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 ...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.展开更多
为进一步探讨高原低涡与高原大气的基本状况及其联系,通过对1981-2015年低涡频次及OLR、500 h Pa经纬向风场的统计,分析其气候变化及低频振荡特征,并初步探讨了低涡频次与其他三者低频信号之间的联系。结果表明:4-8月是低涡的频发时段;...为进一步探讨高原低涡与高原大气的基本状况及其联系,通过对1981-2015年低涡频次及OLR、500 h Pa经纬向风场的统计,分析其气候变化及低频振荡特征,并初步探讨了低涡频次与其他三者低频信号之间的联系。结果表明:4-8月是低涡的频发时段;低涡频次呈逐年增加的趋势,存在显著的2 a、4 a变化周期和55 d、30 d低频振荡周期;在低涡频发期内,OLR平均值为212.2 W·m^(-2),存在显著的10~12 a变化周期和45 d、20 d低频振荡,滤波中心存在东进和西退的移动特征,在纬向上表现为向南移动,500 h Pa纬向风均值为3.56 m·s^(-1),其逐年及逐日变化均呈下降趋势,存在4 a、10 a的变化周期和75 d、45 d的低频振荡周期,30~60 d滤波信号中心以西退和北进为主要移动特征,60~90 d滤波信号中心向南移动特征明显,500 h Pa经向风以北风分量为主,其逐年及逐日变化均为减小趋势,存在4 a变化周期和10-20 d低频振荡;低涡频次与500 h Pa纬向风区域平均值在1996年发生突变;低涡频次与大气低频振荡存在密切联系,其与500 h Pa经向风呈负相关性,7-8月尤为显著,与OLR和500 h Pa纬向风在4月至7月中旬呈显著正相关,7月中旬至8月转为负相关,其中与OLR 30-60 d滤波信号呈高度负相关性;500 h Pa纬向风滤波信号中心的移动能较好的对应低涡频次空间分布的变化。展开更多
基金Core national scientific project in the 9th five-year development plan (96-908-05-06-12)
文摘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.
文摘为进一步探讨高原低涡与高原大气的基本状况及其联系,通过对1981-2015年低涡频次及OLR、500 h Pa经纬向风场的统计,分析其气候变化及低频振荡特征,并初步探讨了低涡频次与其他三者低频信号之间的联系。结果表明:4-8月是低涡的频发时段;低涡频次呈逐年增加的趋势,存在显著的2 a、4 a变化周期和55 d、30 d低频振荡周期;在低涡频发期内,OLR平均值为212.2 W·m^(-2),存在显著的10~12 a变化周期和45 d、20 d低频振荡,滤波中心存在东进和西退的移动特征,在纬向上表现为向南移动,500 h Pa纬向风均值为3.56 m·s^(-1),其逐年及逐日变化均呈下降趋势,存在4 a、10 a的变化周期和75 d、45 d的低频振荡周期,30~60 d滤波信号中心以西退和北进为主要移动特征,60~90 d滤波信号中心向南移动特征明显,500 h Pa经向风以北风分量为主,其逐年及逐日变化均为减小趋势,存在4 a变化周期和10-20 d低频振荡;低涡频次与500 h Pa纬向风区域平均值在1996年发生突变;低涡频次与大气低频振荡存在密切联系,其与500 h Pa经向风呈负相关性,7-8月尤为显著,与OLR和500 h Pa纬向风在4月至7月中旬呈显著正相关,7月中旬至8月转为负相关,其中与OLR 30-60 d滤波信号呈高度负相关性;500 h Pa纬向风滤波信号中心的移动能较好的对应低涡频次空间分布的变化。
