Frequency distributions of magnetic storms and SI+SSC-derived records at Kakioka, Memambetsu, and Kanoya

Abstract

The Japan Meteorological Agency keeps records of geomagnetic phenomena observed at Kakioka (magnetic latitude, 27.47°), Memambetsu (magnetic latitude, 35.44°), and Kanoya (magnetic latitude, 22.00°). We used these records to examine the cumulative frequency distribution of magnetic storms, sudden impulses, and storm sudden commencements. The distributions of magnetic storms resemble the Gutenberg-Richter relation between earthquake frequency and magnitude used in seismology. The coefficients determined with the maximum likelihood method show that when the H-range of a magnetic storm at Kakioka is doubled, the frequency of the magnetic storm is about one seventh, for example. Intense magnetic storms occur less frequently than calculated by the functions. This statistical analysis proves that there are no significant differences between slopes of the frequency distribution functions of the magnetic phenomena at Kakioka, Memambetsu, and Kanoya.

Biological Effects of Magnetic Storms and ELF Magnetic Fields

“…The frequency 14.1 Hz may be a resonance frequency of Mg 2+ in some conditions [226]. On the other hand, the fundamental frequencies of the Schumann resonance are represented by 7.8 Hz, 14.1 Hz, 20.3 Hz, 26.4 Hz, and 32.5 Hz [285] and fall within the frequency ranges of theta (4-7 Hz), alpha (7-12 Hz), sigma (12-14 Hz), beta (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and gamma (30-80 Hz) rhythms of human brain electrical activity [63,[286][287][288][289][290][291]. A high similarity of the human EEG profile to low Schumann resonance frequencies has been described.…”

“…The first and most "obvious" range lies in the frequency and induction limits f (50-60 Hz) and corresponds to industrial MFs. Formally, this range can be divided into two parts: strong ELF-MF effects f (10-300)B(>10 µT) industrial frequencies and their harmonics and subharmonics (fields with such induction are rarely encountered in everyday life and are used in laboratory experiments, for example, to test theories about cyclotron resonances (Figure 7b (1)) [27,28,261]; weak MFs (<10 µT) of the same frequency range are often encountered in everyday life. In addition, in everyday life, we are surrounded by urban background MFs mainly consisting of noise from electrical equipment, transportation, etc.…”

“…Geomagnetic storms cause GMF induction fluctuations with frequencies from 0.00007 to 30 Hz and amplitudes of fluctuations from 70 to 900 nT depending on latitude, but more often they do not exceed 200 nT [26][27][28][29][30]. It is worth noting that despite the low amplitudes, the biological effects of magnetic storms are significant [24].…”

Extreme geomagnetic activities: a statistical study

“…In this study, acknowledging an advantage of Japan's long-term monitoring effort of geomagnetic activities at Kakioka Magnetic Observatory (KAK), their complied event lists of magnetic storms and SCs are used for the statistics to estimate the possible amplitudes of the 100-year and 1000-year events. Using the KAK lists, the possible power-law distributions of the amplitude of magnetic storms as well as SCs were discussed by Minamoto et al (2015).…”

Extremely severe space weather and geomagnetically induced currents in regions with locally heterogeneous ground resistivity

“…Next, three papers deal with statistical studies of the magnetospheric disturbances. Nakamura et al (2015) study the auroral electrojets, and Minamoto et al (2015) address the magnetic storms and SCs observed by the Kakioka Magnetic Observatory. The frequencies of occurrence of severe space weather are useful not only to the scientists but also to society.…”