Seasonal dynamics of internal waves governed by stratification stability and wind: Analysis of high‐resolution observations from the Dead Sea
Seasonal dynamics of internal waves governed by stratification stability and wind: Analysis of high‐resolution observations from the Dead Sea
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受层化稳定性和风控制的内波季节动态：死海高分辨率观测结果分析
DOI：
10.1002/lno.11156
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发表时间：
2019
影响因子：
4.5
通讯作者：
Lensky, Nadav G.
中科院分区：
文献类型：
--
作者：
Arnon, Ali;Brenner, Steve;Selker, John S.;Gertman, Isaac;Lensky, Nadav G.
层结湖泊内波受季节性层结和风强迫的影响。我们通过对死海的高分辨率观测和模型模拟研究了内波的季节动力学。两层流体静力学模型提供了测得的温跃层深度和湖平面振荡之间的高度相关性。在季节上，温跃层波动的幅度与水层之间的密度差相关;在春季/秋季层化较弱时观察到最大波动，在层化充分发展的仲夏观察到中等至弱波动。表面波和内波以约0.5 m s−1的速度沿海岸沿着逆时针方向传播。观测到的风的功率谱以及测量和模拟的湖面和温跃层深度在夏季表现出明显的昼夜周期，这表明强迫的昼夜变化的风。在春季和秋季，当水柱稳定性减弱时，除了昼夜模式外，还出现了较长的风周期。因此，湖平面和温跃层深度波动的响应频率较低。在秋季，较长的风周期接近湖的第一个垂直正常模式，这表明内波的共振放大可以解释所观察到的较低的频率响应的水平和温跃层振荡。在过去的四十年里，由于人为引水，层结稳定性降低，湖平面下降和盐度增加，导致内波振幅和周期增加。
Internal waves in stratified lakes are affected by the seasonally varying stratification and the wind forcing. We studied the seasonal dynamics of internal waves by means of high‐resolution observations and model simulations for the Dead Sea. A two‐layer hydrostatic model provided high correlations between measured thermocline depth and the lake level oscillations. Seasonally, the amplitude of the thermocline fluctuations were anticorrelated with the density difference between the water layers; the largest fluctuations were observed when stratification was weak in spring/fall and moderate to weak fluctuations in mid‐summer when stratification was fully developed. The surface and the internal waves propagated counterclockwise along the coasts at a speed of ~0.5 m s−1. Power spectra of the observed wind as well as the measured and simulated lake level and thermocline depth show a pronounced diurnal period during summer, suggesting forcing by the diurnally varying wind. During spring and fall, when the water column stability diminishes, a hint of longer wind periods appear in addition to the diurnal mode. Accordingly, the lake level and thermocline depth fluctuations respond at lower frequencies. In the fall, the longer wind periods are close to the lake's first vertical normal mode, suggesting that resonant amplification of the internal waves may explain the observed lower frequency response of the level and thermocline oscillations. Reduction of the stratification stability originating from anthropogenic water diversion over the past four decades, associated with lake level decline and salinity increase, have led to increases of internal waves amplitude and periods.
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影响因子：
6.4
作者：
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影响因子：
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DOI：
--
发表时间：
1953
期刊：
Schweizerische Zeitschrift für Hydrologie
影响因子：
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作者：
C. Mortimer
通讯作者：
C. Mortimer
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DOI：
--
发表时间：
2017
期刊：
影响因子：
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作者：
I. Sirota;Y. Enzel;N. Lensky
通讯作者：
N. Lensky
影响因子：
64.8
作者：
GENIN, A;LAZAR, B;BRENNER, S
通讯作者：
BRENNER, S