The Dr. Neil Trivett Global Atmosphere Watch Observatory is an atmospheric baseline station operated by Environment and Climate Change Canada located about 6 km (3.7 mi) south south-west of Alert, Nunavut, on the north-eastern tip of Ellesmere Island, about 800 km (500 mi) south of the geographic North Pole.

[1] Among these 31 stations, Alert is one of three greenhouse gas "intercomparison supersites",[2] along with Mauna Loa in Hawaii and Cape Grim in Australia, which, due to their locations far from industrial activity, provide the international scientific community with a baseline record of atmospheric chemistry.

The region is characterized by recent glacial activity, with still extant glaciers visible among the peaks of the United States Range approximately 40 km (25 mi) to the west.

The landscape immediately surrounding the observatory is undulating, marked by cliffs and crevasses and a number of small rivers which can become impassable during freshet.

These conditions continue through polar sunrise, but reverse dramatically with the onset of spring weather, which brings high, gusting winds.

The weather station frequently provided support for scientific research in Alert, including the collection of weekly flask samples for the measurement of carbon dioxide, the first of which was taken on July 8, 1975.

In 1985, the Canadian Baseline Program was founded, and on August 29 the following year the Alert Background Air Pollution Monitoring Network (BAPMoN) Observatory was officially opened.

[10] In addition to the ongoing flask sample programs, the observatory maintains a core group of continuous measurement programs which include monitoring of aerosols, mercury, greenhouse gases, ozone (both ground level and stratospheric), broadband solar irradiance and albedo, permafrost temperatures,[11] persistent organic pollutants (POPs), and ground level meteorological conditions.

[12] The observatory also supports experimental testing of new monitoring equipment, and short-term, intensive research programs, e.g., NETCARE (Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments).

[19] While it had been known since 1988[20] that ground level ozone underwent periodic rapid depletions during March–June each year, it was not discovered until 1995 that atmospheric mercury behaved in a nearly identical manner.

Until that time, it was generally agreed that elemental mercury persisted in the atmosphere for 6–12 months, which allowed it to reach remote locations such as the Arctic, far from emission sources.