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tokens: respectively. For each of these frequency windows we compute the power spectral density. We selected windows of 16 h to compute each bin. In order to avoid segments containing magnetic experiments or events as the ones reported in Tables 2 and 1 , we apply a mask to the data. To do so we take as a figure of merit the amplitude spectral density in the range . Those segments where this figure of merit is exceed by five sigma are discarded from our analysis. Following this criterion, we exclude 9 segments out of 300. This analysis allows a generic description of the statistical behaviour of the fluctuations without any previous assumption on its stationarity. Fig. 4 shows the results for both frequency ranges. In agreement with our previous analysis, the amplitude of the fluctuations for the low-frequency bin is coherent and follows the same statistical distribution for all four magnetometers. Bins are statistically distributed with similar median values, namely These values are based on the 16th, 50th, and 84th percentiles of the histogram. Also, in this case we can derive a common mean value for the fluctuations in this frequency range of . On the other hand, the noise power in the higher frequency bins show a different amplitude spectral density for each magnetometer. The median values in this case are In the latter we observe that the distribution of the median values is narrower and not overlapping between them. Both behaviours are clearly distinguished in the histograms of Fig. 4 , which characterizes the variability of the magnetic field fluctuations on-board for the two frequency regimes that we have previously identified. Figure 4. Time evolution and statistical distribution of the X-component of the magnetic field fluctuations as measured on-board, for two different frequency regimes. Colours correspond to magnetometers: PX (blue), MX (red), PY (yellow), and MY (green). Time is indicated in DAL, while ASD stands for Amplitude Spectral Density. Top: Fluctuations in the frequency range . Bottom: Fluctuations in the frequency range . In the framework of future gravitational wave detectors in space, the variability in the spectra of magnetic field fluctuations is particularly relevant in the low-frequency regime. There are two main reasons for that: first, the mHz band is the main objective of a gravitational wave detector in space, since these observatories are designed to study the gravitational wave universe in this frequency band. Second, at the same time, the low-frequency fluctuations will be precisely the main contribution to the magnetic induced force noise in the free-falling test masses. According to Armano et al. ( 2016 ), magnetic induced forces could contribute to a maximum of 3 of the measured 12 at 0.1 mHz of the differential acceleration measured on LPF test masses. Although the precise determination of the magnetic noise contribution is still pending, the current estimate is expected to be of the order of other