The spectra of GRACE (2013-)

Hughes and Williams 2010 (PDF) treated sea level spectra as light spectra. I and my co-authors applied their methodology to GRACE, revealing the first “full color” GRACE maps and comparing them to the Noah/GLDAS water storage model. (more…)

Secrets of the Earth: Gravity (2013 Outreach)

The Weather Channel’s Secrets of the Earth aired an episode called Gravity. In it, I described gravity and discussed GRACE, mantle convection, and climate change.

My more nuanced attribution statement didn’t make the cut: “Melting ice is what we expect in a warming world, and most of the warming since 1950 is very likely due to our CO2 emissions.”

Also, melting sea ice doesn’t affect gravity because it’s already floating. GRACE can only detect changes in land ice. (more…)

Antarctic tides from GRACE

This research was presented at the 2012 AGU Fall Meeting.

Earth Science Week 2012 (Outreach)

I submitted a blog post and a soundbite for Earth Science Week 2012. The theme was “Discovering Careers in Earth Science.” (more…)

Op-ed: Jumpstart a clean energy economy (2012)

The Pasadena Star-News asked for an op-ed focusing on local solutions to global warming. Another website reposted my article while adding links and pictures. (more…)

Interview: Climate change and GRACE (2012 Outreach)

I answered some questions about climate change and GRACE. You may want to search for my pseudonym “khayman80” to skip the irrelevant arguments.

JPL open house (2012 Outreach)

At the 2012 JPL open house, I explained how GRACE detects Greenland mass loss, etc.

Global ocean tides from GRACE (2011-)

My previous research into Arctic ocean tides has been extended to solve for global ocean tides using GRACE satellite acceleration data. This research was presented at the 2011 Fall AGU and the 2012 Ocean Sciences conferences. (more…)

Moons, tides, and GRACE (2009 Outreach)

I’m a scientist at the University of Colorado studying ocean tides. Before I started this research project, all I knew about the tides was what I’d seen at the beach. We can watch the tide flow in and out every 12 hours at the beach, but this only tells us about the tide at that one beach. I’m trying to measure how big the tides are everywhere in the ocean, at all the beaches in the world and even in the middle of the open ocean.

What makes this possible is a satellite system called GRACE (Gravity Recovery And Climate Experiment). GRACE is a set of 2 satellites flying over the Earth measuring how strong gravity is at each point on the Earth’s surface. (more…)

Arctic Ocean tides from GRACE (2007-11)

From 2007 to 2011, I used GRACE satellite acceleration data to recover Arctic ocean tides. My advisor Prof. John Wahr provided invaluable guidance, as did our colleagues from JPL: Dr. Shailen Desai, Dr. Dah-Ning Yuan and Dr. Michael Watkins.

Here’s the source code. (more…)

Using GRACE to study hydrology (2006)

At the physics department of the University of Colorado and CIRES, I worked with Dr. Sean Swenson, Dr. John Wahr and Dr. Matt Rodell to study large-scale hydrology using GRACE measurements of Earth’s time-variable gravity field. (more…)

Experimental Wigner functions (2003-04)

While working at the Oregon Center for Optics, I studied transverse spatial Wigner functions of light with Dr. Michael Raymer and Dr. Brian Smith. (more…)

Stroke diagnosis using EEG signals (2002)

When I arrived at the University of Oregon, Dr. Rudy Hwa had been studying EEG signals for some time. He was looking for a way to use these signals to diagnose ischemic strokes. MRI scanners can already do this, but they’re much more expensive and much less portable than a skullcap of electrodes. (more…)


Switch to our mobile site