新标准下梅雨特征量的时间演变及异常梅年环流特征分析

发布时间：2018-01-08 22:21

本文关键词：新标准下梅雨特征量的时间演变及异常梅年环流特征分析　出处：《华东师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文利用降水资料、NCEP/NCAR提供的全球逐日再分析资料以及《梅雨监测业务规定》中入、出梅日的确定,计算出我国梅雨监测区以及四个子气候区(江淮区、长江下游区、长江中游区和江南区)1961-2010年梅雨期入、出梅日期等梅雨特征量,并对得到的出、入梅日进行检验。此外,还分析了梅雨监测区异常梅年环流特征。相关结果如下:(1)江南区平均入、出梅日最早,长江中游区和长江下游区次之,江淮区最晚。除了梅雨监测区外,四个子气候区均有空梅年。(2)长江中游区和长江下游区梅雨期长度和梅雨强度的变化趋势较为一致。上世纪60年代末,梅雨期变长、梅雨强度增强,而后,处于较为稳定的状态,直到90年代末-本世纪初,梅雨期变短、梅雨强度减弱。(3)梅雨监测区以及四个子气候区入梅日和出梅日的相关性较好,均通过了α=0.001显著性检验。梅雨监测区、江淮区和长江中游区出梅日和梅雨期长度、梅雨量以及梅雨强度的相关性比入梅日与它们的相关性高,而江南区的情况则相反。(4)对计算的各区平均入、出梅日期和文献[1]西太副高脊线北跳的时间进行验证,发现平均入梅日与西太副高脊线的第一次北跳对应较好,平均出梅日比西太副高脊线第二次北跳早2-3候。(5)在平均早入梅日前后:早入梅年,西太平洋副高较为强大,位置偏西北,副高脊线超过20° N;晚入梅年,西太平洋副高面积明显减小,位置明显偏东。在平均晚出梅日前后:早出梅年,西太平洋副高位置偏北,西太副高脊线超过30°N;晚出梅年,西太平洋副高依旧强大,西段副高脊线在30° N附近。
[Abstract]:In this paper, the precipitation data are used to determine the global daily reanalysis data provided by NCEP / NCAR and the "Meiyu Monitoring operational regulations". The characteristics of Meiyu in Meiyu monitoring area and four sub-climatic areas (Jianghuai area, lower reaches of Yangtze River, middle reaches of Yangtze River and Jiangnan region from 1961 to 2010) were calculated. In addition, the characteristics of abnormal Meiyue circulation in Meiyu monitoring area are analyzed. The correlation results are as follows: 1) the average entry of Jiangnan region is the earliest. The middle reaches of the Yangtze River and the lower reaches of the Yangtze River are the second, and the Jianghuai area is the last, except for the Meiyu monitoring area. In the middle reaches of the Yangtze River and the lower reaches of the Yangtze River, the variation trend of the Meiyu period and the Meiyu intensity is consistent. At the end of -40s, the Meiyu period becomes longer and the Meiyu intensity increases. Then, it was in a stable state, until the end of 90s to the beginning of this century, the Meiyu period became shorter, the Meiyu intensity weakened. The correlation between Meiyu monitoring area, Jianghuai area and the middle reaches of Yangtze River is higher than that of Meiyu day and Meiyu period, and the correlation of Meiyu rainfall and Meiyu intensity is higher than that of Meiyu day and Meiyu intensity. On the other hand, the situation in Jiangnan District is the opposite. [The results are as follows: 1) the time of northward jump of the ridge line of the West Pacific Subtropical High is verified, and it is found that the average date of entering the plum is better than the first time of the northward jump of the ridge line of the West Pacific Subtropical High. Before and after the average early entry date, the west Pacific subtropical high was stronger than the western Pacific subtropical high, and the ridge line of the subtropical high was more than 20 掳N. The area of the western Pacific subtropical high was obviously decreased and the position was obviously eastward in the late plum year. Before and after the average late plum day, the west Pacific subtropical high was located northward, and the ridge line of the west Pacific subtropical high was more than 30 掳N. The west Pacific subtropical high is still strong, and the ridge line of the western subtropical high is about 30 掳N.
【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P426.6;P434

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