Wind‐induced plume and bloom intrusions into Willapa Bay, Washington
Wind‐induced plume and bloom intrusions into Willapa Bay, Washington
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风引起的羽流和水华入侵华盛顿州威拉帕湾
DOI：
10.4319/lo.2002.47.4.1033
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发表时间：
2002
影响因子：
4.5
通讯作者：
David A. Armstrong
中科院分区：
文献类型：
--
作者：
G. Curtis Roegner;B. Hickey;J. Newton;A. Shanks;David A. Armstrong
1999年5月下旬，在上升流-下降流风周期期间，测量了威拉帕湾和邻近沿海海洋的物理海洋学和叶绿素分布。在间隔4天进行的两组五个跨大陆架断面期间确定了船上的海岸条件，并且仪器系泊同时记录了威拉帕湾近岸区的风速和生物物理水特性。结果表明，河口的物理海洋学和叶绿素浓度的过程发生在近岸海洋，而这些反过来又迫使风应力的变化。在开始的研究期间，南风产生的下降流的条件，迫使哥伦比亚河羽对海岸，低盐度的水平流进入威拉帕湾。这种水的叶绿素含量相对较低（<2 mg m-3）。当风向转向赤道方向时，沿海的上升流随之而来，哥伦比亚的烟柱被近岸冰冷的咸水所取代。一个超过10毫克m-3的浮游植物水华产生的货架上，其核心位于10至40公里的河口。上升流有利的风然后放松，水华显然是平流穿过大陆架到海岸，随后进入威拉帕湾，那里的仪器记录了涨潮时进入河口的叶绿素脉冲。接下来的几天里，弱的下降流条件普遍存在，哥伦比亚河羽流返回海岸，在进入河口之前与近岸富含叶绿素的沃茨混合。这些结果表明，在沿海沃茨产生的初级生产力可以被运送到河口，在那里它可能是一个重要的，但偶发性的食物来源河口生物。
The physical oceanography and chlorophyll distribution in Willapa Bay and the adjacent coastal ocean were measured during an upwelling‐downwelling wind cycle in late May 1999. Coastal conditions were determined shipboard during two sets of five cross‐shelf transects conducted 4 d apart, and instrument moorings simultaneously recorded wind velocity in the nearshore zone and biophysical water properties within Willapa Bay. The results demonstrate that estuarine physical oceanography and chlorophyll concentrations were determined by processes occurring in the nearshore ocean, and these in turn were forced by variation in wind stress. At the start of the study period, southerly winds produced downwelling conditions that forced the Columbia River plume against the coast, and low salinity water was advected into Willapa Bay. This water was relatively low in chlorophyll (<2 mg m-3). As the winds switched to an equatorward direction, coastal upwelling ensued and the Columbia plume was replaced by cold, salty water nearshore. A phytoplankton bloom exceeding 10 mg m-3 was generated on the shelf with its core located 10 to 40 km from the estuarine mouth. The upwelling‐favorable winds then relaxed, and the bloom was apparently advected across the shelf to the coast and subsequently into Willapa Bay, where instruments recorded pulses of chlorophyll entering the estuary on flood tides. Weak downwelling conditions were prevalent for the next several days, and the Columbia River plume returned to the coast where it mixed with the chlorophyll‐enriched waters in the nearshore before entering the estuary. These results demonstrate that primary productivity generated in coastal waters can be transported to estuaries, where it is likely an important yet episodic food source for estuarine organisms.