Chris Dr. Christopher Harig is a post doctoral research associate in the Department of Geosciences at Princeton University. His research covers areas of geodesy and geodynamics. His current work studies the melting of Earth's ice sheets due to climate change measured by satellite gravimetry. In previous work, Chris studied the dynamics of the lithosphere and upper mantle using geodynamic computer models, placing constraints on the rheology of these layers. Frederik
Dr. Frederik J. Simons is an Assistant Professor of Geosciences at Princeton University. His research encompasses various aspects of solid-earth geophysics. More specifically, he studies the physical properties of the lithosphere, focusing on the elastic and thermomechanical properties of the continents, by seismic tomography and the spectral analysis of gravity and topography. With his colleagues, Frederik has developed mathematical methods for the analysis of processes on the sphere, for geodesy, geomagnetism, and cosmology, designed wavelet-based signal processing methods for seismology, and developed oceanic instrumentation to close the seismic coverage gap over the Earth's oceans.
PNAS Harig, Christopher and Frederik J. Simons. Mapping Greeenland's mass loss in space and time. Proc. Natl. Acad. Sc., 109(49), 19934-19937. doi:10.1073/pnas.1206785109, 2012.

Abstract: The melting of polar ice sheets is a major contributor to global sea-level rise. Early estimates of the mass lost from the Greenland ice cap, based on satellite gravity data collected by the Gravity Recovery And Climate Experiment (GRACE), have widely varied. While the continentally and decadally averaged estimated trends have now more or less converged, to this date there has been little clarity on the detailed spatial distribution of Greenland's mass loss, nor on how the geographical pattern has varied on relatively shorter time scales. Here we present a spatially and temporally resolved estimation of the ice mass change over Greenland between April 2002 and August 2011. While the total mass loss trend has remained linear, actively changing areas of mass loss were concentrated on the southeastern and northwestern coasts, with ice mass in the center of Greenland steadily increasing over the decade.

Other Relevant Publications:

Christopher Harig, Shijie Zhong & Frederik J. Simons Constraints on upper-mantle viscosity from the flow-induced pressure gradient across the Australian continental keel
Geochem., Geophys., Geosys., 2010, 11, Q06004 doi:10.1029/2010GC003038

Frederik J. Simons & F. A. Dahlen Spherical Slepian functions and the polar gap in geodesy Geoph. J. Int., 2006, 166 (3), 1039-1061 doi:10.1111/j.1365-246X.2006.03065.x