摘要
利用1970—2012年河南省114个气象站9月日降水量、NCEP/NCAR再分析资料及海温数据,采用统计诊断与合成方法对河南省初秋降水的气候特征、异常年份大气环流特征及降水与ENSO的关系进行分析。结果表明:河南省初秋(9月)降水有明显的年际和年代际变化特征,20世纪70年代前期和80年代前期降水偏多,70年代后期、80年代后期至2003年降水偏少,2000年后降水呈波动变化。河南省初秋的降水场可以划分为南北两个降水区,两个分区降水无显著的线性趋势和突变,20世纪80年代后期至2003年两个降水分区降水均偏少。旱涝年合成高度的差值场表明欧洲地区、西伯利亚地区、蒙古至中国北方地区及西太平洋区域均是影响河南省初秋降水的关键区;西伯利亚地区为正高度异常、中国北方至蒙古为负高度异常及西太平洋副热带高压偏北的环流形势易造成河南省初秋降水偏多;降水偏少年份的环流形势则相反。ENSO为冷位相年,河南省初秋降水易偏多;河南省初秋降水偏少年除受ENSO的影响外,中高纬度环流的影响可能起主导作用。
Based on daily precipitation data at 114 weather stations in September from 1970 to 2012 in He＇nan province, the NCEP/NCAR reanalysis data and sea surface temperature data, climatic characteristics of precipitati- on and circulation anomalies in early autumn and relationships between precipitation and ENSO were analyzed by methods of a statistical diagnosis and a synthesis. The results indicate that there are significantly interannual and in- terdecadal variations for early autumn precipitation in He＇nan province. Precipitation is higher in the early 1970s and early 1980s and less in late 1970s and after the second half of 1980s;it fluctuates after 2000. The early autumn rainfall fields in He＇nan province can be classified into two regions,namely, northern region and southern region. Precipitation has no clear linear trend and abrupt change in these two regions. Precipitation decreases significantly from the late 1980s to 2003 in these two regions. The Europe, Siberia, northern region of China and the West Pacif- ic are proved to be the key regions affecting the early autumn precipitation based on the difference of composited geopotential height field in drought and flood years. When the geopotential height abnormity is positive in the Si- beria and negative in the northern China, it is beneficial for cold air heading down south to affect the north China. The northwest-trending of west pacific subtropical high transports more water vapor to the north. Both cold air and water vapor result in more rainfall in He＇nan province. When ENSO is in cold phase ,early autumn precipitation in He＇nan province tends to be higher. In drought years, atmospheric circulation anomalies of mid-high latitude play an important role except the effect of ENSO.
出处
《气象与环境学报》
2015年第6期93-100,共8页
Journal of Meteorology and Environment
基金
国家自然科学基金面上项目(41371093)
公益性行业(气象)科研专项"气象灾害预警技术和风险评估"(GYHY201106035)
公益性行业(气象)科研专项"基于集合预报的中期概率预报技术研究"(GYHY201006018)共同资助
关键词
初秋降水
降水区划
趋势分析
大气环流异常
ENSO
Early autumn precipitation
Regionalization of rain
Trend analysis
Atmospheric circulation anomalies
ENSO
