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中国沙漠 ›› 2012, Vol. 32 ›› Issue (2): 484-490.

• 天气与气候 • 上一篇    下一篇

贺兰山两侧沙漠及污染城市CCN分布特征的观测研究

桑建人1, 陶 涛1, 岳岩裕2, 舒志亮1, 翟 涛1, 孙艳桥1   

  1. 1.宁夏回族自治区气象科学研究所 宁夏气象防灾减灾重点实验室, 宁夏 银川 750002;
    2.南京信息工程大学 大气物理与大气环境重点实验室, 江苏 南京 210044
  • 收稿日期:2011-03-10 修回日期:2011-11-28 出版日期:2012-03-20 发布日期:2012-03-20

Distribution of Cloud Condensation Nuclei over Desert and Polluted City beside the Helan Mountains

SANG Jian-ren1, TAO Tao1, YUE Yan-yu2, SHU Zhi-liang1, ZHAI Tao1, SUN Yan-qiao1   

  1. 1.Key Laboratory of Preventing and Reducing Meteorological Disaster of Ningxia, Ningxia Institute of Meteorological Sciences, Yinchuan 750002, China;
    2.Key Laboratory for Atmospheric physics & Environment, Nanjing University of Information Science & Technology, Nanjing 210044, China
  • Received:2011-03-10 Revised:2011-11-28 Online:2012-03-20 Published:2012-03-20

摘要: 利用DMT公司生产的连续流单过饱和度云凝结核计数器2007年8月在内蒙古自治区阿拉善左旗、宁夏回族自治区石嘴山市惠农区进行观测,并利用机载PMS观测资料,探讨贺兰山两侧云凝结核(CCN)在近地面和高空的垂直变化。分析表明,CCN主要来源于下垫面,污染地区的浓度明显高于沙漠地区,城市污染对CCN浓度的影响很大。CCN浓度的日变化非常明显。不同过饱和度下粒子谱谱型不同,主要表现为单峰型。过饱和度越大,活化的CCN数目越多,产生的粒子半径越大。高空观测表明,CCN、气溶胶数浓度在近地面较高,随高度的上升逐渐降低,遇到逆温层会出现浓度的跃升,其活化液滴谱型表现为双峰型,与地面相比,粒子谱向大粒子端移动,峰值半径在4 μm和6 μm左右。气溶胶粒子浓度主要集中在粒径0.3 μm以下;根据公式N=CSK对地面的CCN活化谱进行拟合,接近大陆型核谱。不同地区及同一地区不同时间范围,CCN浓度、活化谱及活化后的液滴谱存在差异,需要在不同地区、不同季节对CCN谱型演变特征进行长期连续观测,从而认识CCN浓度及谱型的变化对云雾降水过程及气候变化的作用。不同地区可充当CCN气溶胶的谱分布及表面化学成分不同,其对CCN数浓度及谱分布的影响也不同,在观测中需要增加化学成分的观测,深入了解CCN浓度的时空分布特征。

关键词: 云凝结核, 垂直分布, 对比观测

Abstract: By analyzing observation data from cloud condensation nucleus counter and airborne PMS in August, 2007 in Alxa Left Banner of Inner Mongolian and Huinong District of Shizuishan City in Ningxia, the vertical variations of concentration of cloud condensation nucleus (CCN) near the ground and in the upper layers in the both sides of the Helan Mountains were discussed. CCN came mainly from underlying land surface, and its concentration in contaminated areas was significantly higher than over the desert because its concentration was greatly affected by urban pollution. Daily change of CCN concentration was apparent. The particle spectrum types were different under different supersaturation, mainly as single peak. The greater the supersaturation degree was, the greater number of the activated CCN was, and the greater the radius of particles produced. Observation in upper air showed that CCN concentration and aerosol number concentration were higher in the near-surface, and decreased with height, but the concentration would abruptly increase when it encountered inversion layer. Activated droplet spectrum of CCN presented bimodal type. Compared with CNN near the ground, the particle spectra of CNN in upper air moved to the side of large particles, and particle radius peak values were about 4 μm and 6 μm. Particle sizes of most aerosol particles were less than 0.3 μm. Activated droplet spectrum of CCN was close to the continental nuclear spectrum. CCN concentration, activation spectrum and activated droplet spectrum were different in different areas or different time. In order to understand the effect of CCN concentration and CCN spectral types on precipitation process and climate change, long-term continuous observation for CCN spectral type in different areas and different seasons was needed. Chemical compositions of CCN were different in different areas, and its effects on CCN concentration and spectrum distribution were also different, so observation of chemical composition of CNN was needed to deeply understand the characteristics of CNN spatial-temporal distribution.

Key words: cloud condensation nucleus, vertical distribution, comparative observation

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