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Geomagnetism publications.

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New trend- trigonometric model for interpolation and prediction of the geomagnetic field utilizing the new DGRF models New trend- trigonometric model for interpolation and prediction of the geomagnetic field utilizing the new DGRF models

At the IUGG Assembly at Vancouver during August 1987 new definitive geomagnetic reference field (DGRF) models to degree 10 for 1945, 1950, 1955, and 1960 were adopted by IAGA. Before these new DGRF models were accepted, the author developed a trend and trigonometric model (old trig model) based on the models IGRF 1945, IGRF 1950, IGRF 1955, IGRF 1960, DGRF 1965, DGRF 1970, DGRF 1975...
Authors
L.R. Alldredge

Range indices of geomagnetic activity Range indices of geomagnetic activity

The simplest index of geomagnetic activity is the range in nT from maximum to minimum value of the field in a given time interval. The hourly range R was recommended by IAGA for use at observatories at latitudes greater than 65??, but was superceded by AE. The most used geomagnetic index K is based on the range of activity in a 3 h interval corrected for the regular daily variation. In...
Authors
W.F. Stuart, A.W. Green

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

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...
Authors
W.H. Campbell

Assessment of models proposed for the 1985 revision of the international geomagnetic reference field Assessment of models proposed for the 1985 revision of the international geomagnetic reference field

Geomagnetic measurements from land, marine and aerial surveys conducted in the years 1945-1964 were used to test the 14 models proposed as additions, for that period, to the series of definitive geomagnetic reference field (DGRF) models. Overall, NASA's 'SFAS' models and the BGS (British Geological Survey) models agree best with these data. Comparisons of the two proposed definitive main...
Authors
N.W. Peddie, A.K. Zunde
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