GMD Site Description: ALT


  • Country: Canada Country Flag
  • Latitude: 82.4508° North
  • Longitude: 62.5072° West
  • Elevation: 190.00 masl
  • Time Zone: Local Standard Time + 4.0 hour(s) = UTC


Cooperating Agencies

Alert is the most northerly site in the World MeteorologicalOrganization (WMO) Global Atmosphere Watch (GAW) Network. Itis located on the northeastern tip of Ellesmere Island in Nunavut,far removed from the major industrial regions of the NorthernHemisphere.

Alert is also the site of a military station (CFS Alert)staffed with around 60 personnel, and a MSC Upper Air Weather Station. The air chemistry observatory is located on a plateau about 6 km SSW of the main camp. The plateau rises abruptly to an elevation of about200 m (with local hills rising to 500 m). The plateau forms thenorthern edge of the Hazen Plateau, which continues to rise tothe south, reaching a typical elevation of 1000 m and extendingthrough the central part of northern Ellesmere Island. Thesoutheastern edge of the Hazen Plateau is defined by the 7500km2 Agassiz Ice Cap, a permanent feature with a central elevationgreater than 2000 m.

Southwest of Alert is the rugged UnitedStates range, with peaks exceeding 2500 m. The Greenland coastis 60 km east of Alert. The terrain in the immediate area of Alertis steeply rolling, on the order of 100-150 m above sea level, withfrequent deep ravines and high cliffs. The land is covered withsnow for almost ten months of the year. During the summer, theland is covered with a sparse covering of polar desert vegetation.Alert experiences 106 days of full darkness (October 30th toFebruary 13th), 153 days of 24-hour daylight (April 7th toSeptember 7th), and two 53-day transition periods with some diurnalcycle going from virtually total daylight to total darkness (andvice-versa).

The annual mean air temperature at the Observatory is -18°C and the monthly mean air temperature increases to 3°C in August and decreases to below -30°C from December to the end of March. The annual mean value of the wind velocity is 3.5 m s-1. The prevailing winds are SSE to WWS due to channelling by the mountainous regions of northern Ellesmere Island and Greenland. A more detailed meterological summary can be found in Hopper and Hart [1994].


Hopper, J.F. and W. Hart .Meteorological aspects of the 1992 Polar Sunrise Experiment, Journal of Geophysical Research, 99, (D12), 25315-25328, 1994.

GMD Projects at Alert, Nunavut

Carbon Cycle Surface Flasks

Parameter Formula First Sample Date Status
Carbon Dioxide CO2 1985-06-10 Ongoing
Methane CH4 1985-06-10 Ongoing
Carbon Monoxide CO 1990-10-05 Ongoing
Molecular Hydrogen H2 1990-10-05 Ongoing
Nitrous Oxide N2O 1995-11-03 Ongoing
Sulfur Hexafluoride SF6 1995-11-03 Ongoing
Carbon-13/Carbon-12 in Carbon Dioxide d13C (CO2) 1992-04-30 Ongoing
Oxygen-18/Oxygen-16 in Carbon Dioxide d18O (CO2) 1992-04-30 Ongoing
Carbon-13/Carbon-12 in Methane d13C (CH4) 2000-08-11 Ongoing
D/H in Methane dD (CH4) 2005-04-20 Terminated - 2009-12-09
Methyl Chloride CH3Cl 2005-09-07 Ongoing
Benzene C6H6 2006-11-09 Ongoing
toluene C7H8 2006-11-09 Ongoing
ethane C2H6 2005-09-07 Ongoing
ethene C2H4 2005-09-07 Ongoing
propane C3H8 2005-09-07 Ongoing
propene C3H6 2005-09-07 Ongoing
i-butane i-C4H10 2005-09-07 Ongoing
n-butane n-C4H10 2005-09-07 Ongoing
i-pentane i-C5H12 2005-09-07 Ongoing
n-pentane n-C5H12 2005-09-07 Ongoing
n-hexane n-C6H14 2005-09-07 Ongoing
isoprene C5H8 2006-11-09 Ongoing
Acetylene C2H2 2006-11-22 Ongoing

HATS Flask Sampling

Parameter Formula First Sample Date Status
HFC-134a CH2FCF3 1994-12-08 Ongoing
HCFC-22 CHF2Cl 1992-01-20 Ongoing
Methyl Chloride CH3Cl 1993-12-30 Ongoing
HCFC-142b CH3CF2Cl 1992-01-20 Ongoing
Halon-1211 CBrClF2 1992-01-20 Ongoing
methyl bromide CH3Br 1992-11-28 Ongoing
HCFC-141b CH3CCl2F 1993-02-11 Ongoing
CFC-113 CCl2FCClF2 1992-01-20 Ongoing
dichloromethane CH2Cl2 1994-05-12 Ongoing
tetrachloroethylene C2Cl4 1993-11-18 Ongoing
carbonyl sulfide COS 2000-05-18 Ongoing
HFC-152a CH3CHF2 2000-07-06 Ongoing
Halon 2402 CBrF2CBrF2 1995-02-16 Ongoing
HFC-227ea CF3CHFCF3 2011-05-04 Ongoing
HFC-365mfc CH3CF2CH2CF3 2009-07-22 Ongoing
Methyl Chloroform CH3CCl3 1991-11-15 Ongoing
CFC-11 CCl3F 2009-07-08 Ongoing

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