Abstract: Based on the daily coordinate time series of 12 GPS stations situated in the Greenland with the time span of period from January 2013 to December 2016 under the framework of ITRF2008,and the noise characteristics, velocity field and periodic term amplitude of each GPS coordinate time series before and after surface mass loading correction are analyzed by maximum likelihood estimation.The results show that the optimal noise model of most GPS coordinate time series is white noise+power law noise and white noise + flicker noise.After correcting GPS coordinate time series by surface mass loading deformation, the flicker noise in the up components is obviously increased,and the average velocity is reduced by about 0.36 mm/a. Compared with the vertical components, the surface mass loading correction has relatively minor effects on the horizontal components. At the same time, the amplitudes of the annual and semi-annual signals in the up componentsare reduced by 44.1% and 14.2% respectively.Whereas, the amplitudes of periodic terms in the horizontal components are increased.

Key words: surface mass loading, GPS coordinate time series, noise model, velocity field, periodic term amplitude