），海岸线向西转向，形成了阿尔戈亚湾的东部边界。这里发现，在风向转变为东北风后，冷水在19小时至2.5天后沿海岸线涌上沿着。这种上升流随着风和天气系统的移动而向东北方向发展，尽管较冷的海水也向西南方向移动进入阿尔戈亚湾。风、海流、海平面和海水温度高度相关，海平面测量值>50厘米的波动与沿海陷波（CTW）有关。这种正压风驱动的CTW经常活跃在上升流期间，虽然目前还不清楚这两种现象之间是否有任何相互作用。
As the Agulhas Current flows along the south-east coast of South Africa, a number of processes operate that bring cold, deep water up onto the narrow shelf. As a consequence, upwelling along the coastline is enhanced farther southward and downstream. This situation is investigated off Algoa Bay and along the south-east coast to Port Alfred, where measurements demonstrate that marked temperature variability occurs at the coastline, particularly in summer when temperature structures are more intense and easterly-component winds more common. There is no indication that upwelling is more prevalent at Port Alfred; increasing variability farther south is evident at Woody Cape/Cape Padrone, where the coastline veers westwards, forming the eastern boundary of Algoa Bay. Here it is found that, after a wind change to north-easterly, cold water is upwelled along the shoreline between 19 hours and 2.5 days later. Such upwelling progresses north-eastwards with the movement of the wind and weather systems, although colder water also moves south-westwards into Algoa Bay. Winds, currents, sea level and sea temperatures are highly correlated, with fluctuations in sea level measuring >50 cm being associated with coastal trapped waves (CTWs). Such barotropic wind-driven CTWs are frequently active during upwelling, although it is unclear whether there is any interaction between the two phenomena.