El Nino-Southern Oscillation (ENSO) is the most dominant mode in the interannual timescale. It generates atmospheric teleconnections that modulate the sea surface temperature anomalies (SSTA) over the north tropical Atlantic (NTA). It further affects climate phenomenon over surrounding and remote regions.
Previous studies have indicated that the impact of ENSO on the SSTA over the entire NTA tends to be unstable. A study recently published in the Journal of Climate by Dr. Chen Wei at the Institute of Atmospheric Physics of the Chinese Academy of Sciences has identified that the decadal variation in the ENSO-NTA connection actually concentrates over the eastern part of NTA (NETA). The connection between ENSO and the sea surface temperature anomalies over the western part of NTA is stable.
The results suggest that the influence of ENSO was conveyed to the entire NTA before the mid-1980s. But influence hardly reaches the eastern part of NTA and is only limited to the western part.
The decadal changes in the ENSO-NETA connection are due to the westward shift in the ENSO-related convection and teleconnections. It results from the westward shift of the Pacific Walker Circulation. It is induced by the intensified zonal SST gradient over the equatorial Pacific after the mid-1980s.
The result implies a decadal variation in the ENSO-related NETA sea surface temperature anomalies. It may change the climate structures in the surrounding area.