GMD Site Description: SUM


  • Country: Greenland Country Flag
  • Latitude: 72.5962° North
  • Longitude: 38.422° West
  • Elevation: 3209.54 masl
  • Time Zone: Local Standard Time + 2.0 hour(s) = UTC


Cooperating Agencies


The Greenland Environmental Observatory (GEOSummit) on the summit of the Greenland Ice Sheet (3200 m above sea level) was established by the U.S. National Science Foundation (NSF) and the Danish Commission for Scientific Research in Greenland to provide year-round, long-term measurements for monitoring and investigations of the Arctic environment. The multidisciplinary facility is home to several year-round investigations as well as numerous seasonal campaigns which take advantage of the unique location of the observatory. GEOSummit provides investigators ease of access to the highest site north of the Arctic Circle. Since 1989, when the GISP II ice-coring activities began, the site has hosted numerous atmospheric and glaciological investigations. Following two trial winter over periods (1997-1998, and 2000-2002), the NSF Long Term Observatory (LTO) program committed funding to maintain year-round measurements of key baseline variables of climate change at the site. In addition, several programs funded through European agencies have a year round presence at the site.

Logistical support at Summit is provided by CH2M HILL Polar Services, under contract to NSF. NOAA has maintained a presence at Summit since the mid 1990s, begun mainly to conduct greenhouse gas measurements, with NOAA and NSF technicians working together to ensure continuity of data. From 2005 to present, NOAA Corps Officers have served as technicians during various phases throughout the year. Beginning in August of 2009, NOAA staff became a year-round permanent addition to the station crew, ensuring the long-term continuity of NOAA data and providing additional scientific support for the site.

The NOAA Summit Atmospheric Baseline Observatory was downgraded from its status as a full “Observatory” to a “Sampling Site” on August 1, 2017. NOAA technician time and cargo intensive projects in the NOAA measurement suite were removed from the site. However, surface ozone monitoring instrumentation, a basic meteorology system, aerosol instrumentation, and halocarbon and greenhouse gas flask sampling capabilities continue to operate at the site in partnership with the NSF. The downgrade follows a Global Monitoring Division-wide evaluation of scientific goals and global observing network capabilities that resulted in realignment to best meet NOAA’s mission and the nation’s scientific needs.

All data from Summit are available on the Global Monitoring Division’s website:

GMD Projects at Summit

Carbon Cycle Surface Flasks

Parameter Formula First Sample Date Status
Carbon Dioxide CO2 1997-06-23 Ongoing
Methane CH4 1997-06-23 Ongoing
Carbon Monoxide CO 1997-06-23 Ongoing
Molecular Hydrogen H2 1997-06-23 Ongoing
Nitrous Oxide N2O 1997-06-23 Ongoing
Sulfur Hexafluoride SF6 1997-06-23 Ongoing
Carbon-13/Carbon-12 in Carbon Dioxide d13C (CO2) 1997-06-23 Ongoing
Oxygen-18/Oxygen-16 in Carbon Dioxide d18O (CO2) 1997-06-23 Ongoing
Carbon-13/Carbon-12 in Methane d13C (CH4) 2010-04-27 Ongoing
Methyl Chloride CH3Cl 2004-10-18 Ongoing
Benzene C6H6 2006-07-17 Ongoing
toluene C7H8 2006-07-17 Ongoing
ethane C2H6 2004-10-18 Ongoing
ethene C2H4 2004-10-18 Ongoing
propane C3H8 2004-10-18 Ongoing
propene C3H6 2004-10-18 Ongoing
i-butane i-C4H10 2004-10-18 Ongoing
n-butane n-C4H10 2004-10-18 Ongoing
i-pentane i-C5H12 2004-10-18 Ongoing
n-pentane n-C5H12 2004-10-18 Ongoing
n-hexane n-C6H14 2004-10-18 Ongoing
Wind Speed ws 1997-06-23 Ongoing
Wind Direction wd 1997-06-23 Ongoing
Temperature temp 2004-05-10 Terminated - 2004-08-09
isoprene C5H8 2006-07-17 Ongoing
Acetylene C2H2 2007-09-24 Ongoing

HATS Flask Sampling

Parameter Formula First Sample Date Status
Nitrous Oxide N2O 2004-06-20 Ongoing
Sulfur Hexafluoride SF6 2004-06-20 Ongoing
HFC-134a CH2FCF3 2004-06-20 Ongoing
HCFC-22 CHF2Cl 2004-06-20 Ongoing
CFC-12 CCl2F2 2004-06-20 Ongoing
Methyl Chloride CH3Cl 2004-06-20 Ongoing
CFC-114 CFC-114 2004-06-20 Ongoing
HCFC-142b CH3CF2Cl 2004-06-20 Ongoing
Halon-1211 CBrClF2 2004-06-20 Ongoing
methyl bromide CH3Br 2004-06-20 Ongoing
HCFC-141b CH3CCl2F 2004-06-20 Ongoing
methyl iodide CH3I 2004-06-20 Ongoing
CFC-113 CCl2FCClF2 2004-06-20 Ongoing
dichloromethane CH2Cl2 2004-06-20 Ongoing
chloroform CHCl3 2004-06-20 Ongoing
carbon tetrachloride CCl4 2004-06-20 Ongoing
dibromomethane CH2Br2 2004-06-20 Ongoing
tetrachloroethylene C2Cl4 2009-03-10 Ongoing
bromoform CHBr3 2004-06-20 Ongoing
Benzene C6H6 2004-06-20 Ongoing
carbonyl sulfide COS 2004-06-20 Ongoing
HCFC-21 CHCl2F 2004-06-20 Ongoing
HFC-152a CH3CHF2 2004-06-20 Ongoing
toluene C7H8 2014-08-13 Terminated - 2016-08-30
carbonyl disulfide CS2 2005-03-08 Ongoing
ethane C2H6 2014-08-13 Ongoing
propane C3H8 2014-08-13 Ongoing
i-butane i-C4H10 2014-08-13 Ongoing
n-butane n-C4H10 2014-08-13 Ongoing
i-pentane i-C5H12 2014-08-13 Ongoing
n-pentane n-C5H12 2012-08-15 Ongoing
n-hexane n-C6H14 2012-08-15 Ongoing
Halon 1301 CF3Br 2005-03-22 Ongoing
Halon 2402 CBrF2CBrF2 2009-03-10 Ongoing
HFC-143a CH3CF3 2014-08-13 Ongoing
HFC-227ea CF3CHFCF3 2011-05-08 Ongoing
HFC-365mfc CH3CF2CH2CF3 2009-06-08 Ongoing
CFC-115 CClF2CF3 2014-08-13 Ongoing
HFC-125 CHF2CF3 2014-08-13 Ongoing
CFC-13 CClF3 2014-08-13 Ongoing
Perfluoropropane C3F8 2014-08-13 Ongoing
Acetylene C2H2 2014-08-13 Ongoing
HFC-32 CH2F2 2014-08-13 Ongoing
Methyl Chloroform CH3CCl3 2004-06-20 Ongoing
Chloroiodomethane CH2ClI 2016-09-13 Ongoing
diiodomethane CH2I2 2016-09-13 Ongoing
Bromoiodomethane CH2BrI 2016-09-13 Ongoing
Bromochloromethane CH2BrCl 2016-09-13 Ongoing
Bromodichloromethane CHBrCl2 2016-09-13 Ongoing
CFC-11 CCl3F 2004-06-20 Ongoing
tetrafluoromethane CF4 2014-08-13 Ongoing
hexafluoroethane CF3CF3 2014-08-13 Ongoing
nitrogen trifluoride NF3 2014-08-13 Ongoing
sulfuryl fluoride SO2F2 2014-08-13 Ongoing
HFC-236fa CF3CH2CF3 2014-08-13 Ongoing
HCFC-133a CH2ClCF3 2014-08-21 Ongoing
CFC-112 CCl3CClF2 2014-08-21 Ongoing
HFO-1234yf CH2=CFCF3 2016-07-28 Ongoing
1,2-dichloroethane CH2ClCH2Cl 2016-09-13 Ongoing
1,1-dichloroethane C2H4Cl2 2016-09-13 Ongoing
dibromochloromethane CHBr2Cl 2016-09-13 Ongoing
Ethyl Chloride C2H5Cl 2011-05-08 Ongoing
Propyne C3H4 2011-05-08 Ongoing
Trichloroethylene C2HCl3 2014-08-13 Ongoing

HATS In Situ Observatory

Parameter Formula First Sample Date Status
Methane CH4 2007-07-01 Ongoing
Carbon Monoxide CO 2007-07-01 Ongoing
Molecular Hydrogen H2 2007-07-01 Ongoing
Nitrous Oxide N2O 2007-07-16 Ongoing
Sulfur Hexafluoride SF6 2007-07-16 Ongoing
CFC-12 CCl2F2 2007-07-24 Ongoing
Halon-1211 CBrClF2 2007-11-22 Ongoing
CFC-113 CCl2FCClF2 2007-07-20 Ongoing
chloroform CHCl3 2007-07-01 Ongoing
carbon tetrachloride CCl4 2007-07-20 Ongoing
Methyl Chloroform CH3CCl3 2007-07-20 Ongoing
CFC-11 CCl3F 2007-07-20 Ongoing

Aerosol Surface In-Situ

Parameter Formula First Sample Date Status
Light Scattering Coefficient σsp 2011-01-10 Ongoing
Light Absorption Coefficient σap 2011-01-10 Ongoing
Particle Number Concentration Nt 2011-01-10 Terminated - 2011-07-21

Radiation In-Situ Observatory

Parameter Formula First Sample Date Status
Direct Normal 2006-05-28 Terminated - 2017-04-30
Downwelling Shortwave 2006-05-28 Terminated - 2017-04-30
Diffuse 2006-05-28 Terminated - 2017-04-30
Upwelling Shortwave 2006-05-28 Terminated - 2017-04-30
Downwelling Longwave 2006-05-28 Terminated - 2017-04-30
Upwelling Longwave 2006-05-28 Terminated - 2017-04-30

Surface Ozone

Parameter Formula First Sample Date Status
Ozone O3 2000-06-01 Ongoing


Parameter Formula First Sample Date Status
Ozone O3 2005-02-12 Terminated - 2017-07-25


Parameter Formula First Sample Date Status
Wind Speed ws 2008-06-25 Ongoing
Wind Direction wd 2008-06-25 Ongoing
Temperature temp 2008-06-26 Ongoing
Ambient Pressure press 2008-06-25 Ongoing
Relative Humidity rh 2008-08-15 Ongoing