Ocean nutrient pathways associated with the passage of a storm
Ocean nutrient pathways associated with the passage of a storm
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DOI：
10.1002/2015gb005097
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发表时间：
2015-08-01
影响因子：
5.2
通讯作者：
Henson, Stephanie
中科院分区：
文献类型：
--
作者：
Rumyantseva, Anna;Lucas, Natasha;Henson, Stephanie
影响海洋表层动力学和初级生产的风暴经常发生在开阔的北大西洋。在这项研究中，我们使用一个跨学科的数据集收集在该地区量化与风暴事件相关的两个途径的营养供应：夹带的营养物质在一段时间的大风强迫和随后的剪切尖峰在密度跃层由于风暴产生的惯性流与风的相互作用。风暴后近地层硝酸盐浓度的增加（约20 mmol m（-2））主要是由第一种途径驱动的：风暴期间营养盐的入侵。风暴后的惯性流和表面风应力的对齐造成的剪切不稳定性在海洋密度跃层，形成的第二条途径营养输送到真光层。在排列期间，通过密度跃层的高湍流硝酸盐通量的脉冲（高达1 mmol m（-2）d（-1）;大约比背景通量高25倍）被检测到。然而，由于脉冲持续时间短，风暴后供应的影响比风暴期间低一个数量级。累积起来，风暴通道相当于冬季对流提供的硝酸盐的2.5-5%，并有显着的影响相比，以前报告的（子）中尺度动力学在该地区。由于风暴频繁发生，它们可以成为当地养分收支的重要组成部分。
Storms that affect ocean surface layer dynamics and primary production are a frequent occurrence in the open North Atlantic Ocean. In this study we use an interdisciplinary data set collected in the region to quantify nutrient supply by two pathways associated with a storm event: entrainment of nutrients during a period of high wind forcing and subsequent shear spiking at the pycnocline due to interactions of storm-generated inertial currents with wind. The poststormincrease in surface layer nitrate (by similar to 20mmol m(-2)) was predominantly driven by the first pathway: nutrient intrusion during the storm. Alignment of poststorm inertial currents and surface wind stress caused shear instabilities at the ocean pycnocline, forming the second pathway for nutrient transport into the euphotic zone. During the alignment period, pulses of high-turbulence nitrate flux through the pycnocline (up to 1mmol m(-2)d(-1); approximately 25 times higher than the background flux) were detected. However, the impact of the poststorm supply was an order of magnitude lower than during the storm due to the short duration of the pulses. Cumulatively, the storm passage was equivalent to 2.5-5% of the nitrate supplied by winter convection and had a significant effect compared to previously reported (sub)mesoscale dynamics in the region. As storms occur frequently, they can form an important component in local nutrient budgets.