Based on the precipitation observation data of meteorological stations in the source region of the Yellow River (SRYR) in the past ten years, July is selected as the largest month of precipitation, the maximum positive and negative abnormal year's corresponding to July are 2012 and 2015 respectively. The Lagrange Flexible Particle Dispersion Model (FLEXPART) is driven by NECP reanalysis data to simulate the backward trajectories of target particles in these two months. The characteristics and differences of water vapor transport under abnormal conditions are emphatically analyzed, and the contribution rate of each moisture source to the regional rainfall is calculated quantitatively. The results show that, in July 2012, the moisture transportation to the SRYR is mainly conducted by South Branch which contains two routes entering the SRYR from the southern side of the Qinghai-Tibetan Plateau (QTP):one is the trans-equatorial transport path, that is to say, the Somali jet carries moisture from the Arabian Sea and finally enters the SRYR by way of the Indian Peninsula and Bay of Bengal; the other is that particles carry moisture from the South China Sea and finally enters the SRYR by way of the Sichuan Basin. On the contrary, the North Branch which means moisture enters the SRYR from the Western or northern side of the QTP plays a dominant role in July 2015, including two typical paths as well:one is that the Easterly jet carries the moisture from the South China Sea and finally enters the SRYR by the Bay of Bengal and Indian Peninsula; the other is that the Westerly Jet carries moisture from the northern Africa or eastern European Plain and finally enters the SRYR, via Central Asia. The characteristics of specific humidity variation during the movement of particles show that the southern foot of the Himalayas, the Sichuan Basin, the Bay of Bengal and the northern Tibetan Plateau are potential moisture sources for precipitation in the SRYR. Moreover, the estimation of moisture sources contributions to the precipitation in SRYR shows that:the arid and semi-arid grassland areas on the northern side of the TP are main sources of precipitation for the SRYR in July of dry year. The contribution rate is 52.9%, which is much higher than the other four potential moisture sources. While the contributions of the three main sources in the wet year are far less significant than those in the dry year. No matter what type of precipitation, the southwestern QTP and the northern side of the QTP provide the main external water vapor for the main precipitation in the SRYR.
[1]Dirmeyer P A, Brubaker K L, 1999.Contrasting evaporative moisture sources during the drought of 1988 and the flood of 1993[J].Journal of Geophysical Research Atmospheres, 104(D16):19383-19397.DOI:10.1029/1999JD900222.
[2]Dirmeyer P A, Brubaker K L, 2007.Characterization of the global hydrologic cycle from a back-trajectory analysis of atmospheric water vapor[J].Journal of Hydrometeorology, 8(1):20.DOI:10.1175/JHM557.1.
[3]Gimeno L, Nieto R, Trigo S M, et al, 2010.Where does the Iberian Peninsula moisture come from? An answer based on a Lagrangian approach[J].Journal of Hydrometeorology, 11(2):421-436.DOI:10.1175/2009jhm1182.1.
[4]Gimeno L, Stohl A, Trigo R M, et al, 2012.Oceanic and terrestrial sources of continental precipitation[J].Reviews of Geophysics, 50(4):RG4003.DOI:10.1029/2012RG000389.
[5]Gómez-Hernández M, Drumond A, Gimeno L, et al, 2013.Variability of moisture sources in the Mediterranean region during the period 1980-2000[J].Water Resources Research, 49(10):6781-6794.DOI:10.1002/wrcr.20538.
[6]Hu Y, Maskey S, Uhlenbrook S, et al, 2011.Streamflow trends and climate linkages in the source region of the Yellow River, China[J].Hydrological Processes, 25(22):3399-3411.DOI:10.1002/hyp.8069.
[7]Iqbal M, Wen J, Wang S, et al, 2018.Variations of precipitation characteristics during the period 1960-2014 in the source region of the Yellow River, China[J].Journal of Arid Land, 9(3):1-14.DOI:10.1007/s40333-018-0008-z.
[8]Jiang Z, Jiang S, Shi Y, et al, 2017.Impact of moisture source variation on decadal-scale changes of precipitation in North China from 1951 to 2010[J].Journal of Geophysical Research, 122(2):600-613.DOI:10.1002/2016JD025795.
[9]Reale O, Feudale L, Turato B, 2001.Evaporative moisture sources during a sequence of floods in the Mediterranean region[J].Geophysical Research Letters, 28(10):2085-2088.
[10]Schneider E K, Kirtman B P, Lindzen R S, 1999.Tropospheric water vapor and climate sensitivity[J].Journal of the Atmospheric Sciences, 56(11):1649-1654.
[11]Sodemann H, Masson-Delmotte V, Schwierz C, et al, 2008.Interannual variability of greenland winter precipitation sources:2.Effects of North Atlantic Oscillation variability on stable isotopes in precipitation[J].Journal of Geophysical Research Atmospheres, 113(D12):D12111.DOI:10.1029/2007JD009416.
[12]Stohl A, James P, 2004.A lagrangian analysis of the atmospheric branch of the global water cycle.Part Ⅰ:Method description, validation, and demonstration for the August 2002 flooding in central Europe[J].Journal of Hydrometeorology, 5(4):656-678.
[13]Stohl A, James P, 2005.A Lagrangian analysis of the atmospheric branch of the global water cycle.Part Ⅱ:Moisture transports between earth's ocean basins and river catchments[J].Journal of Hydrometeorology, 6(6):961-984.DOI:10.1175/JHM470.1.
[14]Sun B, Wang H, 2014a.Moisture sources of semiarid grassland in China using the Lagrangian particle model FLEXPART[J].Journal of Climate, 27(6):2457-2474.DOI:10.1175/JCLI-D-13-00517.1.
[15]Sun B, Wang H, 2014b.Analysis of the major atmospheric moisture sources affecting three sub-regions of East China[J].International Journal of Climatology, 35(9):2243-2257.DOI:10.1002/joc.4145.
[16]Trenberth K E, 1998.Atmospheric moisture residence times and cycling:Implications for rainfall rates and climate change[J].Climatic change, 39(4):667-694.
[17]Zhou H, Zhao X, Tang Y, et al, 2005.Alpine grassland degradation and its control in the source region of the Yangtze and Yellow Rivers, China[J].Grassland Science, 51(3):191-203.
[18]陈斌, 徐祥德, 杨帅, 等, 2012.夏季青藏高原地区近地层水汽进入平流层的特征分析[J].地球物理学报, 55(2):406-414.
[19]陈斌, 徐祥德, 施晓晖, 2009a.2005年夏季亚洲季风区下平流层水汽的对流源区[J].自然科学进展, 19(10):1094-1099.
[20]陈斌, 徐祥德, 施晓晖, 2011.拉格朗日方法诊断2007年7月中国东部系列极端降水的水汽输送路径及其可能蒸发源区[J].气象学报, 69(5):810-818.
[21]陈斌, 2009b.青藏高原及其周边区域夏季上对流层水汽变化和输送特征研究[D].北京: 中国气象科学研究院, 1-166.
[22]陈丹, 周长艳, 熊光明, 等, 2018.近53年四川盆地夏季暴雨变化特征分析[J].高原气象, 37(1):197-206.DOI:10.7522/j.issn.1000-0534.2017.00022.
[23]敬文琪, 崔园园, 刘瑞霞, 等, 2017.影响长江中下游夏季降水的青藏高原水汽抽吸作用和水汽路径的定量化研究[J].高原气象, 36(4):900-911.DOI:10.7522/j.issn.1000-0534.2016.00084.
[24]李进, 李栋梁, 张杰, 2012.黄河流域冬、夏季水汽输送及收支特征[J].高原气象, 31(2):342-350.
[25]刘希胜, 李其江, 段水强, 等, 2016.黄河源径流演变特征及其对降水的响应[J].中国沙漠, 36(6):1721-1730.
[26]乔世娇, 袁飞, 王妍, 等, 2015.黄河源区近50a极端气候变化趋势分析[J].人民黄河, 37(5):20-23.
[27]权晨, 2014.三江源区地-气水汽交换及输送的气候效应研究[D].南京: 南京信息工程大学, 1-67.
[28]孙卫国, 程炳岩, 李荣, 2009.黄河源区径流量与区域气候变化的多时间尺度相关[J].地理学报, 64(1):117-127.
[29]王可丽, 程国栋, 丁永建, 2006.黄河、长江源区降水变化的水汽输送和环流特征[J].冰川冻土, 28(1):8-14.
[30]谢欣汝, 游庆龙, 保云涛, 2018.基于多源数据的青藏高原夏季降水与水汽输送的联系[J].高原气象, 37(1):78-92.DOI:10.7522/j.issn.1000-0534.2017.00030.
[31]许建玉, 王慧娟, 李宏毅, 2014.夏季青藏高原地区水汽收支的初步模拟分析[J].高原气象, 33(5):1173-1181.DOI:10.7522/j.issn.1000-0534.2013.00117.
[32]周顺武, 吴萍, 王传辉, 2011.青藏高原夏季上空水汽含量演变特征及其与降水的关系[J].地理学报, 66(11):1466-1478.
[33]周长艳, 唐信英, 李跃清, 2012.青藏高原及周边地区水汽、水汽输送相关研究综述[J].高原山地气象研究, 32(3):76-83.