Characterization and Parametrization of Reynolds Stress and Turbulent Heat Flux in the Stably-Stratified Lower Arctic Troposphere Using Aircraft Measurements

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• 作者：Amir A. Aliabadi ; Ralf M. Staebler ; Michael Liu…
• 关键词：Arctic ; Countergradient flux ; Parametrization schemes ; Planetary boundary layer ; Subgrid ; scale turbulence
• 刊名：Boundary-Layer Meteorology
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：161
• 期：1
• 页码：99-126
• 全文大小：5,618 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Meteorology and Climatology
  Atmospheric Protection, Air Quality Control and Air Pollution
  
• 出版者：Springer Netherlands
• ISSN：1573-1472
• 卷排序：161

文摘

Aircraft measurements are used to characterize properties of clear-air turbulence in the lower Arctic troposphere. For typical vertical resolutions in general circulation models, there is evidence for both downgradient and countergradient vertical turbulent transport of momentum and heat in the mostly statically stable conditions within both the boundary layer and the free troposphere. Countergradient transport is enhanced in the free troposphere compared to the boundary layer. Three parametrizations are suggested to formulate the turbulent heat flux and are evaluated using the observations. The parametrization that accounts for the anisotropic nature of turbulence and buoyancy flux predicts both observed downgradient and countergradient transport of heat more accurately than those that do not. The inverse turbulent Prandtl number is found to only weakly decrease with increasing gradient Richardson number in a statistically significant way, but with large scatter in the data. The suggested parametrizations can potentially improve the performance of regional and global atmospheric models.