【作者】 陈丽； 银燕； 杨军；

【Author】 Chen Li Yin Yan Yang Jun (Jiangsu Key Laboratory of Meteorological Disaster, Nanjing University of Information and Science Technology, Nanjing, 210044)

【机构】 南京信息工程大学江苏省气象灾害重点实验室；

【摘要】 本文采用二维分档云模式对观测得到的气溶胶谱进行对数正态分布拟合,对比背景大气气溶胶分布讨论了扬沙和沙尘暴这两种不同等级的沙尘天气对云和降水的影响。模拟的结果表明:(1)当沙尘仅作为云凝结核时,扬沙和沙尘暴发生时滴谱向小滴方向移动,抑制暖云降水,冰晶的核化和增长变缓抑制冷云降水,云的光学厚度和反照率增加。(2)当沙尘作为云凝结核和冰核时,冰核浓度的增加使各水成物滴谱向小尺度方向移动,有效半径的减小抑制暖云和冷云降水,云的光学厚度和反照率增大。更多还原

【Abstract】 Using observed aerosol spectra of raising dust and sandstorm fitted by lognormal distribution functions into the two-dimensional spectral resolving cloud model, effects of cloud-processed mineral dust particles on the subsequent development of cloud and precipitation are discussed separately in contrast to the aerosol distribution of background condition. Results of the numerical simulation show that 1) if sand dust acts only as cloud condensation nuclei, under appearance of the raising dust and sandstorm the drop spectra moves towards the small end, contributing to an decrease in warm cloud precipitation as well as ice nucleation and decrease the amount of the ice crystals, which, in turn, leads to the reduction of cold cloud precipitation and enhances the cloud optical depth and albedo. 2) If sand dust acts as cloud condensation nuclei and ice nuclei, increase in the initial concentration of ice nuclei makes all the hydrometeors’ spectra shift to small-scale, resulting in decrease in the effective radii, which inhibits cold and warm cloud precipitation and enhances the cloud optical depth and albedo.更多还原