Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, Institut de Recherche pour le Développement, UMR5566, BP A5, Nouméa, New Caledonia.
Mar Pollut Bull. 2010;61(7-12):449-64. doi: 10.1016/j.marpolbul.2010.06.042. Epub 2010 Aug 17.
The upwelling events that follow strong trade wind episodes have been described in terms of their remarkable signature in the sea surface temperature southwest off New Caledonia. Upwelling brings deeper, and colder waters to the surface, causing 2-4 degrees C drops in temperature in a few hours, followed by a slower relaxation over several days. Upwelling may sporadically bring nutrients to the surface under certain conditions, and increase the biological productivity. Two multidisciplinary hydrographic cruises allow the impact of upwelling on the chemical and biological properties of the water to be documented. Both cruises took place in austral summer (December 2004 and December 2005), but the first cruise occurred during a strong upwelling event, while the second cruise occurred in calm conditions. The water properties and planktonic composition show important contrasts, with a strong southeastward current (the "ALIS current of New Caledonia") competing with the upwelling system. Our analysis suggests that, while observed productivities are far less than those of typical upwelling systems, some wind events in New Caledonia may contribute to biological activity. A currentmeter mooring, deployed during the second cruise, documents the ocean response to a changing wind field and the local impact of upwelling on currents and temperatures on the water column. The results are discussed, with the help of climatology, Argo float profiler data, satellite data and of a high-resolution numerical simulation.
新喀里多尼亚西南海域海面温度出现显著特征，表明其后有上升流事件发生。上升流将深层、低温海水带至海面，导致温度在数小时内下降 2-4 摄氏度，随后数天内缓慢恢复。在某些条件下，上升流可能会间歇性地将营养物质带到海面，从而增加生物生产力。两次多学科海洋学考察记录了上升流对水化学和生物学特性的影响。两次考察都发生在南半球夏季（2004 年 12 月和 2005 年 12 月），但第一次考察发生在强上升流事件期间，而第二次考察发生在平静条件下。水特性和浮游生物组成显示出重要的对比，存在强烈的东南向流（“新喀里多尼亚的 ALIS 流”）与上升流系统竞争。我们的分析表明，虽然观测到的生产力远低于典型上升流系统，但新喀里多尼亚的一些风事件可能会促进生物活动。第二次考察期间部署的海流计系泊浮标记录了海洋对风场变化的响应以及上升流对水团中流和温度的局部影响。借助气候学、Argo 浮标剖面仪数据、卫星数据和高分辨率数值模拟，对结果进行了讨论。
