Identification

Title

A numerical investigation on the formation of the stalling of the cross-polar jet in midnight thermospheric winds

Abstract

Thermospheric winds usually flow from noon to the midnight inside the polar cap and spill further equatorward around midnight, due to the combined effects of solar radiation-driven pressure gradient and ion drag. Recent observations from the Scanning Doppler Imager at Poker Flat indicated a distinct feature that the cross-polar jet stalls over short horizontal distances around the magnetic midnight. However, the mechanisms responsible for the occurrence of stalling have not been well understood. In this study, we investigated the physical mechanisms of the stalling of the cross-polar jet based on the Thermosphere Ionosphere Electrodynamics General Circulation Model simulations. The model reproduced the general stalling features at midnight over a short horizontal distance. The occurrence of stalling is mainly associated with Joule heating, which enhances the neutral temperature and then turns winds poleward by the pressure gradient force, and ion-neutral coupling, which drags neutral winds westward in the pre magnetic local time midnight sector and contributes to the poleward turning of the meridional winds by the poleward Coriolis force. Meanwhile, the stalling region has a large latitudinal range and depends on the interplanetary magnetic field (IMF). Under southward IMF Bz, thermospheric winds are likely to stall at lower latitudes associated with strong ionospheric convection. The stalling of the cross-polar jet in the midnight thermospheric winds has UT/longitude dependence, which could be associated with the orientation of the alignment of geomagnetic and geographic poles with respect to ionospheric convection.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7tb1c0z

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

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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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Dataset reference date

date type

publication

effective date

2023-12-04T00:00:00Z

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Conformity

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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