层状云酸化数值模拟

NUMERICAL SIMULATION ON THE ACIDIFICATION OF STRATIFORM CLOUDS

发展、设计了一个一维时变参数化微物理过程的暖性层状降水云化学模式,研究云雨酸化机制及 SO_2、HNO_3、和 H_2O_2的云内雨洗清除和云下冲刷清除。结果表明,SO_2被 H_2O_2的氧化是SO_2氧化的最主要途径;S(Ⅳ)→S(Ⅵ)转化率及氧化和清除的相对重要性随时间演变不断变化。模式结果在一定程度上与实测资料相符。

A one-dimensional time-dependent cloud chemistry model with parameterized microphysics isextended to investigate the acidification mechanisms,the rainout and washout of SO_2,HNO_3 andaerosol particles from warm,precipitating stratiform clouds.The model results indicate that(1)therate of S(Ⅳ)→S(Ⅵ)conversion is depentent on the cloud and rain evolution;(2)the most im-portant aqueous oxidation proccess of SO_2 is through H_2O_2 which is responsible for most of theproduction of sulfate;(3)the relative importance of oxidation and scavenging is changing withtime.The calculated results from the model are in general accordance with observations.