Mauna Loa Observatory

The Observatory on Mauna Loa
Satellite image of the summit of Mauna Loa overlaid with 100-meter contour lines.

The Mauna Loa Observatory (MLO) is an atmospheric baseline station on Mauna Loa, on the island of Hawaii, located in the U.S. state of Hawaii.

Two domes house solar sensors.
The Keeling Curve: Atmospheric CO2 concentrations as measured at Mauna Loa Observatory