Journal of Arid Meteorology ›› 2019, Vol. 37 ›› Issue (2): 226-232.DOI: 10.11755/j.issn.1006-7639(2019)-02-0226

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Climatic Characteristics of Autumn Rain in Shaanxi and Their Relationship with Atmospheric Circulation and SST During 1961-2016

CAI Xinling, LI Yu, LI Qian, HU Shulan   

  1. Shaanxi Provincial Climate Center, Xi’an 710014, China
  • Online:2019-04-30 Published:2019-04-30

1961—2016年陕西秋淋气候变化特征及其与大气环流和海温的关系

蔡新玲,李瑜,李茜,胡淑兰   

  1. 陕西省气候中心,陕西 西安 710014
  • 作者简介:蔡新玲(1969— ),女,硕士,高工,主要从事气候预测研究工作. E-mail:418675654@qq.com。
  • 基金资助:
    陕西省社会发展科技攻关项目(2016SF-416)和中国气象局预报员专项(CMAYBY2019-119)共同资助

Abstract:

In order to strengthen the objective quantification of autumn rain monitoring and evaluation in West China and improve forecast method of autumn rain in Shaanxi, the climatic characteristics of autumn rain in Shaanxi and their relationship with atmospheric circulation and SST during 1961-2016 were analyzed by using correlation analysis and regression analysis based on the daily precipitation at 77 weather stations of Shaanxi, NCEP reanalysis data, NOAA sea surface temperature (SST), moving average SST index from the Climate Prediction Center in USA and SST index from the National Climate Center in China. The results show that the average onset date of autumn rain in Shaanxi was on September 10, the change trend of the onset date wasn’t obvious in Shaanxi from 1961 to 2016 as a whole, but there were obvious interdecadal variation characteristics. The average end date of autumn rain was on October 7, and it had an earlier tendency in the past 56 years. The intensity of autumn rain decreased in Shaanxi during 1961-2016, but the trend wasn’t significant, and the interdecadal variation was obvious. In the year of strong autumn rain in Shaanxi, the anomalous circulation on 500 hPa with ‘+, -, +’ appeared over Eurasian mid-high latitude, and the western Pacific subtropical high and the Indian-Burma trough were stronger. The intensity of autumn rain in Shaanxi was closely related with ENSO events. The development of cooling (warming) SST in equatorial central-eastern Pacific in spring and summer was beneficial to strong (weak) autumn rain in Shaanxi, and the previous SST anomaly in 

Niño3.4 area of tropical Pacific was interannual prediction signal to the intensity of autumn rain in Shaanxi, which had better indication to autumn rain intensity in Shaanxi.

Key words: Shaanxi, autumn rain, atmospheric circulation, SST, interannual signal

摘要: 为增强华西秋雨监测评估的客观量化,改善陕西秋淋强度的预测方法,本文利用1961—2016年陕西中南部地区国家级地面气象观测站逐日降水量、NCEP再分析资料、NOAA海温资料以及国家气候中心的海温指数,通过定义秋淋强度指数,分析了陕西秋淋变化特征及其与大气环流和海温的关系。结果表明:近56 a陕西秋淋开始日期平均是9月10日,年际波动较大,整体上无明显变化趋势,但年代际变化特征明显;结束日期平均是10月7日,变化趋势整体趋于偏早。秋淋强度呈波动减弱趋势,且年代际阶段性变化特征明显。陕西秋淋偏强年,500 hPa欧亚中高纬上空呈现“+、-、+”的异常环流特征,且西太平洋副热带高压和印缅槽偏强。陕西秋淋的强弱与ENSO事件有密切联系,前期春、夏季赤道中东太平洋冷(暖)海温发展有利于陕西秋淋偏强(弱),且Niño3.4区海温异常是陕西秋淋强弱的年际预测信号,对陕西秋淋强度预测有较好的指示意义。

关键词: 陕西, 秋淋, 大气环流, 海温, 年际信号

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