Identification

Title

Westward traveling planetary wave events in the lower thermosphere during solar minimum conditions simulated by SD-WACCM-X

Abstract

We present numerical simulations with the Whole Atmosphere Community Climate Model, eXtended version (WACCM-X), whose dynamics is constrained by atmospheric specifications during recent and historical solar minimum conditions. The focus of this study is to describe how various dynamical conditions of boreal winter affect the dynamical behavior of the lower thermosphere (90–150 km). The model simulations are carried out during solar minimum conditions and the results shown here discuss the period January 1–March 30 for five years (1995, 1996, 2008, 2009, and 2010). These years were selected because they include boreal winters without stratospheric warming (1995 and 1996), with modest or normal stratospheric warming (2008 and 2010), and with a large and persistent stratospheric warming (2009). The ultimate goal of this study is to encapsulate the statistically significant dynamical behavior due to westward propagating, planetary-scale waves (wavenumber 1 and wavenumber 2) in the lower thermosphere that are associated with different stratospheric conditions. To this end we show that the westward zonal acceleration above about 80 km is by and large described by traveling waves with periods between 2 and 10 days. We show that the momentum carried by these waves is unlikely to affect directly the momentum budget of the extra-tropical lower thermosphere, where instead gravity-wave drag figures prominently. However, at the times leading to and following large stratospheric disturbances, we show prominent meridional propagation of wave activity from the mid-latitudes toward the tropics. In combination with strong eastward meridional wind shear, our results provide further evidence that such equatorward propagation of momentum in the lower thermosphere might influence the amplitude of equatorially trapped tides.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d78053kc

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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South bounding latitude

Temporal reference

Temporal extent

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End position

Dataset reference date

date type

publication

effective date

2014-11-01T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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version of format

Constraints related to access and use

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Use constraints

publisher

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