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Investigation:

CD-10 (Wofsy / Kirchhoff / Camargo / A. Nobre)

LBA Dataset ID:

CD10_EDDYFLUX_TAPAJOS

Originator(s):

1. HUTYRA, L.R.
2. WOFSY, S.C.
      3. SALESKA, S.R.

Point(s) of Contact:

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

Dataset Abstract:

This data set contains a single text file that reports eddy flux measurements of CO2 and H2O exchange and associated meteorological measurements at the Para Western (Santarem) - km 67, Primary Forest Tower Site. This site is in the Tapajos National Forest located in north central Brazil. Measurements extend from January 2002 through January 2006. Eddy fluxes of CO2 and H2O were measured at two levels (58m and 47m) using tower-mounted closed-path LICOR 6262 gas analyzers and Campbell CSAT3 sonic anemometers (Figure 1). Eddy-flux measurements were made at a sampling rate of 8 Hz and averaged over a 1 hour interval. A comprehensive set of meteorological parameters (air temperature, pressure, PAR, net radiation, precipitation, etc) were also measured. Co-located measurements included a third LICOR gas analyzer that measured (a) the CO2 and H2O concentration profiles at 8 levels in and above the canopy (1 level every 2 minutes) and (b) the instantaneous integrated canopy storage of CO2 and H2O, using a design that pulled air simultaneously through all 8 inlets (once every 20 minutes). See related data sets. With the permission of the author, Hutyra, L.R. 2007. Carbon and water exchange in Amazonian rainforests. Ph.D. Thesis, Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, is included as a companion file.

Beginning Date:

2002-01-01

Ending Date:

2006-01-18

Metadata Last Updated on:

2008-06-13

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 CD-10 CO2 and H2O Eddy Flux Data at km 67 Tower Site, Tapajos National Forest:  http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds_id=860

Documentation/Other Supporting Documents:

LBA-ECO CD-10 CO2 and H2O Eddy Flux Data at km 67 Tower Site, Tapajos National Forest:  http://daac.ornl.gov/LBA/guides/CD10_EddyFlux_Tapajos.html

Citation Information - Other Details:

Hutyra, L., S. Wofsy and S. Saleska. 2007. LBA-ECO CD-10 CO2 and H2O Eddy Flux Data at km 67 Tower Site, Tapajos National Forest. Data set. Available on-line [http://daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. doi:10.3334/ORNLDAAC/860

Keywords - Theme:

Parameter Topic Term Source Sensor
CARBON DIOXIDE BIOSPHERE ECOLOGICAL DYNAMICS TOWER EDDY CORRELATION APPARATUS
CARBON DIOXIDE BIOSPHERE ECOLOGICAL DYNAMICS TOWER IRGA
HEAT FLUX BIOSPHERE ECOLOGICAL DYNAMICS TOWER EDDY CORRELATION APPARATUS
PRECIPITATION AMOUNT ATMOSPHERE PRECIPITATION METEOROLOGICAL STATION RAIN GAUGE
PRIMARY PRODUCTION BIOSPHERE ECOLOGICAL DYNAMICS FIELD INVESTIGATION ANALYSIS
SOLAR IRRADIANCE ATMOSPHERE ATMOSPHERIC RADIATION METEOROLOGICAL STATION RADIOMETERS
SURFACE WINDS ATMOSPHERE ATMOSPHERIC WINDS TOWER SONIC ANEMOMETER
WATER VAPOR BIOSPHERE ECOLOGICAL DYNAMICS TOWER EDDY CORRELATION APPARATUS
WATER VAPOR BIOSPHERE ECOLOGICAL DYNAMICS TOWER IRGA

Uncontrolled Theme Keyword(s):  845 PARAMETER=HEAT FLUX, CO2, EDDY COVARIANCE, EDDY FLUX, H2O, KM 67, TAPAJOS NATIONAL FOREST

Keywords - Place (with associated coordinates):

Region
(click to view profile)
Site
(click to view profile)
North South East West
Pará Western (Santarém) km 67 Primary Forest Tower Site -2.85700 -2.85700 -54.95900 -54.95900

Related Publication(s):

Huete, A.R., K. Didan, Y.E.R.P. Shimabukuro, S. Saleska, L.R.Y.W. Hutyra, and R.R.M.R. Nemani. 2006. Amazon rainforests green-up with sunlight in dry season. Geophysical Research Letters 33(L06405).

Hutyra, L., J.W. Munger, E.W. Gottlieb, B.C. Daube, P. Camargo, and S. Wofsy. 2007. Controls on energy and carbon exchange in an evergreen tropical rainforest. Journal of Geophysical Research-Biogeosciences.

Hutyra, L.R., J.W. Munger, C.A. Nobre, S.R. Saleska, S.A. Vieira, and S.C. Wofsy. 2007. Climatic variability and vegetation vulnerability in Amazonia. Geophysical Research Letters 32(L24712): 2007.

Ichii, K., H. Hashimoto, M.A. White, C. Potter, L. Hutyra, A. Huete, R.B. Myneni, and R.R. Nemani. 2007. Constraining rooting depths in tropical rainforests using satellite data and ecosystem modeling for accurate simulation of gross primary production seasonality. Global Change Biology 13:67-77.

Saleska, S.R., S.D. Miller, D.M. Matross, M.L. Goulden, S.C. Wofsy, H.R. da Rocha, P.B. de Camargo, P. Crill, B.C. Daube, H.C. de Freitas, L. Hutyra, M. Keller, V. Kirchhoff, M. Menton, J.W. Munger, E.H. Pyle, A.H. Rice, and H. Silva. 2003. Carbon in amazon forests: Unexpected seasonal fluxes and disturbance-induced losses. Science 302(5650):1554-1557.

Xiao, X.M., Q.Y. Zhang, S. Saleska, L. Hutyra, P. De Camargo, S. Wofsy, S. Frolking, S. Boles, M. Keller, and B. Moore. (2005) Satellite-based modeling of gross primary production in a seasonally moist tropical evergreen forest. Remote Sensing of Environment 94(1):105-122.

Data Characteristics (Entity and Attribute Overview):

Data Characteristics:

The flux and meteorological data are reported in one comma separated ASCII text file, km67_eddyflux_2002_2006.txt.



Data File Documentation:





column variable description

1 hours Hour of measurement (GMT, continuous from 1/1/00)



2 JDstart.GMT Decimal day (GMT, continuous from 1/1/00)

NOTE 1: Tapajos Forest Local time (LT) = GMT - 4 hours

NOTE 2: these times are time at the BEGINNING of the hour-long

data aggregation interval, i.e., data at 12:00 are from

aggregating measurements between 12:00 and 13:00



3 ws Sonic wind speed, rotated u (m/sec, @ 57.8 m)



4 wdir Wind direction (degrees (0 - 360 degrees))



5 Tamb Ambient temp at 58m (level 1 eddy) from chilled mirror sensor (deg C)



6 Tdew Ambient dew point temperature @ 58m (deg C)



7 Tson Sonic temp (deg C, unadjusted for moisture @ 57.8m)



8 Tasp Distance weighted aspirated ambient temperature from thermistors (deg C)



9 fheat Heat flux (deg C m/sec)



10 fmom Momentum flux (m2/sec2)



11 co2 CO2 concentration (mmol/mol)



12 fco2 Eddy flux of CO2, (umol/m2/sec) [relative to dry air]



13 h2o.mmol.m H2O concentration (mmol/mol)



14 fh2o Eddy flux of H2O (mmol/m2/sec) [relative to dry air]



15 h2o.mix Mixing ratio (g H2O/kg (dry) air)



16 Pamb.Pa Ambient pressure (Pascals)



17 H Sensible heat flux (W/m2)



18 LHdry Latent heat flux (W/m2) [relative to dry air]



19 ustar Friction velocity, sqrt(-<w*u>) (m/sec),

where w,u are the rotated wind components



20 ppm2umol Density conversion factor for fluxes (mol/m3) [relative to dry air]



21 compiler Which fortran compiler was used in processing [IDs ed1 vs. ed2]



22 NetRad Net Radiation @ 64.1 m (W/m2, corrected)



23 sNetRad Std deviation on hourly mean of NetRad



24 par PAR (umol/m2/sec) level 1 (63.6 m)



25 sPAR1up Std deviation on hourly mean of par



26 PAR2up PAR (umol/m2/sec) level 2 (15.09 m)



27 sPAR2up Std deviation on hourly mean of PAR2up



28 PAR1dn Downward PAR (umol/m2/sec) level 1 (63.6 m)



29 sPAR1dn Std deviation on hourly mean of PAR1dn



30 Tair1 Temp (via thermistor) at profile level 1 (61.94 m) (deg C)



31 Tair2 Temp (via thermistor) at profile level 2 (49.75 m) (deg C)



32 WS1 Wind speed, Cup anemometer #1 (m/sec, 64.1 m)



33 sWS1 Std deviation on hourly mean of WS1



34 rain Precipitation (mm in each hour) (tipping bucket @ 42.6m)



35 co2col.wt Mean column CO2 concentration (ppm)



36 storage.wt Storage flux (umol/m2/sec) below this level = d/dt (CO2 column avg)

based on a discrete integral approach using the profile concentration

measurements



37 nee.wt NEE (umol/m2/sec) = fco2 + storage.wt



38 T.filled Filled temperature for level 1 (filled Tasp). Filled based on adjusted

temperature measurements from the Jamaraqua met. station

(-2.80639, -55.03639). Data courtesy of D. Fitzjarrald (SUNY Albany)



39 GMT GMT time of day



40 yr Year



41 NEE Integrated NEE (umol/m2/sec) [filtered and integrated across gaps],

see status for filling information [u*>0.22]



42 R Respiration based on nighttime NEE with u*>0.22 m/s (umol/m2/sec)

see status for filling information



43 GEE Gross Ecosystem Exchange (umol/m2/sec)

see status for filling information



44 R.light Respiration based on light-curve interpolation to 0 PAR (umol/m2/sec)



45 stg.filled Filled storage (umol/m2/sec). This storage estimate has also been balanced

to 0 on 5 day intervals.



46 par.filled Filled PAR timeseries (umol/m2/sec) see par.status for filling codes



47 par.status Status 0 = unfilled data, measured with Wofsy sensor

Status 1 = filled based on relation between Wofsy PAR sensor & Wofsy NetRad

sensor over 10 day intervals

Status 2 = filled based on relation between D. Fitzjarrald PAR sensor &

Wofsy NetRad sensor over 10 day intervals

Status 3 = filled based on lookup table for a composite year, based on

entire time series.



48 NetRad.filled Filled NetRad timeseries (W/m2), see NetRad.status for filling codes



49 NetRad.status Status 0 = unfilled data, measured with Wofsy sensor

Status 1 = filled based on relation between Wofsy PAR sensor & Wofsy NetRad

sensor over 10 day intervals

Status 2 = filled based on relation between D. Fitzjarrald PAR sensor &

Wofsy NetRad sensor over 10 day intervals

Status 3 = filled based on lookup table for a composite year, based on

entire time series.



50 hr.2 Hour of the day (GMT)



51 Status 6-bit status word to describe what, if any, filling technique was used

on the NEE, R, and GEE data



bit value description

0 1 u* < 0.22 or u* = NA; NEE = R + GEE

1 2 no PAR; PAR filled from lookup table for GEE calculation

2 4 no Tair available; filled in from Jamaraqua for R calculation

3 8 No measured NEE available; filled in with R+GEE

4 16 R calculated, not measured (daytime & calm nights)

5 32 Storage gap of >= 5 days; filled w/mean storage value



Missing value code is NA

Values are comma separated















Sample Data Records:



All of the flux and meteorological data are reported in km67_eddyflux_2002_2006.txt.







hours,JDstart.GMT.,ws,wdir,Tamb,Tdew,Tson,Tasp,fheat,fmom,co2,fco2,h2o.mmol.m.,fh2o,

h2o.mix,Pamb.Pa,H, LHdry,ustar,ppm2umol,compiler,NetRad,sNetRad,par,sPAR1up,PAR2up,sPAR2up,PAR1dn,

sPAR1dn,Tair1,Tair2, WS1,sWS1,rain,co2col.wt,storage.wt,nee.wt,T.filled,GMT,yr,NEE,R,

GEE, R.light,stg.filled,par.filled,par.status,NetRad.filled,NetRad.status,hr.2,Status



17610,733.75,1.95,179.804,29.183,23.13,32.475,29.079,0.043,-0.227,394.86,NA,30.834,4.402,

19.188,97867.5,47.953, 192.815,0.43,37.743,11,NA,0.128,541.576,36.264,138.926,13.245,24.118,

1.604,29.161,28.92, 2.799,0.94,0,373.085,0.539,NA,29.079,2.75,2002,-7.251,9.231,

-16.482, NA,0.437,541.576,0,239.15,3,18,24



17611,733.792,2.226,274.378,27.888,24.574,31.531,27.906,0.052,-0.197,377.74,-6.896,32.106,1.562,

19.98,97929.8,57.2, 68.492,0.41,37.805,11,NA,0.244,570.412,68.772,102.103,14.096,24.946,

2.716,27.978,27.768, 2.138,0.772,0,373.88,0.587,-6.309,27.906,2.792,2002,-6.411,9.231,

-15.642, NA,0.485,570.412,0,190.283,3,19,16



17612,733.833,1.856,275.332,28.21,24.312,31.909,28.337,0.022,-0.114,376.175,-3.952,31.252,1.011,

19.449,97965.3,24.009, 44.332,0.337,37.804,11,NA,0.13,337.28,38.094,67.313,6.905,15.59,

1.868,28.402,28.212, 1.746,0.684,0,374.584,0.518,-3.434,28.337,2.833,2002,-3.536,9.231,

-12.767, NA,0.416,337.28,0,59.45,3,20,16



...



**Line Breaks Added to Improve Readability

Data Application and Derivation:

Eddy flux and associated environmental measurements

Quality Assessment (Data Quality Attribute Accuracy Report):

Quality Assessment:

This data set can be considered final, but as always with data sets this large there are occasional individual points that are bad, but which for one reason or another, have not yet been removed.

Process Description:

Data Acquisition Materials and Methods:

A 64 m tower (Rohn 55G, Peoria, IL) was instrumented for eddy covariance measurements which commenced in April, 2001 and continued until the tower was destroyed when a falling tree hit the guy wires in January 2006 (Figure 2). Three modular enclosures (approximately 1m x 0.6 m x 0.2 m) containing all the key instruments and dataloggers were mounted on the tower to keep inlet tubes short (~ 2 m). Eddy-flux measurements were made at two levels (58m and 47m) with a sample rate of 8 Hz. A 3-axis sonic anemometer (CSAT-3, Campbell Scientific, Logan UT) was mounted with the air sample inlet located 20 cm from the anemometer. The flux system drew sample air from the inlet through a 50 mm diameter Teflon filter and 9.5 mm (inner diameter) Teflon PFA tubing to a closed-path infrared gas analyzer (IRGA, LI-6262, LICOR, Lincoln, NE). The eddy system sample cell (11.9 cm3) was pressure-controlled at 66.6 kPa with a mass flow rate of 6000 sccm, providing a cell-flushing

time of 0.078 s. This system design maintains the advantages of the closed-path sensor (e.g. precise instrument calibration, constant pressure and temperature), while also adding some of the advantages (e.g. minimal attenuation of high-frequency fluctuations) attributed to open-path designs. This system is particularly suitable for deployment with very tall vegetation where problems accrue due to long sample-tubes from the top of the tower.





Calibrations of the eddy system for CO2 were made every 6 hours (April 2001 - November 11, 2002 & March 29, 2003 - November 15, 2003) or 12 hours (November 12, 2002 - March 29, 2003

& November 15, 2003 - January 24, 2006 ) using 325, 400, and 475 ppm CO2 standard gases. The instrument was zeroed every 2 hours.

The long-term accuracy of the instruments was ensured by measuring a surveillance standard (traceable to NOAA/CMDL standards at 380.45 ppm)

once per week, this tank lasted through the duration of the measurements. Calibrations for water vapor were made using the daily

fluctuations of Tv - Tk, where Tv is the sonic temperature (related to the speed of sound provided by the sonic anemometer) and Tk is the

ambient temperature. This approach was necessary due to failures in the chilled mirror hydrometers originally installed for this purpose (see

Hutyra et al, 2007).



Co-located Measurements: (See Related Data Sets)



Vertical profiles of CO2 and H2O concentrations were measured

at 8 levels on the tower (62.2, 50, 39.4, 28.7, 19.6, 10.4, and 0.91

m). Sample air was drawn at 1000 sccm through the 8 profile inlets in

sequence (2 minutes at each level). The profile concentration data were

used to estimate the change in vertical average concentration between

the ground and flux measurement height in order to calculate the column

average storage of CO2. The profile IRGA was zeroed between each

profile sequence and an absolute calibration at 325, 400, and 475 ppm CO2

was made every 6 or 12 hours, as for the eddy CO2 measurements.



A suite of environmental measurements was also made on the

tower. Dataloggers (CR-10X, Campbell Scientific, Logan, UT), controlled

the overall operation of the system. The data were downloaded via

coaxial cable to a computer, housed in a climate controlled hut near

the tower.

References:

Hutyra, L.R. 2007. Carbon and water exchange in Amazonian rainforests. Ph.D. Thesis, Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts.







Hutyra, L. R., J. W. Munger, S. R. Saleska, E. Gottlieb, B. C. Daube, A. L. Dunn, D. F. Amaral, P. B. de Camargo, and S. C. Wofsy. 2007. Seasonal controls on the exchange of carbon and water in an Amazonian rain forest, J. Geophys. Res., 112, G03008, doi:10.1029/2006JG000365.



Saleska, S.R., Miller, S.D.,Matross, D.M., Goulden, M.L., Wofsy, S.C., da Rocha,H., de Camargo, P.B., Crill, P., Daube, B.C., de Freitas, H.C., Hutyra, L., Keller, M., Kirchhoff, V., Menton, M., Munger, J.W., Pyle, E.H., Rice, A.H,Silva, H, Carbon fluxes in old-growth Amazonian rainforest: seasonality and disturbance-induced net carbon loss, Science, 302, 1554-1557, 2003.



Hutyra, L.R., Munger, J.W., Nobre, C.A., Saleska, S.R., Vieira, S.A., Wofsy, S.C., Climatic variability and vegetation vulnerability in Amazonia, Geophysical Research Letters, 32, L24712, 2005.

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