Even as computer models of a changing Earth grow ever more accurate, a major stumbling block remains: marrying models of ice, ocean, atmosphere, the solid Earth, and other components of the earth system to create a truly global picture.
A new modeling method takes a major step in that direction. Created by three members of NASA’s Sea Level Change team, the new method allows researchers, for the first time, to weave high-resolution models of changes in individual glaciers into global models of relative sea level and solid Earth deformation, with great numerical accuracy and computational efficiency.
(Image: The “fingerprints” of sea level rise revealed by a new computer modeling method that links changes in glaciers, ice sheets, and continental water storage to relative sea levels worldwide. Blue areas, near Greenland, reflect a loss of ice mass, counterintuitively resulting in a sea level drop. In redder areas, sea levels are rising faster than global-mean rates. This map shows the linear trend in sea-level change and covers the period from 2003 to 2015. Image courtesy Surendra Adhikari, JPL.)
State-of-the-art simulation code originally dedicated to solving the ice-flow mechanics called the Ice Sheet System Model (ISSM; http://issm.jpl.nasa.gov/), also developed at JPL, served as the scaffolding upon which the new modeling method was built. But the heart of the new approach lies in the intricate mathematics – particularly the so-called Green’s function formulation – of Earth’s gravitational and rotational theory.