Identification

Title

A comparison of the effects of CIR- and CME-induced geomagnetic activity on thermospheric densities and spacecraft orbits: Case studies

Abstract

So far studies of the effect of geomagnetic storms on thermospheric density and satellite orbits have been mainly focused on severe storm events caused by Coronal Mass Ejections (CMEs). The effect of long-duration, less intensive geomagnetic activity that is related to Corotating Interaction Regions (CIRs) has not been fully explored. In this paper, thermospheric densities observed by the CHAMP satellite and its orbit parameters are used to compare the responses of satellite orbital altitudes to geomagnetic activity caused by CMEs and CIRs. Three cases are investigated in this paper. Each case had one or two CME storm(s) and one CIR storm that occurred successively. In these cases three out of four CME-storms were stronger than their corresponding CIR-storms, but the durations of these CME-storms were much shorter. Thus, the satellite orbit decay rates during CME-storms are usually larger than those during CIR-storms. However, CIR-storms often had long durations that perturbed satellite orbits for longer periods of time. As a result, the total thermospheric density changes and satellite orbit decays for the entire periods of CIR-storms were much greater than those for the CME-storms since these parameters were related to the total energy deposited into the thermosphere/ionosphere, which depended on both the strengths and the durations of the storms. This study indicates that more attention should be paid to CIR storms during the declining phase and during solar minimum, when they occur frequently and periodically. Whereas fewer CME storms occurring under these conditions. We also found that changes in thermospheric densities and CHAMP orbit decay rates correlated well with variations of auroral hemispheric power, but lagging by about 3-6 h.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7n87bh9

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

2012-08-16T00:00:00Z

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