Modelling of Stably Stratified Atmospheric Boundary Layers with Varying Stratifications

• A recently developed explicit algebraic Reynolds-stress (EARS) model is validated for an idealized representation of the night-time high-latitude stably stratified atmospheric boundary layer. The simulations are made with four surface cooling rates that result in weakly to moderately stratified stable boundary layers. The predictions of the EARS model are compared to high-resolution large-eddy simulations (LES) of Sullivan et al. (J Atmos Sci 73(4):1815–1840, 2016). First- and second-order statistics are shown to be well predicted by the EARS model. The EARS model also predicts the horizontal turbulent fluxes and turbulence anisotropy and these compare well with the LES results. The sensitivity to the model coefficients is studied by comparing the EARS model results with LES results. Finally, we propose a new scaling for the production of turbulence kinetic energy and show that the EARS model captures the essential trends of the LES results for different cooling rates.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Nyckelord

GABLS1

Reynolds-stress model

Scaling law

Stably stratified atmosphere

Turbulence parametrization

Atmospheric movements

Atmospheric thermodynamics

Boundary layer flow

Cooling

Horizontal wells

Kinetic energy

Kinetics

Large eddy simulation

Reynolds number

Turbulence

High resolution

Model coefficient

Reynolds stress

Second order statistics

Stable boundary layer

Surface cooling

Turbulence anisotropy

Turbulence kinetic energy

Atmospheric boundary layer

boundary layer

computer simulation

numerical model

stratified flow

turbulent flow

Publikations- och innehållstyp

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