Theoretical and Applied Climatology ( IF 3.4 ) Pub Date : 2020-05-12 , DOI: 10.1007/s00704-020-03228-x Zhangqun Li , Ziniu Xiao
Based on reanalysis data from 1979 to 2015, an airflow trajectory model, Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT), is employed to estimate the moisture sources feature and its relationship with the mid-low Lancang River nearby region (LR) precipitation in wet season. The results reveal that the main sources of moisture over LR originate from the Indian Ocean, Western Pacific Ocean (WP), Eurasia continent, North Africa, and North Atlantic Ocean. Detailed analysis indicates that although the largest moisture over LR is sourced from the Indian Ocean, the moisture sourced from WP takes a more important role for LR precipitation variability. It is found that the typical dry/wet years in May (a transition month in the beginning of wet season) precipitation over the LR matches well with the decreasing/increasing of moisture sourced from WP, which indicates that the interannual variability of May precipitation over the LR is significantly modulated by the contributions of the moisture sourced from WP. A similar relationship was found for the precipitation over LR in May and the moisture contributions sourced from WP on decadal time scale. There is a transfer around 1997 from a drier May period (1979–1997) into a wetter May period (1998–2009), which is consistent with the change of the moisture contribution sourced from WP. Further, it is worth noticing that the significant downward trend of May precipitation over LR since the twenty-first century is consistent with the decreasing trend of moisture contribution sourced from WP, highlighting the dominant role of the moisture sourced from WP for the LR precipitation in May.
中文翻译:
澜沧江中低水位附近地区雨季初湿润源的贡献及其变化特征分析
基于1979年至2015年的再分析数据,运用混合颗粒物拉格朗日混合轨迹(HYSPLIT)气流轨迹模型估算了澜沧江中低降水量地区的水分特征及其与降水的关系。雨季。结果表明,LR上的主要水分来源来自印度洋,西太平洋(WP),欧亚大陆,北非和北大西洋。详细的分析表明,尽管LR上方最大的水分来自印度洋,但WP的水分对于LR的降水变化起着更重要的作用。结果表明,LR上典型的5月干湿年(湿季开始的过渡月份)降水与WP产生的水分减少/增加非常吻合,这表明5月降水在年际变化的过程中。 LR受WP水分的贡献显着调节。在十月份的时间尺度上,LR上的降水量和来自WP的水分贡献也发现了类似的关系。1997年前后,从5月的较干燥时期(1979-1997年)转变为5月的较湿时期(1998-2009年),这与WP产生的水分贡献的变化是一致的。进一步,