Importance of Wind for the Excitation of Chandler Wobble as Inferred from Wobble Domain Analysis

Abstract

We explored the atmospheric contribution to the excitation of Chandler wobble (CW), which has spanned about 11 years beginning from September 1983. The atmospheric angular momentum (AAM) function presented by the Japan Meteorological Agency (JMA) and the wobble data set (SPACE93) are employed. We devised a wobble domain method of analysis which enables us to quantify the narrow band power of AAM. The AAM-induced wobble closely resembles the observed wobble, and wind contribution turns out to dominate over atmospheric pressure contribution in the vicinity of the Chandler frequency. When only pressure contribution is taken into account, it is insufficient, as shown in previous studies.