Identification

Title

Zonally symmetric oscillations of the thermosphere at planetary wave periods

Abstract

New mechanisms for imposing planetary wave (PW) variability on the ionosphere-thermosphere system are discovered in numerical experiments conducted with the National Center for Atmospheric Research thermosphere-ionosphere-electrodynamics general circulation model. First, it is demonstrated that a tidal spectrum modulated at PW periods (3-20days) entering the ionosphere-thermosphere system near 100km is responsible for producing +/- 40m/s and +/- 10-15K PW period oscillations between 110 and 150km at low to middle latitudes. The dominant response is broadband and zonally symmetric (i.e.,"S0") over a range of periods and is attributable to tidal dissipation; essentially, the ionosphere-thermosphere system vacillates in response to dissipation of the PW-modulated tidal spectrum. In addition, some specific westward propagating PWs such as the quasi-6-day wave are amplified by the presence of the tidal spectrum; the underlying mechanism is hypothesized to be a second-stage nonlinear interaction. The S0 total neutral mass density (rho) response at 325km consists of PW period fluctuations of order +/- 3-4%, roughly equivalent to the day-to-day variability associated with low-level geomagnetic activity. The variability in rho over short periods (similar to< 9days) correlates with temperature changes, indicating a response of hydrostatic origin. Over longer periods is also controlled by composition and mean molecular mass. While the upper-thermosphere impacts are modest, they do translate to more significant changes in the F region ionosphere.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7028vc4

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

2018-05-01T00:00:00Z

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