Journal of Arid Meteorology ›› 2020, Vol. 38 ›› Issue (4): 543-551.

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Effect of Equatorial Pacific SSTA on Precipitation in July in Ningxia

ZHANG Wen, MA Yang, LI Xin, ZHENG Guangfen,WANG Suyan, HUANG Ying   

  1. (Ningxia Hui Autonomous Region Climate Center, Key Laboratory for Meteorological Disaster Monitoring and
     Early Warning and Risk Management of Characteristic Agriculture in Arid Regions, CMA, Yinchuan 750002, China)
  • Online:2020-08-31 Published:2020-09-04

赤道太平洋海温异常对宁夏7月降水的影响

张雯,马阳,李欣,郑广芬,王素艳,黄莹   

  1. (宁夏气候中心,宁夏气象防灾减灾重点实验室,宁夏银川750002)

  • 通讯作者: 李欣(1983— ),女,高级工程师,主要从事短期气候预测. E-mail: lixin_720@163.com。
  • 作者简介:张雯(1990— ),女,宁夏银川人,硕士,助工,主要从事短期气候预测. E-mail: acaimeme@sina.cn
  • 基金资助:
    2018年宁夏青年拔尖人才培养工程和宁夏回族自治区重点研发(科技惠民)计划项目“宁夏中南部马铃薯关键期气象条件预测技术研究”(2016KJHM129)共同资助

Abstract: Based on the observational rainfall data in July of Ningxia, the NCEP/NCAR reanalysis data and the ERSSTv5 SST data from 1981 to 2018, the variation characteristics of precipitation in July in Ningxia and their formation causes were analyzed. This paper also discussed the influence of the equatorial Pacific SST anomaly on precipitation. The results are as follows: (1) In the past 38 years, the inter-annual variability of precipitation in July was significant, but the extremity and anomaly of precipitation both increased after 2000. (2) The 500 hPa geopotential height anomaly was low over the Balkash lake and it was high between North China, the Northeast China and the Sea of Japan in mid-high latitudes. The active low-pressure system from the Bay of Bengal to the South China Sea, coupled with water vapor transported by the southerly anomaly on 700 hPa from the Northwest Pacific, led to more precipitation in July in Ningxia. (3) Since the 21th century, the implication of equatorial Pacific SST on precipitation in July has strengthened, especially during late winter and early spring during the ENSO decaying phase. When the SST anomaly in the equatorial Pacific characterized  by a dipole pattern, namely, warm (cold) in the west and cold (warm) in the central, and the subtropical western Pacific anomaly cyclone (anticyclone) in July played an important role in transportation of water vapor. The pattern of lower in the west (east) and higher in the east (west) existed on 500 hPa height, which was favorable to more (less) precipitation and reflected the impact of the central pacific type of ENSO on precipitation in Ningxia to some extent.


Key words: Key words: equatorial Pacific SSTA, Ningxia, July, precipitation

摘要: 基于1981—2018年宁夏7月降水资料、NCEP/NCAR再分析资料及ERSSTv5海温资料,分析宁夏7月降水变化规律及其成因,探讨赤道太平洋海温异常对降水的影响。结果表明:(1)7月降水以年际变化为主,2000年之后降水的极端性和异常性增强。(2)7月中高纬500 hPa位势高度距平呈“西低东高”分布型,其中,巴尔喀什湖为负高度距平,中国华北、东北至日本海为正高度距平。低纬孟加拉湾—南海附近低值系统活跃,同时配合700 hPa来自西北太平洋异常偏南风的水汽输送,造成宁夏7月降水异常偏多。(3)21世纪以来赤道太平洋海温对宁夏7月降水的指示意义增强,特别是在ENSO衰减位相的冬末春初,当前期赤道太平洋呈“西暖中冷”(“西冷中暖”)的偶极型分布时,7月副热带西太平洋异常气旋(反气旋)对水汽的输送起到重要作用,配合500 hPa “西低东高”(“西高东低”)的异常形势,使得宁夏7月降水更容易表现出异常偏多(偏少),一定程度上反映出中部型ENSO事件对宁夏降水的影响。


关键词: 关键词:赤道太平洋海温, 宁夏, 7月, 降水

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