Interannual Variability in the Tropical Atlantic and Linkages to the Pacific

Abstract

Abstract The variability of sea surface temperature anomalies (SSTAs) in the tropical Atlantic is examined using data from 1900 to the present. SSTAs are filtered to focus on the interannual band with fluctuations less than 60 months. Both SSTAs over the northern tropical Atlantic (NTA) and the southern tropical Atlantic (STA) are associated with the El Nino–Southern Oscillation (ENSO) variability in the tropical Pacific. SSTAs over the STA are associated with the quasi-biennial component of ENSO with a timescale of 22–32 months, and SSTAs over the NTA are influenced by the low-frequency part of the ENSO signal with a timescale of 36–48 months. The ENSO influence is seasonally dependent. The strongest linkages occur in the spring of each hemisphere. In addition to ENSO, SSTAs in the north equatorial Atlantic are also modulated by the circulation and net heat flux anomalies associated with the North Atlantic oscillation (NAO). The atmospheric impact on the ocean is different in the STA and NTA regions. Whe...