P. Schmoldt, PhD - MTNet - DIAS

List of Figures
2.1. Amplitude of the natural variations in the horizontal geomagnetic field
and corresponding amplitudes in the geoelectric field . . . . . . . . . . . 8
2.2. Annual rate of lightning discharges . . . . . . . . . . . . . . . . . . . . . 9
2.3. A schematic view of the magnetosphere . . . . . . . . . . . . . . . . . . 10
2.4. Layers of the ionosphere with their electron density and predominant ion
populations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5. Monthly average of observed sunspot numbers since 1749 and the more
sporadic observations prior to 1749 . . . . . . . . . . . . . . . . . . . . . 13
2.6. Monthly and monthly smoothed sunspot numbers since 1950 . . . . . . . 13
2.7. Equivalent current system representing the S q field of March equinox,
northern summer, September equinox, and southern summer . . . . . . . 14
2.8. Projection of the dip equator and the geomagnetic equator onto the Earth’s
surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.9. Equivalent current system for lunar daily variations L . . . . . . . . . . . 15
2.10. Schematic representations of a substorm current system intrusion into the
convection electrojets system for a dark ionosphere and possible interaction
between field-aligned currents with convection electrojets and crosspolar
cap current flow the sunlit polar ionosphere . . . . . . . . . . . . . 16
2.11. The shape of the polar electrojet on the northern hemisphere . . . . . . . 17
2.12. Effect of storm events on magnetotelluric time series data recorded at
high-latitudes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.13. Equivalent current model representing DP1 by the use of polar electrojets 19
2.14. Equivalent current model representing DP2 with two current loops . . . . 20
2.15. Solar flare effect in geomagnetic observations at mid latitudes . . . . . . . 21
2.16. Estimation of plane wave validity for magnetotellurics . . . . . . . . . . 23
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