doi:  10.3878/j.issn.1006-9895.1701.16205
2014年夏季青藏高原狮泉河与林芝降水低频振荡及陆—气过程日变化特征

Low Frequency Oscillation of Precipitation and Daily Variation Characteristic of Air-Land Process at Shiquanhe Station and Linzhi Station in Tibetan Plateau in the Summer of 2014
摘要点击 354  全文点击 224  投稿时间:2016-08-02  
查看HTML全文  查看全文  查看/发表评论  下载PDF阅读器
基金:  国家重点基础研究计划2015CB453202、2014CB953902,国家自然科学基金项目91337216、41305065
中文关键词:  青藏高原  低频振荡  近地面层  日内变化  湍流
英文关键词:  Tibetan Plateau  Low frequency oscillation  Surface layer  Diurnal variation  Turbulence
           
作者中文名作者英文名单位
段丽君Duan Lijun成都信息工程大学大气科学学院, 成都 610225;中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG), 北京 100029
段安民Duan Anmin中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG), 北京 100029
胡文婷Hu Wenting中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG), 北京 100029
巩远发Gong Yuanfa成都信息工程大学大气科学学院, 成都 610225
引用:段丽君,段安民,胡文婷,巩远发.2017.2014年夏季青藏高原狮泉河与林芝降水低频振荡及陆—气过程日变化特征[J].大气科学,41(4):767-783,doi:10.3878/j.issn.1006-9895.1701.16205.
Citation:Duan Lijun,Duan Anmin,Hu Wenting,Gong Yuanfa.2017.Low Frequency Oscillation of Precipitation and Daily Variation Characteristic of Air-Land Process at Shiquanhe Station and Linzhi Station in Tibetan Plateau in the Summer of 2014[J].Chinese Journal of Atmospheric Sciences (in Chinese),41(4):767-783,doi:10.3878/j.issn.1006-9895.1701.16205.
中文摘要:
      根据“第三次青藏高原大气科学试验” 2014年7、8月青藏高原西南部狮泉河站、东南部林芝站的3 m涡动相关系统原始数据和10 Hz湍流资料以及中国气象局台站观测资料、JRA-55(Japanese 55-year Reanalysis)逐日再分析资料、GPCP(Global Precipitation Climatology Project)全球降水逐日观测资料,分别讨论了这两个站在10~20天低频振荡的天气背景下其干、湿位相近地层气象要素的日变化特征以及湍流变化特征。结果表明:两站高低空环流场、水汽通量场、热源的10~20天低频分量在其干、湿位相期间的配置相反。低频地表感热和潜热的不同变化对降水的影响分别在高原西部和东部有不同表现。狮泉河站的低频振荡在纬向上自西向东传播,而林芝站的低频振荡在纬向上自东向西传播,结果表明这两个站分别存在两种不同起源的低频振荡。两站干、湿位相的近地面气象要素以及湍流通量具有明显的日变化特征,通常温度极大值出现在午后14时(北京时,下同),但狮泉河站干、湿位相的温度极大值均出现在夜间20时;由波文比可知,狮泉河站湿位相全天以潜热为主导,干位相期间,06时之前以潜热为主,06时之后以感热为主;林芝站干、湿位相均为08时之前以感热为主,08时之后以潜热为主。两站湍流平均动能与平均风速正相关,垂直动量表现为向下传输,热量和水汽表现为向上传输。
Abstract:
      Using the original data of 3 m eddy correlation system and 10 Hz turbulence data at Shiquanhe station and Linzhi station, which are respectively located at the southwestern and southeastern Tibetan Plateau, obtained during "the 3rd Tibetan Plateau atmospheric scientific experiment", station observation data provided by China Meteorological Administration, JRA-55, and GPCP (Global Precipitation Climatology Project) daily reanalysis data in July and August of 2014, the diurnal variations of surface layer meteorological elements and turbulent changes under the background of 10-20-day low frequency oscillation in two stations are studies respectively. The results are as follows. The 10-20-day low frequency component of circulation fields in the upper and lower troposphere and water vapor fields and heat sources at the two stations are opposite during their dry and wet phases. The variations of low frequency surface sensible and latent heat fluxes have influences on precipitation, and these influences are different in the western and eastern Plateau. The low frequency oscillation at Shiqianhe station propagates from west to east, whereas the oscillation at Linzhi station propagates from east to west. Thus, there are two types of low frequency oscillations from different origins. Surface layer meteorological elements and turbulent flux have obvious diurnal variations in the dry and wet phases. The highest temperature usually appears at 1400 BJT (Beijing time) but at 2000 BJT in the dry and wet phases at Shiquanhe station. Based on Bowen ratio, it can be found that the latent heat is dominant throughout the day at Shiquanhe station in the wet phase, while latent heat is dominant before 0600 BJT and sensible heat is dominant after 0600 BJT during the dry phase. At Linzhi station in both wet and dry phases, sensible heat is always dominant before 0800 BJT and latent heat is dominant after 0800 BJT. The average kinetic energy of turbulence and average wind speed are positively correlated at the two stations, and the vertical momentum is transported downward while heat and moisture are transported upward.
主办单位:中国科学院大气物理研究所 单位地址:北京市9804信箱
联系电话: 010-82995051,010-82995052传真:010-82995052 邮编:100029 Email:dqkx@mail.iap.ac.cn
本系统由北京勤云科技发展有限公司设计
京ICP备09060247号