000005325 001__ 5325
000005325 005__ 20210304101214.0
000005325 037__ $$aCTALK-2021-0052
000005325 100__ $$aGobron, Kevin
000005325 245__ $$aInfluence of non-tidal atmospheric and oceanic loading deformation on the stochastic properties of over 10,000 GNSS vertical land motion time series
000005325 260__ $$c2021
000005325 269__ $$c2021-04-27
000005325 520__ $$aOver the past two decades, numerous studies demonstrated that the stochastic variability in GNSS position time series – often referred to as noise – is both temporally and spatially correlated. The time correlation of this stochastic variability can be well approximated by a linear combination of white noise and power-law stochastic processes with different amplitudes. Although acknowledged in many geodetic studies, the presence of such power-law processes in GNSS position time series remains largely unexplained. Considering that these power-law processes are the primary source of uncertainty for velocity estimates, it is crucial to identify their origin(s) and to try to reduce their influence on position time series. Using the Least-Squares Variance Component Estimation method, we analysed the influence of removing surface mass loading deformation on the stochastic properties of vertical land motion time series (VLMs). We used the position time series of over 10,000 globally distributed GNSS stations processed by the Nevada Geodetic Laboratory at the University of Nevada, Reno, and loading deformation time series computed by the Earth System Modelling (ESM) team at GFZ-Potsdam. Our results show that the values of stochastic parameters, namely, white noise amplitude, spectral index, and power-law noise amplitude, but also the spatial correlation, are systematically influenced by non-tidal atmospheric and oceanic loading deformation. The observed change in stochastic parameters often translates into a reduction of trend uncertainties, reaching up to -75% when non-tidal atmospheric and oceanic loading deformation is highest.
000005325 594__ $$aNO
000005325 6531_ $$aGNSS
000005325 6531_ $$aPower-law processes 
000005325 6531_ $$aLoading
000005325 700__ $$aRebischung, Paul
000005325 700__ $$ade Viron, Olivier
000005325 700__ $$aVan Camp, Michel
000005325 700__ $$aDemoulin, Alain
000005325 773__ $$tEGU 2021 meeting
000005325 8560_ $$fmichel.vancamp@observatoire.be
000005325 85642 $$ahttps://meetingorganizer.copernicus.org/EGU21/session/39909
000005325 906__ $$aInvited
000005325 980__ $$aCTALKINVI