Identification

Title

Gray zone partitioning functions and parameterization of turbulence fluxes in the convective atmospheric boundary layer

Abstract

Here, we present the first attempt to fully represent three-dimensional turbulence fluxes in the "Terra Incognita" or the gray zone in other words. In order to derive partitioning functions, representing the partitioning between subgrid and total fluxes, we make use of high-resolution large-eddy simulations (LES), which are performed with the Weather Research and Forecasting (WRF) model. LES computations are performed for various levels of convective instability, ranging from pure buoyant to strongly sheared convection. Then, the resulting reference-LES fields are successively coarse grained from its original microscale grid spacing ( Delta=50 m) up to typical mesoscale grid spacings ( Delta=3 km). The given process is applied by means of an advanced filter, that is, the Butterworth filter. It enables a clear scale-specific filtering that results in a more controlled energy transition from lower to higher wavenumbers, unlike the drawbacks of current filters in use. Finally, we parameterize the subgrid scale (SGS) partitioning functions of 10 SGS turbulence quantities: momentum fluxes (tau(ij), six terms), heat fluxes (q(j), three terms), and turbulence kinetic energy (k). Turbulence partitioning relations are parameterized in a scale-aware, stability-dependent, and height-dependent form, using the sigmoidal Gompertz function. Thus, the new gray zone model provides a framework that bridges the mesoscale and microscale limits and that is suitable for the development of next generation three-dimensional, multiscale turbulence parameterization methods or planetary boundary layer schemes.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d70g3pgn

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

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Temporal reference

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Dataset reference date

date type

publication

effective date

2020-11-27T00:00:00Z

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Conformity

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Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact