Identification

Title

Simulations of the ionospheric annual asymmetry: Sun-Earth distance effect

Abstract

It has been suggested that the difference of the Sun-Earth distance between the December and June solstices has a great impact on the ionospheric annual asymmetry. In this study, the physical mechanisms of the Sun-Earth distance effects on the ionospheric annual asymmetry are investigated using Thermosphere-Ionosphere Electrodynamics General Circulation Model simulations. The main findings are the following: (1) The Sun-Earth distance affects the ionospheric annual asymmetry mainly through photochemical processes. (2) During the daytime, this photochemical process results from the combined effect of ionization rate of atomic oxygen and the recombination with neutral species. The solar irradiation variation between December and June directly leads to about 6% December-June electron density difference via ionization of atomic oxygen, whereas the recombination with neutral composition contributes to 12%-15% December-June electron density difference. (3) In the plasma fountain-prominent region (between 20 degrees and 40 degrees magnetic latitude), ambipolar diffusion can also be modulated by the Sun-Earth distance effect and contribute to the ionospheric annual asymmetry. (4) During the nighttime, the Sun-Earth distance effect impacts the annual asymmetry by changing thermospheric composition and ionospheric diffusion.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7736tb1

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

2017-06-01T00:00:00Z

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