Modes of Oceanic and Atmospheric Circulation during the Quaternary

Paleoclimatic evidence shows that the ocean and atmosphere have undergone major changes during the Quaternary. For atmospheric mean circulation, data are consistent with changes in strength and shifts in position of major atmospheric circulation features (e.g., the westerly wind belt), whereas the structure of these main features appears to have persisted. For the ocean, evidence points to qualitative reorganizations in the thermohaline circulation. Modes of ocean-atmosphere variability, such as El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), also appear to have changed or even been absent at times.