A note on MESA and spectral analysis of the hundred-year geomagnetic data at Zo-se

Abstract

Summary. In the maximum entropy spectrum analysis (MESA) of geomagnetic data, the required order can be estimated by the zero‐frequency half‐power width (ZHW) minimum method proposed in this paper. The spectra of the data for 1876–1975 at Zo‐se showed a period of 40yr, in addition to the well‐known periods. The amplitudes of the variations were estimated with parabolic‐sinusoidal series fitting.