Identification

Title

Observations and Simulations of Eddy Diffusion and Tidal Effects on the Semiannual Oscillation in the Ionosphere

Abstract

We use the National Center for Atmospheric Research TIEGCM (Thermosphere Ionosphere Electrodynamics General Circulation Model) model to investigate the eddy diffusion and tidal effects on the ionosphere SAO (semiannual oscillation). We also use the COSMIC (Constellation Observing System for Meteorology, Ionosphere, and Climate) satellite GPS radio occultation observations to validate the simulation results. The TIEGCM is driven at the 97 km lower boundary by tidal and gravity wave (eddy diffusion coefficient) inputs. The eddy diffusion input can be constant or with an SAO modulation, and the tidal input has on and off options. The TIEGCM simulation with an SAO modulated eddy diffusion (with tidal input) agrees better with the COSMIC observation than that without the SAO. Turning off the tides at the lower boundary makes the TIEGCM-simulated ionospheric density much higher than the COSMIC observation. The simulations showed two results: (1) the need to add the SAO modulation to the eddy diffusion and (2) how tides reduce the ionospheric density and SAO. As to how much of the SAO should be added to the eddy diffusion is dependent on the amplitudes of the tides since both can have effects on the ionospheric density. The TIEGCM results also demonstrate that the ionospheric density diurnal signal is mostly in situ excited, while the semidiurnal signal comes from lower atmosphere.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7z03bsd

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

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South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2017-10-05T00:00:00Z

Frequency of update

Quality and validity

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Conformity

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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