Diurnal Variations of Summer Precipitation in Xinjiang
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摘要: 利用1991-2014年新疆16个国家基准气象站逐时降水资料,分析了新疆夏季不同区域降水日变化基本特征,揭示出新疆夏季降水日变化呈现显著的南、北疆区域差异,有别于我国中东部的一些新事实。结果显示:北疆降水量日变化呈现准单峰型特征,峰值主要发生在傍晚前后(16:00-20:00,地方时,下同);南疆降水量日变化呈现三峰特征,峰值分别出现在傍晚(17:00-18:00)、午夜后(00:00-01:00)和上午(10:00)。新疆夏季降水事件以6 h以内的短历时性质为主(平均为85%,比例明显高于我国中东部),而持续12 h以上的较长历时降水事件偶有发生;在天山东麓以外的新疆绝大部分地区,6 h以内短历时降水事件对总降水量的贡献率达54%,高于我国中东部地区。新疆西部和北疆北部降水量日变化主峰的贡献者是2~3 h短持续性降水为主的事件;而天山中-东部降水量日变化峰值则是来自于12 h内各不同持续时间降水事件的大致均等贡献。Abstract: Fundamental diurnal variation features of summer precipitation over Xinjiang are investigated based on hourly precipitation data of 1991-2014 from all 16 national stations in the target region, and distinct characteristics on the diversity of diurnal variations of summer precipitation between Northern and Southern Xinjiang are revealed. Results show that the diurnal variation of the precipitation amount in Northern Xinjiang presents nearly a single peak and trough, with the maximum at dusk (1600-2000 LST) and minimum about one-third proportion of peak value at noon time, and the precipitation amount almost decrease monotonically during the whole night. Differently, the diurnal variation of the precipitation amount in Southern Xinjiang shows triple peaks and troughs, with peaks at about dusk (1700-1800 LST), after the midnight (0000-0100 LST) and near the noon (1000 LST), respectively. The difference of single peak pattern between Northern Xinjiang and central-east China is the accumulation of different situations instead of similar peak overlay. In addition, the morning when precipitation peak value appears in Southern Xinjiang is opposite to that weaker or weakest time in all day in central-east China.The occurrence time of maximum average precipitation intensity and maximum hourly accumulative precipitation is more consistent with the counterpart of maximum hourly accumulative precipitation frequency, and more remarkable with the region where daily variation of precipitation presents multi-peak patterns, showing more contribution of precipitation intensity than frequency to accumulative precipitation, which is also an important characteristic of Xinjiang, especially in Southern Xinjiang. Short-duration precipitation within 6 hours are dominated events in summer (the average value is 85 percent which is significantly higher than that in central-east China), and precipitation events lasting longer than 12 hours happen rarely. Contribution rates of short-duration precipitation events within 6 hours in total precipitation are up to 54% which is higher than that in central-east China in most region except the east side of Tianshan in Xinjiang.Except in the south edge of Tarim Basin, there are close relations between the precipitation diurnal cycle and its duration in most areas of Xinjiang, but not the same as those in central-east China. Namely, 2-3-hour short-duration precipitation events contribute to the peak value of the total precipitation diurnal cycle in western and Northern Xinjiang, whereas every duration event within 12 hours has nearly equal contribution to the maximum of the total precipitation diurnal cycle in central to eastern Tianshan Mountains.
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Key words:
- Xinjiang;
- summer precipitation;
- diurnal variation;
- precipitation duration
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图 3 1991-2014年北疆各站平均逐时降水标准化后EOF分解(a)第1特征向量,(b)第2特征向量,(c)第3特征向量,(d)第1特征向量对应的时间系数, (e)第2特征向量对应的时间系数, (f)第3特征向量对应的时间系数
Fig. 3 The first 3 leading modes of the standardized meanhourly precipitation over Northern Xinjiang during 1991-2014(a) the first mode, (b) the second mode, (c) the third mode, (d) the corresponding time coefficient of the first mode, (e) the corresponding time coefficient of the second mode, (f) the corresponding time coefficient of the third mode
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[1] 宇如聪, 李建, 陈昊明, 等.中国大陆降水日变化研究进展.气象学报, 2014, 72(5):948-968. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB201405012.htm [2] 宇如聪, 李建.中国大陆日降水峰值时间位相的区域特征分析.气象学报, 2016, 74(1):18-30. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB201601002.htm [3] Wallace J.Diurnal variations in precipitation and thunderstorm frequency over the conterminous United States.Mon Wea Rev, 1975, 103(5):406-419. doi: 10.1175/1520-0493(1975)103<0406:DVIPAT>2.0.CO;2 [4] Dai A G.Global Precipitation and thunderstorm frequencies.PartⅡ:Diurnal variations.J Climate, 2001, 14(6):1112-1128. doi: 10.1175/1520-0442(2001)014<1112:GPATFP>2.0.CO;2 [5] Fujinami H, Nomura S, Yasunari T.Characteristics of diurnal variations in convection and precipitation over the SonthernTibertan Plateau during summer.SOLA, 2005, 1:49-52. doi: 10.2151/sola.2005-014 [6] Dai A, Lin X, Hsu K.The frequency, intensity and diurnal cycle of precipitation in surface and satellite observations over low-and mid-latitudes.Climate Dyn, 2007, 29:727-744. doi: 10.1007/s00382-007-0260-y [7] Yu R C, Zhou T J, Xiong A Y, et al.Diurnal variations of summer precipitation over contiguous China.Geophys Res Lett, 2007, 34(1):L01704. http://adsabs.harvard.edu/abs/2007GeoRL..34.1704Y [8] Yu R C, Xu Y P, Zhou T J, et al.Relation between rainfall duration and diurnal variation in the warm season precipitation over central east China.Geophys Res Lett, 2007, 34(13):L13703. [9] 李红梅, 周天军, 宇如聪.近四十年来我国东部盛夏日降水特性变化分析.大气科学, 2008, 32(2):358-370. http://www.cnki.com.cn/Article/CJFDTOTAL-DQXK200802013.htm [10] 宇文勇, 李建, 宇如聪.中国地区降水持续性的季节变化特征.气象, 2012, 38(4):392-401. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXX201204003.htm [11] 刘海文, 丁一汇.华北夏季降水的年代际变化.应用气象学报, 2011, 22(2):129-137. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20110201&flag=1 [12] 陈波, 史瑞琴, 陈正洪.近45年华中地区不同级别强降水事件变化趋势.应用气象学报, 2010, 21(1):47-54. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20100106&flag=1 [13] 陈炯, 王建捷.北京地区夏季边界层结构日变化的高分辨模拟对比.应用气象学报, 2006, 17(4):403-411. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20060469&flag=1 [14] 王夫常, 宇如聪, 陈昊明, 等.我国西南部降水日变化特征分析.暴雨灾害, 2011, 30(2):117-121. http://www.cnki.com.cn/Article/CJFDTOTAL-HBQX201102004.htm [15] 杨森, 周晓珊, 高杰.辽宁省夏季降水的日变化特征.气象, 2011, 37(8):943-949. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXX201108007.htm [16] 戴泽军, 宇如聪, 陈昊明, 等.湖南夏季降水日变化特征.高原气象, 2009, 28(6):1463-1470. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200906027.htm [17] 李建, 宇如聪, 王建捷, 等.北京市夏季降水的日变化特征.科学通报, 2008, 53(7):829-832. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200807015.htm [18] 张云惠, 杨莲梅, 肖开提·多莱特, 等.1971-2010年中亚低涡活动特征.应用气象学报, 2012, 23(3):312-321. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19940349&flag=1 [19] 杨莲梅, 张庆云.新疆夏季降水年际变化与亚洲副热带西风急流.应用气象学报, 2008, 19(2):171-179. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20080231&flag=1 [20] 肖潺, 宇如聪, 原韦华, 等.中国大陆雨季时空差异特征分析.气象学报, 2015, 73(1):84-92. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB201501007.htm [21] 张家宝, 邓子凤.新疆降水概论.北京:气象出版社, 1987. [22] 辛瑜, 陈洪武, 张广兴, 等.新疆年降水量的时空变化特征.高原气象, 2008, 27(5):993-1003. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200805007.htm [23] 杨莲梅, 史玉光, 汤浩.新疆北部冬季降水异常成因.应用气象学报, 2010, 21(4):491-499. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20100413&flag=1 [24] 王世杰, 杨莲梅, 史玉光.乌鲁木齐1991-2010年降雨特征分析.中国沙漠, 2012, 32(2):509-516. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGSS201202033.htm [25] 唐冶, 陈春艳, 赵克明.伊宁市1991-2011年降雨特征分析.沙漠与绿洲气象, 2014, 8(6):41-46. http://www.cnki.com.cn/Article/CJFDTotal-XJQX201406008.htm [26] 张家宝, 苏起元, 孙沈清, 等.新疆短期预报手册.乌鲁木齐:新疆人民出版社, 1986. [27] 原韦华, 宇如聪, 傅云飞.中国东部夏季持续性降水日变化在淮河南北的差异分析.地球物理学报, 2014, 57(3):752-759. http://www.cnki.com.cn/Article/CJFDTOTAL-DQWX201403006.htm [28] Li J, Yu R C, Yuan W H, et al.Changes in duration-related characteristics of late-summer precipitation over eastern China in the past 40 years.J Climate, 2011, 24(21):5683-5690. doi: 10.1175/JCLI-D-11-00009.1