The relationship between Indian monsoon rainfall and low-pressure systems
The relationship between Indian monsoon rainfall and low-pressure systems
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印度季风降雨与低压系统的关系
DOI：
10.1007/s00382-019-04744-x
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发表时间：
2019
期刊：
影响因子：
4.6
通讯作者：
Hunt K
中科院分区：
文献类型：
--
作者：
Hunt K
印度夏季风降水显著地受到天气尺度热带低压区（LPAs）的调制，其中最强的是季风低压（MDs）。尽管它们显然很重要，但以前的研究试图限制季风降水的比例，这些系统负责产生了一个不令人满意的广泛的估计。在这里，DBSCAN算法的一个变种，实现识别非平凡的，连贯的降雨结构TRMM-3B 42降水数据。使用理论上的考虑和理想化的模型，计算出的有效捕获半径为200公里，提供上限归因分数为57%（17%）的LPAs（MD）在季风核心区和44%（12%）在整个印度。这些结果也被放置在更简单的归因技术的背景下。这些集群的气候学表明，孟加拉湾（BoB）的中央是最强的天气组织的区域。Ak-means聚类技术被用来识别四个不同的分区LPA（和MD）的轨迹，并评估其区域贡献季风降水。印度上空的大部分天气性降雨都是由来自孟加拉湾顶部的短寿命低气压造成的，尽管需要较长寿命的系统才能给印度西部和巴基斯坦东部带来降雨。来自阿拉伯海和南BoB系统的次级贡献分别对西巴基斯坦和斯里兰卡很重要。最后，一个数据库的降水事件类型显示，小规模的深对流发生独立的MD，而大规模的对流和层状事件的密度是敏感的，他们的存在证明使用的噪声拒绝算法。
Indian summer monsoon precipitation is significantly modulated by synoptic-scale tropical low pressure areas (LPAs), the strongest of which are known as monsoon depressions (MDs). Despite their apparent importance, previous studies attempting to constrain the fraction of monsoon precipitation for which such systems are responsible have yielded an unsatisfyingly wide range of estimates. Here, a variant of the DBSCAN algorithm is implemented to identify nontrivial, coherent rainfall structures in TRMM-3B42 precipitation data. Using theoretical considerations and an idealised model, an effective capture radius is computed to be 200 km, providing upper-bound attribution fractions of 57% (17%) for LPAs (MDs) over the monsoon core zone and 44% (12%) over all India. These results are also placed in the context of simpler attribution techniques. A climatology of these clusters suggests that the central Bay of Bengal (BoB) is the region of strongest synoptic organisation. Ak-means clustering technique is used to identify four distinct partitions of LPA (and two of MD) track, and their regional contributions to monsoon precipitation are assessed. Most synoptic rainfall over India is attributable to short-lived LPAs originating at the head of the BoB, though longer-lived systems are required to bring rain to west India and east Pakistan. Secondary contributions from systems originating in the Arabian Sea and south BoB are shown to be important for west Pakistan and Sri Lanka respectively. Finally, a database of precipitating-event types is used to show that small-scale deep convection happens independently of MDs, whereas the density of larger-scale convective and stratiform events are sensitive to their presence—justifying the use of a noise-rejecting algorithm.
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影响因子：
8.9
作者：
Hurley, John V.;Boos, William R.
通讯作者：
Boos, William R.
印度季风洼地与西北中层干燥入侵的相互作用
DOI：
--
发表时间：
2018
期刊：
影响因子：
--
作者：
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通讯作者：
M. Govindankutty
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影响因子：
8.9
作者：
Kieran M. R. Hunt;A. Turner
通讯作者：
A. Turner
影响因子：
0.6
作者：
S. Rajamani;K. Rao
通讯作者：
K. Rao
气候模式模拟中季风平均降水与低压系统的关系
影响因子：
4.9
作者：
V. Praveen;S. Sandeep;R S Ajayamohan
通讯作者：
R S Ajayamohan