Scaling laws from geomagnetic time series

The notion of extended self-similarity (ESS) is applied here for the X-component time series of geomagnetic field fluctuations. Plotting n^th order structure functions against the fourth order structure function we show that low-frequency geomagnetic fluctuations up to the order n = 10 follow the same scaling laws as MHD fluctuations in solar wind, however, for higher frequencies (f > 1/5[h]) a clear departure from the expected universality is observed for n >6. ESS does not allow to make an unambiguous statement about the non triviality of scaling laws in ”geomagnetic“ turbulence. However, we suggest to use higher order moments as promising diagnostic tools for mapping the contributions of various remote magnetospheric sources to local observatory data.