Instituto de Investigación en Agrobiotecnología, CIALE, Universidad de Salamanca, Villamayor 37185, Salamanca, Spain.
Instituto de Investigación en Agrobiotecnología, CIALE, Universidad de Salamanca, Villamayor 37185, Salamanca, Spain.
Sci Total Environ. 2022 Nov 10;846:157537. doi: 10.1016/j.scitotenv.2022.157537. Epub 2022 Jul 22.
Soil moisture (SM) plays a key role in the water cycle, and its variability is intimately linked to coupled land-atmosphere processes. Having a good knowledge of soil-atmospheric interactions is thus essential to assess the impact of climate change on SM; however, many aspects of how water and energy exchanges occur in the soil-atmosphere continuum are still uncertain. In particular, it is known that atmospheric circulation patterns influence climate conditions over Europe but their impact on SM has only rarely been studied. This study provides insight into how atmospheric patterns influence soil moisture dynamics in Europe, where an increase in temperature and agricultural droughts are expected as an impact of climate change. To do so, we analysed the influence of the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), and the El Niño Southern Oscillation (ENSO) on European SM, including lagged responses, for the period 1991-2020 at a monthly scale. Two methods have been used: a lagged correlation analysis and a more sophisticated causality approach using the PCMCI (PC method combined with the momentary conditional independence (MCI) test). SM series from two different databases were considered: the hydrological model LISFLOOD and the reanalysis dataset ERA5-Land. The results from the correlation analysis showed a significant, predominantly negative relationships of SM with NAO and AO over almost all of Europe and no significant relation with ENSO. With the causality analysis, similar patterns are obtained for NAO and AO; however, the PCMCI analysis revealed clear patterns of ENSO influencing SM with a delayed response of one-to-two months in central and northwest Europe. The results obtained in this work highlight that there are causal relations between the main modes of interannual climate oscillations and SM variations in Europe, underlining the importance of accounting for global atmospheric circulations to study current changes in regional soil water-related processes.
土壤湿度（SM）在水循环中起着关键作用，其变化与陆气耦合过程密切相关。因此，充分了解土壤-大气相互作用对于评估气候变化对 SM 的影响至关重要；然而，水和能量在土壤-大气连续体中交换的许多方面仍然不确定。特别是，众所周知，大气环流模式会影响欧洲的气候条件，但它们对 SM 的影响很少被研究。本研究深入探讨了大气模式如何影响欧洲的土壤湿度动态，预计气候变化将导致该地区温度升高和农业干旱。为此，我们分析了北大西洋涛动（NAO）、北极涛动（AO）和厄尔尼诺南方涛动（ENSO）对欧洲 SM 的影响，包括在 1991-2020 年期间以月为时间尺度的滞后响应。使用了两种方法：滞后相关分析和更复杂的因果关系方法，使用 PCMCI（PC 方法与瞬时条件独立性（MCI）测试相结合）。考虑了来自两个不同数据库的 SM 系列：水文模型 LISFLOOD 和再分析数据集 ERA5-Land。相关分析的结果表明，SM 与 NAO 和 AO 之间存在显著的、主要为负相关关系，几乎遍及整个欧洲，与 ENSO 没有显著关系。使用因果关系分析，也得到了与 NAO 和 AO 类似的模式；然而，PCMCI 分析显示 ENSO 明显影响 SM，在中欧和西北欧有一到两个月的滞后响应。本工作的结果表明，在欧洲，主要的年际气候振荡模式与 SM 变化之间存在因果关系，强调了考虑全球大气环流来研究区域土壤水分相关过程当前变化的重要性。
