Aircraft Program

Overview

Since its inception in 1992, the Global Greenhouse Gas Reference Network’s aircraft program has been dedicated to collecting air samples in vertical profiles over North America. The program's mission is to capture seasonal and inter-annual changes in trace gas mixing ratios throughout the boundary layer and free troposphere (up to 8000m/26,000 ft). At present, most aircraft program flights collect 12 flask samples at different altitudes (up to 13,279 m/43,555 ft). These samples are stored in glass flasks for later analysis of Carbon Dioxide (CO2), Carbon Monoxide (CO), Nitrous Oxide (N2O), Methane (CH4), Molecular Hydrogen (H2), and Sulfur Hexafluoride (SF6), as well as isotopes of CO2 and CH4, and multiple Halo- and Hydrocarbons.

Data collected by the aircraft program provide a view of how the large-scale horizontal and vertical distribution of the measured trace gases change throughout a given year over the continent. The large-scale, three-dimensional picture of how trace mixing ratios change throughout the year has provided a means to estimate the contribution of the North America continent to the atmospheric concentration of long-lived tracers like carbonyl sulfide and CO2 (e.g Montzka et al. 2007 and Crevoisier et al. 2010) and an essential benchmark for forward and inverse modeling (i.e. Stephens et al. 2007; Yang et al., 2007; Peters et al. 2007; Maddy et al. 2008; Xiong et al. 2008; Campbell et al. 2008).

Project Goals

To facilitate a broad-scale sampling program across North America it was important to establish a sampling protocol that would not require technical expertise at the sampling sites. This was accomplished by developing a portable, automated system for obtaining air samples that can be quickly shipped back to NOAA/ESRL for carefully calibrated and quality-controlled measurements. At a predetermined altitude, the sampling system is simply activated by a toggle switch that is easily accessible to the pilot. Time, location and auxiliary variables such as temperature and relative humidity are logged with each sample and downloaded into the NOAA/ESRL database when the samples are returned to the laboratory.

The aircraft program is actively pursuing alternative sampling strategies. Intensive sampling campaigns are focused on specific processes such as Lagrangian flux experiments or fossil fuel emission validation experiments. Additionally, work is being done to pursue in-situ measurements on commercial aircraft. It is anticipated that data resulting from commercial aircraft will significantly enhance the frequency and spatial distribution of profiles.

Sampling frequency and height distribution varies at each site, but samples are collected from 500 m above ground to 8000 m above sea level at the majority of aircraft sites. While sampling flights have been conducted at some sites as often as two to three times per week, sample flights at most sites are only carried out once every two to three weeks.

Sites

Code Name Lat Lon Elevation (masl) First Sample Date Most Recent Sample Date Status Bottom altitude (m) Top altitude (m) Average Flight Frequency1 (days)
AAO Airborne Aerosol Observatory, Bondville, Illinois 40.0500 -88.3700 230.00 2006-06-07 2009-09-18 Terminated 374 4860 4
ACG Alaska Coast Guard 57.7366 -152.5042 6.00 2009-04-30 2022-10-13 Ongoing 0 8857 82
BGI Bradgate, Iowa 42.8200 -94.4100 355.10 2004-09-13 2005-11-18 Terminated 599 8075 14
BNE Beaver Crossing, Nebraska 40.8000 -97.1800 465.90 2004-09-15 2011-05-11 Terminated 597 8157 27
CAR Briggsdale, Colorado 40.6347 -104.3269 1488.00 1992-11-09 2023-03-10 Ongoing 1586 11879 20
CMA Offshore Cape May, New Jersey 38.8300 -74.3200 0.00 2005-08-17 2023-02-27 Ongoing 247 8143 13
CRV Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) 64.9863 -147.5980 611.43 2011-03-29 2017-11-05 Terminated 2 7850 9
DND Dahlen, North Dakota 47.5000 -99.2400 472.44 2004-09-21 2016-11-15 Terminated 518 8131 19
ESP Estevan Point, British Columbia 49.3830 -126.5441 7.00 2002-11-22 2023-02-28 Ongoing 18 5820 15
ETL East Trout Lake, Saskatchewan 54.3541 -104.9868 493.00 2005-10-15 2023-03-07 Ongoing 599 7823 45
FAM FAAM Aircraft -99.9999 -999.9999 -9999.99 2014-07-09 2015-05-12 Terminated 129 2000 38
FTL Fortaleza -3.5200 -38.2800 3.00 2000-12-09 2003-03-25 Terminated 152 4267 93
FWI Fairchild, Wisconsin 44.6600 -90.9600 334.30 2004-09-20 2005-11-18 Terminated 590 8073 14
HAA Molokai Island, Hawaii 21.2300 -158.9500 3.00 1999-05-31 2008-04-22 Terminated 4 8104 21
HFM Harvard Forest, Massachusetts 42.5378 -72.1714 340.00 1999-11-11 2007-11-18 Terminated 582 8063 19
HIL Homer, Illinois 40.0700 -87.9100 201.50 2004-09-16 2023-03-05 Ongoing 322 8117 15
HOW Howland, Maine 42.2000 -68.1300 -9999.99 1996-12-21 1997-06-23 Terminated 122 3048 184
INX INFLUX (Indianapolis Flux Experiment) 39.5805 -86.4207 -9999.99 2010-10-27 2016-05-19 Terminated 302 3518 40
LEF Park Falls, Wisconsin 45.9451 -90.2732 472.00 1998-04-10 2023-02-06 Ongoing 549 5060 16
MRC Marcellus Pennsylvania 41.4662 -76.4188 592.00 2015-05-21 2015-06-03 Terminated 163 3123 3
NHA Offshore Portsmouth, New Hampshire (Isles of Shoals) 42.9500 -70.6300 0.00 2003-09-12 2023-03-10 Ongoing 0 8136 13
NSK Northern Saskatchewan 58.7300 -104.9000 401.00 2020-12-26 2021-02-13 Terminated 820 6799 24
OIL Oglesby, Illinois 41.2800 -88.9400 192.60 2004-09-16 2005-11-19 Terminated 530 8121 12
PFA Poker Flat, Alaska 64.9000 -148.7600 210.00 1999-06-27 2023-03-08 Ongoing 131 7618 17
RTA Rarotonga -21.2500 -159.8300 3.00 2000-04-16 2023-02-24 Ongoing 16 6528 36
SAN Santarem -2.8500 -54.9500 78.00 2000-12-07 2003-08-20 Terminated 300 5200 43
SCA Offshore Charleston, South Carolina 32.7700 -79.5500 0.00 2003-08-22 2023-03-07 Ongoing 218 13279 19
SGP Southern Great Plains, Oklahoma 36.6070 -97.4890 314.00 1998-03-02 2023-01-13 Ongoing 152 12949 19
TGC Offshore Corpus Christi, Texas 27.7300 -96.8600 0.00 2003-09-09 2023-02-22 Ongoing 19 8217 33
THD Trinidad Head, California 41.0541 -124.1510 107.00 2003-09-02 2023-03-01 Ongoing 152 8131 23
UGD Kajjansi Airfield, Kampala, Uganda 0.2000 32.5500 1141.00 2020-12-15 2022-06-22 Ongoing Not available
ULB Ulaanbaatar 47.4000 106.0000 1350.00 2004-03-25 2009-03-05 Terminated 1512 5944 25
WBI West Branch, Iowa 41.7248 -91.3529 241.70 2004-09-14 2023-03-10 Ongoing 543 8204 15
WGC Walnut Grove, California 38.2645 -121.4904 2.00 2008-05-23 2009-03-08 Terminated 6 3177 19
1 Average number of days between flights during the last two years of sampling.

Airborne Aerosol Observatory, Bondville, Illinois (AAO)

40.0500 °N | 88.37 °W | 230.00 m

  • First Sample Date: 2006-06-07
  • Last Sample Date: 2009-09-18
  • Top Altitude: 4860 m/15944 ft
  • Bottom Altitude: 374 m/1227 ft
  • Average Flight Frequency: Every 4 days
  • Aircraft: Fixed Wing Single-Engine T206H Cessna
  • Status: Terminated
  • Data Visualization
AAO Aircraft
Aircraft
AAO Inlet
Sample Inlet
The NOAA Airborne Aerosol Observatory was a mobile observatory based near Bondville, Illinois. Samples were collected over the flat, agricultural lands of east central Illinois. The AAO aircraft is specifically outfitted for atmospheric monitoring. Instruments on the aircraft make measurements of aerosol optical properties, hygroscopic growth, aerosol composition, particle number, and size distribution. In addition to aerosol measurements, the aircraft also carried the automated sampling equipment for carbon cycle gas collection. AAO was one of the most frequently sampled locations, often conducting two sampling flights per week. Sample collection began in June 2006, but the site was discontinued in September 2009 because of funding cuts.

Alaska Coast Guard (ACG)

57.7366 °N | 152.5042 °W | 6.00 m

  • First Sample Date: 2009-04-30
  • Last Sample Date: 2022-10-13
  • Top Altitude: 8857 m/29058 ft
  • Bottom Altitude: 0 m/0 ft
  • Average Flight Frequency: Every 82 days
  • Aircraft:
  • Status: Ongoing
  • Data Visualization
ACG Aircraft
Aircraft
ACG Inlet
Sample Inlet

Bradgate, Iowa (BGI)

42.8200 °N | 94.41 °W | 355.10 m

  • First Sample Date: 2004-09-13
  • Last Sample Date: 2005-11-18
  • Top Altitude: 8075 m/26492 ft
  • Bottom Altitude: 599 m/1965 ft
  • Average Flight Frequency: Every 14 days
  • Aircraft: Cessna 421B
  • Status: Terminated
  • Data Visualization
BGI Aircraft
Aircraft
BGI Inlet
Sample Inlet
BGI samples were collected over flat, agricultural lands near Bradgate in northwestern Iowa. Sample collection at BGI started in September 2004, but the site was discontinued in November 2005 because of funding cuts. BGI flights were conducted by Jeff Smalley and Dr. Dirk Brom of Hap’s Air Service based in Ames, Iowa.

Beaver Crossing, Nebraska (BNE)

40.8000 °N | 97.18 °W | 465.90 m

  • First Sample Date: 2004-09-15
  • Last Sample Date: 2011-05-11
  • Top Altitude: 8157 m/26761 ft
  • Bottom Altitude: 597 m/1958 ft
  • Average Flight Frequency: Every 30 days
  • Aircraft: Cessna 421B
  • Status: Terminated
  • Data Visualization
BNE Aircraft
Aircraft
BNE Inlet
Sample Inlet
Samples are collected over flat, agricultural land near Beaver Crossing in southeastern Nebraska. Sample collection at BNE started in September 2004. These flights are conducted by Jeff Smalley and Dr. Dirk Brom of Hap’s Air Service based in Ames, Iowa.

Briggsdale, Colorado (CAR)

40.6347 °N | 104.3269 °W | 1488.00 m

  • First Sample Date: 1992-11-09
  • Last Sample Date: 2023-03-10
  • Top Altitude: 11879 m/38973 ft
  • Bottom Altitude: 1586 m/5203 ft
  • Average Flight Frequency: Every 24 days
  • Aircraft: Cessna 210
  • Status: Ongoing
  • Data Visualization
CAR Aircraft
Aircraft
CAR Inlet
Sample Inlet
Samples are collected over flat, mixed plains and agricultural land near Briggsdale in northeastern Colorado. The Carbon Cycle group’s longest vertical-profile record comes from this area, with sample collection beginning in November 1992 during the initial development and testing phase of the automated flask sampling system. Sampling flights were originally conducted over Carr, Colorado, but in December 2004 the site was moved 40 miles southeast to Briggsdale to be in proximity to an Ameriflux tower. Regular sampling flights continue to be flown, but CAR also acts as the test site for new and modified sampling equipment. Flights at CAR are conducted by John Weisbart, ATP, of Weisbart Aircraft Services, LLC.

Offshore Cape May, New Jersey (CMA)

38.8300 °N | 74.32 °W | 0.00 m

  • First Sample Date: 2005-08-17
  • Last Sample Date: 2023-02-27
  • Top Altitude: 8143 m/26715 ft
  • Bottom Altitude: 247 m/810 ft
  • Average Flight Frequency: Every 15 days
  • Aircraft: Cessna Piper Comanche Twin
  • Status: Ongoing
  • Data Visualization
CMA Aircraft
Aircraft
CMA Inlet
Sample Inlet
CMA samples are collected over the Atlantic Ocean off the coast of Cape May, New Jersey. Sample collection at CMA started in August 2005.

Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) (CRV)

64.9863 °N | 147.598 °W | 611.43 m

  • First Sample Date: 2011-03-29
  • Last Sample Date: 2017-11-05
  • Top Altitude: 7850 m/25754 ft
  • Bottom Altitude: 2 m/6 ft
  • Average Flight Frequency: Every 14 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
CRV Aircraft
Aircraft
CRV Inlet
Sample Inlet

Dahlen, North Dakota (DND)

47.5000 °N | 99.24 °W | 472.44 m

  • First Sample Date: 2004-09-21
  • Last Sample Date: 2016-11-15
  • Top Altitude: 8131 m/26676 ft
  • Bottom Altitude: 518 m/1699 ft
  • Average Flight Frequency: Every 16 days
  • Aircraft: Cessna 340A
  • Status: Terminated
  • Data Visualization
DND Aircraft
Aircraft
DND Inlet
Sample Inlet
Samples are collected over flat, agricultural land in northeastern North Dakota. Sample collection at DND started in November 2004.

Estevan Point, British Columbia (ESP)

49.3830 °N | 126.5441 °W | 7.00 m

  • First Sample Date: 2002-11-22
  • Last Sample Date: 2023-02-28
  • Top Altitude: 5820 m/19094 ft
  • Bottom Altitude: 18 m/59 ft
  • Average Flight Frequency: Every 16 days
  • Aircraft: Cessna 182
  • Status: Ongoing
  • Data Visualization
ESP Aircraft
Aircraft
ESP Inlet
Sample Inlet
Samples are collected over the Estevan Point Lighthouse on the west coast of Vancouver Island, British Columbia. Sample collection at ESP started in November 2002. Flights are conducted by Hal Schulz who is based in Comox, British Columbia.

East Trout Lake, Saskatchewan (ETL)

54.3541 °N | 104.9868 °W | 493.00 m

  • First Sample Date: 2005-10-15
  • Last Sample Date: 2023-03-07
  • Top Altitude: 7823 m/25666 ft
  • Bottom Altitude: 599 m/1965 ft
  • Average Flight Frequency: Every 19 days
  • Aircraft: Beechcraft King Air A100
  • Status: Ongoing
  • Data Visualization
ETL Aircraft
Aircraft
ETL Inlet
Sample Inlet
Samples are collected over forest land in central Saskatchewan and directly above a tower beside East Trout Lake, Saskatchewan. Flights are synchronized with the collection of air samples from two air inlets at different heights on the tower. The coordination of the sampling and the subsequent analysis of the tower air are conducted by our collaborators in the Climate Chemistry Measurements and Research Division (CRD) of Environment Canada’s Atmospheric Science and Technology Directorate. Sample collection began in October 2005. Flights are conducted by Transwest Air out of Prince Albert, Saskatchewan.

FAAM Aircraft (FAM)

-99.9999 °N | 999.9999 °W | -9999.99 m

  • First Sample Date: 2014-07-09
  • Last Sample Date: 2015-05-12
  • Top Altitude: 2000 m/6561 ft
  • Bottom Altitude: 129 m/423 ft
  • Average Flight Frequency: Every 38 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
FAM Aircraft
Aircraft
FAM Inlet
Sample Inlet

Fortaleza (FTL)

-3.5200 °N | 38.28 °W | 3.00 m

  • First Sample Date: 2000-12-09
  • Last Sample Date: 2003-03-25
  • Top Altitude: 4267 m/13999 ft
  • Bottom Altitude: 152 m/498 ft
  • Average Flight Frequency: Every 85 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
FTL Aircraft
Aircraft
FTL Inlet
Sample Inlet

Fairchild, Wisconsin (FWI)

44.6600 °N | 90.96 °W | 334.30 m

  • First Sample Date: 2004-09-20
  • Last Sample Date: 2005-11-18
  • Top Altitude: 8073 m/26486 ft
  • Bottom Altitude: 590 m/1935 ft
  • Average Flight Frequency: Every 14 days
  • Aircraft: Cessna 421B
  • Status: Terminated
  • Data Visualization
FWI Aircraft
Aircraft
FWI Inlet
Sample Inlet
Samples were collected over mixed agricultural and forested land near Fairchild in west central Wisconsin. Sample collection at FWI started in September 2004, but the site was discontinued in November 2005 because of funding cuts. Flights were conducted by Jeff Smalley and Dr. Dirk Brom of Hap’s Air Service based in Ames, Iowa.

Molokai Island, Hawaii (HAA)

21.2300 °N | 158.95 °W | 3.00 m

  • First Sample Date: 1999-05-31
  • Last Sample Date: 2008-04-22
  • Top Altitude: 8104 m/26587 ft
  • Bottom Altitude: 4 m/13 ft
  • Average Flight Frequency: Every 16 days
  • Aircraft: Cessna 421
  • Status: Terminated
  • Data Visualization
HAA Aircraft
Aircraft
HAA Inlet
Sample Inlet
Samples were collected over the Pacific Ocean west of Honolulu, Hawaii. In addition to providing a vertical profile of carbon cycle gas measurements in this area, HAA samples were also used to help calibrate the Measurement Of Pollution In The Troposphere (MOPITT) instrument flown aboard NASA's Earth System Enterprise (ESE) Terra satellite. Sample collection at HAA started in May 1999, but the site was discontinued in April 2008 because of funding cuts.

Harvard Forest, Massachusetts (HFM)

42.5378 °N | 72.1714 °W | 340.00 m

  • First Sample Date: 1999-11-11
  • Last Sample Date: 2007-11-18
  • Top Altitude: 8063 m/26453 ft
  • Bottom Altitude: 582 m/1909 ft
  • Average Flight Frequency: Every 18 days
  • Aircraft: Cessna TU206
  • Status: Terminated
  • Data Visualization
HFM Aircraft
Aircraft
HFM Inlet
Sample Inlet
Samples were collected over the forest lands of Harvard Forest in north central Massachusetts. In addition to providing a vertical profile of carbon cycle gas measurements in this area, HFM samples were also used to help calibrate the Measurement Of Pollution In The Troposphere (MOPITT) instrument flown aboard NASA's Earth System Enterprise (ESE) Terra satellite. Sample collection at HFM started in November 1999, but the site was discontinued in December 2007 because of funding cuts. These flights were conducted by Dick Hordom of Four Star Aviation.

Homer, Illinois (HIL)

40.0700 °N | 87.91 °W | 201.50 m

  • First Sample Date: 2004-09-16
  • Last Sample Date: 2023-03-05
  • Top Altitude: 8117 m/26630 ft
  • Bottom Altitude: 322 m/1056 ft
  • Average Flight Frequency: Every 15 days
  • Aircraft: Piper PA 34-220T
  • Status: Ongoing
  • Data Visualization
HIL Aircraft
Aircraft
HIL Inlet
Sample Inlet
Samples are collected over relatively flat, agricultural land near Homer in east central Illinois. Sample collection at HIL started in September 2004.

Howland, Maine (HOW)

42.2000 °N | 68.13 °W | -9999.99 m

  • First Sample Date: 1996-12-21
  • Last Sample Date: 1997-06-23
  • Top Altitude: 3048 m/10000 ft
  • Bottom Altitude: 122 m/400 ft
  • Average Flight Frequency: Every 184 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
HOW Aircraft
Aircraft
HOW Inlet
Sample Inlet

INFLUX (Indianapolis Flux Experiment) (INX)

39.5805 °N | 86.4207 °W | -9999.99 m

  • First Sample Date: 2010-10-27
  • Last Sample Date: 2016-05-19
  • Top Altitude: 3518 m/11541 ft
  • Bottom Altitude: 302 m/990 ft
  • Average Flight Frequency: Every 33 days
  • Aircraft: Beechcraft
  • Status: Terminated
  • Data Visualization
INX Aircraft
Aircraft
INX Inlet
Sample Inlet

Park Falls, Wisconsin (LEF)

45.9451 °N | 90.2732 °W | 472.00 m

  • First Sample Date: 1998-04-10
  • Last Sample Date: 2023-02-06
  • Top Altitude: 5060 m/16601 ft
  • Bottom Altitude: 549 m/1801 ft
  • Average Flight Frequency: Every 17 days
  • Aircraft: Cessna 172
  • Status: Ongoing
  • Data Visualization
LEF Aircraft
Aircraft
LEF Inlet
Sample Inlet
Samples are collected over forest land near Park Falls in north central Wisconsin. Flights are conducted over a tall communications tower that also houses air sampling equipment. Air samples are collected at the surface as well as from the tower. Sample collection via aircraft at LEF began in April 1998.

Marcellus Pennsylvania (MRC)

41.4662 °N | 76.4188 °W | 592.00 m

  • First Sample Date: 2015-05-21
  • Last Sample Date: 2015-06-03
  • Top Altitude: 3123 m/10246 ft
  • Bottom Altitude: 163 m/534 ft
  • Average Flight Frequency: Every 3 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
MRC Aircraft
Aircraft
MRC Inlet
Sample Inlet

Offshore Portsmouth, New Hampshire (Isles of Shoals) (NHA)

42.9500 °N | 70.63 °W | 0.00 m

  • First Sample Date: 2003-09-12
  • Last Sample Date: 2023-03-10
  • Top Altitude: 8136 m/26692 ft
  • Bottom Altitude: 0 m/0 ft
  • Average Flight Frequency: Every 16 days
  • Aircraft: Cessna T210
  • Status: Ongoing
  • Data Visualization
NHA Aircraft
Aircraft
NHA Inlet
Sample Inlet
Samples are collected over the Atlantic Ocean off the coast of New Hampshire and just south of the Isle of Shoals. Sample collection at NHA started in September 2003.

Northern Saskatchewan (NSK)

58.7300 °N | 104.9 °W | 401.00 m

  • First Sample Date: 2020-12-26
  • Last Sample Date: 2021-02-13
  • Top Altitude: 6799 m/22306 ft
  • Bottom Altitude: 820 m/2690 ft
  • Average Flight Frequency: Every 24 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
NSK Aircraft
Aircraft
NSK Inlet
Sample Inlet

Oglesby, Illinois (OIL)

41.2800 °N | 88.94 °W | 192.60 m

  • First Sample Date: 2004-09-16
  • Last Sample Date: 2005-11-19
  • Top Altitude: 8121 m/26643 ft
  • Bottom Altitude: 530 m/1738 ft
  • Average Flight Frequency: Every 12 days
  • Aircraft: Piper PA 31-325
  • Status: Terminated
  • Data Visualization
OIL Aircraft
Aircraft
OIL Inlet
Sample Inlet
Samples were collected over flat, agricultural land near Oglesby in central Illinois. Sample collection at OIL started in September 2004, but the site was discontinued in November 2005 because of funding cuts.

Poker Flat, Alaska (PFA)

64.9000 °N | 148.76 °W | 210.00 m

  • First Sample Date: 1999-06-27
  • Last Sample Date: 2023-03-08
  • Top Altitude: 7618 m/24993 ft
  • Bottom Altitude: 131 m/429 ft
  • Average Flight Frequency: Every 20 days
  • Aircraft: Piper PA 31-325
  • Status: Ongoing
  • Data Visualization
PFA Aircraft
Aircraft
PFA Inlet
Sample Inlet
Samples are collected over the forest land of Poker Flat Research Range northeast of Fairbanks, Alaska. In addition to providing a vertical profile of carbon cycle gas measurements in this area, PFA samples were also used to help calibrate the Measurement Of Pollution In The Troposphere (MOPITT) instrument flown aboard NASA's Earth System Enterprise (ESE) Terra satellite. Sample collection at PFA started in June 1999.

Rarotonga (RTA)

-21.2500 °N | 159.83 °W | 3.00 m

  • First Sample Date: 2000-04-16
  • Last Sample Date: 2023-02-24
  • Top Altitude: 6528 m/21417 ft
  • Bottom Altitude: 16 m/52 ft
  • Average Flight Frequency: Every 38 days
  • Aircraft: Embraer Bandeirante 110
  • Status: Ongoing
  • Data Visualization
RTA Aircraft
Aircraft
RTA Inlet
Sample Inlet
Samples are collected over the South Pacific near Rarotonga in the Cook Islands. In addition to providing a vertical profile of carbon cycle gas measurements in this area, RTA samples were also used to help calibrate the Measurement Of Pollution In The Troposphere (MOPITT) instrument flown aboard NASA's Earth System Enterprise (ESE) Terra satellite. This is a unique site because these are currently the only CCGG network vertical profiles being measured in the Southern Hemisphere. Sample collection at RTA started in April 2000. Flights are conducted by Alistair Macquarie & crews from Air Rarotonga.

Santarem (SAN)

-2.8500 °N | 54.95 °W | 78.00 m

  • First Sample Date: 2000-12-07
  • Last Sample Date: 2003-08-20
  • Top Altitude: 5200 m/17060 ft
  • Bottom Altitude: 300 m/984 ft
  • Average Flight Frequency: Every 73 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
SAN Aircraft
Aircraft
SAN Inlet
Sample Inlet

Offshore Charleston, South Carolina (SCA)

32.7700 °N | 79.55 °W | 0.00 m

  • First Sample Date: 2003-08-22
  • Last Sample Date: 2023-03-07
  • Top Altitude: 13279 m/43566 ft
  • Bottom Altitude: 218 m/715 ft
  • Average Flight Frequency: Every 19 days
  • Aircraft: Cessna 337C Turbo
  • Status: Ongoing
  • Data Visualization
SCA Aircraft
Aircraft
SCA Inlet
Sample Inlet
Samples are collected over the Atlantic Ocean off the coast of Charleston, South Carolina. Sample collection at SCA started in August 2003.

Southern Great Plains, Oklahoma (SGP)

36.6070 °N | 97.489 °W | 314.00 m

  • First Sample Date: 1998-03-02
  • Last Sample Date: 2023-01-13
  • Top Altitude: 12949 m/42483 ft
  • Bottom Altitude: 152 m/498 ft
  • Average Flight Frequency: Every 19 days
  • Aircraft: Cessna 337C Turbo
  • Status: Ongoing
  • Data Visualization
SGP Aircraft
Aircraft
SGP Inlet
Sample Inlet
Samples are collected over relatively flat, agricultural land of the Southern Great Plains region of north central Oklahoma. Sampling is conducted in collaboration with Lawrence Berkeley National Laboratory and the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Program / Cloud and Radiation Testbed. Limited sample collection via aircraft at SGP started in September 2002 using a modified manual sampling method. Sample collection with the current programmable flask packages at SGP started in March 2006.

Offshore Corpus Christi, Texas (TGC)

27.7300 °N | 96.86 °W | 0.00 m

  • First Sample Date: 2003-09-09
  • Last Sample Date: 2023-02-22
  • Top Altitude: 8217 m/26958 ft
  • Bottom Altitude: 19 m/62 ft
  • Average Flight Frequency: Every 38 days
  • Aircraft: Cessna 421B
  • Status: Ongoing
  • Data Visualization
TGC Aircraft
Aircraft
TGC Inlet
Sample Inlet
Samples are collected over the Gulf of Mexico off the coast of Corpus Christi, Texas. Sample collection started at TGC in September 2003.

Trinidad Head, California (THD)

41.0541 °N | 124.151 °W | 107.00 m

  • First Sample Date: 2003-09-02
  • Last Sample Date: 2023-03-01
  • Top Altitude: 8131 m/26676 ft
  • Bottom Altitude: 152 m/498 ft
  • Average Flight Frequency: Every 36 days
  • Aircraft: Mooney M20M
  • Status: Ongoing
  • Data Visualization
THD Aircraft
Aircraft
THD Inlet
Sample Inlet
Samples are collected over the Pacific Ocean off the coast of Trinidad Head, California. Sample collection started at THD in September 2003.

Kajjansi Airfield, Kampala, Uganda (UGD)

0.2000 °N | 32.55 °E | 1141.00 m

  • First Sample Date: 2020-12-15
  • Last Sample Date: 2022-06-22
  • Top Altitude: m/0 ft
  • Bottom Altitude: m/0 ft
  • Average Flight Frequency: Not available
  • Aircraft:
  • Status: Ongoing
  • Data Visualization
UGD Aircraft
Aircraft
UGD Inlet
Sample Inlet

Ulaanbaatar (ULB)

47.4000 °N | 106 °E | 1350.00 m

  • First Sample Date: 2004-03-25
  • Last Sample Date: 2009-03-05
  • Top Altitude: 5944 m/19501 ft
  • Bottom Altitude: 1512 m/4960 ft
  • Average Flight Frequency: Every 33 days
  • Aircraft: Cessna 208
  • Status: Terminated
  • Data Visualization
ULB Aircraft
Aircraft
ULB Inlet
Sample Inlet
Samples were collected over the forested mountains of central Mongolia, southwest of the capital Ulaanbaatar. These flights were conducted in collaboration with the Mongolian Hydrometeorological Research Institute. Sample collection at ULB started in March 2004, but the site was discontinued in March 2009 because of funding cuts.

West Branch, Iowa (WBI)

41.7248 °N | 91.3529 °W | 241.70 m

  • First Sample Date: 2004-09-14
  • Last Sample Date: 2023-03-10
  • Top Altitude: 8204 m/26916 ft
  • Bottom Altitude: 543 m/1781 ft
  • Average Flight Frequency: Every 15 days
  • Aircraft: Cessna 421B
  • Status: Ongoing
  • Data Visualization
WBI Aircraft
Aircraft
WBI Inlet
Sample Inlet
Samples are collected over flat agricultural land near West Branch in east central Iowa. Flights are conducted over a tall communications tower that also houses air sampling equipment. Sample collection via aircraft began in September 2004, originally over Rawley, Iowa (RIA), approximately 90 km to the northwest of the current site. The aircraft sampling was relocated to WBI in January 2008 to coordinate with air sample collection and monitoring at the WBI tower. Flights are conducted by Jeff Smalley and Dr. Dirk Brom of Hap’s Air Service based in Ames, Iowa.

Walnut Grove, California (WGC)

38.2645 °N | 121.4904 °W | 2.00 m

  • First Sample Date: 2008-05-23
  • Last Sample Date: 2009-03-08
  • Top Altitude: 3177 m/10423 ft
  • Bottom Altitude: 6 m/19 ft
  • Average Flight Frequency: Every 19 days
  • Aircraft:
  • Status: Terminated
  • Data Visualization
WGC Aircraft
Aircraft
WGC Inlet
Sample Inlet