GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.3 GNGTS 2024 Greenland and Antarctca ice mass balance (2002-2017) through source decompositon in hypercompact atoms. M. Maiolino 1 , M. Fedi 1 , G. Florio 1 1 University of Naples “Federico II” – DiSTAR, Dipartmento di Scienze della Terra dell’Ambiente e delle Risorse We present a new estmaton based on a novel approach named ECS (Extremely Compact Sources) of the ice-sheet total mass variaton in Greenland and Antarctca using tme varying NASA GRACE (Gravity recovery and climate experiment) Stoke’s coefcient data in the tme span 2002-2017. Over a 15-year period the NASA missions GRACE (Gravity Recovery and Climate Experiment) and the following GRACE-FO provided a unique opportunity to map the changes in Earth's gravitatonal feld and gave to the scientfc community a new vision of the major ice sheet dynamics. In the last years, it has become clear that the ice sheet total mass response to climate change is crucial for understanding the sea level rising phenomena related to grounded ice meltng and to quantfy the ice sheet front retreat in the polar regions. Even if an approximaton of the total mass changes in the polar regions can be done with the standard methods, namely the conversion method (Wahr et al., 1998) or the point mass inversion (Baur et al., 2011), a major issue in the GRACE data interpretaton comes from the leakage efect caused by the presence of outlying meltng ice bodies which gravity efects interfere each other. Our estmaton uses a novel approach that, exploitng the non-uniqueness of the gravity feld, retrieves a hypercompact model of the sources by an iteratve inversion. We will show that this approach solves the inherent leakage efects of the GRACE data and, thanks to the extreme compactness of the sources, allow us to do a quantfcaton of the total mass loss in the study area with less ambiguity. References Baur, O., Sneeuw, N.; 2011: Assessing Greenland ice mass loss by means of point-mass modeling: a viable methodology . J Geod 85, 607–615. DOI htps://doi.org/10.1007/s00190-011-0463-1. Wahr, J., M. Molenaar, and F. Bryan.; 1998: Time variability of the Earth's gravity feld: Hydrological and oceanic efects and their possible detecton using GRACE . J. Geophys. Res. , 103(B12), 30205–30229, DOI : 10.1029/98JB02844 .