利用拉格朗日轨迹追踪模式FLEXPART（the Flexible Particle Model）和水汽源区定量贡献分析方法，研究了超强台风“威马逊”登陆期间（2014年7月17日06：00至19日06：00，协调世界时）强降水的水汽来源和源区定量贡献。结果表明，大量目标气块源自目标降水区西南侧和东侧，西南侧气块可追溯到阿拉伯海和孟加拉湾等地区，且大部分气块来自相对较低层大气，高度在输送途中变化不大，来自东侧的气块可追溯到西太平洋海域，气块初始位置相对较高，在输送途中逐渐降低；源区定量贡献分析显示：南海区域（C）贡献最大，目标降水区域（T）局地贡献次之，孟加拉湾（B）和西太平洋南部区域（D）贡献相当且均低于区域T；区域C和T对“威马逊”登陆期间降水贡献较大源于其较高的源区水汽摄取率（尤其是区域C）和较低的沿途损耗率（尤其是区域T）；区域B源地水汽摄取量高于区域D，但从前者摄取的水汽到达目标降水区域而未被释放的比例明显高于后者，同时，两者沿途损耗率相当，造成两者对目标降水区域的最终贡献也相当；尽管阿拉伯海区域（A）水汽摄取亦较明显，但由于沿途的显著消耗，导致其对目标降水区域的最终贡献显著降低。FLEXPART轨迹追踪模式和水汽源区定量贡献分析方法，与以往常用的环流和水汽通量进行定性分析相比，可更为清晰和定量地揭示热带气旋降水的水汽来源特征。
Using the Flexible Particle (FLEXPART) model, a Lagrangian particle dispersion model, and the areal source-receptor attribution method, the moisture sources for super typhoon Rammasun (landfalling from 0600 UTC July 17, 2014 to 0600 UTC July 19, 2014) were studied, and the contributions from these moisture sources were quantified. Results indicated that the vast majority of the target particles were from southwest and east of the target precipitation region. The former originated from the relatively lower layers of the atmosphere and could be traced back to regions such as the Arabian Sea and the Bay of Bengal, and particle height did not change much in transit. The latter could be traced back to the Western Pacific Ocean, and the particles were relatively higher at their source, descending during transportation. The South China Sea region (C) made the largest contribution, followed by the target precipitation region (T), while the Bay of Bengal (B) and the southern Western Pacific region (D) both contributed similar amounts that were less than those from region T. The greater contributions of regions C and T to the precipitation during Rammasun landfall were attributed to their higher uptake by the storm (especially from region C) and reduced loss in transit (especially from region T). The uptake from region B was higher than that from region D, but the unreleased proportion from the former was significantly higher than that from the latter. Meanwhile, the moisture loss in transit to the storm from both regions B and D was equivalent, resulting in roughly equal contributions to the target precipitation area. Although uptake from the Arabian Sea region (A) was also substantial, its ultimate contribution to the target precipitation region was dramatically reduced due to evaporation in the air parcels. Our study demonstrated that the FLEXPART model and areal source to receptor attribution method can reveal relative moisture source contributions to tropical cyclone precipitation more clearly and quantitatively than the qualitative commonly-used circulation and water vapor flux analysis.
薛一迪,崔晓鹏.“威马逊”（1409）降水水汽来源和源区定量贡献分析.大气科学,2020,44(2):341~355 XUE Yidi,CUI Xiaopeng.Moisture Sources and Quantitative Analyses of Source Contributions of Precipitation Associated with Rammasun (1409).Chinese Journal of Atmospheric Sciences (in Chinese),2020,44(2):341~355复制