GOCE is the Gravity field and steady-state OCean Explorer, and will launch from northern Russia on March 16th at 14:21 GMT (10:21 am EDT, 7:21 am PDT).
GOCE will map variations in the gravitational field around the Earth. That doesn't sound overly exciting, but it will allow more accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change.
(Actually, the Earth's deviations from a sphere is a long, deep and interesting subject. In undergraduate classical mechanics, we spent a few weeks doing detailed perturbative calculations on the gravitational field resulting from a nonspherical Earth. It involved lots of interesting mathematics, not too complex but heady enough. You kind of feel like a rocket engineer. Look into it if you want to lose yourself for a few good weeks.)