气象学报2018，Vol.76Issue(3)：361-378,18.DOI:10.11676/qxxb2018.005
高空急流对青藏高原切变线影响的数值试验与动力诊断
Numerical experiments and dynamic diagnosis of the upper-level jet stream impact on the Tibetan Plateau shear line
摘要
Abstract
Using the NCEP 1°×1°FNL analysis data and the mesoscale model WRF,numerical experiments have been conduc-ted to simulate a Tibetan Plateau shear line process.The study focuses on the impact of the upper-level jet stream intensity on the Tibetan Plateau shear line.In combination with the ω equation,factors affecting the ascending motion in the Tibetan Plat-eau shear line are also analyzed.The results show that the intensity of the upper-level jet stream has an important influence on low-level wind fields.The increases in jet stream will intensify the wind shear along the Tibetan Plateau shear line,and the shear line will become longer.Meanwhile,the enhancement of the upper-level jet intensity is also favorable for the convergence of water vapor along the Tibetan Plateau shear line.The upper jet can affect positive vorticity,convergence and ascending mo-tion along the Tibetan Plateau shear line by influencing the vertical configuration of lower-level convergence and upper-level di-vergence.The diagnostic analysis of the ωequation shows that the Laplace term of temperature advection plays a dominant role in the ascending motion along the Tibetan Plateau shear line,and the low-level warm advection is favorable for the development of ascending motion along the shear line.The influence of the variation of upper-level jet stream intensity on the differential term of the vorticity advection is greater than that of the Laplace term of temperature advection,and the enhancement of the up-per-level jet intensity will enlarge the positive contributions of the differential vorticity advection term and the temperature advection term,which is more favorable for the development of ascending motion and the maintenance of the Tibetan Plateau shear line.关键词
高空急流/青藏高原切变线/强度/数值试验/ω方程Key words
Upper-level jet stream/Tibetan Plateau shear line/Intensity/Numerical experiments/ω equation分类
天文与地球科学引用本文复制引用
罗雄,李国平..高空急流对青藏高原切变线影响的数值试验与动力诊断[J].气象学报,2018,76(3):361-378,18.基金项目
国家自然科学基金(41675057、91337215、41765003、41675042). （41675057、91337215、41765003、41675042）
