Statistical significance and climatic role of the Global Atmospheric Oscillation

The statistical significance of Global Atmospheric Oscillation (GAO), whose main element is the well-known El Nino–Southern Oscillation in the equatorial Pacific, was assessed from monthly mean atmospheric pressure data at sea level at the nodes of a regular 5° × 5° grid covering the entire surface of the Earth. The data were collected in 1920–2012. It was found that statistically reliable GAO signals cover almost the entire tropical zone and they also appear at mid- and high latitudes of both hemispheres.