Application of EOF/CEOF methodology to understand correlation between geomagnetic secular variation and decadal time-variable gravity

In this presentation we discuss the application of EOF and Complex EOF approaches to examine possible correlation between temporal-spatial distributions of the time variable gravity (TVG) and magnetic secular variations (SV) on decadal time scales and longer. The advantage of such approaches is to enable us identifying approximately 3 to 4 EOF/CEOF modes that account for the most of the signals. We apply these approaches to examine the gravity and magnetic field data generated by the MoSST numerical core dynamics model and the PREM model. Our results show that the first 3 EOF modes reproduce the most significant features of the spatial distributions, thus sufficient for understanding the correlation between the two potential fields. We are currently working on applying this analysis to the 20-year time variable gravity from SLR and satellite measurements, and the surface geomagnetic field from GUFM1.