{"title":"惯性框架中朗缪尔湍流的缩放和流动结构","authors":"Yun Chang, Alberto Scotti","doi":"10.1175/jpo-d-23-0258.1","DOIUrl":null,"url":null,"abstract":"\nThis paper provides a framework that unifies the characteristics of Langmuir turbulence, including the vortex force effect, velocity scalings, vertical flow structure, and crosswind spacing between surface streaks. The widely accepted CL2 mechanism is extended to explain the observed maximum alongwind velocity and downwelling velocity below the surface. Balancing the extended mechanism in the Craik-Leibovich equations, the scalings for the along-wind velocity u, cross-wind velocity v, and vertical velocity w are formulated as Here, Uf is the friction velocity, Us is the Stokes drift on the surface, and La = (Uf /Us)1/2 is the Langmuir number. Simulations using the Stratified Ocean Model with Adaptive Refinement in Large Eddy Simulation mode (LES-SOMAR) validate the scalings and reveal physical similarity for velocity and crosswind spacing. The horizontally averaged velocity along the wind ū/U on the surface grows with time, whereas v/V and w/W are confined. The root mean square (rms) of w peaks at wrms/W ≈ 0.85 at a depth of 1.3Zs, where Zs is the e-folding scale of the Stokes drift. The crosswind spacing L grows linearly with time but is finally limited by the depth of the water H, with maximum L/H = 3.3. This framework agrees with measurement collected in six different field campaigns.","PeriodicalId":56115,"journal":{"name":"Journal of Physical Oceanography","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Scaling and flow structure of Langmuir turbulence in inertial frames\",\"authors\":\"Yun Chang, Alberto Scotti\",\"doi\":\"10.1175/jpo-d-23-0258.1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\nThis paper provides a framework that unifies the characteristics of Langmuir turbulence, including the vortex force effect, velocity scalings, vertical flow structure, and crosswind spacing between surface streaks. The widely accepted CL2 mechanism is extended to explain the observed maximum alongwind velocity and downwelling velocity below the surface. Balancing the extended mechanism in the Craik-Leibovich equations, the scalings for the along-wind velocity u, cross-wind velocity v, and vertical velocity w are formulated as Here, Uf is the friction velocity, Us is the Stokes drift on the surface, and La = (Uf /Us)1/2 is the Langmuir number. Simulations using the Stratified Ocean Model with Adaptive Refinement in Large Eddy Simulation mode (LES-SOMAR) validate the scalings and reveal physical similarity for velocity and crosswind spacing. The horizontally averaged velocity along the wind ū/U on the surface grows with time, whereas v/V and w/W are confined. The root mean square (rms) of w peaks at wrms/W ≈ 0.85 at a depth of 1.3Zs, where Zs is the e-folding scale of the Stokes drift. The crosswind spacing L grows linearly with time but is finally limited by the depth of the water H, with maximum L/H = 3.3. This framework agrees with measurement collected in six different field campaigns.\",\"PeriodicalId\":56115,\"journal\":{\"name\":\"Journal of Physical Oceanography\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-05-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Physical Oceanography\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1175/jpo-d-23-0258.1\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"OCEANOGRAPHY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physical Oceanography","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1175/jpo-d-23-0258.1","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"OCEANOGRAPHY","Score":null,"Total":0}
引用次数: 0
摘要
本文提供了一个统一朗缪尔湍流特征的框架,包括涡力效应、速度标度、垂直流结构和表面条纹之间的横风间距。对广为接受的 CL2 机制进行了扩展,以解释观测到的最大顺风速度和表面以下的下沉速度。在克雷克-莱博维奇方程中平衡扩展机制,顺风速度 u、横风速度 v 和垂直速度 w 的标度公式为 Uf 为摩擦速度,Us 为表面斯托克斯漂移,La = (Uf /Us)1/2 为朗缪尔数。利用大涡模拟模式下的自适应细化分层海洋模式(LES-SOMAR)进行的模拟验证了这些标度,并揭示了速度和横风间距的物理相似性。沿海面风向的水平平均速度 ū/U 随时间增长,而 v/V 和 w/W 则受到限制。在深度为 1.3Zs 时,w 的均方根(rms)达到峰值,即 wrms/W ≈ 0.85,其中 Zs 是斯托克斯漂移的电子折叠尺度。横风间距 L 随时间线性增长,但最终受到水深 H 的限制,最大 L/H = 3.3。这一框架与在六次不同的实地测量中收集到的数据相吻合。
Scaling and flow structure of Langmuir turbulence in inertial frames
This paper provides a framework that unifies the characteristics of Langmuir turbulence, including the vortex force effect, velocity scalings, vertical flow structure, and crosswind spacing between surface streaks. The widely accepted CL2 mechanism is extended to explain the observed maximum alongwind velocity and downwelling velocity below the surface. Balancing the extended mechanism in the Craik-Leibovich equations, the scalings for the along-wind velocity u, cross-wind velocity v, and vertical velocity w are formulated as Here, Uf is the friction velocity, Us is the Stokes drift on the surface, and La = (Uf /Us)1/2 is the Langmuir number. Simulations using the Stratified Ocean Model with Adaptive Refinement in Large Eddy Simulation mode (LES-SOMAR) validate the scalings and reveal physical similarity for velocity and crosswind spacing. The horizontally averaged velocity along the wind ū/U on the surface grows with time, whereas v/V and w/W are confined. The root mean square (rms) of w peaks at wrms/W ≈ 0.85 at a depth of 1.3Zs, where Zs is the e-folding scale of the Stokes drift. The crosswind spacing L grows linearly with time but is finally limited by the depth of the water H, with maximum L/H = 3.3. This framework agrees with measurement collected in six different field campaigns.
期刊介绍:
The Journal of Physical Oceanography (JPO) (ISSN: 0022-3670; eISSN: 1520-0485) publishes research related to the physics of the ocean and to processes operating at its boundaries. Observational, theoretical, and modeling studies are all welcome, especially those that focus on elucidating specific physical processes. Papers that investigate interactions with other components of the Earth system (e.g., ocean–atmosphere, physical–biological, and physical–chemical interactions) as well as studies of other fluid systems (e.g., lakes and laboratory tanks) are also invited, as long as their focus is on understanding the ocean or its role in the Earth system.