1. GRACE Gravity Recovery and Climate Experiment
Matt Malina
8/2/07

2. GRACE
Launched March, 2002
2 twin satellites that measure the earth’s gravitational field

3. How does it work? 2 twin satellites fly one in front of the other
The lead one is deflected when itgoes over an area of the earth with a different gravity field.
GRACE 1 & 2 can detect a change in distance between them up to 1 micron!
They circle the earth 16 times per day
Complete a full map of the earth’s gravity once per month.

4. What areas of research does it help?
Oceanography
Climate change
Hydrology

5. Gravity

6. Oceanography
GRACE
Direct observation
Other satellite

7. Climate change
The Greenland ice sheet has been losing mass due to global warming

8. Climate Change cont’d Similar effects have been measured in Antarctica
It is estimated such melting has lead to mm/yr in sea level rise

9. Hydrology
GRACE can also detect if aquifers are filling or being depleted
This is important because…

10. Hydrology cont’d
In Western Asia it is estimated that an underwater aquifer near Uzbekistan is filling at a rate of 25 km3 of water per year.
Most of this water is water that was intended for irrigation but seeped into the soil.

11. The end