An extended Empirical Orthogonal Function (EEOF) analysis is applied to pentad velocity potential at 200-hPa for ENSO-neutral and weak ENSO winters
(November-April) during 1979-2000. The first EEOF is composed of ten time-lagged patterns.
We construct ten MJO indices by regressing the daily data onto the ten patterns of the
first EEOF. The figures below show the ten MJO indices (normalized) for the previous 6 and 12 months. Note that the blueish (reddish) color represents the enhanced (suppressed ) convection, and the x-axis labels the centers (20°E, 70°E, 80°E, 100°E, 120°E,
140°E, 160°E, 120°W, 40°W and 10°W) of enhanced convection for the ten indices, which are determined from the ten time-lagged patterns of the first EEOF of CHI200.