Identification

Title

Terannual variation in the F₂ layer peak electron density (NmF₂) at middle latitudes

Abstract

Ionosonde data from 33 stations in three longitude sectors from 1969 to 1986 have been used to study the seasonal variations of ionospheric FIonosonde data from 33 stations in three longitude sectors from 1969 to 1986 have been used to study the seasonal variations of ionospheric F₂ layer peak electron densities (NmF₂). We found that there is a periodic oscillation in daytime NmF₂ with a period of 4 months (terannual). Our analysis shows that there is a very good phase match between the annual and semiannual oscillations and the terannual oscillations. These three oscillations vary with solar activity in the same way: large amplitudes during solar maximum. The amplitude of the terannual oscillation is also correlated with the product of the amplitudes of annual and semiannual oscillations. These suggest that the terannual oscillation might be related to the nonlinear interaction between the annual and semiannual oscillations. In addition, the terannual oscillation is stronger in the midlatitude region in the Northern Hemisphere than in the Southern Hemisphere. Furthermore, there are large differences in the ionospheric seasonal variations between daytime and nighttime. No obvious terannual oscillation signature is seen in the nighttime F₂ layer.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7wq04gc

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

2012-01-12T00:00:00Z

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