This data set provides concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from air samples collected at several heights on towers at three locations in upland old growth forests in the Brazilian Amazon during the wet and dry seasons of 2004 and 2005. Towers are located in the Caxiuana National Forest, in the state of Amazonas; the Manaus, Para, site in the Cuieiras Reserve; and the Sinop site, located north of that city in the state of Mato Grosso. Two sampling campaigns were conducted at each location. Samples were collected from each height 3-5 times on several nights and at least once during well-mixed daytime conditions during each campaign for a total of 75 profiles on 19 dates. There is one comma-delimited ASCII file with this data set.
Cite this data set as follows:
do Carmo, J.B., M. Keller, J.D. Dias, P.B. de Camargo and P.M. Crill. 2012. LBA-ECO TG-07 Seasonal Trace Gas Profiles in Brazilian Amazon Forests: 2004-2005. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. http://dx.doi.org/10.3334/ORNLDAAC/1107
The LBA Data and Publication Policy [http://daac.ornl.gov/LBA/lba_data_policy.html] is in effect for a period of five (5) years from the date of archiving and should be followed by data users who have obtained LBA data sets from the ORNL DAAC. Users who download LBA data in the five years after data have been archived must contact the investigators who collected the data, per provisions 6 and 7 in the Policy.
This data set was archived in July of 2012. Users who download the data between July 2012 and June 2017 must comply with the LBA Data and Publication Policy.
Data users should use the Investigator contact information in this document to communicate with the data provider. Alternatively, the LBA website [http://lba.inpa.gov.br/lba/] in Brazil will have current contact information.
Data users should use the Data Set Citation and other applicable references provided in this document to acknowledge use of the data.
Project: LBA (Large-Scale Biosphere-Atmosphere Experiment in the Amazon)
LBA Science Component: Trace Gas and Aerosol Fluxes
Team ID: TG-07 (Keller / Oliveira)
The investigators were Keller, Michael M.; Albuquerque, Sergio Silva; Alexander, Jess Everett; Araujo, Flavia ; Bowley, Evilene; Braswell, Bobby H.; Camargo, Plinio Barbosa de; Carmo, Janaina Braga do; Crill, Patrick Michael; Dias, Jadson Dezincourt ; Dias, Joelma ; Filho, Deusdedith Cruz; Hagen, Stephen Charles; Hunter, Maria O'Healy; Li, Changsheng ; Lima, Risonaldo Leal; Mello, William Zamboni de; Mosedale, Andrew H; Palace, Michael William; Pepler, Paul Thomas; Pereira, Cleuton Alessandro; Pereira, Rodrigo Antonio; Rivera Costa, Maria Milagros; Sampaio, Irene Cibelle Goncalves; Scaranello, Marcos Augusto; Silva, Hudson Cleber Pereira; Silva, Kadson Oliveira; Silva, Kemeson Oliveira da; Sousa Neto, Eraclito; Varner, Ruth; Xiao, Xiangming and Zweede, Johan Cornelis. You may contact Carmo, Janaina Braga do (firstname.lastname@example.org).
LBA Data Set Inventory ID: TG07_Trace_Gas_Profiles
This data set provides concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from air samples collected at several heights on towers at three locations in upland old growth forests in the Brazilian Amazon during the wet and dry seasons of 2004 and 2005. Towers are located in the Caxiuana National Forest, in the state of Amazonas; the Manaus, Para, site in the Cuieiras Reserve; and the Sinop site, located north of that city in the state of Mato Grosso. Two sampling campaigns were conducted at each location. Samples were collected from each height 3-5 times on several nights and at least once during well-mixed daytime conditions during each campaign for a total of 75 profiles on 19 dates.
Data are reported in one comma-delimited ASCII file:
|1||Site||Sampling location: Caxiuana, Manaus, Sinop|
|2||Sample_date||yyyymmdd||Sample date (yyyymmdd)|
|3||Sample_time||hh:mm||Time at which each sample was collected in local time which is GMT -5 (hh:mm, 24 hour clock)|
|4||Season||Season in which samples were collected: wet or dry|
|5||Collection_period||Samples were either collected during the daylight hours (diurnal) or late at night ( nocturnal)|
|6||Jar_ID||Sample identification for laboratory use|
|7||Height||m||Sample height in meters above the ground|
|8||Conc_CO2||ppm||Concentration of carbon dioxide in parts per million,|
|9||Conc_N2O||ppm||Concentration of nitrous oxide in parts per million,|
|10||Conc_CH4||ppm||Concentration of methane in parts per million|
|11||Mix_ratio_CO2||ppm||Height weighted average mixing ratio for carbon dioxide in parts per million|
|12||Mix_ratio_N2O||ppm||Height weighted average mixing ratio for nitrous oxide in parts per million|
|13||Mix_ratio_CH4||ppm||Height weighted average mixing ratio for methane in parts per million|
|Missing data are represented by -9999|
Example data records:
Site boundaries: (All latitude and longitude given in decimal degrees)
|Site (Region)||Westernmost Longitude||Easternmost Longitude||Northernmost Latitude||Southernmost Latitude||Geodetic Datum|
|Para Eastern (Belem) - FLONA Caxiuana (Para Eastern (Belem))||-51.45360||-51.45360||-1.74830||-1.74830||World Geodetic System, 1984 (WGS-84)|
|Amazonas (Manaus) - Cuieras (Amazonas (Manaus))||-60.021||-60.021||-2.609||-2.609||World Geodetic System, 1984 (WGS-84)|
|Mato Grosso - Sinop (Mato Grosso)||-55.32470||-55.32470||-11.41230||-11.41230||World Geodetic System, 1984 (WGS-84)|
Platform/Sensor/Parameters measured include:
Trace gas fluxes from undisturbed tropical forests are important components of the global carbon and nitrogen budgets. These time series of atmospheric concentrations of N2O, CH4, and CO2 reveal important seasonal and diurnal variations in flux and provide insight to the environmental and biological controls in this ecosystem.
The infra-red gas analyzer (IRGA) was calibrated with secondary standards traceable to NOAA CMDL standards before and after each campaign. Span and zero drifts were less than 1 ppm. The analytical accuracy was traceable to NOAA CMDL standards. The precision expressed as the standard error of the mean for multiple measurements from standards was better than 1 ppm CO2.
Analytical accuracy was better than 0.02 ppm CH4 and precision was better than 0.005 ppm expressed as the standard error of the mean for multiple measurements of standards.
Dry and wet season measurements were made at three towers used for micrometeorological studies in upland old growth forest in the Brazilian Amazon.
Annual mean temperatures across sites range from 24.1 to 26.7 degrees C.
Six heights were sampled at the Caxiuana and Sinop locations. The sampling heights in meters, which were the maximum heights of the trees in the vicinity of the towers, were 0.2, 1, 5, 10, 20, and 37 m for Caxiuana (during the dry season, the top heights for Caxiuana were 15, 25, and 40 m), and 0.2, 1, 5, 10, 20, and 32 m at Sinop.
Only five levels were sampled at Manaus and those were at 0.2, 1, 5, 25, and 45 m.
Carbon Dioxide Sampling and Analysis
We used a portable profile system for gas sampling and measurement. Four (approximately 6 mm) o.d. nylon tubes were mounted on each tower at heights of 5 to 45 m, and two tubes were placed at 0.2 and 1 m height about 10 m distant from the tower base. Teflon filters (0.45 mm pore size, Cole Parmer, Vernon Hills, IL, USA) protected each tube inlet.
A valve manifold received six tubes that were flushed continuously at 1 liter per minute using separate pumps (UNMP08L, KNF, Trenton, NJ, USA). Sequential selection of each tube outflow to an IRGA (Li-6262, LiCor, Lincoln, NE, USA) allowed us to monitor CO2 mixing ratios corrected for the effects of water vapor in real time.
The IRGA was calibrated with secondary standards traceable to NOAA CMDL standards before and after each campaign. Span and zero drifts were less than 1 ppm. The analytical accuracy was traceable to NOAA CMDL standards. The precision expressed as the standard error of the mean for multiple measurements from standards was better than 1 ppm CO2.
Air samples were collected from each level 3-5 times on several nights and at least once during well-mixed daytime conditions during each campaign for a total of 75 profiles on 19 dates.
Note that the CO2 data reported in this data set were selected from the continuous CO2 measurements to coincide with the discrete flask CH4 and N2O measurements.
Canister Air Samples
Air samples for CH4 and N2O were collected in stainless steel canisters. Samples from the profile system were pressurized to 2 atm using a secondary pump (MOA-P101-HJ, GAST Manufacturing, Benton Harbor, MI, USA) into 500 ml electropolished stainless steel canisters closed with stainless steel valves (SS-14DPM-A, Swagelok, Solon, OH, USA) and stored for up to 10 days prior to analysis. Tests of air samples and standards lasting up to 60 days showed no appreciable drift.
Nitrous Oxide Analysis
Samples were analyzed off site for N2O using gas chromatography with an electron capture detector.
Samples were analyzed for CH4 using flame ionization gas chromatography off site (Varner et al., 2003). An automated analysis routine was used to inject canister samples and CH4 standards traceable to NOAA CMDL standards. Samples and standards passed through Drierite1 to remove water vapor prior to analysis. Each canister sample was analyzed at least twice. Analytical accuracy was better than 0.02 ppm CH4 and precision was better than 0.005 ppm expressed as the standard error of the mean for multiple measurements of standards.
Mixing ratio calculations
We calculated a height weighted average mixing ratio of each gas for the canopy layer (defined as ground level to maximum sampling height) by linear interpolation between levels to obtain estimates every meter to the maximum height and dividing by the maximum height.
This data is available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).
Contact for Data Center Access Information:
Telephone: +1 (865) 241-3952
do Carmo, J.B., M. Keller, J.D. Dias, P.B. de Camargo and P. Crill. 2006. A source of methane from upland forests in the Brazilian Amazon. Geophysical Research Letters 33:doi:10.1029/2005GL025436.
Trumbore, S. E., M. Keller, S. C. Wofsy, and J. M. Costa (1990), Measurements of soil and canopy exchange rates in the Amazon rain forest using 222Rn, J. Geophys. Res., 95, 16865-16873.
Varner, R. K., M. Keller, J. R. Robertson, J. D. Dias, H. Silva, P. M. Crill, M. McGroddy, and W. L. Silver (2003), Experimentally induced root mortality increased nitrous oxide emissions from tropical forest soil, Geophys. Res. Lett., 30(3), 1144, doi:10.1029/2002GL016164.