地球动力学扁率与南极涛动年际变化的小波相干分析
摘要
Variations in the Earth's dynamic oblateness (<italic>J</italic><sub>2</sub>) reflect large-scale interactions and dynamic changes in global layers. Previous research on the correlation between 4-6 year variations in <italic>J</italic><sub>2</sub> and changes in global atmosphere, marine activity, and surface water, indicates that dominant interannual signals in <italic>J</italic><sub>2</sub> arise from latitudes higher than 75°, and that variations in <italic>J</italic><sub>2</sub> may be related to the ENSO (EI Niño-Southern Oscillation) phenomenon. This study, for the first time, uses a cross wavelet and wavelet coherence method to analyze the correlation between interannual variability in <italic>J</italic><sub>2</sub> and the Antarctic Oscillation Index (AAOI)/Southern Oscillation Index (SOI), representing the ENSO phenomenon. The results demonstrate a strong correlation between <italic>J</italic><sub>2</sub> signals and the Antarctic Oscillation (AAO) at 4-6 year time scales during 1986-2010 (correlation coefficient larger than 0.8), and show that <italic>J</italic><sub>2</sub> signals lag the AAO by about 0-5 months. However, there is no significant or better correlation between variability in <italic>J</italic><sub>2</sub> and other SOI signals over the same time period and scales, which may be related to differences in large scale air movement and its spatial distribution characteristics, that are reflected by the AAO and the SOI, respectively.