Abstract:

Air parcel backward trajectory during periods with acid and no-acid rain from 2008 to 2009 in Dalian was calculated based on a Hysplit model, and external source of acid rain was analyzed by methods of a conditional probability distribution and a trajectory clustering. The result shows that the external source transported through atmosphere makes a greater contribution to acid deposition in Dalian area. The main source of acid rain owe to near-surface atmospheric transportation comes from the East China coast to Shandong peninsula, passing through north Huanghai Sea or Bohai Sea and its west coast, and the lower-air atmospheric transportation from the inland area of southward and eastward of China and East Asia countries around Japan Sea provides additional sources. On the contrary, source of no-acid rain comes from ocean air mass or northward land air mass.

Key words: Acid rain, External source, Trajectory model, The cloud of acid