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arXiv 1702.00218physics.ao-ph
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在非常低和高季节性降水的全球模式中不同ENSO特征的不同印记

Differential imprints of distinct ENSO flavors in global patterns of very low and high seasonal precipitation

Marc Wiedermann, Jonatan F. Siegmund, Jonathan F. Donges, Reik V. Donner

摘要:

近年来,厄尔尼诺的两种不同类型--东太平洋(EP)和中太平洋(CP)/莫多基(Modoki)厄尔尼诺对全球气候变率的影响得到了广泛的研究。这些研究大多使用线性多元统计或复合分析。特别是前者假定在厄尔尼诺-南方涛动(ENSO)的不同阶段适用同样类型的线性统计相关性,这似乎不一定是一个合理的假设。在这里,我们统计评估了全球大部分陆地表面非常高或非常低的季节性降水量之间同时发生的可能性,以及厄尔尼诺和拉尼娜的各自EP和CP类型的存在。通过采用事件巧合分析,我们发现了这两种口味在全球不同地区的非常低和非常高的季节性降水模式上的差异印记,这可能会严重影响农业和生物质生产或公共卫生等。我们特别发现,EP期间表现出统计上显着的事件符合率与水文气象异常在较大的空间尺度,而稀疏的模式出现随着CP期间。我们的统计分析证实了以前报道的EP期间的相互关系,并揭示了额外的不同区域的模式非常高/低的季节性降水,如增加降雨在中亚地区的CP期间,我们所知道的还没有报道到目前为止。我们的研究结果表明,彻底区分厄尔尼诺和拉尼娜两种各自的风格可能是至关重要的,以了解出现强烈的区域水文气象异常,并预测其相关的生态和社会经济影响。

英文摘要:

The effects of El Niño's two distinct flavors, East Pacific (EP) and Central Pacific (CP)/Modoki El Niño, on global climate variability have been studied intensively in recent years. Most of these studies have made use of linear multivariate statistics or composite analysis. Especially the former assumes the same type of linear statistical dependency to apply across different phases of the El Niño--Southern Oscillation (ENSO), which appears not necessarily a justified assumption. Here, we statistically evaluate the likelihood of co-occurrences between very high or very low seasonal precipitation sums over vast parts of the global land surface and the presence of the respective EP and CP types of both, El Niño and La Niña. By employing event coincidence analysis, we uncover differential imprints of both flavors on very low and very high seasonal precipitation patterns over distinct regions across the globe, which may severely affect, among others, agricultural and biomass production or public health. We particularly find that EP periods exhibit statistically significant event coincidence rates with hydrometeorological anomalies at larger spatial scales, whereas sparser patterns emerge along with CP periods. Our statistical analysis confirms previously reported interrelations for EP periods and uncovers additional distinct regional patterns of very high/low seasonal precipitation, such as increased rainfall over Central Asia alongside CP periods that have to our knowledge not been reported so far. Our results demonstrate that a thorough distinction of El Niño and La Niña into their two respective flavors could be crucial for understanding the emergence of strong regional hydrometeorological anomalies and anticipating their associated ecological and socioeconomic impacts.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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