秦岭南北降水空间分异研究

为了探讨秦岭南北降水空间分异特征,本文以秦岭山脊线南北22个气象站点2011~2018年间的逐日降水量及全球资料同化系统风向数据为基础,借助协同克里金插值和混合单粒子拉格朗日积分扩散传输模型(HYSPLIT模型)的后向轨迹模式等方法,对秦岭山区降水进行了空间格局分析、水汽轨迹追踪及水汽源地贡献率计算。结果表明:(1)秦岭山区等降水量线南北空间变化格局反映了山地水汽阻隔效应,同时北麓年降水总量空间差异较小,而南麓年降水总量自西向东则有高-低-高的分布特征、空间变异较大;(2)秦岭山区水汽输送路径主要有三条:源自印度洋孟加拉湾的西南水汽、源自西太平洋的东南水汽、来自蒙古-西伯利亚的北方极地大陆水汽;(3)夏季的秦岭西部山地对西南水汽的阻隔作用效果大于东部山地作用于东南水汽,而秋季的印度洋水汽输送基本对山脉北麓降水没有显现影响,而西太平洋水汽的输送路径只是向东有所偏移。

Study on Spatial Differentiation of Precipitation between North and South of Qinling Mountains

In order to explore the spatial differentiation characteristics of precipitation in north and south of Qinling Mountains, data of daily precipitation of 22 meteorological stations in north and south of Qinling Mountain Ridge during 2011-2018 and the wind direction of global data assimilation system was collected to perform the spatial pattern analysis, water vapor trajectory tracking and water vapor source contribution rate calculation by means of co-Kriging interpolation and backward trajectory model of mixed single particle Lagrange integral diffusion transmission model. The results showed that the spatial pattern of the equal precipitation line in Qinling Mountains reflects the mountain water vapor barrier effect, while the spatial difference in the annual precipitation in the northern foot is small. The annual precipitation in the southern foot has the distribution characteristics of high-low-high from west to east, and the spatial variation is large. There are three main water vapor transport paths in Qinling Mountains: Southwest water vapor from Indian Ocean Bay of Bengal, southeast water vapor from western Pacific Ocean, and northern polar continent water vapor from Mongolia-Siberia. In summer, the blocking effect of western Qinling Mountains on southwest water vapor is greater than that of eastern Qinling Mountains on southeast water vapor, while in autumn, the Indian Ocean water vapor transport basically has no effect on precipitation at the northern foot of the mountains, while the water vapor transport path in western Pacific Ocean only deviates eastward.