Identification

Title

Large-eddy simulation of the stratocumulus-capped boundary layer with explicit filtering and reconstruction turbulence modeling

Abstract

Large-eddy simulation (LES) has been an essential tool in the development of theory and parameterizations for clouds, but when applied to stratocumulus clouds under sharp temperature inversions, many LES models produce an unrealistically thin cloud layer and a decoupled boundary layer structure. Here, explicit filtering and reconstruction are used for simulation of stratocumulus clouds observed during the first research flight (RF01) of the Second Dynamics and Chemistry of the Marine Stratocumulus field study (DYCOMS II). The dynamic reconstruction model (DRM) is used within an explicit filtering and reconstruction framework, partitioning subfilter-scale motions into resolvable subfilter scales (RSFSs) and unresolvable subgrid scales (SGSs). The former are reconstructed, and the latter are modeled. Differing from traditional turbulence models, the reconstructed RSFS stress/fluxes can produce backscatter of turbulence kinetic energy (TKE) and, importantly, turbulence potential energy (TPE). The modeled backscatter reduces entrainment at the cloud top and, meanwhile, strengthens resolved turbulence through preserving TKE and TPE, resulting in a realistic boundary layer with an adequate amount of cloud water and vertically coupled turbulent eddies. Additional simulations are performed in the terra incognita, when the grid spacing of a simulation becomes comparable to the size of the most energetic eddies. With 20-m vertical and 1-km horizontal grid spacings, simulations using DRM provide a reasonable representation of bulk properties of the stratocumulus-capped boundary layer.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7pv6p2d

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

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2018-02-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

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