大气科学2011，Vol.35Issue(1)：41-54,14.
辐射雾雾滴谱拓宽的微物理过程和宏观条件
The Microphysical Processes and Macroscopic Conditions of the Radiation Fog Droplet Spectrum Broadening
摘要
Abstract
In order to study the physical-chemical processes of fog in Nanjing, field observations were conducted in Nanjing University of Information Science ＆ Technology during the winters of 2006 and 2007, when 27 fog cases were acquired, including 22 cases of contiguous fog droplet spectrum data. According to the droplet spectrum distribution the radiation fog could be divided into wide-spectrum one, which is all extremely dense fog with the maximum diameter more than 40 μm , and narrow-spectrum one, most of which is dense fog with the maximum diameter less than 22μm. During developing from dense fog to extremely dense fog, the radiation fog is characterized by the explosive deepening, whose nature is the fog droplet spectrum burst broadening, and the increase of number concentration and LWC. The macroscopic condition and microphysical process of the fog droplet spectrum burst broadening were detailedly analyzed in this paper, and the result shows that: the fog droplet spectrum burst broadening occurred during the period of temperature rapid decline (Super-saturation increase). The weak cold advection or the water evaporation from the wet surface after sunrise during the dense fog episode is apt to cause the burst broadening of the fog droplet spectrum. Early fog droplet spectrum broadening was mainly based on nucleation and condensation, but coalescence and condensation during the late period. The droplet spectrum “widening” has the characteristic of a ladder-type, but when the cooling rate and the degree of supersaturation are very large, the number of fog drops in all bins could increase, and the maximum diameter could enlarge continuously. The turbulence not only plays an important role in the vertical transmission of momentum, heat, and water vapor, but also is the importantcondition for fog droplet collision broadening.关键词
辐射雾/雾滴谱/拓宽/南京Key words
radiation fog/ fog droplet spectrum/ broadening/ Nanjing分类
天文与地球科学引用本文复制引用
李子华,刘端阳,杨军..辐射雾雾滴谱拓宽的微物理过程和宏观条件[J].大气科学,2011,35(1):41-54,14.基金项目
国家自然科学基金资助项目40975085,公益性行业(气象)专项GYHY(QX)2007-6-26、GYHY200906012,中国气象局云雾物理环境重点开放实验室开放课题项目(2009006),江苏省自然科学基金重点招标项目BK2007727 （气象）
