thumbnail

Some effects of quiet geomagnetic field changes upon values used for main field modeling

Physics of the Earth and Planetary Interiors

By:
DOI: 10.1016/0031-9201(87)90144-0

Links

Abstract

The effects of three methods of data selection upon the assumed main field levels for geomagnetic observatory records used in main field modeling were investigated for a year of very low solar-terrestrial activity. The first method concerned the differences between the year's average of quiet day field values and the average of all values during the year. For H these differences were 2-3 gammas, for D they were -0.04 to -0.12???, for Z the differences were negligible. The second method of selection concerned the effects of the daytime internal Sq variations upon the daily mean values of field. The midnight field levels when the Sq currents were a minimum deviated from the daily mean levels by as much as 4-7 gammas in H and Z but were negligible for D. The third method of selection was designed to avoid the annual and semi-annual quiet level changes of field caused by the seasonal changes in the magnetosphere. Contributions from these changes were found to be as much as 4-7 gammas in quiet years and expected to be greater than 10 gammas in active years. Suggestions for improved methods of improved data selection in main field modeling are given. ?? 1987.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Some effects of quiet geomagnetic field changes upon values used for main field modeling
Series title:
Physics of the Earth and Planetary Interiors
DOI:
10.1016/0031-9201(87)90144-0
Volume
48
Issue:
3-4
Year Published:
1987
Language:
English
Publisher:
Elsevier
Publisher location:
Amsterdam, Netherlands
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Physics of the Earth and Planetary Interiors
First page:
193
Last page:
199
Number of Pages:
7