Asymptotic Theories of Ice Sheets and Ice Shelves

Abstract

In climate dynamics of the Globe the atmosphere, hydrosphere and cryosphere interplay with one another with various different time scales, typically from years to several millennia. Ice sheets and ice shelves, which are the grounded and floating components of the large ice masses such as Greenland and Antarctica and the former Fennoscandinavian and Laurentide ice sheets are those subsystems of the geosphere, which respond to and interplay with climate variations with periods of 103 to 105 years. 100000 years ago the amount of water bound in solid ice was so large that the ocean surface was about 120--150 m below its present level; alternatively, the complete melting of the Greenland ice sheet or Antarctica under a future Greenhouse scenario would raise the ocean surface by approximately 7 and 65 m, respectively. Because the socio-economic impact of the sea level rise due to an increase of the mean temperature of the Earth’s surface is immense, it is absolutely vital that the nourishment and wastage of the large ice masses are properly understood and transformed into sea level status. This requires careful computation of the flow, phase change mechanisms as well as geometric evolution of such ice masses.