摘要
利用美国环境预测中心(NCEP)资料,对2005年9月1日至10月10日汉江上游秋涝期500 hPa环流条件和700 hPa水汽场的时空分布特征进行了分析。结果表明:在汉江上游秋涝盛期,500 hPa高度距平场呈现出"+,-,+"波列结构。700 hPa主要水汽源在孟加拉湾和南海地区。同时段水汽通量散度场EOF分析表明,汉江上游水汽通量散度同南海和孟加拉湾北部具有相同的变化符号;小波分析进一步揭示出汉江上游和南海地区水汽通量散度都存在准2周和准1周的振荡。强降水一般出现在几种不同频率振荡的负值位相叠加的时段。
An analysis is made of the temporal and spatial characteristics of the circulation pattern at 500 hPa and vapor field at 700 hPa during the autumn waterlogging in upstream of the Han River in 2005 with NECP data. The results indicate that the height departure field at 500 hPa took on the wave train of ＂ ＋ , - , ＋ ＂ The primary sources of vapor at 700 hPa came from the Bay of Bengal and the South China Sea. The EOF analysis shows that the vapor flux divergence showed the same variation trend in upstream of the Han River and the Bay of Bengal and the South China Sea. The wavelet analysis reveals that the vapor flux divergence has oscillations of quasi-two week and quasi-one week in upstream of the Han River and the South China Sea. The strong precipitation appears frequently in the period of the superposed negative phase of several different frequency oscillations.
出处
《气象科技》
2007年第4期514-518,共5页
Meteorological Science and Technology
关键词
秋涝
水汽通量
水汽通量散度
EOF分析
小波分析
autumn waterlogging, vapor flux, vapor flux divergence, EOF, wavelet analysis
