Understanding linkages between global climate indices and terrestrial water storage changes over Africa using GRACE products
Understanding linkages between global climate indices and terrestrial water storage changes over Africa using GRACE products
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DOI：
10.1016/j.scitotenv.2018.04.159
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发表时间：
2018-09-01
影响因子：
9.8
通讯作者：
Khaki, M.
中科院分区：
文献类型：
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作者：
Anyah, R. O.;Forootan, E.;Khaki, M.
非洲拥有丰富的水资源，维持其农业活动，但日益受到极端气候（干旱和洪水）影响的威胁，这使非常宝贵的水资源处于危险之中。因此，了解气候变率与整个大陆的储水量之间的关系对于为未来的水资源管理战略提供信息至关重要。利用GRACE卫星数据和高阶（四阶累积量）统计独立分量分析（ICA）方法，研究了陆地储水量（TWS）变化与全球气候遥相关指数的关系；2003-2014年非洲地区厄尔尼诺-南方涛动（ENSO）、北大西洋涛动（NAO）、麦登-朱利安涛动（MJO）、准两年一次涛动（QBO）和印度洋偶极子（IOD）。Pearson相关分析用于提取这些气候指数（CIs）和TWS之间的联系，从中发现了一些已知的强ci -降雨关系（例如赤道非洲东部）。结果表明，CIs和TWS之间存在独特的线性关系和区域。此外，还确定了具有强CI-TWS连接的独特区域，这些区域与非洲东部和南部典型的enso降雨连接完全不同。此外，结果表明，CIs的第一主导独立分量（IC）与NAO有关，其特征是南部非洲的TWS显著减少。第二个主导ic与IOD有关，其特征是赤道东部非洲的TWS显著增加，而ENSO和MJO的组合显然与第三个ic有关，这也与南部非洲和赤道东部非洲的TWS变化显著增加有关。(C) 2018 Elsevier B.V.版权所有
Africa, a continent endowed with huge water resources that sustain its agricultural activities is increasingly coming under threat from impacts of climate extremes (droughts and floods), which puts the very precious water resource into jeopardy. Understanding the relationship between climate variability and water storage over the continent, therefore, is paramount in order to inform future water management strategies. This study employs Gravity Recovery And Climate Experiment (GRACE) satellite data and the higher order (fourth order cumulant) statistical independent component analysis (ICA) method to study the relationship between terrestrial water storage (TWS) changes and five global climate-teleconnection indices; El Nino-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Madden-Julian Oscillation (MJO), Quasi-Biennial Oscillation (QBO) and the Indian Ocean Dipole (IOD) over Africa for the period 2003-2014. Pearson correlation analysis is applied to extract the connections between these climate indices (CIs) and TWS, from which some known strong CI-rainfall relationships (e.g., over equatorial eastern Africa) are found. Results indicate unique linear-relationships and regions that exhibit strong linkages between CIs and TWS. Moreover, unique regions having strong CI-TWS connections that are completely different from the typical ENSO-rainfall connections over eastern and southern Africa are also identified. Furthermore, the results indicate that the first dominant independent components (IC) of the CIs are linked to NAO, and are characterized by significant reductions of TWS over southern Africa. The second dominant ICs are associated with IOD and are characterized by significant increases in TWS over equatorial eastern Africa, while the combined ENSO and MJO are apparently linked to the third ICs, which are also associated with significant increase in TWS changes over both southern Africa, as well as equatorial eastern Africa. (C) 2018 Elsevier B.V. All rights reserved.