Correlation between aeromagnetic data rejection and geomagnetic indicesGeomagnetic Indices

Abstract Predicting the rejection of aeromagnetic data would be a useful tool for aeromagnetic survey planning. To relate aeromagnetic survey requirements to geomagnetic activity monitoring and prediction, we analyzed the relationship between the rejection of aeromagnetic data as it is measured during surveys and the variations in existing geomagnetic indices. The magnetic data were collected at Canadian magnetic observatories during 2001 and covered the polar cap, auroral, and subauroral zones. The geomagnetic indices were global and local indices. The global indices included the Kp, ap, and Dst indices. The local indices were the three-component hourly ranges, the three-component maximum rate of change, and the Pc3 pulsation index. The goodness of fit was used to compare the results between the different indices at different locations. In general, there was some correlation between global geomagnetic indices and the rate of rejection of aeromagnetic data. Good correlation with a global index was obtained with the daily mean of the Ap index for a station located in the subauroral zone. The best correlation was obtained with local indices and particularly with the Pc3 index amplitude. From these results we conclude that forecasting Pc3 index amplitude would be a useful tool for planning aeromagnetic surveys.