云凝结核浓度对南京地区一次冰雹云过程影响的数值模拟研究
投稿时间: 2018-02-03  最后修改时间: 2018-04-01  点此下载全文
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作者单位E-mail
刘晓莉 南京信息工程大学 liuxiaoli2004y@nuist.edu.en 
朱煜 南京信息工程大学  
基金项目:国家自然科学基金项目(41375137)
中文摘要:采用WRF模式与包含了云凝结核(CCN)浓度和霰雹密度预报的NSSL微物理方案模拟了不同CCN初始浓度条件下南京地区的一次冰雹云过程,分析了不同CCN初始浓度条件下冰雹云过程的宏微观演变特征,以及对流发展不同阶段的水凝物粒子及流场、温度场的垂直分布特征。研究发现:(1)较大的CCN初始浓度虽然抑制了前期的对流降水,但对后期对流降水的产生有促进作用;(2)CCN初始浓度的增加使得模拟雷达回波的强回波区域(大于40dBZ)缩小,中等强度区域区域(小于40dBZ)扩张。(3)CCN初始浓度增大不利于对流发展初期云雨自动转化过程的发生,但是促进了冰晶与雪的产生,使得冰雹含量峰值出现的时间推迟。(4)CCN浓度增大抑制了雨水产生,间接使得霰粒子更倾向于干增长,平均密度更小;(5)较大的CCN促使冰雹云单体的发展更持久。
中文关键词:冰雹云,云凝结核,中尺度数值模式,微物理过程
 
Numerical simulation of the influence of cloud condensation nucleus concentration on a hail cloud in Nanjing area
Abstract:Bsed on WRF model simulation with NSSL microphysical scheme, which including prediction of cloud condensation nuclei(CCN) concentration and volume of graupel an hail, a hail storm developed in Nanjing is simulated under three different CCN initial concentrations, The variation of precipitation and hydrometeor , as well as the vertical distribution of hydrometeor, temperature and wind at different stage of storm developing are investigated. It is found that: (1)Greater CCN concentration decrease the precipitation during the early stage, but increase the precipitation during the later stage. (2)Greater CCN concentration lead to the enlargement of high dBZ area(>40dBZ) and the atrophy of middle dBZ area(<40dBZ). (3) Greater CCN concentration increase the amount of snow and ice, decrease the graupel and delay the appearance of the high peak of amount of hail. (4) Increased concentration of CCN inhibits rain production, indirectly making helium particles more prone to dry growth, with lower average density. (5) Greater CCN concentration suppress early warm cloud process, but promote the production of snow and ice, which make the hail storm stronger and lasting longer.
keywords:hail cloud, cloud condensation nucleus, meso-scale numerical model, microphysical processes
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