Three heavily instrumented fixed-location atmospheric observatories that represent a broad range of climate conditions are operated by the ARM Climate Research Facility to gather massive amounts of climate data. These are:
- Southern Great Plains (SGP) – centered near Lamont, Oklahoma, United States
- North Slope of Alaska (NSA) – centered at Barrow, Alaska, United States
- Eastern North Atlantic (ENA) – located on Graciosa Island, Azores, Portugal.