An Evaluation of Long-term Variations in Magnetic Variometer Data

Abstract:

Standard magnetic observatories in the world have been the backbone of the data source for constructing the international geomagnetic field model. Networks of magnetic variometers that do not necessarily meet the strict requirements in the baseline control, on the other hand, are vital to the observations of fast magnetic field oscillations associated with Geospace phenomena. It has been considered that the vast amount of variometer data may supplement those collected by standard observatories and improve the modeling of geomagnetic variations in the intermediate time scales. In this study, we examine more than a decade of magnetic variometer data collected by the UCLA ground-based magnetometer stations in North America. We compare these records with the International Geomagnetic Reference Field (IGRF) model to understand the stability of the baseline and how it might vary with the method of sensor installation. The results may provide a useful reference for future deployment of magnetic variometers and for use of variometer data in modeling short-term and intermediate-term geomagnetic variations.