RELATIONSHIP BETWEEN HEAVY PRECIPITATION AND ATMOSPHERIC WAVE WITH DIFFERENT TIME SCALES DURING MEIYU PERIOD IN YANGTZE-HUAI RIVER REGION
-
摘要: 中国的江淮梅雨具有多时间尺度特征,利用1979—2017年欧洲中期预报中心逐日再分析资料(ERA-interim)和台站逐日降水观测数据,采用滤波和合成分析等统计方法,分析了江淮梅雨期间不同时间尺度强降雨过程的特征,对比研究了不同时间尺度强降水对应的大气环流系统波动的演变特征。研究表明江淮梅雨降水集中期开始前1~9天和10~20天尺度的强降水首先增多,而21~30天时间尺度的强降水在降水集中期开始增多。低频周期波动(10~20天和21~30天)比天气尺度波动可以提供更持续和更深厚的暖平流输送,触发持续时间更长的垂直运动和水汽输送,有利于持续性强降水的发生。与1~9天天气尺度波动相关的强降水主要与上游自中亚经青藏高原向下游传播并不断发展加强的Rossby波能量传播有关,青藏高原对天气尺度涡旋的增强有重要作用;对10~20天尺度强降水,高层中纬度东北亚低频反气旋环流西移南压,长时间维持在江淮地区,低层南海-西太平洋地区准双周振荡西北向传播,伴随西北太平洋副热带高压加强西伸是主要影响过程;对21~30天尺度强降水而言,江淮上空移动性环流不明显,高层反气旋性环流增强的过程与其北南两侧,即贝加尔湖及其以东地区气旋环流和南海-西太平洋气旋环流的发展移动有密切的联系,同时伴随了对流层中低层西北太平洋地区21~30天尺度低频波的西北传播。Abstract: The heavy rainfall in the Yangtze-Huai Rive region during Meiyu period is subject to the influence of several different meteorological phenomena at different time scales. In the present study, we analyzed the characteristic of the heavy rainfall associated with synoptic, biweekly and 21-30-day background and compared the evolution characteristics of corresponding atmospheric circulation system by using the daily reanalysis data provided by the European Centre for Medium-Range Weather Forecast(ECMWF) and daily precipitation observational data from meteorological stations in China during 1979—2017. The results showed that heavy rainfall with synoptic and biweekly background are active before the concentration period of Meiyu in the Yangtze-Huai River region, while the heavy rainfall with 21-30-day background increases during the concentration period. The low frequency background (10-20-day and 21-30-day) can transport longer and thicker warm airstream than the synoptic distribution does, and trigger longer vertical ascending motion and continuous water vapor, facilitating the development of continuous rainfall processes. Synoptic-scale heavy rainfall is mainly related to the upstream propagation of Rossby wave energy from central Asia. The Qinghai-Tibet Plateau plays an important role in enhancing the synoptic scale vortex. Biweekly scale heavy rainfall is mainly related to the southwest movement of northeast Asia anticyclone, which later remains in the Yangtze-Huai River region for several days. It is also influenced by the northwest propagation of quasi-biweekly oscillations in the lower troposphere over the South China Sea and western Pacific region, and by the western extension of the subtropical high. For the 21-30-day-scale heavy rainfall, the circulation in the lower troposphere of the Yangtze-Huai Rive region is relatively stable; the anticyclone in the high troposphere enhancement is closely related to the development and movement of the circulations on both the north and the south side, and the northwest propagation of low frequency oscillations in the lower troposphere of the western Pacific region.
-
-
[1] 丁一汇, 柳俊杰, 孙颖, 等. 东亚梅雨系统天气-气候学研究[J]. 大气科学, 2007, 31(6): 1 082-1 101. [2] 张庆云, 陶诗言. 亚洲中高纬度环流对东亚夏季降水的影响[J]. 气象学报, 1998, 56(2): 199-211. [3] 张庆云, 郭恒. 夏季长江淮河流域异常降水事件环流差异及机理研究[J]. 大气科学, 2014, 38(4): 656-669. [4] 冯志刚, 程兴无, 陈星, 等. 淮河流域暴雨强降水的环流分型和气候特征[J]. 热带气象学报, 2013, 29(5): 824-832. [5] 金荣花, 矫梅燕, 徐晶, 等. 2003年淮河多雨期西太平洋副高活动特征及其成因分析[J]. 热带气象学报, 2006, 22(1): 60-66. [6] 丁一汇. 1991年江淮流域持续性特大暴雨研究[M]. 北京: 气象出版社, 1993: 69-106. [7] 陶诗言, 倪允琪, 赵思雄, 等. 1998年夏季中国暴雨的形成机理与预报研究[M]. 北京: 气象出版社, 2001: 12-31. [8] 袁媛, 高辉, 李维京, 等. 2016年和1998年汛期降水特征及其物理机制对比分析[J]. 气象学报, 2017, 75(1): 19-38. [9] 陶诗言. 中国之暴雨[M]. 北京: 气象出版社, 1980: 1-255. [10] 陶诗言, 张庆云, 张顺利. 1998年长江流域洪涝灾害的气候背景和大尺度环流条件[J]. 气候与环境研究, 1998, 3(4): 290-299. [11] 张顺利, 陶诗言, 张庆云, 等. 长江中下游致洪暴雨的多尺度条件[J]. 科学通报, 2002, 47(6): 467-473. [12] LIU H B, YANG J, ZHANG D L, et al. Roles of synoptic to quasi-biweekly disturbance in generating the summer 2003 heavy rainfall in east China[J]. Mon Wea Rev, 2014, 142: 886-904. [13] YANG H, LI C Y. The relation between atmospheric intraseasonal oscillation and summer severe flood and drought in the Changjiang-Huaihe River Basin[J]. Adv Atmos Sci, 2003, 20(4): 540-553. [14] YANG J, WANG B, WANG B, et al. Biweekly and 21-30day variations of the subtropical summer monsoon rainfall over the Lower Reach of the Yangtze River Basin[J]. J Climte, 2010, 23(5): 1 146-1 159. [15] 琚建华, 孙丹, 吕俊梅. 东亚季风区大气季节内振荡经向与纬向传播特征分析[J]. 大气科学, 2008, 32(3): 523-529. [16] 黄桢, 李双林, 张超. 1991、1998和2016年三个大水年长江中下游夏季降水季节内特征的对比[J]. 热带气象学报, 2020, 36(1): 13-24. [17] 李崇银, 周亚萍. 热带大气中的准双周(10-20天)振荡[J]. 大气科学, 1995, 19(4): 435-444. [18] 曹鑫, 任雪娟, 杨修群, 等. 中国东南部5-8月持续性强降水和环流异常的准双周振荡[J]. 气象学报, 2012, 70(4): 766-778. [19] 占瑞芬, 孙国武, 赵兵科, 等. 中国东部副热带夏季风降水的准双周振荡及其可能维持机制[J]. 高原气象, 2008, 27(增刊): 98-108. [20] 琚建华, 孙丹, 吕俊梅. 东亚夏季风的低频振荡对长江中下游旱涝的影响[J]. 热带气象学报, 2008, 21(2): 163-372. [21] 龙晴柔, 金荣花, 肖天贵, 等. 夏季东亚副热带西风急流不同尺度波的特征分析[J]. 热带气象学报, 2017, 33(6): 1 000-1 008. [22] 张妤晴, 林爱兰, 温之平. 南海周边越赤道气流的多时间尺度变化特征及其与环流和降水的联系[J]. 热带气象学报, 2019, 35(4): 504-516. [23] 吴洪宝, 吴蕾. 气候变率诊断和预测方法[M]. 北京: 气象出版社, 2005: 198-245. [24] 黄嘉佑. 气象统计分析与预报方法[M]. 北京: 气象出版社, 2000: 19-21. [25] 李勇, 金荣花, 周宁芳, 等. 江淮梅雨季节强降雨过程特征分析[J]. 气象学报, 2017, 75(5): 717-728. [26] 王志毅, 高庆九, 胡邦辉, 等. 近50a江淮地区梅雨期水汽输送特征研究[J]. 大气科学学报, 2017, 40(1): 48-60.