{"title":"用随机建模方法捕捉湍流Ekman-Stokes边界层的特征","authors":"M. Klein, H. Schmidt","doi":"10.5194/asr-20-55-2023","DOIUrl":null,"url":null,"abstract":"Abstract. Atmospheric boundary layers (ABLs) exhibit transient processes on various time scales that range from a few days down to seconds, with a scale separation of the large-scale forcing and the small-scale turbulent response.\nOne of the standing challenges in modeling and simulation of ABLs is a physically based representation of complex multiscale boundary layer dynamics.\nIn this study, an idealized time-dependent ABL, the so-called Ekman–Stokes boundary layer (ESBL), is considered as a simple model for the near-surface flow in the mid latitudes and polar regions.\nThe ESBL is driven by a prescribed temporal modulation of the bulk–surface velocity difference.\nA stochastic one-dimensional turbulence (ODT) model is applied to the ESBL as standalone tool that aims to resolve all relevant scales of the flow along a representative vertical coordinate.\nIt is demonstrated by comparison with reference data that ODT is able to capture relevant features of the time-dependent boundary layer flow.\nThe model predicts a parametric enhancement of the bulk–surface coupling in the event of a boundary layer resonance when the flow is forced with the local Coriolis frequency.\nThe latter reproduces leading order effects of the critical latitudes.\nThe model results suggest that the bulk flow decouples from the surface for high forcing frequencies due to a relative increase in detached residual turbulence.\n","PeriodicalId":30081,"journal":{"name":"Advances in Science and Research","volume":"101 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Capturing features of turbulent Ekman–Stokes boundary layers with a stochastic modeling approach\",\"authors\":\"M. Klein, H. Schmidt\",\"doi\":\"10.5194/asr-20-55-2023\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Atmospheric boundary layers (ABLs) exhibit transient processes on various time scales that range from a few days down to seconds, with a scale separation of the large-scale forcing and the small-scale turbulent response.\\nOne of the standing challenges in modeling and simulation of ABLs is a physically based representation of complex multiscale boundary layer dynamics.\\nIn this study, an idealized time-dependent ABL, the so-called Ekman–Stokes boundary layer (ESBL), is considered as a simple model for the near-surface flow in the mid latitudes and polar regions.\\nThe ESBL is driven by a prescribed temporal modulation of the bulk–surface velocity difference.\\nA stochastic one-dimensional turbulence (ODT) model is applied to the ESBL as standalone tool that aims to resolve all relevant scales of the flow along a representative vertical coordinate.\\nIt is demonstrated by comparison with reference data that ODT is able to capture relevant features of the time-dependent boundary layer flow.\\nThe model predicts a parametric enhancement of the bulk–surface coupling in the event of a boundary layer resonance when the flow is forced with the local Coriolis frequency.\\nThe latter reproduces leading order effects of the critical latitudes.\\nThe model results suggest that the bulk flow decouples from the surface for high forcing frequencies due to a relative increase in detached residual turbulence.\\n\",\"PeriodicalId\":30081,\"journal\":{\"name\":\"Advances in Science and Research\",\"volume\":\"101 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-07-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advances in Science and Research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.5194/asr-20-55-2023\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"Earth and Planetary Sciences\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Science and Research","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.5194/asr-20-55-2023","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
Capturing features of turbulent Ekman–Stokes boundary layers with a stochastic modeling approach
Abstract. Atmospheric boundary layers (ABLs) exhibit transient processes on various time scales that range from a few days down to seconds, with a scale separation of the large-scale forcing and the small-scale turbulent response.
One of the standing challenges in modeling and simulation of ABLs is a physically based representation of complex multiscale boundary layer dynamics.
In this study, an idealized time-dependent ABL, the so-called Ekman–Stokes boundary layer (ESBL), is considered as a simple model for the near-surface flow in the mid latitudes and polar regions.
The ESBL is driven by a prescribed temporal modulation of the bulk–surface velocity difference.
A stochastic one-dimensional turbulence (ODT) model is applied to the ESBL as standalone tool that aims to resolve all relevant scales of the flow along a representative vertical coordinate.
It is demonstrated by comparison with reference data that ODT is able to capture relevant features of the time-dependent boundary layer flow.
The model predicts a parametric enhancement of the bulk–surface coupling in the event of a boundary layer resonance when the flow is forced with the local Coriolis frequency.
The latter reproduces leading order effects of the critical latitudes.
The model results suggest that the bulk flow decouples from the surface for high forcing frequencies due to a relative increase in detached residual turbulence.