PRELIMINARY ANALYSIS OF EFFECTS OF OLR FIELDS ON ANNUAL FREQUENCY OF TROPICAL CYCLONE IN FUJIAN

Outgoing Longwave Radiation (OLR) has been shown to play an important role in climatic diagnosis and long-term prediction and research. With the OLR data 1974 ~ 1997 as observed by satellites, the characteristics are computed. The results are used to depict the location and intensity of the subtropical high in the study of the relationship between the annual frequency of tropical cyclones affecting the Fujian province and ITCZ / subtropical high. It is shown that in years of fewer (more) tropical cyclones, the ITCZ is southward (northward) located with weaker (stronger) intensity, and the subtropical high is southward (northward). As shown in the relationship between the anomalous years of tropical cyclones and characteristics of preceding OLR fields, the OLR anomalies are just oppositely distributed in the Pacific Ocean for years of more (fewer) tropical cyclones. In other words, the years of fewer (more) tropical cyclones are associated with positive anomalies of OLR in the tropical west Pacific but negative (positive) anomalies in the equatorial central and eastern Pacific. It is hoped that our study be setting foundation for short-term climatological prediction of tropical cyclones.

OLR场对福建热带气旋频数影响的初步研究

根据1974～1997年卫星观测的OLR（射出长波辐射）资料。计算OLR特征量表征ITCZ和副热带高压的位置和强度．分析影响福建热带气旋（TC）年频数异常年份的特征。结果表明，TC异常偏少（多）年，ITCZ位置偏南（北）。强度偏弱（强），副高位置偏南（北）。然后，分析TC异常年份前期和同期的OLR场特征，发现TC异常偏多年和异常偏少年太平洋上的OLR距平场配置相反，即TC异常偏少（多）年。西太平洋热带地区OLR为正距平。而赤道中东太平洋为负（正）距平区。

OLR场对福建热带气旋频数影响的初步研究

根据１９７４～１９９７年卫星观测的ＯＬＲ（射出长波辐射）资料计算ＯＬＲ的特征量，用其表征ＩＴＣＺ和副热带高压的位置和强度，分析影响福建热带气旋（ＴＣ）年频数与ＩＴＣＺ和副热带高压的关系。结果表明，ＴＣ异常偏少（多）年，ＩＴＣＺ位置偏南（北），强度偏弱（强），副高位置偏南（北）；ＴＣ异常年份前期ＯＬＲ场特征关系表明，ＴＣ异常偏多年和异常偏少年太平洋上的ＯＬＲ距平场配置相反，即ＴＣ异常偏少（多）年，西太平洋热带地区ＯＬＲ为正距平，而赤道中东太平洋为负（正）距平区。