The Responses of High Latitude Clouds and High and Mid-Latitude Surface
Pressures to the Solar Wind Sector Structure.
Abstract
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.