Footprints of El Niño La Niña on the evolution of particulate matter over subtropical Island Taiwan

Particulate matter (PM) pollution has become a major problem worldwide, with significant adverse health impacts, but the climatology of annual variations in and the effect of climate change on PM levels are still not comprehensively evaluated. Here we show that the vertical motions of the East Asian winter and summer monsoons regulate the annual variation in PM over Taiwan. The PM pollution season starts and ends earlier during El Niño episodes than during La Niña episodes. Furthermore, the onset, active, break, revival, and retreat phases of the PM pollution lifecycle are innovatively defined. Our results demonstrate that the annual seasonal cycle dominates wintertime PM pollution climate development during the active phase with a minor modulation by El Niño and La Niña episodes, whereas October and March, the seasonal transition periods, are significantly modulated by these two episodes. The findings suggest a new dimension of PM pollution research—the lifecycle evolution effect.