• Atlantic multidecadal oscillation (AMO);
  • polar vortex oscillation (PVO);
  • North Africa–West Asia (NAWA) index;
  • Mediterranean climate;
  • Sahelian rainfall


More linkages between the Atlantic multidecadal oscillation (AMO, and thermohaline circulation), the Polar vortex oscillation (PVO, and vorticity intrusion), the North Africa–West Asia index (NAWA, and NA–WA poles) and Sahelian rainfall, are investigated. Significant positive correlations are found between winter/spring AMO and spring NA pole. Significant positive (negative) correlations are found between winter PVO and NAWA (WA pole). NAWA is shown being modulated by winter AMO to the west, and winter PVO over Eurasia to the east. Winter AMO and PVO can thus be used operationally by decision makers as early predictors of Mediterranean climate and Sahelian rainfall during summer. Copyright © 2008 Royal Meteorological Society