The atmosphere strongly affects the Earth’s spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth’s spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth’s pole has been observed. The change in the Earth’s inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated.

• Sung-Ho Na(Department of Space Survey Information Technology, Ajou University University of Science and Technology) Corresponding Author
• Jungho Cho(Korea Astronomy and Space Science Institute)
• Tu-Hwan Kim(Department of Space Survey Information Technology, Ajou University)
• Kiweon Seo(Department of Earth Science Education, Seoul National University)
• Kookhyoun Youm3(Department of Earth Science Education, Seoul National University)
• Sung-Moon Yoo(Korea Astronomy and Space Science Institute)
• Byungkyu Choi(Korea Astronomy and Space Science Institute)
• Hasu Yoon(Korea Astronomy and Space Science Institute)