Zusammenfassung
Mass redistributions within and mass exchanges among the Earth's subsystems are reflected in the fundamental observables of geodesy, i.e., the Earth's shape, its rotation and gravity field. Since all these parameters of the Earth are precisely observed with various space- and ground-based geodetic techniques, in principle, underlying dynamical processes in the Earth system are monitored. However, due to the integral character of geodetic observations and restrictions concerning resolution in time and space, the processing as well as the interpretation and utilization of the data require independent, interdisciplinary, and consistent methods, e.g., from theory and modelling. Here, a numerical model approach covering transient dynamics and corresponding mass redistributions in the atmosphere-hydrosphere system is presented. This modular system model allows for the connection of fundamentally different measurements as, e.g., atmospheric and hydrospheric mass anomalies, load induced vertical deformations, sea-surface height variations as well as changes in Earth rotation, and therefore provides the opportunity to jointly interpret different types of geodetic and geophysical observations. Exemplarily, ocean mass anomalies from GRACE satellite gravimetry and sea surface height anomalies from Jason 1 satellite altimetry will be connected by means of output of the global ocean model OMCT consistently forced by operational analyses from ECMWF and freshwater fluxes simulated with a hydrological discharge model. Beside the discussion of individual short-comings of both observation techniques as well as of the applied ocean model, it will be demonstrated how reliable information about climate relevant oceanic heat transports can be derived from the global monitoring data.
