摘要
采用逐次滤波法逐次提取东海气温资料序列中蕴涵的太阳活动影响信息并加以分析,发现东海气候年代际变化特征十分清楚,主要表现为:(1)突变性,东海夏季7月海平面层及对流层大气温度场在过去半个多世纪中发生过一次急剧变化,突变点是1978年7月.从1978年7月由历时30多年的温度偏低时期跃变为持续高温时期,高温期持续至20世纪末,升温幅度超过0.4℃.资料分析表明,整个对流层东海夏季大气温度都具有这种年代际变化特征;(2)高空气候持续增温型,东海夏季7月平流层中部10 hPa大气温度表现为一种波动式的持续升温过程,50多年来温度升高4℃,年升温率超过0.075℃/a.东海平流层底部100 hPa温度也具有持续升温的特点,从1948年至今呈缓慢升高的趋势,53 a升高了1.9℃,升温率为0.036℃/a;(3)周期性,东海不同高度大气温度都具有显著程度不同的22 a周期性年代际变化特征,22 a周期分量的振幅由高空到低空迅速减小,表明22 a周期高空清楚,低空不太明显.东海对流层中部和平流层底部还具有显著的11 a周期性年代际变化.据分析认为22 a周期是太阳黑子磁场磁性变化周期所激发,11 a周期与太阳黑子相对数11 a周期相吻合,二者均为太阳活动在大气气候中的反映.
The information of influence of solar activities in the data series is picked-up by using step-bystep filtering and analyzed. It is revealed that the interdecadal variability of the monsoon climate over the East China Sea is very clear and represented in the following aspects. （1） The abrupt change. The atmospheric temperature at the sea level pressure layer and in the troposphere in July （summer） over the East China Sea has undergone a sharp change in the past half century which occurred in July 1978. Since July 1978, a period of persistent high temperature has began after a period of more than 30 a with comparatively low temperature. It lasted until the end of the 20th century. The temperature rising was more than 0. 4 ℃. The data analysis indicates that the atmosphere temperature at all levels in the troposphere over the East China Sea in summer has this interdecadal variability. （2） Persistent increasing of the air temperature at the upper levels of the atmosphere. The atmosphere temperature at the middle part of the stratosphere （10 hPa） over the East China Sea in July （summer） is a persistent process of temperature rising with a wave form. The temperature has increased over 4 ℃ in the recent more than 50 years. The yearly ratio of the temperature rising is more than 0. 075 ℃/a. The temperature at the bottom of the stratosphere （100 hPa） over the East China Sea also has the characteristic of the persistent rising of the temperature, which has shown a tendency of slowly rising since 1948 and has increased by 1.9 ℃ in the recent 53 a. The yearly ratio of the temperature rising is 0. 036 ℃/a. （3） The periodicity. The air temperatures at different atmosphere levels over the East China Sea have the interdecadal variability with a 22 a period in various degrees. The amplitudes of the 22 a components rapidly decrease from upper to lower atmosphere levels. This indicates that the 22 a period is clear at the upper air, but not clear at the lower levels. There are also obvious decadal variations with an 11 a period at the middle part of the troposphere and the bottom of the stratosphere over the East China Sea. Based on the analysis, it is known that the 22 a period is caused by the period magnetic variation of the magnetic field of the sunspots. The 11 a period corresponds to the 11 a period of the relative number of the sunspots, and both are the reflection of the solar activity in the atmospheric climate.
出处
《海洋学报》
CAS
CSCD
北大核心
2006年第2期39-45,共7页
基金
国家自然科学基金项目(4047503340305009)
关键词
东海气候
年代际变化
太阳活动
climate over East China Sea
interdecadal variability
solar activity
