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Investigation:

TG-06 (Tans / Miller / Artaxo / Gatti / Martinelli)

LBA Dataset ID:

TG06_VERTICAL_PROFILES

Originator(s):

1. MILLER, J.B.
2. GATTI, L.V.
3. D\'AMELIO, M.T.S.
4. CROTWELL, A.
      5. DLUGOKENCKY, E.
6. BAKWIN, P.S.
7. ARTAXO, P.E.
8. TANS, P.

Point(s) of Contact:

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Dataset Abstract:

LBA-ECO TG-06 Vertical Profiles of Carbon Dioxide and other Trace Gas Species over the Amazon Basin using Small Aircraft We collect air samples during regular (weekly) flights over the Santarem area and over the Atlantic Ocean off the coast near Fortaleza. Small charter aircraft are used for the flights, and the samples are collected using automated equipment. The samples are shipped to our laboratory in Boulder for analysis for CO2, CO, CH4, H2, N2O, SF6 and the stable isotopes of C and O in CO2. Since the average air flow over this region is dominated by the easterly Trade Winds, the data will give a measure of the change in trace gas and isotope composition during advection of air across the Amazon Basin. Regional sources and sinks leave imprints on the trace gas concentrations that we observe. Measurements of the anthropogenic tracer SF6 provide an indicator for the penetration of Northern Hemisphere air into the study region. Measurements of the 13C/12C isotope ratio in CO2 should provide information about the relative rates of C-3 (generally forest) and C-4 (savanna & pasture) photosynthesis, since these processes have very different isotopic signatures.
When using these data please acknowledge the National Oceanic and Atmospheric Administration (NOAA), Climate Monitoring and Diagnostics Laboratory (CMDL), Carbon Cycle Greenhouse Gases Group and Instituto de Pesquisas Energeticas Nucleares (IPEN). The principal investigators would appreciate receiving preprints of publications that use the data to insure that the quality and limitations of the data are accurately represented. Feedback from users may also help us to improve the quality of the data and the locations of the sampling sites. Comments regarding the README files and the data files are encouraged. Please send comments and/or questions to the e-mail address given in the database.

Beginning Date:

2000-12-07

Ending Date:

2005-11-01

Metadata Last Updated on:

2013-07-26

Data Status:

Archived

Access Constraints:

PUBLIC

Data Center URL:

http://daac.ornl.gov/

Distribution Contact(s):

ORNL DAAC User Services Office Oak Ridge National Laboratory Oak Ridge, Tennessee 37 (ornldaac@ornl.gov)

Access Instructions:

PUBLIC

Data Access:

IMPORTANT: The LBA-ECO Project website is no longer being supported. Links to external websites may be inactive. Final data products from the LBA project can be found at the ORNL DAAC. Please follow the fair use guidelines found in the dataset documentation when using or citing LBA data.
Datafile(s):

LBA-ECO TG-06 Vertical Profiles of Atmospheric Trace Gases over the Amazon Basin :  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=1175

Documentation/Other Supporting Documents:

LBA-ECO TG-06 Vertical Profiles of Atmospheric Trace Gases over the Amazon Basin :  http://daac.ornl.gov/LBA/guides/TG06_Vertical_Profiles.html

Citation Information - Other Details:

Miller, J.B., L.V. Gatti, M.T.S. D'Amelio, A. Crotwell, E. Dlugokencky, P.S. Bakwin, P. Artaxo, and P. Tans. 2013. LBA-ECO TG-06 Vertical Profiles of Atmospheric Trace Gases over the Amazon Basin. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, USA http://dx.doi.org/10.3334/ORNLDAAC/1175

Keywords - Theme:

Parameter Topic Term Source Sensor
CARBON DIOXIDE ATMOSPHERE ATMOSPHERIC CHEMISTRY AIRCRAFT NDIR GAS ANALYZER (NONDISPERSIVE INFRARED GAS ANALYZER)
CARBON DIOXIDE ATMOSPHERE ATMOSPHERIC CHEMISTRY AIRCRAFT GC-MS (GAS CHROMATOGRAPH/MASS SPECTROMETRY)
NITROGEN COMPOUNDS ATMOSPHERE ATMOSPHERIC CHEMISTRY AIRCRAFT GC (GAS CHROMATOGRAPH)
SULFUR COMPOUNDS ATMOSPHERE ATMOSPHERIC CHEMISTRY AIRCRAFT GC (GAS CHROMATOGRAPH)

Uncontrolled Theme Keyword(s):  AIR SAMPLE, CARBON DIOXIDE, CARBON MONOXIDE, CARBON-13, CH4, CO, CO2, FORTALEZA, H2, HYDROGEN, ISOTOPES, MANAUS, METHANE, N2O, NITROUS OXIDE, OXYGEN-18, SANTAREM, SF6, SULFUR HEXAFLUORIDE, VERTICAL PROFILE

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
  PARA WESTERN (SANTAREM) AMAZONAS (MANAUS) CEARA -2.50000 -4.50000 -37.00000 -60.20910

Related Publication(s):

Bergamaschi, P., C. Frankenberg, J.F. Meirink, M. Krol, M.G. Villani, S. Houweling, F. Dentener, E.J. Dlugokencky, J.B. Miller, L.V. Gatti, A. Engel, and I. Levin. 2009. Inverse modeling of global and regional CH4 emissions using SCIAMACHY satellite retrievals. Journal of Geophysical Research-Atmospheres 114.

d\'Amelio, M.T.S., L.V. Gatti, J.B. Miller, and P. Tans. 2009. Regional N2O fluxes in Amazonia derived from aircraft vertical profiles. Atmospheric Chemistry and Physics 9(22):8785-8797.

Gatti, L.V., J.B. Miller, M.T.S. d\'Amelio, A. Martinewski, L.S. Basso, M.E. Gloor, S. Wofsy, and P. Tans. 2010. Vertical profiles of CO2 above eastern Amazonia suggest a net carbon flux to the atmosphere and balanced biosphere between 2000 and 2009. Tellus Series B-Chemical and Physical Meteorology 62(5):581-594.

Meirink, J.F., P. Bergamaschi, and M.C. Krol. 2008. Four-dimensional variational data assimilation for inverse modelling of atmospheric methane emissions: method and comparison with synthesis inversion. Atmospheric Chemistry and Physics 8(21):6341-6353.

Miller, J.B., L.V. Gatti, M.T.S. d\'Amelio, A.M. Crotwell, E.J. Dlugokencky, P. Bakwin, P. Artaxo, and P.P. Tans. 2007. Airborne measurements indicate large methane emissions from the eastern Amazon basin. Geophysical Research Letters 34(10):L10809, doi:10.1029/2006GL029213

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

Study Area



Spatial Coverage:

Data were collected over three primary sites:



Fortaleza, Santarem and Manaus, Brazil. Detailed coordinates are as follows:

A. Fortaleza

The Fortaleza samples are taken at about 3deg 31min S, 38deg 17min W.

The altitudes are:



Sample Altitude

number (feet)

01 14000

02 13000

03 12000

04 11000

05 10000

06 9000

07 8000

08 7250

09 6500

10 5750

11 5000

12 4250

13 3500

14 2750

15 2000

16 1250

17 500



B. Santarem

From December, 2000 through June, 2005, we flew two separate profiles. We take 10 samples over the km 67 tower (2deg 51.305 S, 54deg 57.563 W), and do a second profile of 7 samples about 30km east of the tower (2deg 52.547min S, 54deg 41.725min W). The altitudes are as follows:



Sample Altitude

number (feet)

01 12000

02 10500

03 9000

04 7500

05 6000

06 5000

07 4000

08 3000

09 2000

10 1000

11 1000

12 3000

13 5000

14 7000

15 9000

16 11000

17 12000



NOTE: The first Santarem flight, on December 7 2000, was an exception: The first 10 samples were obtained near 3deg 17min S, 55deg 5min W, and the last 7 samples were taken over the tower. Altitudes were as above, except that the last sample was at 13,000 feet.





C. Manaus.

At Manaus, two separte profiles were also flown through June 2005. The first location is above site 'ZF-2', the Km-34 eddy-flux tower (2 deg, 32 min S, 60 deg, 12 min W) and the second profile is NorthEast of Manaus (2 deg, 30 min S, 59 deg, 5 min W). The second profile was designed to ensure that samples were free of any potential pollution from the city of Manaus.



Sample Altitude

number (feet)

01 12000

02 10500

03 9000

04 7500

05 6000

06 5000

07 4000

08 3000

09 2000

10 1000

11 1000

12 3000

13 5000

14 7000

15 9000

16 11000

17 12000



D. New Altitudes for both MAN and SAN

From 2006 to the present, only a single profile has been flown after analysis showed that there were not large differences between the two profiles at either site. The new altitudes are as follows:



Sample Altitude

number (feet)



1 14000

2 13000

3 12000

4 11000

5 10000

6 9000

7 8000

8 7000

9 6000

10 5000

11 4000

12 3500

13 3000

14 2500

15 2000

16 1500

17 1000




Spatial Resolution:</b>

Spatial resolution of the air sampling is a function of the groundspeed of the aircraft and the time taken to fill a sampling flask. Given groundspeed of 200 km/hr, a 30 second sampling time, we estimate that the air sample integrates over about 2 km, which projects onto a portion of a typical sampling circumfrence of about 10 km.




Projection:</b>

N/A


Grid Description:</b>

N/A






Temporal Coverage:</b>

Data collection was in discrete time periods that was highly intermittent. The full time span described is between Dec. 2000 and Dec. 2005. Each data file describes the year, month, day, hour, and minute of each air sampling event.





Parameters or Variables:

VARIABLE AND DESCRIPTION

The variables described in the data set are dry air mole fractions of the following gases:

CO2, CH4, CO, H2, N2O, SF6



and the 13C/12C ratio of CO2 (and the 18O/16O ratio of CO2, which is not valid due to moisture contamination in sampling)



UNITS:

CO2: micromole CO2/mole dry air (ppm)

CH4: nanomole CH4/mole dry air (ppb)

CO: nanomole CO/mole dry air (ppb)

H2: nanomole H2/mole dry air (ppb)

N2O: nanomole N2O/mole dry air (ppb)

SF6: picomole SF6/mole dry air (ppt)

{delta}13CO2: per mil relative to V-PDB



Mole fraction measurements are made relative to NOAA scales, which in most cases are the sanctioned World Meteorological Organization scale for the trace gas.



INSTRUMENTS

Air samples are collected using a programmable flask package (PFP) and samples analyzed on a suite of instruments in the lab using the following technologies:

CO2: NDIR

CH4: GC-FID

CO: GC-RGD

H2: GC-RGD

N2O: GC-ECD

SF6: GC-ECD

d13CO2: Isotope Ratio Mass Spectrometer



For further details see www.esrl.noaa.gov/gmd/ccgg and Miller et al, 2007, GRL.



RANGE

-999.9 is used as a missing value. However: WARNING: YOU MUST PAY ATTENTION TO THE FLAG VARIABLES IN THE DATA SET AS WE INCLUDE **ALL** DATA, EVEN THOSE WITH KNOWN ERRORS.





Data Organization

1. Data from the three sampling locations are located in folders with the same name.



2. Within each folder, there are files for each flight, which contain

values for all gases measured: CO2, CH4, CO, H2, N2O, SF6, d13C of CO2 and d18O of CO2. Isotopic ratios are only available on samples obtained prior to 2004. Files are named according to the following conventions:

a. [site].[yyyymmdd].mrg

site= 'san' (santarem); 'ftl' (fortaleza); 'man' (manaus)

yyyy= year

mm= month

dd= day

'.mrg' means all gases are included in the file

b. [site].mrg

these files contain data from all flights from a given site



c. Example and explanation of data format (see also README.pfpmergedfile)

Aircraft merged files contain one line for each

Portable Flask Package (PFP) sample.



Lines may read using the following FORTRAN format statement:



A3,1X,A16,1X,A8,1X,A1,3(1X,F8.2),1X,2(F7.1,1X),F6.1,1X,I8,8(1X,F9.3,1X,A3)





The fields in a single line are defined as follows:



sta yyyy mm dd hh mm xxxxx-xx c ddd.dd dddd.dd ddddd.dd dddd.d dddd.d dddd.d

xxxxxx dddd.ddd fff dddd.ddd fff dddd.ddd fff dddd.ddd fff dddd.ddd fff dddd.ddd fff

dddd.ddd fff dddd.ddd fff



where:



sta = the three-letter station code.



yyyy mm dd = the UTC year, month, and day (four digit year,

two digit month and day) when the sample was collected



hh mm = the UTC time (hour, minutes; two digits

each) of sample collection



xxxxx-xx = the flask sample I.D. number. This

field can contain up to eight

characters but may contain fewer.

This field may contain letters as well

as numbers.



c = a one letter code that identifies the sample

collection method.



ddd.dd = Latitude during collection in decimal degrees



dddd.dd = Longitude during collection in decimal degrees



dddd.dd = Altitude during collection in meters above sea level



dddd.d = air temperature in degree C (default = -40.0)



dddd.d = air pressure in millibars (default = -99.0)



dddd.d = percent relative humidity (default = 11.3)



xxxxxxxx = internal CMDL event number; unique for each sampling event



ddddd.ddd fff = CO2 mixing ratio in ppm. Missing values

are denoted by -999.99. fff is a

three-character flag indicating the results

of our data selection process.



An alphanumeric other than a period (.) in the FIRST

column indicates samples with obvious problems during

sample collection or analysis.



An alphanumeric other than a period (.) in the SECOND

column indicates samples which are believed to be

non-background.



An alphanumeric other than a period (.) in the THIRD

column is a sample qualifier that is not presently used.



ddddd.ddd fff = CH4 mixing ratio in ppb and flag. Missing

values are denoted by -999.99.



ddddd.ddd fff = CO mixing ratio in ppb and flag. Missing

values are denoted by -999.99.



ddddd.ddd fff = H2 mixing ratio in ppb and flag. Missing

values are denoted by -999.99.



ddddd.ddd fff = N2O mixing ratio in ppb and flag. Missing

values are denoted by -999.99.



ddddd.ddd fff = SF6 mixing ratio in ppt and flag. Missing

values are denoted by -999.99.



dddd.ddd fff = d13C (CO2) isotope ratio in per mil and flag.

Missing values are denoted by -999.999.



dddd.ddd fff = d18O (CO2) isotope ratio in per mil and flag.

Missing values are denoted by -999.999.

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!NOTE!!: NO D18O CO2 DATA ARE RELIABLE !!!!!!

!!!!SITES DUE TO HUMIDITY CONTAMINATION.!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!





Example Data Records:

SAN 2000 12 07 16 22 214-01 A -2.85 -54.95 3658.00 -40.0 -1000.0 11.3 187182 339.690 N.. 1802.244 N.. 234.190 N.. 571.660 N.. -999.990 *.. 5.130 A.. -8.001 ..S 0.802 ..S

SAN 2000 12 07 16 28 214-02 A -2.85 -54.95 3200.00 -40.0 -1000.0 11.3 187183 358.710 N.. 1811.305 N.. -999.990 N.. 569.100 N.. 317.850 A.. 5.000 A.. -7.903 ..S 1.094 ..S

Data Application and Derivation:

Typical Application of Data



The data contained in these data sets is most useful for the evaluation and estimation of surface trace gas fluxes. See Miller et al, 2007, GRL for an example.



Theory of Measurements

The theory of the measurements is based on standard optical absorption (CO2), gas chromatographic (CH4, CO, H2, N2O, SF6) and isotope mass spectrometric techniques (d13CO2). However, the most important aspect of these measurements is the attention paid to careful calibration relative to WMO standards.



Derivation Techniques and Algorithms

N/A

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

Data Usage Guidance:



Users should keep in mind issues of representativeness of aircraft trace gas measurements. In general, data closer to the ground has a small footprint. But, the extent of the \'footprint\' of these measurements is an open research question. That said, we feel that these measurements are influenced by \'regional\' as opposed to \'local\' sources, which we define for the time-being as: regional ~ 10^5 - 10^6 km^2; local ~ 10^2 - 10^3 km ^2.





Errors and Limitations:

Error Sources:

Analytical errors for trace gas measurements are as follows:

Measurement precision for each gas is as follows:

a. CO2 0.1 ppm

b. CH4 1-2 ppb

c. CO 1 ppb

d. H2 5 ppb

e. N2O 0.3 ppb

f. SF6 0.05 ppt

g. d13C 0.01 per mil

h. d18O xxx [data corrupted]



From the point of view of interpretation, other uncertainties like that of representativeness described above are likely to dominate relative to measurement precision.





Known Problems with the Data:

Problematic data are identified with flags in the data files.



Quality Assessment Activities

When samples are measured in the lab, tanks of air, treated as unknowns are also measured. The long term stability of these unknowns and the lack of bias relative to their independently known values suggests that the accuracy of our measurements is of the same order as the measurement precisions listed above.

Process Description:

Data Acquisition Materials and Methods:

Field Collection Environment:

Air samples were collected in the field aboard aircraft and analyzed in the laboratory (NOAA before 2004; IPEN after 2004).



Field Campaign Mission Objectives:

To monitor the air above eastern Amazonia, to lead to understanding of surface fluxes of radiatively important trace gases, and to provide an integrating context for local-scale studies (flux chambers, eddy-flux, etc.) during LBA.



Field Campaign Program Management:

This study was funded by NASA as part of LBA. The project was undertaken by NOAA and IPEN.

References:

Miller, J.B., L.V. Gatti, M.T.S. d\'Amelio, A.M. Crotwell, E.J. Dlugokencky, P. Bakwin, P. Artaxo, and P.P. Tans. 2007. Airborne measurements indicate large methane emissions from the eastern Amazon basin. Geophysical Research Letters 34:10.



See www.esrl.noaa.gov/gmd/ccgg for information on data collection, quality control flags and similar data

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