Identification

Title

Modelling seasonal and diurnal effects on the magnetospheric and ionospheric plasma dynamics

Abstract

The present study focuses on a modeling of the seasonal and diurnal effects on the dynamics of the coupled magnetosphere-ionosphere system under different solar illumination conditions, to try to reproduce some of the observations concerning the region 2 (R2) field-aligned currents (FAC). This is performed by introducing in the Ionosphere Magnetosphere Model (IMM) the Earth's rotation axis tilt, the dipole axis tilt and an eccentric dipole. The simulated patterns of the R2 FAC agree rather well with the observations. In particular the dayside FAC density is two times greater in the summer hemisphere than in the winter one. The results show that seasonal tilt of the dipole axis affects the distributions of the Pedersen conductances and FAC by 28.5-52.8% and do not have much influence on the distribution of the magnetospheric plasma, which is modified by only 0.9-3.9%. The diurnal variations induced by the tilt of the dipole axis are of the same order of magnitude, 5.5-29% for the Pedersen conductances and FAC and 0.4–7.1% for the magnetospheric plasma. They modulate the interhemispheric asymmetry of the FAC by 26–59%. The eccentric dipole induces an increase (decrease) of the daily variations of the conductances and the FAC by a factor 1.2-2.3 in the Southern (Northern) Hemisphere, irrespective of the season, which contributes to increase the asymmetry between the two hemispheres. This results in an increase of the daily variations of the ion maximum pressure and of the electron maximum energy flux at the December solstice and at the March and September equinoxes, but a decrease at the June solstice. The maximal variation of the magnetospheric plasma distribution amounts to 6.7% at December solstice. These results underline the importance of considering the three different effects at the same time.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7b27vg6

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

2007-09-25T00:00:00Z

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