A Study on Future Projections of Precipitation Characteristics around Japan in Early Summer Combining GPM DPR Observation and CMIP5 Large-Scale Environments
A Study on Future Projections of Precipitation Characteristics around Japan in Early Summer Combining GPM DPR Observation and CMIP5 Large-Scale Environments
复制标题
结合GPM DPR观测和CMIP5大尺度环境对日本周边初夏降水特征的未来预测研究
DOI：
10.1175/jcli-d-18-0656.1
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发表时间：
2019
影响因子：
4.9
通讯作者：
Ose Tomoaki
中科院分区：
文献类型：
--
作者：
Yokoyama Chie;Takayabu Yukari N.;Arakawa Osamu;Ose Tomoaki
本研究通过结合全球降水测量降水雷达观测和耦合模式相互比较项目气候模式大尺度预测的第5阶段，使用大尺度环境的变化来估计日本周围初夏降水特征的未来变化。分析基于卫星的数据，我们首先涉及降水的三种类型的降雨事件（小，有组织的，和中纬度），这是通过他们的特点，大尺度的环境。选择两个环境场来确定降水的大尺度条件：海表温度场和中层大尺度垂直速度场。前者与对流层低层的热不稳定性有关，而后者则通过对流层中层的增湿/干燥来影响降水。因此，就这两种环境场而言，三种类型之间的有利条件不同。利用这些降水-环境关系，我们然后重建的降水分布为每一种类型的参考气候模式中的两个环境指数为现在和未来的气候。重建的降水量的未来变化被发现与大尺度环境之间的三种类型之间的差异很大。在90%以上的模式中，受有组织降水影响的区域将向北扩展，导致日本海沿着附近、太平洋一侧的日本北方和东部等目前降水量相对较少的地区的有组织降水量大幅增加。这一结果表明，在这些地区的大雨的风险增加，因为最大的降水强度是更强烈的有组织的类型的降水比其他两种类型。
This study estimates future changes in the early summer precipitation characteristics around Japan using changes in the large-scale environment, by combining Global Precipitation Measurement precipitation radar observations and phase 5 of the Coupled Models Intercomparison Project climate model large-scale projections. Analyzing satellite-based data, we first relate precipitation in three types of rain events (small, organized, and midlatitude), which are identified via their characteristics, to the large-scale environment. Two environmental fields are chosen to determine the large-scale conditions of the precipitation: the sea surface temperature and the midlevel large-scale vertical velocity. The former is related to the lower-tropospheric thermal instability, while the latter affects precipitation via moistening/drying of the midtroposphere. Consequently, favorable conditions differ between the three types in terms of these two environmental fields. Using these precipitation–environment relationships, we then reconstruct the precipitation distributions for each type with reference to the two environmental indices in climate models for the present and future climates. Future changes in the reconstructed precipitation are found to vary widely between the three types in association with the large-scale environment. In more than 90% of models, the region affected by organized-type precipitation will expand northward, leading to a substantial increase in this type of precipitation near Japan along the Sea of Japan, and in northern and eastern Japan on the Pacific side, where its present amount is relatively small. This result suggests an elevated risk of heavy rainfall in those regions because the maximum precipitation intensity is more intense in organized-type precipitation than in the other two types.