Identification

Title

To which degree do the details of stochastic perturbation schemes matter for convective-scale and mesoscale perturbation growth?

Abstract

This study compares the impacts of two stochastic parameterization schemes in a convective-scale model. The implementation of the physically based stochastic perturbation (PSP) scheme in the Weather Research and Forecasting (WRF) Model represents uncertainties arising from unresolved boundary layer processes due to the finite grid size. Uncertainty in the microphysical processes is represented by the stochastic parameter perturbation applied to the microphysics parameterization (SPPMP) scheme. We examine the regime dependence of the impacts with 48-h forecasts of days with weakly and strongly forced convection, as well as winter storms. Early in the forecasts, the two stochastic parameterizations have different effects. The PSP scheme responds to boundary layer turbulence and produces strong perturbations that grow in phase with the diurnal cycle of convection. In regions with existing precipitation, SPPMP produces perturbations that grow more slowly with lead time, independent of the time of day. Perturbation growth in the PSP experiments is stronger for convective weather and can increase the total precipitation by triggering new convection, but SPPMP can dominate when precipitation occurs under stable conditions at night or in winter storms. The differences between the two schemes are relatively short-lived, and within a day of simulation, the amplitude and structure of differences introduced by both schemes are similar. This is found to be associated with saturation of perturbation growth on small scales (up to about 50 km). The locations and amplitudes of upscale perturbation growth appear to be determined by the larger-scale dynamics, independent of the details of the stochastic physics.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d7pc36th

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

2025-03-01T00:00:00Z

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