中国东北区域盛夏雨季的客观识别

鉴于我国东北三省雨季客观识别方法不尽相同,且无东北区域统一的雨季监测指标.为了更好地开展区域关键天气过程的客观化识别和监测,本文从区域角度出发,采用东北三省102站逐日降水量资料,通过对东北区域多年平均5点平滑处理的4月1日—10月31日逐日降水量序列的综合分析,及对历年逐日滑动平均雨量的对比试验,确定了东北盛夏雨季判别的阈值参数及通过阈值后的持续时间参数,进而研发了适合东北区域盛夏雨季开始和结束日期的客观识别方法.并采用美国环境预报中心和国家大气研究中心逐日再分析的风场、位势高度场资料,通过对盛夏雨季前、中、后期不同高度层大气环流场的对比分析,验证了该客观识别方法的合理性.结果表明,东北区域1981—2010年气候态平均的盛夏雨季的起止日期分别为每年的6月26日和8月30日.

Objective identification study of midsummer rainy season in the northeast China

Owing to the fact that the objective identification methods of rainy season are not totally identical in the three provinces of Northeast China, no unified monitoring criterion of rainy season is available in this area. In order to implement the regional key climate monitoring and to meet the needs of the national weather service, from the angle of the whole region, based on the daily precipitation data of 102 observational stations, by comprehensively analyzing the daily precipitation series disposed by 5-point moving average, the objective identification method of midsummer rainy season in the northeast China is presented in this paper. Then based on the daily reanalysis data of wind field and geopotential height field provided by NCEP/NCAR, the atmospheric circulation fields of different levels before, during and after the midsummer rainy season are contrastively analyzed, and the rationality of the objective identification method is validated. Finally, the partition criterion of the beginning and ending dates are determined. Results show that: the average beginning and ending dates of midsummer rainy season in the northeast China respectively are June 26th and August 30th. The partition criterion of midsummer rainy season in the northeast China by using the objective identification method is reasonable.
Keywords： northeast China midsummer rainy season beginning and ending dates objective identification