El Niño–Southern Oscillation (ENSO) effect on interannual variability in spring aerosols over East Asia

Abstract. Effects of the El Niño–Southern Oscillation (ENSO) on interannual variability in spring aerosols over East Asia are investigated using Modern Era Retrospective analysis for Research and Applications Version 2 (MERRA-2) reanalysis aerosol data. Results show that ENSO has a crucial effect mainland South Asia, southern China, ocean south Japan. The above-normal (below-normal) found these regions during ensuing Niño (La Niña). In contrast to local diffusion winter, affects Asian following mainly via modulation upstream generation transport processes. underlying physical mechanism is Niña), dry (wet) air reduced (enhanced) precipitation beneficial increase (reduction) biomass burning activities northern resulting more (fewer) carbonaceous emissions. On other hand, anomalous anticyclone (cyclone) north-western Pacific (WNP) associated with Niña) enhances (weakens) low-level south-westerly wind from Japan, which transports (less) downstream. Anomalous plays role reducing source region, but its washout downstream region limited. ENSO's impact attributed eastern rather than central ENSO.