古气候记录指示的天文周期分析  

Astronomical Periodic Analysis of Paleo-climate Record Indexes

作　　者：顾震年[1] 

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《天文学报》2002年第4期432-442,共11页Acta Astronomica Sinica

基　　金：自然科学资金(19833030);中国科学院九五重大项目(KJ951-1-304);中国科学院西安黄土与第四纪地质国家重点实验室资助项目

摘　　要：利用西峰市以西16km处的巴家嘴黄土剖面的上新世以来的(6.2-2.5MaB.P.)磁化率和粒度及太平洋深海沉积物资料,用不同的数据分析方法,不仅得到地球轨道主要参数中(对应于偏心率、交角和气候岁差)的 0.1Ma、0.04Ma和0.023Ma几个天文周期,而且还得到了0.20Ma、0.15Ma、0.08Ma和0.06Ma其他周期,它们都在80％置信度水平以上.此外,通过小波变换表明,所有这些周期呈现出时变特性,随不同的地质年代增强或逐渐消失.这说明古气候的变化受多种古环境的影响所致.近来提出0.1Ma周期变化不但和地球轨道偏心率有关,而且可能和星际尘埃粒子沉降速率和青藏高原的隆升有着密切的关系.因此,地球轨道参数变化影响气候长期变化只是其中一种因素.Using the sequences of both susceptibility and particle size of loess-paloosol located at Ba Jia Zui loess profile 16km west from Xi Feng city, as well as deep sea sediments in the Pacific ocean at the interval of 6.2 - 2.5Ma BP, they are analyzed with several methods of data analysis . It is revealed that not only some astronomical periods of 0.1 Ma,0.041 Ma and 0.023Ma in main Earth orbital parameters (corresponding to eccentricity ,obliquity and climatic precession) are derived , but also more periods of 0.2Ma,0.15Ma0.08Ma and 0.06Ma are obtained. It is shown that the spectra peaks are of 80% confidence level. Furthermore, from the periods and amplitudes by wavelet transform , there exist spatial and temporal characteristics, either strong or week, even gradual disappearance with the geological epochs. It tells us that the paleo-clirnate variation was induced by various paleo-environments. It has been recently suggested that the variation with period of 0.1Ma might relate closely to not only the eccentricity of the Earth orbit , but also the rate of accretion of interplanetary dust particles and the uplift of Qing -Zang plateau. Therefore, the change of Earth orbital parameters is just one of factors, which could lead to the paleo-climate variation.

关 键 词：古气候 天文周期 地球轨道 小波变换 偏心率 星际尘埃 

分 类 号：P183.5[天文地球—天文学] P532