Alert Nunavut (82o28'N, 62o30'W)

The Alert observatory is located on the northeastern tip of Ellesmere Island in the Canadian Arctic. Alert is also the site of a military station (CFS Alert) and an Environment Canada Upper Air Weather Station. The Observatory is situated 210 m above sea level; 6 km SSW of CFS Alert. The terrain in the vicinity is comprised of steeply rolling hills, with peaks between 100 to 150 m high and frequent deep ravines and high cliffs.

Alert is far removed from the major industrial regions in the Northern Hemisphere and therefore ideally situated for monitoring changes in global atmospheric pollutants. 

A photo of a small building partially covered with snow.
The Dr. Neil Trivett Global Atmosphere Watch (GAW) Observatory at Alert, Nunavut

The greenhouse gas measurement program began at Alert in 1975 with a simple flask sampling program to assess the concentration of carbon dioxide in the arctic atmosphere. Over time, other measurements were established until, in 1986, Canada's first research station for the continuous monitoring of greenhouse gases and aerosols was opened. Many collaborative international sampling programs for greenhouse and other trace gases are also conducted at Alert. The Alert station also serves as one of the three international greenhouse gas intercomparison sites. These intercomparison activities provide an on-going assessment for network comparability amongst agencies conducting similar greenhouse measurement programs at other locations around the globe. Alert is the most northerly site in the World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) Network.

Environment Canada’s Greenhouse Gas Measurements at Alert
MeasurementSampling FrequencySampling Record
Carbon Dioxide (CO2)Weekly Flask1975 - Present
Carbon Dioxide (CO2)Hourly1988 - Present
Methane (CH4)Hourly1988 - Present
Chlorofluorocarbons (CFC-11 and CFC-12)Hourly1995 - 2009
Carbon Monoxide (CO)Hourly1998 - Present
Hydrogen (H2)Hourly1998 - 2002
CO2, CH4, CO, N2O, SF6, H2, 13C and 18O in CO2Weekly Flask1998 - Present
Sulphur hexafluoride (SF6)Hourly2000 - 2006
Nitrous Oxide (N2O)Hourly2000 - 2006