Observations of Nonlinear Internal Wave Run-Up to the Surfzone
Observations of Nonlinear Internal Wave Run-Up to the Surfzone
复制标题
非线性内波爬升至表面区的观测
DOI：
10.1175/jpo-d-17-0210.1
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发表时间：
2016
影响因子：
3.5
通讯作者：
E. Terrill
中科院分区：
文献类型：
--
作者：
G. Sinnett;F. Feddersen;A. Lucas;G. Pawlak;E. Terrill
摘要利用致密热敏电阻阵列和ADCP观测了8m深度到岸边的非线性内波的跨岸演化过程。恒温振荡以不同的周期横跨大部分水柱。有时，NLIW传播到冲浪区，在5分钟内使温度降低1℃≈。当层结较强时，温度变率较强，在18~6m深度的半日周期和调和周期内温度变率较强且一致。当层结减弱时，温度变率降低，并且在18到6米深度之间在所有频率下都是不一致的。在8m深度，近岸相干传播的近海事件伴随着高达1.7C的快速降温(ΔT)，锋面速度在1.47.4 cm S−1之间，入射角在−5°~23°之间。四个事件的前沿位置、ΔT和两层相当高度zIW被向上跟踪，直到传播终止。前锋位置随时间呈二次曲线变化，归一化ΔT和ZIW均下降，呈线性衰减。
AbstractThe cross-shore evolution of nonlinear internal waves (NLIWs) from 8-m depth to shore was observed by a dense thermistor array and ADCP. Isotherm oscillations spanned much of the water column at a variety of periods. At times, NLIWs propagated into the surfzone, decreasing temperature by ≈1°C in 5 min. When stratification was strong, temperature variability was strong and coherent from 18- to 6-m depth at semidiurnal and harmonic periods. When stratification weakened, temperature variability decreased and was incoherent between 18- and 6-m depth at all frequencies. At 8-m depth, onshore coherently propagating NLIW events had associated rapid temperature drops (ΔT) up to 1.7°C, front velocity between 1.4 and 7.4 cm s−1, and incidence angles between −5° and 23°. Front position, ΔT, and two-layer equivalent height zIW of four events were tracked upslope until propagation terminated. Front position was quadratic in time, and normalized ΔT and zIW both decreased, collapsing as a linearly decaying funct...