1971—2010年中国大陆潜在蒸散变化的年代际转折及其成因

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 1971-2010年中国大陆潜在蒸散变化的年代际转折及其成因 DOI: 10.5846/stxb201309022184 作者: 作者单位: 安徽省气象科学研究所,安徽省气候中心,南京信息工程大学江苏省农业气象重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(41405111,41105098); 安徽省自然科学基金项目(1408085QD73); 淮河流域气象开放研究基金项目(HRM201209) Inter-decadal breakpoint in potential evapotranspiration trends and the main causes in China during the period 1971-2010 Author: Affiliation: Anhui Meteorological Institute,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:潜在蒸散时间演变的年代际转折研究有助于全面认识潜在蒸散对气候变化的响应。基于修正的FAO56 Penman-Monteith公式和中国580个台站逐日气象观测资料,利用气候变化趋势转折判别模型分析了1971-2010年中国潜在蒸散变化的年代际转折特征,并探讨转折前、后的变化趋势及其主导因素。结果表明:1971-2010年中国年平均潜在蒸散在20世纪90年代初期由显著下降(-2.46 mm/a)转变为显著上升(1.57 mm/a),这与影响潜在蒸散变化的4个气象因子趋势的年代际转折密切相关。90年代之前,全国风速和日照时数普遍下降引起的负贡献超过气温上升引起的正贡献,导致潜在蒸散显著下降;90年代之后,全国大部分地区的增暖加剧和干旱化使得气温和相对湿度的正贡献明显增大,超过由于风速和日照时数下降趋势减缓甚至转折而减小的负贡献,导致潜在蒸散显著上升。潜在蒸散趋势转折现象在全国80%以上的站点普遍存在,且转折前、后主导因子的空间分布格局存在差异。90年代之前,风速和日照时数分别是北方和南方多数站点的主导因子;90年代之后,以气温和相对湿度为主导因子的站点明显增多,尤其是在西北地区、青藏高原和东南沿海部分地区。 Abstract:In the context of global warming, the impact of climate change on water resources is becoming increasingly significant and is thus drawing more attention. As a main component of the hydrological cycle, potential evapotranspiration (ET0) represents the maximum possible evaporation and is the rate of evaporation that would occur under given meteorological conditions from a continuously saturated surface. ET0 is essential for scheduling of irrigation system running times, preparing input data for hydrological models used in water balance studies, and assessing the hydrological impacts of the changing climate. Therefore, the trends of the changes in ET0 and its dominant factors across different regions of the world have been studied by many researchers in recent decades. Despite the global warming, decreasing trends in ET0 have been detected in several countries, including the United States, Russia, India, China, Australia, and New Zealand. Decreasing sunshine hours, declining wind speed, and increasing relative humidity have been considered to be the main causes of the decreasing ET0.Analysis of the linear trend of the time series is frequently used in climate change research. The linear trend can reflect the overall trend of climate change over a time period, but it cannot describe the undulating character of climate change over a long time period. Thus, the characteristics of interdecadal turning of climatic factors, including air temperature, precipitation, and solar radiation, have become a topic of concern for many researchers worldwide.Thorough exploration of the interdecadal turning of ET0 trends can lead to a better understanding of the evolution and abrupt changes of ET0 related to climate change. Based on the FAO56 Penman-Monteith equation, interdecadal breakpoints in ET0 trends were studied using Tomé and Miranda's climate-trend turning discriminatory model for 580 meteorological stations across China during 1971-2010. Differences in the trends and determining factors between the before and after breakpoint periods were also analyzed. The results showed that annual average ET0 decreased significantly (-2.46 mm/a) before the 1990s but increased significantly (1.57 mm/a) after the 1990s across China. This phenomenon was closely related to the interdecadal breakpoints in the trends of four meteorological factors affecting ET0 variations. The decrease in ET0 that occurred before the 1990s was attributed to a larger absolute value of the negative contributions caused by decreasing wind speed and sunshine duration compared to that of the positive contribution caused by increasing air temperature. After the 1990s, positive contribution from the air temperature and relative humidity increased due to the more intensive warming and climatic aridity across most of the areas in China and exceeded the smaller absolute value of the negative contribution from the wind speed and sunshine duration, causing the increasing trend in ET0. The interdecadal breakpoints existed at more than 80% of the meteorological stations across China, and there were differences between the pre- and post-breakpoint distribution patterns. Before the 1990s, wind speed and sunshine duration were the determining factors for most stations in North China and South China, respectively. After the 1990s, the number of stations with air temperature or relative humidity as a determining factor increased, especially in Northwest China, the Tibetan Plateau, and some parts of the southeastern coastal area. 参考文献 相似文献 引证文献