Abstract

A spherical harmonic analysis has been made of the quiet-day diurnal variation of the geogmagnetic field during the IGY, based on mean hourly values from 64 observatories. Each of the 18 months has been analysed separately, and the coefficients have been averaged over each of four seasons. Fourier coefficients were expressed as functions of latitude and longitude by the Gram-Schmidt method, and non-significant coefficients of the orthogonal functions were discarded. The dependence on longitude was restricted so that only smooth departures from the local time dependence were allowed. The potential was derived by averaging that found from the east and north components. External and internal potentials were derived from the surface potential and vertical component. Ratios of, and phase differences between, the external and internal potentials were derived for each harmonic. They were also computed as functions of latitude and longitude, but no significant geographical distribution was found. The ratios and phase differences generally agree fairly well with those derived from earlier analyses. The amplitudes of the harmonics are generally about twice as great as those derived by Chapman for the 1905 data. This is probably because 1957 and 1958 were years of very high sunspot number. Tables of coefficients and maps of the elements and current functions are given.
Google map showing geographic bounding box with values North bound East bound West bound South bound
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Product Type/Sub Type

nonGeographicDataset

Constraints

Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

1977-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

83 Product http://www.ga.gov.au/metadata-gateway/metadata/record/83/

Keywords

GA Publication
Bulletin
geophysics
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Digital Transfer Options

onLine

Distributor

Role
distributor
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

a05f7892-7fad-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
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