Fig. 4From: Narrow and wide India–Burma trough-like circulations: their different impacts on precipitation over southern ChinaTime series of the normalized winter (December, January, and February) NIBT (red) and WIBT (black) indices for the period 1979–2019. The blue dashed lines from top to bottom denote + 0.75 and − 0.75 standard deviationsBack to article page