Mauna Loa Observatory (MLO) is located on the north flank of Mauna Loa Volcano, on the Big Island of Hawaii, at an elevation of 3397 meters, or 11,135 feet above sea level. The observatory is a premier atmospheric research facility that has been continuously monitoring and collecting data related to atmospheric change since the 1950's.

The observatory protrudes through the strong marine temperature inversion layer present in the region, which separates the more polluted lower portions of the atmosphere from the much cleaner free troposphere. The undisturbed air, remote location, and minimal influences of vegetation and human activity at MLO are ideal for monitoring constituents in the atmosphere that can cause climate change.

MLO has supported hundreds of cooperative research programs with national and international universities and government organizations. A staff of 8 operates and maintains the observatory, with offices in Hilo, Hawaii.