Identification

Title

Climatology of the middle atmosphere in LMDz: Impact of source-related parameterizations of gravity wave drag

Abstract

Gravity wave (GW) parameterizations control the mean state and variability of the middle atmosphere in present-day climate models. The most recent parameterizations relate the GWs to their nonorographic sources (fronts and convection), which impacts the annual cycle of the GW drag, and makes the GWs respond to the changing climate. These issues are addressed using the Laboratoire de Meteorologie Dynamique Zoom (LMDz) climate model, showing first a climatology of the middle atmosphere in the presence of nonorographic GW sources. The model performance is comparable with that documented in earlier model versions, illustrating that there are no major difficulties in including nonorographic GW sources in models. A twin experiment where the parameterization of GWs has no link with the nonorographic sources is also performed. Provided that in the twin experiment the launched GW stress is very intermittent, its climatology compares reasonably well with the experiment with sources. This illustrates that GW intermittency is a key factor in GW dynamics, but also that the dynamical filtering of the waves by the background flow strongly modulates the significance of the sources. Some impacts of having GW sources on the annual cycle of the zonal mean circulation of the middle atmosphere are nevertheless evident. In a changing climate, the impact of introducing GW sources also seems to be substantially mitigated by the dynamical filtering. The experiments and diagnostics are nevertheless limited in time and to the averaged climatology, respectively, calling for longer tests to measure the impacts on the atmospheric low frequency variability.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7s1849b

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

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Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2016-12-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

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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