El Niño in the Indian Ocean
In October, there was a large eastwardly wind burst in the central Pacific. At the same time, there was a westwardly wind burst in the central Indian Ocean. Wind bursts in these two oceans are well correlated during El Niño events as shown in the bottom left figure. The wind bursts are associated with the Southern Oscillation, as shown in the bottom right figure. El Niño events are marked with arrows.
Monthly wind stress anomalies, averaged over the central Pacific (±5°N, 180°E to 200°E) and the central Indian Ocean (±5°N, 80°E - 100°E). Positive values are eastwardly (Pacific) or westwardly (Indian). Data are from Florida State Univ., Center for Ocean-Atmospheric Prediction Studies.
Difference in Indian and Pacific eastwardly wind stress, compared against the Southern Oscillation Index (SOI). The SOI is determined from the difference in pressure at Darwin, Australia and Tahiti.