Abstract
Comparisons of proposed and adopted geomagnetic reference field models are made against North American test data for the period 1965 to 1985. These test data (X, Y, Z, and F) include Canadian map and aeromagnetic data and USGS land-based data. Model values are also tested against predicted component values for 1982 and 1984 derived from 27 magnetic observatories on or near the North American continent.
These tests indicate that all candidate models provide an excellent fit to North American test data at epochs 1965, 1970, and 1975. Only the USGS and NASA models fit these data satisfactorily at 1980. The best secular variation models for 1980-1985 appear to be the IGS and USGS models.
Finally, our tests indicate that the recently adopted series of reference field models provides a reasonable and satisfactory fit to North American test data.
