Modelling of global mass effects in hydrology, atmosphere and oceans on surface gravity

• A comprehensive tool for the analysis of gravity effects induced by large scale mass variations.
• Default support of majority of freely available hydrological, oceanic and atmospheric models.
• Novel approach for reducing impact of low resolution of atmospheric models on surface gravity effect.

We present a MatlabTM/Octave-based software tool mGlobe to compute the effect of atmospheric, continental water storage, and non-tidal ocean mass variations on surface gravity. These effects must be considered or reduced prior to any analysis of geophysical phenomena using observations of superconducting gravimeters. Contrary to the alternative providers, mGlobe allows the computation for an arbitrary location worldwide, supports a larger number of input models and offers more flexibility in terms of computation settings. The high number of supported models is important for assessment of model uncertainties. Discrepancies exceeding 75% were found. The continental water storage effect showed low sensitivity to spatial and temporal resolution. The deficient temporal resolution affects the non-tidal loading and atmospheric effects significantly. The same holds true for the influence of the spatial resolution on atmospheric effects. To compensate this effect, we introduce a site-specific correction factor based on differences between the real topography and model's orography.