The Natal pulse: An extreme transient on the Agulhas Current
The Natal pulse: An extreme transient on the Agulhas Current
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纳塔尔脉冲：厄加勒斯洋流的极端瞬变
DOI：
10.1029/jc093ic01p00631
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发表时间：
1988
影响因子：
--
通讯作者：
H. R. Roberts
中科院分区：
文献类型：
--
作者：
J. Lutjeharms;H. R. Roberts
对 9 年期间收集的卫星数据以及历史水文数据的分析表明，北部厄加勒斯洋流受到大型、间歇性和孤立的曲流的影响。这些瞬态事件统称为纳塔尔脉冲，以 21 厘米/秒的一致速率向下游发展。当到达架子变宽的区域时，它们的行进速度减慢至 5 厘米/秒。它们至少在 17% 的时间内出现在某些发展阶段，平均向海岸延伸约 170 公里，并在向下游移动时表现出持续的横向增长。除少数例外，脉冲在纳塔尔湾以冷核、气旋、受困背风涡的形式产生。它们是在南部非洲海岸厄加勒斯洋流近岸观察到的间歇性沿海逆流的原因，并且可能在大陆架沉积物分布中发挥至关重要的作用。
An analysis of satellite data collected over a period of 9 years as well as historic hydrographic data show that the northern Agulhas Current is subject to large, intermittent, and solitary meanders. These transient events, collectively named the Natal pulse, progress downstream at consistent rates of 21 cm/s. Upon reaching the area where the shelf broadens, their rate of progression slackens to 5 cm/s. They are present in some stages of development at least 17% of the time, extend offshore by about 170 km on average, and show a continuous lateral growth on moving downstream. With few exceptions the pulses are spawned as cold core, cyclonic, trapped lee eddies in the Natal Bight. They are held responsible for the intermittent coastal counter currents observed inshore of the Agulhas Current along the southern African coast and may play a crucial role in sediment distribution on the shelf.