b Shan‘hai Astronomical Observatory \ Chinese Academy of Sciences \ Shan‘hai \ China

• Main Author: Benjamin Fong
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Chandler; North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.613.7746; http://www.ncu.edu.tw/~ncu5680/deans/class/eng/1999-Chao-JG-Meteorological excitation of interannual polar motion by the North Atlantic Oscillation.pdf

Variations of the atmospheric angular momentum "AAM # is responsible for almost all of the observed length!of!day "LOD # variation on time scales from several days to several years \ and much of the observed polar motion on the intra!seasonal time scale [ El Nino:Southern Oscillation "ENSO # and Quasi!Biennial Oscillation "QBO # have been singled out to successfully explain interannual LOD variations [ However\ excitation sources for the interannual polar motion \ including the 03 month Chandler wobble \ have not been positively identi_ed [ This paper studies the correlation of the observed polar motion C with the North Atlantic Oscillation "NAO# \ an interannual \ mid!latitude \ north!south seesaw in the atmosphere!ocean system [ An index "NAOI # used as a proxy to measure the strength of NAO is compared with the observed interannual polar motion excitation during 08530883 [ Cross!correlation functions and coherence spectra demonstrate signi_cant correlations between NAOI and C \ especially in the x component as expected from NAO|s location and general pattern [ This constitutes a positive identi_cation of excitation of interannual polar motion by a meteorological system [ Furthermore \ our corresponding results with respect to ENSO strongly suggest that a combination of meteorological systems will better explain the observed interannual