Earth rotation deceleration/acceleration due to semidiurnal oceanic/atmospheric tides:Revisited with new calculation

作     者：Sung-Ho Na Wenbin Shen Jungho Cho Kiweon Seo Young-Hong Shin Kwan-Dong Park Kookyoun Youm Sung-Moon Yoo 

作者机构：KASI-SLR Observatory(on Leave from Ajou University)276-73 Wolsangongdan-roSejong30060Republic of Korea Department of GeophysicsSchool of Geodesy and GeomaticsKey Laboratory of Geospace Environment and Geodesy of Ministry of EducationWuhan UniversityWuhan430079China Korea Astronomy and Space Science776 Daedeok-DaeroYuseong-GuDaejeon34055Republic of Korea Seoul National UniversitySeoul08826Republic of Korea Korea Institute of Geoscience and Mineral ResourcesRepublic of Korea Inha University22207Republic of Korea 

出 版 物：《Geodesy and Geodynamics》 (大地测量与地球动力学（英文版）)

年 卷 期：2019年第10卷第1期

页      面：37-41页

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：supported by the Space Geodesy Technology Development Program of Korea Astronomy and Space Science Institute supported by the NSFC(grant Nos.41631072,41721003,41574007 and 41429401) the Discipline Innovative Engineering Plan of Modern Geodesy and Geodynamics(grant No.B17033) 

主　　题：Earth rotation Oceanic and atmospheric tides Tidal torque Secular deceleration and acceleration 

摘      要：The global oceanic/atmospheric tides exert decelerating/accelerating secular torques on the Earth rotation. We developed new formulations to accurately calculate amounts of two kinds of secular tidal torques. After Melchior, we found that an additional factor 1+k-l = 1.216, which has been formerly neglected, must be multiplied unto the tidal torque integral. By using our refined formulations and the recent oceanic/atmospheric global tide models, we found that:(i) semidiurnal oceanic lunar/solar tides exert decelerating torques of about-4.462 × 10^(16)/-0.676 × 10^(16) Nm respectively and(ii) atmospheric S_2 tide exerts accelerating torque of 1.55 × 10^(15) Nm. Former estimates of the atmospheric S_2 tidal torque were twice as large as our estimate due to improper consideration of loading effect. We took the load Love number for atmospheric loading effect from Guo et al.(2004). For atmospheric loading of spherical harmonic degree two, the value of k′=-0.6031 is different from that for ocean loading as k′ =-0.3052,while the latter is currently used for both cases-ocean/atmospheric loading-without distinction. We discuss(i) the amount of solid Earth tidal dissipation(which has been left most uncertain) and(ii) secular changes of the dynamical state of the Earth-Moon-Sun system. Our estimate of the solid Earth tidal torque is-4.94×10^(15) Nm.