徐敏,丁小俊,罗连升,程智,徐胜. 2013. 淮河流域夏季旱涝急转的低频环流成因[J]. 气象学报, 71(1):86-95, doi:10.11676/qxxb2013.007
淮河流域夏季旱涝急转的低频环流成因
A possible cause of the low frequency circulation of summer-time drought-fiood abrupt alternation over the Huaihe River basin
投稿时间：2011-12-06  修订日期：2012-02-04
DOI：10.11676/qxxb2013.007
中文关键词:  淮河流域  旱涝急转  低频振荡  波作用通量
英文关键词:Huaihc River basin  Drought-flood abrupt alternation  Low frequency oscillation  Wave-activity flux
基金项目:水利部2009年公益项目“淮河流域洪涝特征研究”(200901024);2010年淮河流域气象开放研究基金“淮河流域汛期气候预测方法研究”(HRM201001)
作者单位
徐敏 安徽省气候中心, 合肥, 230031 
丁小俊 安徽省气候中心, 合肥, 230031 
罗连升 安徽省气候中心, 合肥, 230031 
程智 安徽省气候中心, 合肥, 230031 
徐胜 淮河水利委员会水文局, 蚌埠, 233001 
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中文摘要:
      利用1960-2007年4-8月逐日降水资料挑选了淮河流域各分区旱涝急转事件,分析了旱涝急转夏季,逐日降水的低频振荡特征.结果表明,旱涝急转夏季逐日降水30-60d周期振荡明显加强,流域大部分地区30-60d低频振荡的方差贡献与夏季降水量呈正相关,低频方差贡献大(小)对应夏季降水量多(少),并且,相关显着区域位于流域南部.欧亚中高纬度高度场、经向风场的低频位相在少雨、多雨期呈相反纬向分布是造成旱涝急转的环流成因.通过对典型年份分析,给出了低频分布型的形成过程.在少雨期,北半球中高纬度扰动场为4-5波列,从东北大西洋经欧洲和贝加尔湖至东亚太平洋沿岸为“+、-、+、-”,与低频位相分布一致.在多雨期,副极地波导从欧洲北部沿急流流向亚洲高纬度地区,并在鄂霍次克海形成强盛的正扰动中心,有利于鄂霍次克海阻塞形势的形成与维持.当中纬度中亚为负扰动中心,印度季风偏弱时,由于下游效应在日本海形成负扰动,导致副热带高压位置偏南.在低纬度孟加拉湾到中国南海对流层高层为负扰动时,中国南海对流活动偏弱.少雨、多雨期的欧亚中高纬度纬向低频环流型实际上反映了副极地、副热带急流罗斯贝波导结构及其传播的异常.
英文摘要:
      The daily rainfall data in April-August during 1960-2007 are used to select drought-flood abrupt alternation events of the Huaihe river basin, and the characteristics of the low frequency oscillation about the summertime daily rainfall of drought-flood abrupt alternation are analyzed.The results are as follow; the 30-60 d oscillation about the summertime daily rainfall of drought-flood abrupt alternation obviously intensify. The positive correlation between the variance contribution of 30-60 d oscillation and the summertime rainfall over most part of the Huaihc river basin is shown with the large (small) variance contribution corresponding to much(rare) summertime rainfall. Furthermore, the significant correlation region is located over the south of the river basin. The opposite patterns of the tonal 30-60 d oscillation phase of both the height and meridional wind over the Eurasian mid-high latitudes are a possible circulation cause for the flood-drought abrupt alternation. In addition, the evolution of the low frequency distribution is given by analyzing the cases in typical years. During the drought period the global tcleconnection variability pattern over the mid-high latitudes has a tonal wavenumer -4 or wavenumer-5 structure with the variability centers over Eurasian ranking as "+—-—+—-" from northeastern Atlantic to East Asia through Europe and Lake Baikal, which is corresponding to the low frequency oscillation distribution. During the flood period the subpolar waveguide emanates from northern Europe to the high-latitude region of Asia along the westerly jet stream, then the strong positive variability center is developed over the sea of Okhotsk, which is favorable to forming and maintaining Okhotsk high blocking. Meanwhile the negative variability centers are found over the mid-latitude region of central Asia with the Indian monsoon weaker than normal, and then negative variability forms over the sea of Japan as a result of the down-stream effect, resulting in the subtropical high shift to more southern than normal. The negative variability is found over the lower latitudes of Bay of Bengal to the high levels of the troposphere over the South China Sca, therefore the connective activities over the South China Sca are weaker than normal. The tonal low frequency circulation pattern over the Eurasian mid-high latitudes during the drought period and the flood period reflects actually the subpolar and subtropical jet stream Rossby waveguide structure and its anomalous propagation.
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