Regression Derivatives and Their Application to the Study of Geomagnetic Jerks

Resumo

New mathematical constructions are developed for the regression smoothing of discrete time series defined on an irregular grid. The new method is used to study secular trends for the period 1991–2015 and relies on observations of three components of the magnetic field at five geomagnetic observatories of the INTERMAGNET network. The detected changes in the trend coincided in time with the jerk properties calculated by conventional methods, which indicates the applicability of the method of regression derivatives to geophysical problems.