期刊文献+

南京地区一次降水过程湍流特征研究 预览 被引量:1

Turbulent characteristics of surface layer during a heavy precipitation event over the Nanjing area,eastern China
在线阅读 免费下载
收藏 分享 导出
摘要 利用南京大学浦口校区大气科学园的近地层湍流脉动资料及Meteorological InformationComprehensive Analysis and Process System气象数据资料,针对2008年5月南京地区一次降水过程,分析比较了降水前后的湍流强度、归一化湍流动能、近地层通量输送和速度能谱特征.结果表明:从气象要素上看,降水临近时风速变化大,温度、气压降低明显,降水期间湿度很高.从湍流特征上看,降水时湍流强度突变增大,归一化湍流动能也变大,湍流活动增强;u、v方向动量输送-u′w′、-v′w′强度都增大,但输送方向相反,此时近地层归一化摩擦速度也明显变大;感热通量w′T′迅速减小,甚至微弱逆向输送;降水前后风速能谱惯性副区基本满足Kolmogorov的-2/3次方律,降水时u、v能谱低频段峰值频率左移明显,分析低频段峰值对应涡的尺度发现,近地层中降水前后贡献湍流能量最大的涡尺度存在很大差异. We measured the surface layer turbulence data in the Pukou Campus of Nanjing University.In a combination with the datasets from Meteorological Information Comprehensive Analysis and Process System,a heavy precipitation process over the Nanjing area in May 2008 is discussed here.Turbulence,its intensity,normalized kinetic energy,surface layer turbulence flux as well as the energy spectrum of wind speed are specifically analyzed to illustrate progressing states of precipitation.By contrasting different states in a temporal sequence,we obtain several conclusions: as to meteorological elements,wind speed sharply increased along with a significant decrease of air temperature and pressure when rain was approaching.During the rain,surface layer humidity remained high;when it comes to turbulent characteristics,turbulence intensity and normalized turbulence kinetic energy increased sharply.Specifically,vertical momentum flux of u and v both intensified in magnitude but transferred reversely.Meanwhile,the sensible heat flux decreased rapidly to zero,even slightly negative.In the wind spectrum,the inertial sub-range adjusted to Kolmogorov's-2/3 law at any time of the experiment.However,the frequency at the low end peaked pronouncedly much more left.With further interpretation on corresponding vortex scales,great differences are observed with the progressing of precipitation itself.
作者 杜云松 彭珍 张宁 宋丽莉 Du Yun-Song1,Peng Zhen1,Zhang Ning1,Song Li-Li2(1.School of Atmospheric Science,Nanjing University,Nanjing,210093,China;2.Guangzhou Institute of Tropical and Marine Meteorology,China Meteorological Administration,Guangzhou,510080,China)
出处 《南京大学学报:自然科学版》 CSCD 北大核心 2011年第6期703-711,共9页 Journal of Nanjing University: Nat Sci Ed
基金 国家自然科学基金(40905002,40775071) 南京大学新教师基金(20090091120039) 国家重点基础研究发展计划(2010CB428501)
关键词 近地层 降水 湍流特征 湍流通量 能谱 surface boundary layer,rain event,turbulence characteristic,turbulence flux,spectrum
  • 相关文献

参考文献16

二级参考文献205

共引文献231

同被引文献14

引证文献1

投稿分析

相关作者

内容加载中请稍等...

相关机构

内容加载中请稍等...

相关主题

内容加载中请稍等...

浏览历史

内容加载中请稍等...
;
使用帮助 返回顶部 意见反馈