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甘肃省春季强冷空气时空分布特征及其延伸期预报探索

林  纾1,2李丹华1卢国阳1刘卫平1   

  1. 1.西北区域气候中心,甘肃 兰州 730020;
    2.中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,中国气象局干旱气候变化与减灾重点实验室,甘肃 兰州 730020
  • 出版日期:2017-12-29 发布日期:2017-12-29
  • 作者简介:林纾(1964— ),女,福建福州人,正研级高级工程师,主要从事短期气候预测业务及研究. E-mail:treewest@163.com。
  • 基金资助:

    中国气象局2017年核心业务发展专项(YBGJXM(2017)04-06)和中国气象局气候变化专项(CCSF201612)共同资助

Temporal and Spatial Distribution Characteristics of Strong Cold Air and Exploration of Extended Period Prediction in Gansu in Spring During 1981-2015

LIN Shu1,2, LI Danhua1, LU Guoyang1, LIU Weiping1   

  1. 1. Northwest Regional Climate Center, Lanzhou 730020, China;
    2. Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climatic Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climatic Change and Disaster Reducing of China Meteorological Administration, Lanzhou 730020, China
  • Online:2017-12-29 Published:2017-12-29

摘要:

利用1981—2015年春季甘肃省77站逐日最低温度资料,分析甘肃省1981—2015年以来春季强冷空气的时空分布特征。在此基础上,结合1981—2015年NCEP逐日500 hPa高度场资料和准150 d韵律方法,对甘肃省春季强冷空气的延伸期预报进行探索。结果表明,1981年以来甘肃省春季强冷空气发生频次1980年代最少,21世纪以来明显增多。全省范围和河东区域的强冷空气多出现在3—4月,而河西区域的强冷空气则多在4—5月,且河西区域的强冷空气频次是河东区域的两倍。经相似系数的计算及阈值的确定,制定了评估标准及多层筛选方法,从而选出4个针对甘肃省春季强冷空气活动具有天气学意义的典型预报场,在综合4个典型场的情况下,预报准确率明显提高,空报率降为零,漏报率显著降低,为甘肃省春季强冷空气的延伸期预报提供了新的预报途径。

关键词: 春季, 强冷空气, 延伸期预报

Abstract:

Based on the daily minimum temperature data of 77 weather stations in spring in Gansu Province and daily geopotential height field on 500 hPa during 1981-2015, the temporal and spatial distribution characteristics of strong cold air affecting Gansu in spring were analyzed. And on this basis the extended period prediction of strong cold air in spring in Gansu was explored by using the quasi 150-day rhythm method. The results show that the frequency of strong cold air in spring in Gansu was the lowest in the 1980s, and it increased obviously since 2000. The strong cold air in whole province and Hedong area of Gansu mainly appeared in March and April, while in Hexi area it tended to occur in April and May, and the frequency of strong cold air in Hexi area was two times of that in Hedong area. The evaluation criteria and multilayer screening method were established by calculating similarity coefficients and determining of thresholds, and then four typical fields of weather forecast to strong cold air in spring in Gansu were selected. In the case of combining four typical forecast fields, the prediction accuracy improved obviously, the null rate of forecast reduced to zero, and the omission rate reduced greatly, which provided a new prediction way for the extended period forecast to strong cold air in Gansu.

Key words: spring, strong cold air, extended period prediction

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