The Pico Mountain International Chemical Observatory (ICO) station is located at 2225 m above seal level on the summit caldera of Pico Mountain, an inactive volcano on Pico Island in the Azores, and the tallest mountain of Portugal (summit at 2352 m). The research station was established in 2001 by scientists from the University of the Azores and Michigan Technological University. The objective of the original research project was to study the impacts that air pollutants emitted in North America and Europe have on the atmosphere over the North Atlantic Ocean.
The station has proven highly valuable for research on air pollution transport and chemical processing of emissions from urban regions in North America and Europe, and of the atmospheric effects of large wild fires in North America and even Siberia. The research program at Pico Mountain continues to grow, and now includes observations of greenhouse gases for climate research, atmospheric radiation measurements, aerosol research, and measurements of gaseous air pollutants.
In 2008 ownership of the station was transferred to the Regional Government of the Azores, which since has implemented several station infrastructure improvements. Coordination of the station operation is facilitated by the University of the Azores in partnership with scientists from Michigan Technological University and the University of Colorado.