Fig. 3: Atmospheric circulation patterns during the strongly negative and positive IOD years.

Vertically integrated moisture flux fields (a, b) and moisture flux field anomalies (c, d) at 1000–500 hPa during the strongly negative (a, c) and positive (b, d) IOD years. The anomalies are defined as the mean values during the strongly negative and positive IOD years subtracted by the mean values during 1961–1998, respectively. The black dots indicate the location of Hong Kong, and the black rectangles mark the region of southern East Asia. The solid line circles or rectangles with pink mark the areas of increased moisture flux, and the dashed line circles or rectangles with pink mark the areas of decreased moisture flux.