An Analysis of PM_2.5 Distribution, Variation and Formation in the Eastern China for 2000-2015

Using satellite-based PM_2.5 data for 2000-2015, we found that the temporal-spatial variation of PM_2.5 in the Eastern China was characterized by the high concentrations in the northern part and low in the southern part of the East China with seasonally high in autumn and winter but low in spring and summer, that the regional averaged PM_2.5 concentration showed an approximative high of 70.69 μg·m^-3 and the low of 51.65 μg·m^-3 in 2007 and 2000, respectively. The available emissions of atmospheric compositions showed asimilar yearly variation trend as the PM_2.5 even the synchronization is not meet to each other of composition, implying that the intensity of anthropogenic emissions dominates the temporal variation of PM_2.5 in East China. The empirical orthogonal function analysis demonstrated that the dominant variability in the seasonal PM_2.5 in East China was closely associated with the specific climate index of Asia Polar Vortex intensity in the spring, the Western North Pacific Typhoon number, the Northern Hemisphere subtropical high ridge position and the Pacific/ North American Pattern for the leading mode and the Kuroshio Current SST for the second mode in the summer, the Total Sunspot Number and the Asia Polar Vortex Area for the leading mode and the Pacific polar vortex Intensity, the number of landing typhoon on China and the East Asian trough intensity for the second mode in the autumn, the cold air activity and the Niño A (25°—35°N, 130°—150°E)SSTA for the leading mode and the Pacific Decadal Oscillation together with the Pacific polar vortex area for the second mode in the winter. Therefore, apart from anthropogenic emissions effect, our results also provide robust evidence that the climate factor has played a significant role in modulating the PM_2.5 in the eastern China for the 16 years.