Abstract:In order to explore the influence of ENSO events on GNSS ZTD(PWV) and their relationship, this paper takes Hebei province as an example to conduct a study on the influence of ENSO events on GNSS ZTD and its periodic variation. Firstly, using the method of fast Fourier transform to select the common cycle of southern oscillation index(SOI) and GNSS water vapor, and we use the wavelet transform to extract the common cycle of SOI and GNSS water vapor in high frequency. We analyze the correlation between the reconstructed high frequency term and SOI, finding that the negative correlation between SOI and GNSS ZTD in Hebei province. We conclude that the ENSO event is related to the periodic variation of GNSS ZTD. Then, using the method of fast Fourier transform to extract the GNSS ZTD change cycles under ENSO events and normal climate and analyze the influence of ENSO events on the change of GNSS ZTD cycle. The result shows that ENSO warm event(El Niño event) has a significant influence on the longest significant cycle of GNSS ZTD. The longest significant cycle of GNSS ZTD is slightly affected by ENSO cold event(La Niña event).
WANG Yong,YU Tengli,LIU Yanping et al. Study on the Periodic Variation of SOI and GNSS ZTD Based on FFT and Wavelet Transform[J]. jgg, 2021, 41(3): 254-261.