Seasonal and Short-Term Load Deformation at Antarctic GPS Stations

Abstract:

We compare vertical surface deformation time series from 64 mainly coastal Antarctic GPS stations to vertical deformation predicted from various geophysical models and observations: Antarctic surface mass balance (RACMO 2.3/ANT and GRACE), atmospheric loading (ERA-Interim), and non-tidal ocean loading (ECCO). The goal is to account for vertical deformation in terms of air and water loads. Linear trends were removed from all time series to focus on seasonal and shorter time scales, evident in all the series. Annual and semiannual sinusoids were fit and compared in terms of amplitude and phase. At most stations, atmospheric loads dominate shorter period variations, but ocean and surface mass balance loading effects are observable at seasonal time scales.