Measuring Methane

WHOI scientist Anna Michel is developing new ways to measure gases in the air over long distances using a technique called laser spectroscopy. Some of the light from a laser is absorbed by gas molecules—such as the greenhouse gas methane—before it reaches a detector. The more gas that is in the air, the less light is detected by the receiving sensor. The technique allows researchers to make measurements outdoors, on site, without disturbing the environment or having to take samples back to the lab. (Illustration by Eric S. Taylor, Woods Hole Oceanographic Institution)