Can solar variability influence climate

Excerpts from Australian Antarctic Division

Scientists have long searched for linkages between solar variability and weather. The sun varies on a wide-range of time scales, most dramatically on an ~11 year cycle which is strongly associated with the number and extent of sunspots on the sun and the occurrence of aurora at high latitudes.

Any mechanism for changing weather and climate by solar variability must involve influencing the distribution of the energy within the weather system. One possible mechanism is via the Earth's geoelectric field.

Cosmic ray ionisation, the magnitude of which can be controlled by solar activity via the solar wind, modulates the resistance of this global electric circuit in which thunderstorms are the generators. By controlling the ease with thunderstorms can dissipate current it is feasible that solar activity may modulate the intensity of thunderstorm development, thus modulating the distribution of energy within the meteorological system.

Additional solar influences on the geoelectric field occur at high latitudes, via the same processes that generate the aurora. In conjunction with Russian and American colleagues, we presently measure the geoelectric field at the Russian station, Vostok, on the Antarctic plateau. We have shown that solar variability can influence the geoelectric field measured at ground level in polar regions, and are continuing to develop research instrumentation and methods of testing the viability of a solar variability influence on weather and climate through modulation of the geoelectric circuit.