华南前汛期不同降水时段的特征分析
投稿时间: 2004-09-06  最后修改时间: 2004-12-16  点此下载全文
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作者单位
池艳珍 南京信息工程大学, 大气科学系, 江苏, 南京, 210044 
何金海 南京信息工程大学, 大气科学系, 江苏, 南京, 210044;中国气象局, 广州热带海洋气象研究所, 广东, 广州, 510080 
吴志伟 南京信息工程大学, 大气科学系, 江苏, 南京, 210044 
基金项目:广东省自然科学基金资助项目(0400391);“热带海洋气象科学研究基金”资助
中文摘要:利用1957—2001年华南地区74个测站逐日降水资料和同期NCEP/NCAR逐日再分析格点资料,对华南前汛期(4—6月)不同降水时段的特征进行了比较。分析发现,华南前汛期降水由锋面降水和夏季风降水两个时段组成。锋面降水时段主要集中在4月,为典型的由冬到夏过渡的环流形势,华南地区高空为平直的副热带西风急流,大气层结稳定,水汽来源主要是阿拉伯海的西风输送和西太平洋副高南侧东风的转向输送;南海夏季风爆发前,副高仍控制南海地区,华南地区水汽输送主要来源于阿拉伯海的西风输送和西太平洋副高南侧东风的转向输送及孟加拉湾的西南输送;南海夏季风爆发后,副高东撤退出南海地区,南半球越赤道水汽输送加强并与孟加拉湾水汽输送连通,华南区域内对流发展;夏季风降水时段盛期主要集中在6月,此时南亚高压跃上高原,华南地区处于南亚高压东部,对流发展极其旺盛,强大的南半球越赤道水汽输送越过孟加拉湾和南海地区向华南地区输送。
中文关键词:华南前汛期  锋面降水  夏季风降水
 
Features Analysis of the Different Precipitation Periods in the Pre-flood Season in South China
Abstract:Based on the daily precipitation data of 74 observational stations in South China and the daily NCAR/NCEP reanalysis dataset in 1957—2001,the features of different precipitation periods in the pre-flood season(AMJ) in South China are compared.The main results are obtained as follow:the pre-flood season in South China is composed of the frontal precipitation period and the summer monsoon precipitation period.The former mainly appears in April,accompanied with a typical transition circulation pattern from winter to summer,where in strong subtropical westerly jet streams prevail in the high level over South China,the atmospheric stratification is stable,and the moisture is mainly originated from the westerly transport over the Arabian Sea and the easterly transport on the south side of WPSH;before the onset of SCSSM,the subtropical high dominates over the SCS and the moisture in South China mainly comes from the westerlies over the Arabian Sea,the easterlies on the south side of WPSH and the southwesterlies over the Bay of Bengal.After the onset of SCSSM,the subtropical high withdraws out of the SCS,accompanied with the strengthening of the cross-equatorial moisture transport from the Southern Hemisphere;the summer monsoon precipitation peaks in June when the South Asian High prevails over the Tibetan Plateau and South China,vigarous convection develops and the powerful cross-equatorial flow cross the Bay of Bengal and transports moisture towards South China.
keywords:pre-flood season in South China  frontal precipitation  summer monsoon precipitation
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