Identification

Title

The longitudinal variations of upper thermospheric zonal winds observed by the CHAMP satellite at low and midlatitudes

Abstract

In this work, we investigate the longitudinal patterns of thermospheric zonal winds (similar to 400 km) and their seasonal and solar activity dependence using CHAllenging Minisatellite Payload cross-track wind data and Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) simulations. CHAllenging Minisatellite Payload data show that there are large longitudinal variations in thermospheric zonal winds. These longitudinal variations do not have significant solar activity dependence. In the northern hemisphere at low and middle latitudes, the daytime zonal winds are more westward between -90 degrees and 90 degrees longitudes and more eastward at other longitudes. The nighttime zonal wind direction with pattern is opposite to that in the daytime. In the southern hemisphere at low and middle latitudes, the local time variation of the longitudinal wind structure, including positive and negative peak locations, is almost the reverse of that in the northern hemisphere. Thus, the zonal wind patterns also show great hemispheric asymmetry. In addition, the longitudinal patterns of zonal winds in both hemispheres show seasonal variations. The longitudinal patterns during the June solstice are significantly different from those in other seasons. These observational results are well reproduced in TIEGCM simulations. To elucidate the physical processes responsible for the observed and simulated longitudinal patterns of the zonal winds, the TIEGCM is also run for different geomagnetic field configurations. A comparison between the TIEGCM results shows that geomagnetic field structure is the main cause of the large longitudinal variations of thermospheric zonal winds and their local time, hemispheric asymmetry, and seasonal changes at low and middle latitudes.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7x63qzz

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

2018-11-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

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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