Changes in Earth's temperature cause changes in the size of the polar ice caps, with corresponding changes in global sea levels as water moves between the oceans and the continental ice sheets. Sea levels are currently rising as a result of present-day increases in global mean temperature and some claim that West Antarctica and Greenland glaciers are melting rapidly.

But how do we know this - how are changes in ice and ocean volumes estimated? Observations of the motions of close-earth satellites and measurements from these satellites to the surface of the Earth enable these changes to be measured and they provide important constraints on the physical properties of the planet and on the physical processes occurring on and within it.

This course covers:

• The Earth's gravity field and the geophysical interpretation of temporal gravity changes
• The measurement of sea level variations from tide gauges and satellite altimetry
• Mass balance estimates of polar regions
• The theory and observation of the motion of satellites
• Position determination on the Earth from satellite tracking data