I am interested in all sorts of planetary dynamics problems, but in particular the study of potential fields such as the planetary gravitational and magnetic fields. I look at all aspects, from observation to modeling to understanding the underlying physics. It is a rich and complex field of study which serves as an interface between numerous planetary science disciplines including dynamo theory, geodynamics, geochemistry and applied mathematics.
Earthquake source parameter estimation from GRACE observed geopotential anomalies
To what extent can we use observations of changes in Earth's geopotential field to characterize earthquakes? This is ongoing work which might help to constrain estimates of source parameters for earthquakes that are poorly observed.
A test of recent inferences of net polar ice mass
balance based on long-wavelength gravity
Estimates of net polar ice sheet mass balance may be independently tested using the rate of change of the degree four zonal harmonic of the Earth's potential. The J4 harmonic is relatively insensitive to the uncertainties associated with signals from the 18.6 year Earth tide and core-mantle coupling that must be accounted for in analyses of the J2 harmonic. More...
- Paper accepted for publication in Journal of Climate
Bias in GRACE estimates of ice-mass change due to accompanying sea-level change
The diminished gravitational attraction of a melting ice sheet causes a migration of water away, which in turn induces a change in crustal loading. These two effects contribute to the observed geopotential anomaly, but are not typically accounted for.
Paper published in Journal of Geodesy
Thermal evolution of planetesimals
The question if early solar system planetesimals could have had dynamos, how strong, and for how long, is largely determined by their mode of cooling. We investigate how mantle convection might have played a role.
Paper published in
Physics of the Earth and Planetary Interiors
-norm regularization of magnetic field models may be more appropriate than the L2
-norm traditionally used to regularize field models.