Our lab specializes in studying trapped air in polar ice cores to re-construct past climate.  We use stable isotopes of argon, nitrogen, oxygen, krypton, and xenon.  Each provide clues into past climate and aid us in fine tuning our models to look into the future.  Mass spectrometers are the primary tools we have to glean information from these special, inert gases in nature.  Each of the 4 mass specs in our lab are specially tuned for a particular gas (mass) range.