Irradiances from long-lived stratus-type clouds at Alert (Canada), Summit (Greenland), and South Pole, previously measured, show correlations with the day-to-day input to the global atmospheric electric circuit from the solar wind, as well as with the inputs of low- and mid-latitude thunderstorms and shower clouds. We analyze the measured Alert cloud irradiances, and find differences in the responses to 2, 4, or more solar wind sectors per 27-day solar rotation. We find seasonal variations in the correlations, with sign reversal in the summer. The correlation coefficients that were found previously for all-year, all sector types show further increases for just winter months and in addition, for just 2-sector intervals. At high magnetic latitudes the ionospheric potential correlates strongly with the solar wind sector structure, and determines the flow of current density (Jz) to the Earth;s surface that passes through clouds and modifies space charge in them. Parameterizations of the potential distribution near the magnetic pole are used in the correlations. The daily average values depend mainly on the solar wind (interplanetary) magnetic field (IMF) By component, with lesser influence of the solar wind speed and IMF Bz. Mechanisms by which space charge in clouds can affect cloud microphysics and cloud opacity are described and are qualitatively consistent with the correlations, but need quantitative testing.

The opacity of clouds at Alert, Canada have been shown by measurements of their infrared irradiances to change with the day-to-day solar wind input to the global atmospheric electric circuit, as well as to the inputs of global thunderstorms and magnetic storms. These cloud changes appear to be the cause of surface pressure changes in the Arctic and Antarctic that have long been observed to correlate with the solar wind sector structure. We analyze large data sets of cloud irradiances and surface pressures, and find differences in the responses to 2, 4, or more sectors per 27-day solar rotation. There are seasonal variations, with sign reversal in the summer, which we interpret as due to changing geometry of solar insolation input. The correlation coefficients that were shown to be statistically significant at near the 95% confidence level for all-year, all sector types show further increases for just winter months and for just 2-sector intervals. The phase relationship of the pressure responses compared to those of the cloud responses are consistent but not understood. There are also interannual variations, whose cause has yet to be determined. A parameterization of the potential distribution near the magnetic poles and out through the high latitude ionospheric region affected by solar wind inputs has been made, giving correlations of IR irradiance and pressure with these parameterizations stronger than with those for the IMF B alone. The effects analyzed are an indication of more extensive influences of global atmospheric electricity on cloud microphysics and cloud development.