ENAC Seminar Series by Prof. Isabella Velicogna
Event details
| Date | 21.12.2018 |
| Hour | 08:30 › 09:30 |
| Speaker | Prof. Isabella Velicogna |
| Location | |
| Category | Conferences - Seminars |
8:30 – 9:30 – Prof. Isabella Velicogna
Full Professor, Dept. of Earth System Science, University of California Irvine, USA
Time-variable gravity studies of ice sheets and glacier mass balance and partitioning of the water cycle in high mountain environment
Time series of time-variable monthly gravity data from the Gravity Recovery and Climate Experiment (GRACE) mission (2002-2017) have revolutionized the way we look at water/ice mass changes at the surface of the Earth despite a spatial resolution limited to about 350 km. Using GRACE data, we established the first mass balance of the Antarctic ice sheet in 2006, illustrating that the ice sheet was losing mass, the mass loss was concentrated in a few sectors and a few years later, we added evidence that the mass loss was increasing with time. The GRACE data were also compared with surface mass balance model output products to provide the first evaluation of these products, hence establishing GRACE data are a tool for validation climate models.
In Greenland, we obtained the first comprehensive, monthly estimates of mass balance that showed that the mass loss had spread around the entire ice sheet and was also accelerating with time. Comparison with surface mass balance products was used to detect the weaknesses of these models or whether other processes were important, e.g. ice dynamics. For the mountain glaciers and ice caps of the World (GIC), GRACE provided the first estimates based on a comprehensive survey with the same instrument, instead of extrapolating numbers from a few in situ observations. The results showed a large mass loss, however, negligible contribution from the Antarctic peripheral glaciers, an acceleration of the mass loss over the last 16 years, a dominance of the mass loss from the Arctic and a mass loss from High Mountain Asia. In High Mountain Asia, we started a broad multidisciplinary project to investigate the role of glaciers and climate change in controlling freshwater supply in the region.
The GRACE data have been instrumental to constrain the terrestrial water storage and close the water budget of the upper and lower basins of the main river in the region. This allows for the first time to understand the partitioning between glacier/snow runoff and precipitation in river discharge. The GRACE data are key to evaluate the climate models that will be used to project the evolution of the freshwater supply in years to decades to come. This work has been supported by research grants from NASA.
Full Professor, Dept. of Earth System Science, University of California Irvine, USA
Time-variable gravity studies of ice sheets and glacier mass balance and partitioning of the water cycle in high mountain environment
Time series of time-variable monthly gravity data from the Gravity Recovery and Climate Experiment (GRACE) mission (2002-2017) have revolutionized the way we look at water/ice mass changes at the surface of the Earth despite a spatial resolution limited to about 350 km. Using GRACE data, we established the first mass balance of the Antarctic ice sheet in 2006, illustrating that the ice sheet was losing mass, the mass loss was concentrated in a few sectors and a few years later, we added evidence that the mass loss was increasing with time. The GRACE data were also compared with surface mass balance model output products to provide the first evaluation of these products, hence establishing GRACE data are a tool for validation climate models.
In Greenland, we obtained the first comprehensive, monthly estimates of mass balance that showed that the mass loss had spread around the entire ice sheet and was also accelerating with time. Comparison with surface mass balance products was used to detect the weaknesses of these models or whether other processes were important, e.g. ice dynamics. For the mountain glaciers and ice caps of the World (GIC), GRACE provided the first estimates based on a comprehensive survey with the same instrument, instead of extrapolating numbers from a few in situ observations. The results showed a large mass loss, however, negligible contribution from the Antarctic peripheral glaciers, an acceleration of the mass loss over the last 16 years, a dominance of the mass loss from the Arctic and a mass loss from High Mountain Asia. In High Mountain Asia, we started a broad multidisciplinary project to investigate the role of glaciers and climate change in controlling freshwater supply in the region.
The GRACE data have been instrumental to constrain the terrestrial water storage and close the water budget of the upper and lower basins of the main river in the region. This allows for the first time to understand the partitioning between glacier/snow runoff and precipitation in river discharge. The GRACE data are key to evaluate the climate models that will be used to project the evolution of the freshwater supply in years to decades to come. This work has been supported by research grants from NASA.
Practical information
- General public
- Free
Organizer
- ENAC
Contact
- Cristina Perez