厄尔尼诺-南方涛动在年际尺度对超导重力观测的可能影响OA

We select CB and MB superconducting gravimeter(SG)stations with longer data length(2004-2020)and better observation quality,and use the oceanic Niño index(ONI)as the El Niño-southern oscillation(ENSO)index to assess the possible impact on SG observations at the interannual timescale(primarily 1-5 a).First,we remove the influences of instrument response,atmospheric tides,tidal effects,hydrological factors,and polar motion from the CB and MB observation series.Then,we apply the Morlet wavelet transform and cross-wavelet analysis to the data.The results show there is a significant correlation between SG observations and ONI,primarily at periods of approxi-mately 1.5 a and 3 a.Specifically,gravity variations at CB station exhibit a negative correlation with ONI,while at MB station,the correlation is positive,with a time delay in the gravity observation rel-ative to ONI.Furthermore,the ENSO effect on CB station is more pronounced than that on MB sta-tion,especially at about 3 a period,where ENSOshows a negative correlation with gravity variations at CB station.We hypothesize that this discrepancy is largely due to the different geographical loca-tions of stations.However,more detailed quantitative studies are needed to further explore this rela-tionship.