A note on the annual wobble excitation due to the seasonal atmospheric loading on continents

  • Author(s): Sung-Ho Na, Jungho Cho, Ki-Weon Seo, Kook-Hyoun Youm, and Wenbin Shen
  • DOI: 10.3319/TAO.2018.08.24.01
  • Keywords: Polar motion, Atmospheric excitation, Siberia
  • Annual wobble of the Earth is a forced motion caused by diverse seasonal variation
  • Winter cold air on Siberia has been regarded as one major source of the annual wobble
  • The excitations due to atmospheric loading on continents are compared with the observation
Abstract

Northern Eurasian continent has been regarded to contribute as the major source area, of which seasonal atmospheric pressure loading and unloading cycle leads to the annual wobble of the Earth. In the early days when reliable data of global coverage were not accessible, this dominance was remained as only a hypothesis. Nowadays, however, European Centre for Medium-Range Weather Forecasts and National Centers for Environmental Prediction produce reliable datasets, therefore, such unique feature has become clearer with quantitative evidences. Having both the Earth’s polar motion and the global atmospheric state known with unprecedented accuracy, we hereby identify and scrutinize whether Siberia and Manchuria dominate the annual polar motion of the Earth.

 

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