An investigation into the correlation of geomagnetic storms with tropospheric parameters over the South Pole

Abstract. We test the proposal that the Sun’s magnetic activity, communicated via the solar wind, provides a link between solar variability and the Earth’s climate in the Antarctic troposphere. The strength of a geomagnetic storm is one indicator of the state of the solar wind; therefore, we use the dates of 51 moderate to strong winter geomagnetic storms from the period 1961–1990 to conduct a series of superposed epoch analyses of the winter South Pole isobaric height and temperature, at pressures of between 100–500 mbar. Using Student’s t -test to compare the mean value of the pre- and post-storm data sets, we find no evidence to support the hypothesis that there is a statistically-significant correlation between the onset of a geomagnetic storm and changes in the isobaric temperature or height of the troposphere and lower stratosphere over the South Pole during winter months. This concurs with a similar study of the variability of the troposphere and lower stratosphere over the South Pole (Lam and Rodger, 2002) which uses drops in the level of observed galactic cosmic ray intensity, known as Forbush decreases, as a proxy for solar magnetic activity instead of geomagnetic storms.

Key words. Interplanetary physics (solar wind plasma; cosmic rays) – Atmospheric composition and structure (pressure, density and temperature)