UC Irvine

The World's Glaciers and Ice Caps (GIC) contain a sea level rise (SLR) equivalent of about 0.4 m. Although their potential sea level contribution is small compared to Greenland (7.4 m) or Antarctica (58.3 m), the GIC are the largest contributor to global SLR at present. During the last 20 years, the GIC contributed 2.5 cm SLR vs 1 cm for Greenland and Antarctica. Rising global sea levels and posing a significant problem to society.

Runoff from the melting GIC has an impact on the regional hydrology and freshwater supply. The latter is of great concern in highly populated regions such as Central Asia where it negatively affects economic activities and political stability.

Defining consistent methodologies to monitor the state of GIC in these regions and reduce uncertainties regarding their specific ice mass loss and relative contribution to SLR is critical not only to science but to the public, policy development, and implementation.

In this dissertation, we use available satellite and modeling techniques to estimate recent contribution to sea level rise by the ice-covered regions outside the two ice sheets during the last two decades.

We estimate glacier mass balance employing: time-variable gravity measurements by the NASA GRACE mission, and satellite altimetry by the NASA ICESat and the ESA CryoSat-2 mission. These techniques are applied in key regions of the Arctic, where increasing atmospheric and ocean temperatures have led to accelerating glacier mass losses.

In the second part of this work is focused on the glaciers High Mountains of Asia, the largest freshwater reservoir outside the Polar Regions. Here, we use a mixture of remote sensed observations and atmospheric models to characterize the effect of glacier mass loss on the water cycle of the Indus River Basin.

This work helps improve our general understanding of the mechanisms driving current glaciers and ice caps mass change and its relative impact on freshwater availability and sea level rise during the next century.