Dr. Norman Loeb, an atmospheric scientist at NASA’s Langley Research Center in Hampton, Virginia, is the principal investigator for an experiment called the Clouds and the Earth’s Radiant Energy System (CERES). CERES instruments measure how much of the sun’s energy is reflected back to space and how much thermal energy is emitted by Earth to space.

 Air, Water, Land, & Life: A Global Perspective

The ocean's surface is not level, and sea levels change in response to changes in chemistry and temperature. Sophisticated satellite measurements are required for scientists to document current sea level rise.