Characteristics of Perturbations in Recent Length of Day and Polar Motion
Various features of the existing perturbations in the Earth’s spin rotation are investigated for the recent and most reliable data by spectral analysis, filtering, and comparison with idealized model. First, theory of Earth’s spin rotational perturbation is briefly re-derived in the Earth-fixed coor...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
The Korean Space Science Society
2013-03-01
|
| Series: | Journal of Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2013/v30n1/OJOOBS_2013_v30n1_33.pdf |
| Summary: | Various features of the existing perturbations in the Earth’s spin rotation are investigated for the recent and most reliable data by spectral analysis, filtering, and comparison with idealized model. First, theory of Earth’s spin rotational perturbation is briefly re-derived in the Earth-fixed coordinate frame. By spectral windowings, different periodic components of the length of day perturbation are separated, and their characters and excitations are discussed. Different periodic components of polar motion are acquired similarly and described with further discussion of their excitations. Causes of the long time trends of both the length of day and polar motion are discussed. Three possible causes are considered for the newly discovered 490-day period component in the polar motion. |
|---|---|
| ISSN: | 2093-5587 2093-1409 |