Is Tropical Atlantic Variability driven by the North Atlantic Oscillation?

Abstract

The role of the North Atlantic Oscillation (NAO) on the genesis of the Tropical Atlantic Variability (TAV) is studied in a coupled ocean-atmosphere general circulation model using two modeling approaches of partial coupling and partial blocking. It is found that the NAO is not a necessary precondition for the genesis of the TAV although it can enhance climate variability in the tropical North Atlantic significantly via extratropical-tropical teleconnections. Instead, local ocean-atmosphere interaction plays a dominant role for the full development of TAV. Our results do not rule out the possible influence of ENSO on TAV.