The use of GRACE-based geopotential models for estimating mass variations over Poland

Since the launch of GRACE (Gravity Recovery And Climate Experiment) satellite mission in 2002, a significant progress in the knowledge regarding the temporal variations of the Earth gravity field has been achieved. The main objective of this contribution is to study the suitability of the latest release, i.e. the 5th release, GRACE-based Global Geopotential Models (GGMs) for estimating mass variations in the Earth system, in particular, the total water storage variations, over the area of Poland. It is aimed also to define an optimum filter for reducing the noise contained in those GGMs.
With the use of different filters, e.g. the Gaussian filter with different radii as well as DDK (de-correlating in post-processing approach) filters, GRACE-based GGMs provided by different computational centres have been examined globally. They have also been examined over two basins, i.e. the Wisła basin and the Odra basin. Moreover, with the use the principal component analysis (PCA) approach, mass variations in the Earth system obtained from RL05 GRACE-based GGMs have been compared with the corresponding ones obtained from the hydrology model. The results of the comparison have been analysed and discussed.

Keywords: GRACE, GGM, filter, terrestrial water storage