Jordklodens statiske og tidsvariable gravitasjonsfelt

Static and time variable regional gravity field modelling The gravity field of the earth is a fundamental quantity in Earth System Sciences. Detailed observations of the gravity field and its temporal variations allow monitoring of many dynamic processes in the earth system. This is due to the fact that the structure of the gravity field is generated by the mass distribution in the system. A change in the mass distribution therefore changes the structure of the gravity field. Relevant examples are effect s caused by continental hydrology or the melting of glaciers and polar ice sheets. The aim of the project is to contribute to regional modelling of the gravity field on different time scales (static and time variable components). Proper base functions will be selected to represent the field. Data from satellite, airborne and ground based instruments will be combined to ensure global coverage as well as high spatial resolution. Investigations will be conducted to select adequate data analysis tools to identify different time variable components. The methods will be applied to derive an optimal combined gravity field for the Nordic area. Time series analysis of the regional gravity field from space will be applied to large continental glaciers for gla ciological mass balance studies.