华南地区春季冷锋云系中污染物的输送

TRANSPORT OF POLLUTANTS ASSOCIATED WITH COLD FRONT IN SOUTH CHINA IN SPRING

研究了华南春季冷锋云系中污染物的三维输送和酸沉降特点.该地区低空经常存在一个稳定的逆温层结构,且混合层顶也较低,有利于污染物在层内聚集.冷锋南下时,锋前上升气流把原稳定层中的污染物抬升并送入云内,形成“逆温层内累积——被锋面抬升——高空平流输送——湿沉降到地面”的循环.一个地方排放的污染物可以造成其周围几百公里范围内云和降水的酸化.轨迹烟团模式计算的结果也表明,即使在冷锋的北来气流作用下,本地源的影响仍是主要的.

Three dimensional air Parcel trajectories associated with the cold front are Proposed to estimate the transport and deposition of acid pollutants when the cold front moves southward.The pollutants in original stable layer is lifted into the clouds. There is a cycle of pollutants accumulating transporting at high level and wet depositing to the ground. The SO2 and sulfate emitted from one source can make acid precipitation in a distance of several hundred kilometers. The trajectory puff model showed also that those local sources are still playing primary roles for pollutant transport when the cold front moved from north to south.