Relative contributions of weather systems to mean and extreme global precipitation
Relative contributions of weather systems to mean and extreme global precipitation
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DOI：
10.1002/2016jd025222
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
N. Utsumi;Hyungjun Kim;S. Kanae;T. Oki
中科院分区：
文献类型：
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作者：
N. Utsumi;Hyungjun Kim;S. Kanae;T. Oki
这项研究首次对热带气旋、温带气旋中心和锋面等不同天气系统对平均和极端降水的相对贡献进行了全球估计。利用2001-2010年再分析数据集和基于卫星的降水产品，采用了对降水天气系统进行客观分类的方法。热带气旋、伴随锋面的温带气旋和其他天气系统分别贡献了全球(60°S-60°N)平均降水量的4%、37%和59%。在不同的降水强度等级和不同的降水时间尺度上，天气系统的相对贡献是不同的。在热带气旋和温带气旋活动的大多数海洋区域，热带气旋和温带气旋对极端小时降水量的贡献大于对年降雨量的贡献。热带气旋对极端降水的贡献在24-72h的时间尺度上有明显的峰值，温带气旋对极端降水的贡献对时间尺度的依赖性小于热带气旋。对多种天气系统的综合分析表明，在北美东部和东亚，与热带气旋有关的极端24小时降水中，有很大一部分(分别为22%和19%)是由热带气旋和锋面共存造成的。然而，这种贡献在其他陆地地区很少发现。在大多数时间尺度上，远离温带气旋中心的锋面对极端降水的贡献与温带气旋中心的贡献一样大。
This study presents the first global estimates of the relative contributions of different weather systems, i.e., tropical cyclone, center and front of extratropical cyclone, and others, to mean and extreme precipitation. An objective method of classification of the precipitating weather systems was used with a reanalysis data set and a satellite‐based precipitation product for 2001–2010. Tropical cyclones, extratropical cyclones with associated fronts, and other weather systems contribute about 4%, 37%, and 59%, respectively, of the global (60°S–60°N) mean precipitation. The relative contributions of the weather systems were found to be different both in terms of the different classes of precipitation intensity and in terms of the different temporal scales of precipitation. Tropical cyclones and extratropical cyclones produced greater contributions to extreme hourly precipitation than to annual precipitation in most of the oceanic regions of their activity. The contributions of tropical cyclones to extreme precipitation showed clear peaks on temporal scales of 24–72 h. The contributions of extratropical cyclones showed less dependence on the temporal scale than tropical cyclones. Consideration of combinations of multiple weather systems revealed that in eastern North America and East Asia, substantial portions (22% and 19%, respectively) of the extreme 24 h precipitation related to tropical cyclones are contributed by the coexistence of tropical cyclones and fronts. However, such contributions were found rarely in other land regions. On most temporal scales, fronts at locations remote from the centers of extratropical cyclones were found to contribute to extreme precipitation as much as the centers of extratropical cyclones.