Capturing features of turbulent Ekman–Stokes boundary layers with a stochastic modeling approach
- 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 theAtmospheric 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.…
Author: | Marten KleinORCiD, Heiko SchmidtORCiD |
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URL: | https://asr.copernicus.org/articles/20/55/2023/ |
DOI: | https://doi.org/10.5194/asr-20-55-2023 |
ISSN: | 1992-0636 |
ISSN: | 1992-0628 |
Title of the source (English): | Advances in Science and Research |
Document Type: | Scientific journal article peer-reviewed |
Language: | English |
Year of publication: | 2023 |
Tag: | one-dimensional turbulence; periodic forcing; rotating flow; stochastic modeling; turbulent boundary layer |
Volume/Year: | 20 |
First Page: | 55 |
Last Page: | 64 |
Comment: | This article is part of the special issue “EMS Annual Meeting: European Conference for Applied Meteorology and Climatology 2022”. |
Comment: | This research is supported by the German Federal Government, the Federal Ministry of Education and Research and the State of Brandenburg within the framework of the joint project EIZ: Energy Innovation Center with funds from the Structural Development Act (Strukturstärkungsgesetz) for coal-mining regions. |
Fundername (not EU): | Bundesministerium für Bildung und Forschung |
Project number (not EU): | 85056897; 03SF0693A |
Way of publication: | Open Access |
Faculty/Chair: | Fakultät 3 Maschinenbau, Elektro- und Energiesysteme / FG Numerische Strömungs- und Gasdynamik |
Zentrale Einrichtungen / Energie-Innovationszentrum / Scientific Computing Lab |