Zittis George, Bruggeman Adriana, Lelieveld Jos
Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia, Cyprus.
Energy, Environment and Water Research Center, The Cyprus Institute, Nicosia, Cyprus.
Weather Clim Extrem. 2021 Dec;34:100380. doi: 10.1016/j.wace.2021.100380.
Global warming is anticipated to intensify the hydrological cycle. However, this is neither expected to be globally uniform nor is the relationship between temperature increase and rainfall intensities expected to be linear. The objective of this study is to assess changes in annual rainfall extremes, total annual precipitation, and their relationship in the larger Mediterranean region. We use an up-to-date ensemble of 33 regional climate simulations from the EURO-CORDEX initiative at 0.11° resolution. We analyse the significance of trends for 1951-2000 and 2001-2100 under a 'business-as-usual' pathway (RCP8.5). Our future projections indicate a strong north/south Mediterranean gradient, with significant, decreasing trends in the magnitude of daily precipitation extremes in the south and the Maghreb region (up to -10 mm/decade) and less profound, increasing trends in the north. Despite the contrasting future trends, the 50-year daily precipitation extremes are projected to strongly increase (up to 100%) throughout the region. The 100-year extremes, derived with traditional extreme value approaches from the 1951-2000 simulations, underestimate the magnitude of these extreme events in the 2001-2100 projections by 30% for the drier areas of the Mediterranean (200-500 mm average annual rainfall) and by up to 20-30% for the wetter parts of the region. These 100-year extremes can occur at any time in any Mediterranean location. The contribution of the wettest day per year to the annual total precipitation is expected to increase (5-30%) throughout the region. The projected increase in extremes and the strong reductions in mean annual precipitation in the drier, southern and eastern Mediterranean will amplify the challenges for water resource management.
预计全球变暖将加剧水文循环。然而，这种情况预计在全球范围内并非均匀一致，而且气温升高与降雨强度之间的关系也预计不是线性的。本研究的目的是评估地中海较大区域年极端降雨量、年总降水量及其关系的变化。我们使用了来自EURO-CORDEX计划的33个区域气候模拟的最新集合，分辨率为0.11°。我们分析了在“照常营业”路径（RCP8.5）下1951 - 2000年和2001 - 2100年趋势的显著性。我们对未来的预测表明，地中海地区存在明显的南北梯度，南部和马格里布地区日极端降水量的幅度呈现显著下降趋势（高达-10毫米/十年），而北部的趋势则不那么明显且呈上升趋势。尽管未来趋势相反，但预计整个区域50年一遇的日极端降水量将大幅增加（高达100%）。通过传统极值方法从1951 - 2000年模拟得出的100年一遇极值，在地中海较干旱地区（年平均降雨量200 - 500毫米）的2001 - 2100年预测中，低估了这些极端事件幅度的30%，在该地区较湿润地区则低估了多达20 - 30%。这些100年一遇的极端事件可能在任何时候出现在地中海的任何地点。预计每年最湿润日对年总降水量的贡献在整个区域将增加（5 - 30%）。预计极端事件的增加以及地中海较干旱的南部和东部地区年平均降水量的大幅减少，将加大水资源管理面临的挑战。
