Summary
Pressure variations at 11 Antarctic and 7 Arctic sites show significant day-to-day correlations with a proxy for the meteorological generators (thunderstorms and strongly electrified clouds) of the atmospheric circuit. The proxy is derived from electric field measurements at Vostok (78.5ºS, 107ºE). These correlations provide evidence that careful electric field measurements at a single site contain a global signal on daily timescales. In polar regions, the solar wind affects the local atmospheric circuit via interaction with the Earth’s magnetic field. This solar variability is superimposed on the stronger, globally-uniform, meteorological control. The daily-averaged, solar-wind-imposed, ionosphere-to-ground potential difference at polar stations is influenced by the east-west component of the Interplanetary Magnetic Field (IMF By) and the magnetic latitude of the site. The correlation of IMF By with pressure variations at Antarctic sites for a solar-cycle (1995-2005), is small (0.9% average covariance for magnetic latitudes >83º) but significant (99.7% confidence level). The proportional pressure variations of the internal (meteorological generators) and external (solar wind) drivers of the atmospheric circuit, particularly for the Antarctic Plateau (magnetic latitude >83º) where the solar link is demonstrated with the highest statistical significance, provides evidence that the pressure variations are due to the influence of the atmospheric circuit.