Seasonal Variation, Sources and Transport of Aerosols at Lijiang, Southeast Tibetan Plateau

Abstract

Aerosol samples were collected during pre-monsoon, monsoon and post-monsoon periods in 2009 in Lijiang, a tourism city located on the southeast Tibetan Plateau, southwest China. To determine the seasonal variation and sources of aerosol species, main elements and water soluble ions were analyzed. The results showed that crustal elements (Si, K, Ca, Ti and Fe) were the main elements with an enrichment whose enrichment factor (EF) value were lower than 10, with the large value (except Ca) occurring during the pre-monsoon period. The EF values of S, Cl, Zn, As, Br, Sb, Pb, and Cu were higher than those of the crustal elements and the large concentration appeared during the monsoon period. Ca 2+ and SO 4 2-were the dominant cation and anion, respectively. The greatest value of total ionic concentration was found during the monsoon period, mainly because of the high concentration of SO 4 2-and NH 4 + . Using the positive matrix factorization model, it was found that the main sources of species were from crustal source, transport from south Asia and eastern China, local vehicle emissions and sea salt. Further results indicated that the pollutants mixed with dust, anthropogenic pollutants and biomass burning emissions can be transported to Lijiang from south Asia and Southeast Asia during the premonsoon period. In addition, pollutants rich in SO 4 2-and heavy metal from the Sichuan Basin and eastern Yunnan Province can also be occasionally transported to Lijiang during the monsoon period. The seasonal differences in chemical composition and transportation pathway may have important implications for regional climate change.

Radiative effects of absorbing aerosols over northeastern India: Observations and model simulations

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“…The May aerosol index increased from about 2.5 before 1993 to about 4 in 2000 and more than 11 in 2003. Similarly, over the southeast Tibetan Plateau, Zhang et al [2016] have reported that the largest values of UVAI appeared at south edge of Tibetan Plateau (TP) and western China. Based on the modeling study on transport of summer dust and anthropogenic aerosols over the Tibetan Plateau, Liu et al [2015] have also reported the presence of highly absorbing aerosols around the Taklimakan desert, the southern slope, and the area east of the TP based on the high values of AI.…”

Spatial‐temporal characteristics of aerosol loading over the Yangtze River Basin during 2001–2015

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