摘要
地球自转变化用日长来表征,即LOD.摩擦力矩是由于地球和大气摩擦产生的轴向力矩,是组成大气角动量的重要部分,是表征地球大气角动量传输的重要的参量之一.本文利用NCEP/NCAR再分析数据,计算出从1948年至2011年的全球摩擦力矩,与从国际地球自转服务网站得到的日长数据进行对比分析,来寻找两者之间的关系.结果发现,在年代际尺度上,地球自转的变化不仅只受地核地幔角动量的传输的影响,大气对地球摩擦的长时间累积也起到了重要的作用.在年际尺度上,二者的关系不明显,摩擦力矩不能体现日长变化.在年内尺度上,二者的变化具有很高的相似性,具有相同的周期,说明在这一时间尺度上大气活动对地球自转速度的影响最为显著.
The Earth’s rotation speed change can characterize by length of day（ LOD）. Frictional torque is axial moment of earth which is produced by atmospheric friction. It is an important part of the angular momentum transport between atmospheric and solid earth. In this paper,we use the NCEP / NCAR Reanalysis data to calculate the frictional torque,and compare with LOD which is got from International Earth Rotation and Reference Systems Service（ IERS）. It was found that in the decadal scale,the earth’s rotation not only affected by the core and mantle,the cumulative value of the friction between atmosphere and earth also play an important role. In the time scale of interannual,those two variables have different change and relationship is not obvious,the frictional torque does not reflect the changes in earth rotation. On the scale of year,both of them have same periods and significant correlation.
出处
《地球物理学进展》
CSCD
北大核心
2016年第4期1438-1443,共6页
Progress in Geophysics
基金
国家重点基础研究发展计划973项目(2012CB957802)资助
关键词
摩擦力矩
地球自转
日长
大气角动量
frictional torque
earth rotation
LOD
atmospheric angular momentum
