Coupling Between the Coastal Ocean and Yaquina Bay, Oregon: Importance of Oceanic Inputs Relative to Other Nitrogen Sources
Coupling Between the Coastal Ocean and Yaquina Bay, Oregon: Importance of Oceanic Inputs Relative to Other Nitrogen Sources
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DOI：
10.1007/s12237-008-9128-6
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发表时间：
2009-03-01
影响因子：
2.7
通讯作者：
Ozretich, Robert J.
中科院分区：
文献类型：
--
作者：
Brown, Cheryl A.;Ozretich, Robert J.
了解海洋输入在营养盐负荷中的作用对于了解邻近沿海涌升区河口的营养盐和浮游植物动态以及确定自然背景条件是重要的。我们研究了氮源的亚基纳河口（俄勒冈州，美国）以及物理强迫和营养盐和浮游植物的海洋输入总量之间的关系。在旱季（5月至10月），海洋是亚基纳湾下部溶解无机氮（DIN）和磷酸盐的主要来源。在这段时间内，高水平的溶解无机氮（主要以硝酸盐的形式）和磷酸盐进入河口滞后上升流有利的风2天。与海岸上升流进入海湾的硝酸盐和磷酸盐水平与4-6天的时间尺度上的风应力集成。此外，有一个显着的进口叶绿素a的海湾从沿海地区，特别是在7月和8月。涨潮叶绿素a的变化滞后上升流有利的风6天，这表明浮游植物需要这个量的时间来利用最近上升的氮，并被运送到整个货架到河口。由海洋条件决定的水性质的变化传播到河口大约11-13公里。氮源比较亚基纳湾表明，海洋是旱季（5月至10月）的主要来源，河流是雨季的主要来源，流域氮输入主要与林地上的固氮。
Understanding of the role of oceanic input in nutrient loadings is important for understanding nutrient and phytoplankton dynamics in estuaries adjacent to coastal upwelling regions as well as determining the natural background conditions. We examined the nitrogen sources to Yaquina Estuary (Oregon, USA) as well as the relationships between physical forcing and gross oceanic input of nutrients and phytoplankton. The ocean is the dominant source of dissolved inorganic nitrogen (DIN) and phosphate to the lower portion of Yaquina Bay during the dry season (May through October). During this time interval, high levels of dissolved inorganic nitrogen (primarily in the form of nitrate) and phosphate entering the estuary lag upwelling favorable winds by 2 days. The nitrate and phosphate levels entering the bay associated with coastal upwelling are correlated with the wind stress integrated over times scales of 4-6 days. In addition, there is a significant import of chlorophyll a to the bay from the coastal ocean region, particularly during July and August. Variations in flood-tide chlorophyll a lag upwelling favorable winds by 6 days, suggesting that it takes this amount of time for phytoplankton to utilize the recently upwelled nitrogen and be transported across the shelf into the estuary. Variations in water properties determined by ocean conditions propagate approximately 11-13 km into the estuary. Comparison of nitrogen sources to Yaquina Bay shows that the ocean is the dominant source during the dry season (May to October) and the river is the dominant source during the wet season with watershed nitrogen inputs primarily associated with nitrogen fixation on forest lands.