摘要
天山山脉对流层大气温湿要素的季节与长期变化,是研究新疆区域气候与资源环境的基础。根据1976—2017年期间天山山脉周围6个气象站探空观测资料,采用时空分析等方法,研究了天山山脉对流层中标准层月平均假相当位温、混合比以及抬升指数季节与年际时空变化与机制。各层假相当位温季节与年际变化存在2种时空模态,850 h Pa层假相当位温模态季节周期变化以非对称型分量为主,700、500、400 h Pa层假相当位温模态季节周期变化为准对称型分量。各层假相当位温模态垂直传播过程存在绝热与非绝热形态。各层混合比季节与年际变化存在2、3种时空模态,850、700 h Pa层混合比模态季节周期变化以准对称型分量为主; 500、400 h Pa层混合比模态季节周期变化以非对称型分量为主,各层混合比模态季节与年际变化的主要影响机制是水汽蒸发-凝结、输送过程,并且季节周期变化位相从低层传播至高层。抬升指数季节与年际变化存在2种时空模态,天山南坡地区7—9月份;北坡地区5—6月份大气层结状况最易于发生强对流天气。天山山脉对流层热湿结构年际变化出现显著线性趋势变化,目前天山山脉对流层热湿结构和大气不稳定层结易于发生异常旱涝灾害以及冰雪消融。
The seasonal and long-term variations of tropospheric atmospheric temperature and humidity in the Tianshan Mountains are the basis for the study of regional climate,resources and environment in Xinjiang,China.Sounding data from six meteorological stations around the Tianshan Mountains were collected from 1976 to 2017.The seasonal and inter-annual spatio-temporal variations of the mean monthly pseudo-equivalent potential temperature,mixing ratio and lifted index of the standard layer in the troposphere were studied through spatiotemporal analysis and so on.The results indicated that there existed two spatio-temporal modes of the seasonal and inter-annual variations of the pseudoequivalent potential temperature in each layer.The seasonal variation of the pseudoequivalent potential temperature mode in the 850 hPa layer was dominated by the asymmetric component,and in the 700,500 and 400 hPa layers by quasi-symmetric component.There were adiabatic and non-adiabatic forms in the vertical propagation of pseudoequivalent potential temperature modes in each layer.There were 2 and 3 spatio-temporal modes in the seasonal and inter-annual variations of mixing ratio in each layer.The seasonal variation of the mixing ratio mode in the 850,700 hPa layers were dominated by quasi-symmetric components,and in the 500,400 hPa layers by asymmetric components.The main mechanism affecting the seasonal and inter-annual variations of mixing ratio in each layer were evaporation,condensation and transportation process of water vapor,and the seasonal cycle changes from lower level to higher level.There were 2 kinds of spatio-temporal modes in the seasonal and inter-annual changes of the lifted index.The strong convective weather most likely occurred under the atmospheric stratification status between July and September along the southern slope of the Tianshan Mountains and between May to June along the north slope of the Tianshan Mountains.The inter-annual changes of thermal and wet structure within troposphere in the Tianshan Mountains had a significant linear trend.At present,the thermal and wet structure of troposphere and the unstable stratification of the atmosphere in the Tianshan Mountains are prone to result in abnormal droughts and floods,ice melting and snow.
作者
石强
SHI Qiang(Key Laboratory of Marine Spill Oil Identification and Damage Assessment Technology,SOA,Qingdao 266033,China;North China Sea Environmental Monitoring Center,SOA,Qingdao 266033,China;Shandong Province Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation,Qingdao 266033,China)
出处
《山地学报》
CSCD
北大核心
2018年第6期844-856,共13页
Mountain Research
基金
海洋溢油鉴别与损害评估技术国家海洋局重点实验室项目(2015010)~~
关键词
天山山脉
对流层
假相当位温
混合比
抬升指数
时空模态
the Tianshan Mountains
troposphere
pseudoequivalent potential temperature
mixing ratio
lifted index
spatio-temporal mode
