AURORAL OVAL PLOTTER AND NOMOGRAPH FOR DETERMINING CORRECTED GEOMAGNETIC LOCAL TIME, LATITUDE, AND LONGITUDE FOR HIGH LATITUDES IN THE NORTHERN HEMISPHERE

Abstract : A nomographic computer is presented which graphically converts geographical coordinates and universal time into geomagnetic coordinates and geomagnetic local time in the Corrected Geomagnetic system of Hultqvist. The computer is formulated as a map of high latitudes in the Northern Hemisphere on which the position of the auroral oval can be projected directly for any time of day, for any magnetic activity, with account being taken of seasonal variation of the geomagnetic local time coordinate. Instructions for its use, discussion of its accuracy, and examples of its application are given.