Advancing glacier and ice-sheet mass-change observations with GRACE-C, NGGM and MAGIC

Abstract

GRACE and GRACE-FO have transformed observations of glacier and ice-sheet mass change, but their monthly solutions and correlated noise limit the detection of short-lived melt and accumulation events, and long-term ice-dynamic signals. We assess ESA’s inclined Next Generation Gravity Mission (NGGM; ~70° inclination), which provides denser, more uniform sampling throughout the non-polar latitude band than a near-polar pair. End-to-end simulations with ESA-funded SING project show that NGGM improves the recovery of lower-latitude glacier mass change, more clearly resolving seasonal variability and long-term trends, showing additional potential for hydrological applications. For Greenland and Antarctica, NGGM improves sensitivity to short-lived melt and accumulation events and provides independent constraints on long-term accelerations in ice-dynamic discharge. Within MAGIC, NGGM complements the near-polar GRACE-C pair to provide more homogeneous near-global observations of glaciers and ice sheets, strengthening constraints on regional climate and ice-sheet models and future sea-level rise.