Internal wave weather in a stratified lake
Internal wave weather in a stratified lake
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分层湖中的内波天气
DOI：
10.4319/lo.1998.43.8.1780
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
J. Imberger
中科院分区：
文献类型：
--
作者：
Â. Saggio;J. Imberger
利用在日本琵琶湖强层化期间收集的热电阻链数据来确定水柱对风强迫的响应的性质。在三维数值模拟中再现了湖中盆地尺度波浪的演化过程，并基于热电阻链记录的频谱分析讨论了内波谱的时间变异性。在本报告所述期间，与三个台风过境有关的强风激发了盆地尺度的开尔文波和庞卡雷波，这些波与湖泊地形和非线性效应相互作用，产生高频内波。温度信号的时频分析表明，内波谱的ω−2斜率很可能是由通过波导的具有高间歇性的波群组成的结果。在强风事件后观察到的内波能量的快速衰减似乎主要是由于湖泊坡度边界的高耗散。
Thermistor chain data collected in Lake Biwa (Japan) during a period of strong stratification were used to determine the nature of the water column response to wind forcing. The evolution of the basin‐scale waves in the lake were reproduced in three‐dimensional numerical simulations and the time variability of the internal wave spectrum is discussed based on spectral analysis of the thermistor chain records. Severe winds associated with the passage of three typhoons during the sampling period excited basin‐scale Kelvin and Poincaré waves, which, by interaction with the topography of the lake and non‐linear effects, generate trains of high‐frequency internal waves. Time‐frequency analysis of the temperature signals suggests that the ω−2 slope of the internal wave spectrum is probably the result of the composition of groups of waves with high intermittence travelling through the wave guide. The observed rapid decay of internal wave energy after severe wind events seemed to be due mostly to high dissipation at the sloping boundaries of the lake.