Gq, a Galactic Component of the Geomagnetic Field Variation

Abstract

A quiet time galactic component, Gq, of the geomagnetic field variations has been extracted from observatory data of San Juan, Puerto Rico, and Honolulu, Hawaii, for the quiet sun years of 1965 and 1966. In the search for this effect, days of active solar‐terrestrial disturbances ere excluded, and the contributions of the solar quiet current (Sq) and the lunar tidal current (L) were first removed. Nighttime data show the Gq most effectively as a 1.5‐gamma variation that is diurnal in H with an increase at about 2200 sidereal time (SiT). The D and Z sidereal variations are less clear in the present data sample