秦巴山区夏季降水异常年水汽输送特征分析  

Summer Water Vapor Transport and Sources in Anomalous Precipitation Years over the Qinba Mountains

作　　者：杨镒如 王斌 李双双 邢莉 毛兴莉 尚溦 石培宏 程颖 段克勤 YANG Yiru;WANG Bin;LI Shuangshuang;XING Li;MAO Xingli;SHANG Wei;SHI Peihong;CHENG Ying;DUAN Keqin(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,Shaanxi,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《高原气象》2025年第2期421-434,共14页Plateau Meteorology

基　　金：国家自然科学基金面上项目(42072208);陕西省自然科学基础研究计划面上项目(2018JM4027);陕西省自然科学基金面上项目(2023-JC-YB-259)。

摘　　要：秦岭-大巴山合称秦巴山区,被称为我国的“中央水塔”,是南北过渡带的主体组成部分,对我国自然环境演变起着至关重要的调节作用。然而当前对于秦巴山区降水的水汽源地贡献量和变化成因尚不清楚,严重制约了对其影响我国南北地理分界深层机理的理解。鉴于此,基于HYSPLIT(Hybrid Single Particle Lagrangian Integrated Trajectory)拉格朗日轨迹追踪模式,对1970-2020年降水高、低值年夏季降水进行后向轨迹追踪模拟,并结合欧拉方法计算水汽通量及风场距平,系统分析了秦巴山区6-8月不同垂直高度层上的水汽输送路径与源地贡献特征。研究结果表明:(1)秦巴山区夏季主要水汽通道有:局地通道、欧亚通道、西太平洋通道、南海通道及印度洋通道。(2)从通道强度看,降水高值年低层主要水汽通道为局地和南海通道;中、高层主要通道为欧亚通道和印度洋通道。降水低值年6-8月各层主要通道几乎均为欧亚通道。(3)从源地贡献看,高值年低层主要水汽源地为局地及南海地区,低值年低层南海、欧亚及西太平洋地区水汽贡献相当,中、高层主要源地为欧亚和印度洋地区。(4)东南地区环流异常与秦巴山区夏季降水量变化高度一致,该地反气旋性及气旋性异常环流特征对降水高、低值年水汽输送差异影响显著。研究结果初步揭示了秦巴山区夏季降水异常年的水汽输送特征和变化成因,为进一步理解“中央水塔”的成因和秦巴山区的地理分界作用提供了关键证据。The Qinling-Daba Mountains(Qinba Mountains)are referred to as the‘Central Water Tower’of China.They constitute the main transitional zone between the north and south and play a crucial regulatory role in the evolution of the natural environment.However,the current understanding of the contributions and causes of water vapor sources in the Qinba Mountains remains unclear,significantly impeding the comprehension of the underlying mechanisms that influence the geographical division between the north and south of China.In this study,we simulate the vapor trajectory in summer of years with high and low precipitation from 1970 to 2020 using the HYSPLIT model,and calculates the anomalies of vapor and wind using Eulerian method.The characteristics of vapor transport pathways and source contributions at different vertical levels from June to August over the Qinba Mountains were systematically analyzed.The results showed that:(1)The main summer water vapor channels in the Qinba Mountains are:the local channel,the Eurasian channel,the Western Pacific channel,the South China Sea channel and the Indian Ocean channel.(2)In terms of channel strength,the main vapor channels at the lower levels in high precipitation years are the local and South China Sea channels;that at the middle and upper levels are the Eurasian channel and the Indian Ocean channel.In the low precipitation year,the main channel at all levels is the Eurasian channel.(3)In terms of source contributions,the main source at the lower level in high precipitation years is the local and the South China Sea,that at the lower level in low years is the local,South China Sea and western Pacific.The main source at the middle and upper levels is the north Indian Ocean.(4)The anomalous characteristics of anticyclones and cyclonic circulation in the southeast have a significant impact on the difference in water vapor transport between high and low precipitation years.This study provides preliminary insights into the vapor transport characteristics during summer over the

关 键 词：HYSPLIT模式 秦巴山区 降水异常 水汽输送 水汽源地 

分 类 号：P426[天文地球—大气科学及气象学]