The equatorial Atlantic oscillation and its response to ENSO

The Atlantic Niño is much weaker than its Pacific counterpart.

“However, the Atlantic Niño is much weaker than its Pacific counterpart (Carton and Huang, 1994, Latif and Grötzner, 2000, Servain et al., 2003, Zebiak, 1993).”

At quasi-biennial time scales, a winter El Niño event leads an Atlantic El Niño the following summer with no significant simultaneous relationship.

“Latif and Grötzner (2000) showed how, at quasi-biennal time scales, a winter El Niño event leads an Atlantic El Niño the following summer with no significant simultaneous relationship.”

Our results disagree with Latif and Grötzner (2000), Florenchie et al. (2003), and Wang (2006) with regard to the oceanic wave propagation's role in the origin of the equatorial and South Atlantic SST variability.

“Our results presented above disagree with Latif and Grötzner (2000), Florenchie et al. (2003), and Wang (2006) with regard to the oceanic wave propagation's role in the origin of the equatorial and South Atlantic SST variability.”

The equatorial Atlantic mode differs from ENSO in having significantly weaker variability, a much shorter duration (3 months) of extreme warm/cold events, and spectral characteristics hardly discernible from red noise.

“The main differences to ENSO are the significantly weaker variability, the much shorter duration (3 months) of extreme warm/cold events, and spectral characteristics hardly discernable from red noise (Zebiak 1993;Carton and Huang 1994;Latif and Grötzner 2000).”

Coupled models that simulate ENSO-like variability in the Atlantic exist with and without flux adjustment.

“However, coupled models that simulate ENSO-like variability in the Atlantic do exist with (Latif and Grötzner 2000) and without (Wu et al. 2002;Huang et al. 2004) flux adjustment.”

Spectral analysis shows that the equatorial Atlantic variability is only weakly oscillatory (2yr period) and otherwise similar to a red noise process.

“However, spectral analysis shows that the variability is only weakly oscillatory (2yr period) and otherwise similar to a red noise process (Latif and Grötzner 2000;Ruiz-Barradas et al. 2000).”

It is well accepted that ENSO has an atmospheric impact over the tropical Atlantic, which includes perturbations to the western Atlantic equatorial zonal surface winds.

“It is well accepted that ENSO has an atmospheric impact over the tropical Atlantic, which includes perturbations to the western Atlantic equatorial zonal surface winds (e.g., Latif and Grötzner 2000).”