Regional submicron particles (PM₁) compositions, sources and interaction are still not clear as the desynchrony in observation. This study focused on PM₁ at five sites synchronously in North China Plain (NCP) and Central China (CC) during January 2018. The average PM₁ mass concentrations decreased from north to south, with higher values in LH (125 ± 59.4 µg m⁻³), followed by borderline cities (54.1−93.3 µg m⁻³) and a south site of WH (63.6 ± 21.5 µg m⁻³). Organic matter (41.8%−51.0%) and secondary inorganic aerosols (28.2%−33.2%) occupied the high fractions for all the five sites. Coal combustion and industrial processes mainly raised the differences in PM₁ chemical compositions between regions. The changes of NO₃⁻/SO₄²⁻ between sites were different as a function of relatively humidity and temperature, reflecting the differences of secondary formation mechanism. For a short intra-regional transport case from south to north, PM₁ increased from 102 to 185 µg m⁻³ as the accumulation and aerosol-planet boundary layer interaction under a stable meteorological condition. For a long-range transport case from north to south with a high wind speed (5.5 m s⁻¹) and boundary layer height (529 m), PM₁ decreased by only 0.9 µg m⁻³ (−1.3%) as the enhanced formation of SIA by 12.6% under increased relative humidity (by 7.2%) and enhanced industrial emission (by 19.1%) at the south site. The results provide a useful dataset for modeling PM₁ chemical compositions and their impacts and are helpful for regional-joint control of atmospheric particles and precursor gases.
 

PMF,SOURCE APPORTIONMENT,HYSPLIT模式,TRANSPORT