GMD Site Description: NWR


  • Country: United States Country Flag
  • Latitude: 40.0531° North
  • Longitude: 105.5864° West
  • Elevation: 3523.00 masl
  • Time Zone: Local Time + 7.0 hour(s) = UTC


Cooperating Agencies

Niwot Ridge is located approximately 35 km west of Boulder, Colorado, with the entire study site lying above 3000 m elevation. There is a cirque glacier (Arikaree Glacier), extensive alpine tundra, a variety of glacial landforms, glacial lakes and moraines, cirques and talus slopes, patterned ground, and permafrost. The research area is bounded on the west by the Continental Divide, with runoff on the two sides being destined for the Colorado and Mississippi Rivers. The alpine study area is reached by an unimproved road from the Mountain Research Station (2895 m) which leads to within 2 km of the main tundra research site, the Saddle (3528 m). Niwot Ridge, including the main alpine study site, is part of the Roosevelt National Forest and has been designated a Biosphere Reserve (United Nations Educational, Scientific and Cultural Organization, UNESCO) and an Experimental Ecology Reserve (USDA Forest Service).

The Niwot Ridge web site is at

GMD Projects at Niwot Ridge, Colorado

Carbon Cycle Surface Flasks

Parameter Formula First Sample Date Status
Carbon Dioxide CO2 1967-05-18 Ongoing
Carbon Dioxide CO2 2005-09-16 Ongoing
Methane CH4 2005-09-16 Ongoing
Methane CH4 1983-05-11 Ongoing
Carbon Monoxide CO 1988-12-13 Ongoing
Carbon Monoxide CO 2005-09-16 Ongoing
Molecular Hydrogen H2 1988-12-27 Ongoing
Molecular Hydrogen H2 2005-09-16 Ongoing
Nitrous Oxide N2O 1997-04-22 Ongoing
Nitrous Oxide N2O 2005-09-16 Ongoing
Sulfur Hexafluoride SF6 2005-09-16 Ongoing
Sulfur Hexafluoride SF6 2014-12-23 Ongoing
Sulfur Hexafluoride SF6 1997-04-22 Ongoing
Carbon-13/Carbon-12 in Carbon Dioxide d13C (CO2) 2005-09-16 Ongoing
Carbon-13/Carbon-12 in Carbon Dioxide d13C (CO2) 1990-01-09 Ongoing
Oxygen-18/Oxygen-16 in Carbon Dioxide d18O (CO2) 1990-01-09 Ongoing
Oxygen-18/Oxygen-16 in Carbon Dioxide d18O (CO2) 2005-09-16 Ongoing
Carbon-13/Carbon-12 in Methane d13C (CH4) 1998-01-06 Ongoing
Carbon-14/Carbon in Carbon Dioxide D14C (CO2) 2003-05-27 Ongoing
D/H in Methane dD (CH4) 2005-05-24 Terminated - 2009-12-01
HFC-134a CH2FCF3 2012-04-10 Ongoing
HCFC-22 CHF2Cl 2012-04-10 Ongoing
CFC-12 CCl2F2 2012-04-10 Ongoing
Methyl Chloride CH3Cl 2015-02-24 Ongoing
Methyl Chloride CH3Cl 2005-12-06 Ongoing
Methyl Chloride CH3Cl 2012-04-10 Ongoing
CFC-114 and CFC-114a (combined) CFC-114 and CFC-114a (combined) 2012-04-10 Ongoing
HCFC-142b CH3CF2Cl 2012-04-10 Ongoing
Halon-1211 CBrClF2 2012-04-10 Ongoing
methyl bromide CH3Br 2012-04-10 Ongoing
CFC-11 (ion 101) CCl3F (ion 101) 2012-04-10 Ongoing
CFC-11 (ion 103) CCl3F (ion 103) 2014-12-23 Ongoing
HCFC-141b CH3CCl2F 2012-04-10 Ongoing
methyl iodide CH3I 2012-04-10 Ongoing
CFC-113 CCl2FCClF2 2012-04-10 Ongoing
dichloromethane CH2Cl2 2012-04-10 Ongoing
chloroform CHCl3 2012-04-10 Ongoing
methyl chloroform (ion 97) CH3CCl3 2012-04-10 Ongoing
carbon tetrachloride CCl4 2012-04-10 Ongoing
dibromomethane CH2Br2 2012-04-10 Ongoing
tetrachloroethylene C2Cl4 2012-04-10 Ongoing
bromoform CHBr3 2012-04-10 Ongoing
Benzene C6H6 2015-02-24 Ongoing
Benzene C6H6 2010-01-19 Ongoing
Benzene C6H6 2012-04-10 Ongoing
carbonyl sulfide COS 2012-04-10 Ongoing
HCFC-21 CHCl2F 2015-06-15 Ongoing
HFC-152a CH3CHF2 2012-04-10 Ongoing
HCFC-124 CHClFCF3 2012-04-10 Ongoing
toluene C7H8 2014-12-23 Ongoing
toluene C7H8 2015-02-24 Ongoing
toluene C7H8 2010-01-19 Ongoing
carbonyl disulfide CS2 2012-04-10 Ongoing
ethane C2H6 2014-12-23 Ongoing
ethane C2H6 2015-02-24 Ongoing
ethane C2H6 2005-12-06 Ongoing
ethene C2H4 2015-02-24 Ongoing
ethene C2H4 2005-12-06 Ongoing
ethene C2H4 2014-12-23 Ongoing
propane C3H8 2015-02-24 Ongoing
propane C3H8 2005-12-06 Ongoing
propane C3H8 2012-04-10 Ongoing
propene C3H6 2015-02-24 Ongoing
propene C3H6 2014-12-23 Ongoing
propene C3H6 2005-12-06 Ongoing
i-butane i-C4H10 2015-02-24 Ongoing
i-butane i-C4H10 2005-12-06 Ongoing
i-butane i-C4H10 2014-12-23 Ongoing
n-butane n-C4H10 2005-12-06 Ongoing
n-butane n-C4H10 2012-04-10 Ongoing
n-butane n-C4H10 2015-02-24 Ongoing
i-pentane i-C5H12 2015-02-24 Ongoing
i-pentane i-C5H12 2012-04-10 Ongoing
i-pentane i-C5H12 2005-12-06 Ongoing
n-pentane n-C5H12 2012-04-10 Ongoing
n-pentane n-C5H12 2015-02-24 Ongoing
n-pentane n-C5H12 2005-12-06 Ongoing
n-hexane n-C6H14 2005-12-06 Ongoing
n-hexane n-C6H14 2015-02-24 Ongoing
n-hexane n-C6H14 2014-12-23 Ongoing
Wind Speed ws 1992-07-21 Ongoing
Wind Direction wd 1992-07-21 Ongoing
Temperature temp 2006-12-14 Ongoing
Temperature temp 2004-08-31 Terminated - 2004-09-14
Ambient Pressure press 2006-12-14 Ongoing
Relative Humidity rh 2006-12-14 Ongoing
isoprene C5H8 2010-01-19 Ongoing
isoprene C5H8 2015-02-24 Ongoing
Halon 1301 CF3Br 2012-04-10 Ongoing
Halon 2402 CBrF2CBrF2 2012-04-10 Ongoing
HFC-143a CH3CF3 2012-04-10 Ongoing
HFC-227ea CF3CHFCF3 2012-04-10 Ongoing
HFC-365mfc CH3CF2CH2CF3 2012-04-10 Ongoing
CFC-115 CClF2CF3 2012-04-10 Ongoing
HFC-125 CHF2CF3 2012-04-10 Ongoing
CFC-13 CClF3 2012-04-10 Ongoing
Chloroethane CH3CH2Cl 2012-04-10 Ongoing
HFC-23 CHF3 2012-04-10 Ongoing
Perfluoropropane C3F8 2012-04-10 Ongoing
Acetylene C2H2 2012-04-10 Ongoing
Acetylene C2H2 2015-04-21 Ongoing
HFC-32 CH2F2 2012-04-10 Ongoing
HFC-134 CHF2CHF2 2012-04-10 Ongoing
CH2BrCl CH2BrCl 2014-12-23 Ongoing
tetrafluoromethane CF4 2014-12-23 Ongoing
hexafluoroethane CF3CF3 2014-12-23 Ongoing
nitrogen trifluoride NF3 2015-05-19 Ongoing
sulfuryl fluoride SO2F2 2015-05-19 Ongoing
HFC-236fa CF3CH2CF3 2014-12-23 Ongoing
HCFC-133a CH2ClCF3 2014-12-23 Ongoing
CFC-112 CCl3CClF2 2014-12-23 Ongoing
C2HCl3 C2HCl3 2014-12-23 Ongoing

Carbon Cycle Airborne Flasks

HATS Flask Sampling

Parameter Formula First Sample Date Status
HFC-134a CH2FCF3 1994-12-13 Ongoing
HCFC-22 CHF2Cl 1991-12-24 Ongoing
Methyl Chloride CH3Cl 1995-02-14 Ongoing
HCFC-142b CH3CF2Cl 1992-02-18 Ongoing
Halon-1211 CBrClF2 1991-12-24 Ongoing
methyl bromide CH3Br 1993-09-28 Ongoing
HCFC-141b CH3CCl2F 1992-12-15 Ongoing
CFC-113 CCl2FCClF2 1991-12-24 Ongoing
dichloromethane CH2Cl2 1995-04-04 Ongoing
tetrachloroethylene C2Cl4 1993-12-07 Ongoing
carbonyl sulfide COS 2000-03-14 Ongoing
HFC-152a CH3CHF2 2000-08-01 Ongoing
Halon 2402 CBrF2CBrF2 1995-02-14 Ongoing
HFC-227ea CF3CHFCF3 2011-06-07 Ongoing
HFC-365mfc CH3CF2CH2CF3 2009-08-04 Ongoing
Methyl Chloroform CH3CCl3 1991-12-24 Ongoing

HATS In Situ Observatory

Parameter Formula First Sample Date Status
Nitrous Oxide N2O 2001-01-08 Ongoing
Sulfur Hexafluoride SF6 2001-01-08 Ongoing
HCFC-22 CHF2Cl 2000-12-09 Ongoing
CFC-12 CCl2F2 2001-01-17 Ongoing
Methyl Chloride CH3Cl 2001-01-24 Ongoing
HCFC-142b CH3CF2Cl 2001-06-15 Ongoing
Halon-1211 CBrClF2 2001-05-02 Ongoing
CFC-113 CCl2FCClF2 2001-05-05 Ongoing
carbon tetrachloride CCl4 2001-05-01 Ongoing
Methyl Chloroform CH3CCl3 2001-05-01 Ongoing
CFC-11 CCl3F 2001-05-01 Ongoing

Surface Ozone

Parameter Formula First Sample Date Status
Ozone O3 1990-07-26 Ongoing


NEUBrew UV and Ozone

Trace gases from GGGRN Flasks