Improved Prediction of Polar Motions by Piecewise Parameterization

• Autorzy: Wu Yuanwei , Zhao Xin , Yang Xinyu

Identyfikatory

DOI

10.2478/arsa-2022-0025

• Konferencja: Proceedings of the Second Earth Orientation Parameters Prediction Comparison Campaign (2nd EOP PCC) Workshop, online, February 15-16, 2022
• Języki publikacji: EN

Abstrakty

EN

Natioinal Time Service Center of Chinese Academy of Sciences, Lintong, Shaanxi, China e-mail: [e-mail] ABSTRACT. On seanonal timescale, the variation of Earth rotation is mainly regulated by angular momentum exchanges between the solid Earth and the fluidal atmosphere, ocean and hydrosphere. In the 2nd EOP PCC, we developed Dill2019’s method for polar motion prediction, using piecewise autoagressive parameters. The maximum prediction errors within 90 days are 36 and 16 mas for polar motion x and y components, respectively. Compared with Bulletin A, the mean absolute error of polar motion y prediction is improved by 20% in all timescale, and with a maximum improvement of 49% on the 5th day. Whereas, for polar motion x, the performance is slightly better (2% - 8%) within 30 days but worse (−7%∼ −19%) within 30∼90 days. We found that the prediction accuracy is very sensitive to the quality of the angular momentum data. For example, on average, the prediction of polar motion y is around 2 times better than polar motion x. In addition, we found the accuracy of 30-90 days prediction is dramatically decreased in the year 2020. We suspect that such deterioration might be due to the pandemic of coronavirus COVID-19, which suppressed global airline activities by more than 60%, then result in a lose of air-borne meteorological data, which are important for weather forecast.

Słowa kluczowe

EN

earth rotation prediction; effective angular momentum functions; AAM; OAM

• Wydawca: Centrum Badań Kosmicznych PAN ; De Gruyter
• Czasopismo: Artificial Satellites : Journal of Planetary Geodesy
• Rocznik: 2022
• Tom: Vol. 57, Special Issue 1
• Strony: 290--299
• Opis fizyczny: Bibliogr. 10 poz., rys., tab.

Twórcy

autor

Wu Yuanwei

• Natioinal Time Service Center of Chinese Academy of Sciences, Lintong, Shaanxi, China

autor

Zhao Xin

• Natioinal Time Service Center of Chinese Academy of Sciences, Lintong, Shaanxi, China

autor

Yang Xinyu

• Natioinal Time Service Center of Chinese Academy of Sciences, Lintong, Shaanxi, China

Bibliografia

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• Brockwell, P.J., Davis, R.A., (1996) Introduction to Time Series and Forecasting, Springer, New York, 420 pp.
• Dill R., Dobslaw H, Thomas M. (2013) Combination of modeled shortterm angular momentum function forecasts from atmosphere, ocean, and hydrology with 90-day EOP predictions, Journal of Geodesy, Vol.87, 567-577.
• Dill R., Dobslaw H, Thomas M. (2019) Improved 90-day Earth orientation predictions from angular momentum forecasts of atmosphere, ocean, and terrestrial hydrosphere, Journal of Geodesy, Vol.93, 287-295.
• Dobslaw H., Dill R., Grötzsch A., Brzezinski A., Thomas M. (2010) Seasonal polar motion excitation from numerical models of atmosphere, ocean, and continental hydrosphere. Journal of Geophysical Research (Solid Earth), Vol. 115, Issue B10, 406-417.
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Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).