西北地区东部汛期降水季节内分布特征分析

摘要/Abstract

摘要： 基于西北地区东部1961-2015年54个台站汛期（5~9月）逐日降水资料，通过表征时间分配特征的参数-降水集中度和集中期，对西北地区东部5~9月逐旬降水的季节内非均匀性分布特征进行分析，结果表明：西北地区东部5~9月降水集中度和集中期的平均空间分布存在明显差异，从集中度来看，其东北部降水较集中，西南部较分散，而集中期主要在7月中旬到8月上旬，相比较甘肃陇东地区集中期较晚；从降水集中度与集中期的异常特征来看，第一模态均表现为全区一致性，第二模态均表现西北和东南反向变化特征，而集中度第三模态表现为东北和西南反向变化特征，集中期第三模态表现为东西反向变化特征；从降水集中度与集中期的变化趋势来看，近50 a来降水集中度越来越小，而降水集中期越来越早；另外从汛期降水量同同期降水集中度与集中期的关系来看，其与两者均存在正相关，其中集中度与降水的显著相关区在内蒙古西部以及陕西和宁夏北部，而集中期与降水的显著相关区在陕西和甘肃南部。另外利用前期大气环流指数对降水集中度和集中期建立的预报模型具有一定的预测能力，从而为西北东部汛期降水的季节内非均匀性分布特征的短期气候预测提供参考依据。

关键词: 西北东部, 汛期降水, 季节内, 非均匀性

Abstract: Located in the hinterland of east Asia and the edge of the Qinghai-Tibet Plateau, the east part of northwestern China is characterized by complex topography and various types of climate. It is a typical rain-fed agriculture area and also the most vulnerable areas in ecological environment. The complex climate makes the inter-annual precipitation show large inhomogeneity in the same period. During the growing seasons(from May to September, also the rainy seasons), the seasonal distribution characteristics of rainfall directly determine the grain yield. Therefore, it is of great importance to determine the seasonal distribution of precipitation during this time. Based on daily precipitation of 54 stations during rainy seasons from 1961 to 2013, this study analyzed the inter-seasonal distribution pattern of ten-day precipitation from May to September by using Precipitation Concentration Degree(PCD)and Precipitation Concentration Period(PCP). The results show that there were large spatial differences in the distribution of PCD and PCP. Compared with the northeast part including Ningxia, northern Shaanxi and western Inner Mongolia where the precipitation was relatively concentrating, the precipitation in the southwest part including eastern Qinghai, southern Gansu and Shaanxi was more scattering. The PCP was mainly in middle July and early August, while the PCP in Longdong region of Gansu was relatively late. The Empirical Orthogonal Function(EOF)analysis indicate that the first EOF mode of PCD and PCP in the whole east region was consistent. The second mode exhibited adverse variation characteristics between northwest and southeast, while the third mode of PCD exhibited adverse variation characteristics between northeast and southwest, and the third mode of PCP exhibited adverse variation characteristics between east and west. The trend analysis indicates that the PCP tended to scatter in the past 50 years, while the PCD tended to be earlier. In addition, positive correlations were found between the total precipitation and PCP as well as PCD, and areas of PCD significantly correlating to precipitation included western region of Inner Mongolia, northern Shaanxi and Ningxia, areas of PCP significantly correlating to precipitation included south of Shaanxi and Gansu. The prediction model based on previous atmospheric index is able to predict both the PCP and PCD, and can provide basis for the shortterm climate prediction of inter-seasonal precipitation distribution during rainy seasons in the east part of northwest China.

Key words: the east part of northwest China, rainfall, inter-seasonal, inhomogeneity

中图分类号:

P426.61

杨金虎, 靳荣, 刘晓云, 张小明, 李文举, 尚军林. 西北地区东部汛期降水季节内分布特征分析[J]. 干旱区地理, 2017, 40(5): 942-950.

YANG Jin-hu, JIN Rong, LIU Xiao-yun, ZHANG Xiao-ming, LI Wen-jun, SHANG Jun-lin. Inter-seasonal distribution pattern of rainy season precipitation in the east region of northwest China[J]. , 2017, 40(5): 942-950.

参考文献

[1] 李栋梁, 谢金南, 王文.中国西北夏季降水特征及其异常分析[J]. 大气科学, 1997, 21(3):331-340[. LI Dongliang, XIE Jinnan, WANG Wen. A study of summer precipitation features and anomaly in northwest China[J]. Scientia Atmospheric Sinica, 1997, 21(3):331-340.]

[2] 李耀辉, 李栋梁, 赵庆云. 中国西北春季降水与太平洋秋季海温的异常特征及其相关分析[J]. 高原气象, 2000, 19(1):100-110.[LI Yaohui, LI Dongliang, ZHAO Qingyun. A study on spring rainfall anomaly in northwest China and pacific SSTA features in autumn and their correlations[J]. Plateau Meteorology, 2000, 19(1):100-110.]

[3] 李耀辉, 李栋梁, 赵庆云. 中国西北地区秋季异常的特征分析[J]. 高原气象, 2001, 20(2):158-164[. LI Yaohui, LI Dongliang, ZHAO Qingyun. An analysis on characteristic of autumn rainfall anomaly in northwest China[J]. Plateau Meteorology, 2001, 20(2):158-164.]

[4] 蔡晓军, 李栋梁, 姚辉. 中国西北地区春末夏初降水异常的时空变化特征[J]. 高原气象, 1998, 17(2):170-181[. CAI Xiaojun, LI Dongliang, YAO Hui. The spatial and temporal variation feartures of precipitation anomaly during late spring and early summer over northwest China[J]. Plateau Meteorology, 1998, 17(2):170-181.]

[5] 杨金虎, 杨启国, 姚玉璧, 等. 西北东部夏季干湿演变及环流特征[J]. 气象, 2006, 32(10):94-101[. YANG Jinhu, YANG Qiguo, YAO Yubi, et al. Analysis of drought and moist evolution and circulation features over the east of northwest China in summer[J]. Meteorological Monthly, 2006, 32(10):94-101.]

[6] 吕廷珍, 邓少格, 胡铁佳, 等. 利用年际增量法对西北东部汛期降水的定量预测研究[J]. 干旱气象, 2015, 33(3):386-394.[LV Tingzhen, DENG Shaoge, HU Tiejia, et al. Quangtitative prediction of precipitation in the east of Northwest China during the flood period by using the year-to-year increment approach[J]. Meteorological Monthly, 2006, 32(10):94-101.]

[7] 杨建玲, 郑广芬, 王素艳, 等.印度洋海盆模影响西北东部降水的大气环流分析[J]. 高原气象, 2015, 34(3):700-705.[YANG Jianling, ZHENG Guangfen, WANG Suyan, et al. Analyses of atmospheric circulation of tropical Indian Ocean Basin mode influencing precipitation in east of Northwest China[J]. Plateau Meteorologica, 2015, 34(3):700-705.]

[8] 李潇, 李栋梁, 王颖. 中国西北东部汛期降水对青藏高原东部春季感热在准3 a周期上的响应[J]. 气象学报, 2015, 73(4):737-748[. LI Xiao, LI Dongliang, WANG Ying. Quasi 3-year period response of the rainy season precipitation over the eastern parts of Northwest China to the spring sensible heat flux over the eastern part of the Tibetan Plateau[J]. Acta Meteorologica Sinica, 2015, 73(4):737-748.]

[9] 李艳春, 杨建玲, 朱晓炜. 赤道中东太平洋关键区海温对宁夏春季降水的影响[J]. 干旱区地理, 2015, 38(6):1087-1094[. LI Yanchun, YANG Jianling, ZHU Xiaowei. Effect of equatorial east Pacific SST of key areas on spring rainfall in Ningxia[J]. Acta Meteorologica Sinica, 2015, 38(6):1087-1094.]

[10] 蔡新玲, 李茜, 方建刚. 陕西区域性气象干旱事件及变化特征[J]. 干旱区地理, 2016, 39(2):294-300[. CAI Xinling, LI Qian, FANG Jiangang. Variation characteristics of regional meteorological drought events of Shaanxi Province[J]. Acta Meteorologica Sinica, 2016, 39(2):294-300.]

[11] 刘闻, 曹明明, 刘琪, 等. 1951-2012年渭河流域降水频次变化特征分析[J]. 干旱区地理, 2015, 38(1):18-24[. LIU Wen, CAO Mingming, LIU Qi, et al. Frequency of precipitation for the Weihe River Basin during 1951-2012[J]. Acta Meteorologica Sinica, 2015, 38(1):18-24.]

[12] 纳丽, 郑广芬, 任少云, 等. 宁夏春、夏、秋季干旱与降水集中期及集中度的关系[J]. 冰川冻土, 2013, 35(4):1015-1021[. NA Li, ZHENG Guangfen, REN Shaoyun, et al. Relationship of drought with precipitation-concentration period and precipitationconcentration degree in Ningxia in spring, summer and fall[J]. Journal of Glaciology and Geocryology, 2013, 35(4):1015-1021.]

[13] 纳丽, 李欣, 朱晓炜, 等. 宁夏近50 a降水集中度与集中期特征分析J]. 干旱区地理, 2012, 35(5):724-731[. NA Li, LI Xin, ZHU Xiaowei, et al. Research of precipitation-concentration degree(PCD)and precipitation-concentration period(PCP)in Ningxia[J]. Arid Land Geography, 2012, 35(5):724-731.]

[14] 黄少妮, 许新田, 王丹. 陕西降水季节及季节内振荡的气候特征[J]. 干旱气象, 2014, 32(1):46-51.[HUANG Shaoni, XU Xintian, WANG Dan. Climatological feature of seasonal and intraseasonal oscillation of rainfall in Shaanxi[J]. Journal of Arid Meteorology, 2014, 32(1):46-51]

[15] 杨金虎, 江志红, 王鹏祥, 等. 西北地区东部夏季极端降水量非均匀性特征[J]. 应用气象学报, 2008, 19(1):111-115[. YANG Jinhu, JIANG Zhihong, WANG Pengxiang, et al. Intra-seasonal inhomogeneity of summer extreme precipitation in the east part of Northwest China[J]. Journal of Applied Meteorological Science, 2008, 19(1):111-115.]

[16] 杨金虎, 江志红, 王鹏祥, 等. 中国西北极端降水事件年内非均匀性特征分析[J]. 中国沙漠, 2008, 28(1):178-184[. YANG Jinhu, JIANG Zhihong, WANG Pengxiang, et al. Analysis on inner-annual inhomogeneity characteristic of extreme precipitation events over Northwest China[J]. Journal of Applied Meteorological Science, 2008, 28(1):178-184.]

[17] 杨金虎, 江志红, 魏锋, 等. 近45 a来中国西北年极端高、低温的变化及对区域性增暖的响应[J]. 干旱区地理, 2006, 29(5):625-631[. YANG Jinhu, JIANG Zhihong, WEI Feng, et al. Variability of extreme high temperature and their response to regional warming in Northwest China in recent 45 a[J]. Arid Land Geography, 2006, 29(5):625-631.]

[18] 杨金虎, 张强, 王劲松, 等. 近60 a来中国西西南春季持续性干旱异常特征分析[J]. 干旱区地理, 2015, 38(2):215-222.[YANG Jinhu, ZHANG Qiang, WANG Jinsong, et al. Spring persistent droughts anomaly characteristics of over the southwest China in recent 60 years[J]. Arid Land Geography, 2015, 38(2):215-222.]

[19] 张存杰, 谢金南, 李栋梁, 等. 东亚季风对西北地区干旱气候的影响[J]. 高原气象, 2002, 21(2):193-198[. ZHANG Cunjie, XIE Jinnan, LI Dongliang, et al. Effect of east-asian monsoon on drought climate of Northwest China[J]. Plateau Meteorology, 2002, 21(2):193-198.]

[20] 杨金虎, 江志红, 王鹏祥, 等. 太平洋SSTA同西北东部夏季极端降水事件的遥联[J]. 高原气象, 2008, 27(2):331-338.[YANG Jinhu, JIANG Zhihong, WANG Pengxiang, et al. Teleconnection between pacific SSTA and summer extreme precipitation event of east of Northwest China[J]. Plateau Meteorology, 2008, 27(2):331-338.]