Context

The Mass change And Geosciences International Constellation (MAGIC) mission aims to extend and improve the monitoring of the gravity field from space. An international cooperation between ESA and NASA led to the development of a joint satellite constellation designed to extend the measurements of the gravity field in time with enhanced spatial and temporal resolution, and, reduced latency in data availability. The MAGIC constellation will comprise two pairs of satellites launched a few years apart:

• The GRACE-C (GRACE-Continuity) pair developed by NASA and German agencies will be launched first in a near-polar orbit at an altitude of ~500 km. 

• The NGGM (Next Generation Gravity Mission) pair developed by ESA will be launched next in an inclined orbit of 65–70 degrees at an altitude of ~400 km. 

Objectives of the SING project

The SING project aims to evaluate the added value of the NGGM and MAGIC missions for scientific applications and operational services in hydrology, ocean sciences, glaciology, climate sciences, solid earth sciences, and geodesy. 

Using a closed-loop simulator with a comprehensive description of instrumental and dealiasing errors, synthetic observations of the gravity field will be generated to assess the observability of mass changes occurring in the atmosphere, ocean, hydrosphere, cryosphere, and solid earth for different mission configurations, including GRACE-C (single polar pair), NGGM (single inclined pair), and MAGIC (double pair). 

Significant benefits are expected from the higher spatial and temporal resolution of future satellite gravity missions, particularly in flood prediction, drought monitoring, and water resource management. These aspects will be explored through dedicated hydrological data assimilation and data fusion studies. Additionally, the improved spatial resolution will be critical for detecting changes in the Atlantic Meridional Overturning Circulation (AMOC) in the context of climate change. The SING project will also assess the impact of the NGGM and MAGIC missions on monitoring ice mass changes in mountain glaciers and ice sheets. The greater spatial and temporal resolution of future satellite gravimetry missions may also improve the recovery of the Ocean Heat Content and Earth Energy Imbalance due to better consistency with other ocean monitoring systems such as satellite altimetry. The added value of a second satellite pair will be estimated for monitoring co-seismic and post-seismic processes, as well as improving predictive modeling for geohazards, with a focus on providing timely forecasts that are socially relevant. Finally, the project will investigate the impact of the NGGM and MAGIC missions on geodesy by enhancing gravity and geoid models in support of the IHRF realization, its time evolution, and precise orbit determination. 

The results of the SING project will provide further validation for the NGGM and MAGIC mission concepts and contribute to the preparation of NGGM and MAGIC products into operational services.