Diversity in global patterns of observed precipitation variability and change on river basin scales: A conditional quantile approach
Diversity in global patterns of observed precipitation variability and change on river basin scales: A conditional quantile approach
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观测到的降水变率和流域规模变化的全球模式的多样性：条件分位数方法
DOI：
10.1007/s10584-018-2225-z
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发表时间：
2018
期刊：
影响因子：
4.8
通讯作者：
Jain, Shaleen
中科院分区：
文献类型：
--
作者：
Lausier, Anne M.;Jain, Shaleen
全面描述全球降水变异和变化模式的多样性是评估气候适应和复原力的一个重要起点。捕获降水概率分布函数（PDF）的性质是评估变异性和变化的关键。传统的基于线性回归的分析假设PDF的湿尾和干尾的斜率系数与条件平均趋势一致。这一假设在历史记录的分析中并不总是得到证实。鉴于海表温度（SST）和降水之间的关系，全球SST的最近趋势使降水变率和风险的解释变得复杂。在这项研究中，年降水量（1951-2011年）在全球流域尺度的PDF的变化进行了分析，使用分位数回归（QR）。QR是一种灵活的方法，可以根据反映厄尔尼诺-南方涛动和大西洋多年代际涛动的全球SST的主要经验正交函数（SST）模式评估降水变率。为此，提出的框架（a）提供了整个PDF的特征及其对SST变率主要模态的敏感性，（B）捕获PDF中的一系列响应，包括不对称性，（c）突出了可能经历降水过多和不足以及年际变率风险较高的区域，以及（d）提供了一种在指定分位数上量化风险的方法。结果显示，在PDF在世界所有地区的不对称的反应，无论是在单尾或双尾。在一个实例中，QR检测到对东非塔纳盆地SST主要模式的不同响应，突出了变异性和风险的变化。
Comprehensive characterization of diversity in global patterns of precipitation variability and change is an important starting point for climate adaptation and resilience assessments. Capturing the nature of precipitation probability distribution functions (PDF) is critical for assessing variability and change. Conventional linear regression-based analyses assume that slope coefficients for the wet and dry tails of the PDF are consonant with the conditional mean trend. This assumption is not always borne out in the analyses of historical records. Given the relationship between sea surface temperature (SST) and precipitation, recent trends in global SST complicate interpretations of precipitation variability and risk. In this study, changes in the PDF of annual precipitation (1951–2011) at the global river basin scale were analyzed using quantile regression (QR). QR is a flexible approach allowing for the assessment of precipitation variability conditioned on the leading empirical orthogonal function (EOF) patterns of global SST that reflect El Niño–Southern Oscillation and Atlantic Multi-decadal Oscillation. To this end, the framework presented (a) offers a characterization of the entire PDF and its sensitivity to the leading modes of SST variability, (b) captures a range of responses in the PDF including asymmetries, (c) highlights regions likely to experience higher risks of precipitation excesses and deficits and inter-annual variability, and (d) offers an approach for quantifying risk across specified quantiles. Results show asymmetric responses in the PDF in all regions of the world, either in single or both tails. In one instance, QR detects a differential response to the leading patterns of SST in the Tana basin in eastern Africa, highlighting changes in variability as well as risk.