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LBA-ECO CD-04 Meteorological and Flux Data, km 83 Tower Site, Tapajos National Forest
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Revision date: October 21, 2009

Summary:

Tower flux measurements of carbon dioxide, water vapor, heat, and meteorological variables were obtained at the Tapajos National Forest, km 83 site, Santarem, Para, Brazil. For the period June 29, 2000 through March 11, 2004, 30-minute averaged and calculated quantities of fluxes of momentum, heat, water vapor, and carbon dioxide, storage of carbon dioxide in the air column, are reported. 

Data are reported in three comma separated files: (1) 30 minute-averages,  (2) the daily (24 hour) averages, and (3) the monthly (calendar) averages.

The variables measured on the 67 m tower relate to meteorology, soil moisture, respiration, fluxes of momentum, heat, water vapor, and carbon dioxide, and were used to calculate storage of carbon dioxide, Net Ecosystem Exchange, and Gross Primary Productivity. Most of the variables have not been gap filled. However, CO2 flux and storage have been filled to avoid biases in Net Ecosystem Exchange; a fill index flag is included to indicate which data points were filled. Variables derived from the filled variables (respiration, NEE, GPP) are essentially filled also. Net ecosystem exchange has been filtered for calm nighttime periods.

instruments


Instruments positioned at the top of the flux tower located at km 83, Tapajos National Forest

Data Citation:

Cite this data set as follows:

Miller, S., M. Goulden, and H.R. da Rocha, 2009. LBA-ECO CD-04 Meteorological and Flux Data, km 83 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/946

Implementation of the LBA Data and Publication Policy by Data Users:

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 Users who download LBA data in the five years after data have been archived must contact the investigators who collected the data, per provisions 6 and 7 in the Policy.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 October of 2009. Users who download the data between October 2009 and September 2014 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 Web Site [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.

Table of Contents:

1. Data Set Overview:

Project: LBA (Large-Scale Biosphere-Atmosphere Experiment in the Amazon)

Activity: LBA-ECO

LBA Science Component: Carbon Dynamics

Team ID: CD-04 (Goulden / Rocha)

The investigators were Goulden, Prof. Michael L.; Miller, Dr. Scott Dennis and Rocha, Prof. Humberto Ribeiro da . You may contact Miller, Dr. Scott D. (smiller@albany.edu)

LBA Data Set Inventory ID: CD04_Meteorology_Fluxes

Over 3.5 years of 30-minute averaged measured and calculated quantities were compiled at the km 83 tower site (June 29, 2000-March 11, 2004). The variables relate to meteorology, soil moisture, fluxes of momentum, heat, water vapor, and carbon dioxide, including the storage of carbon dioxide in the air column beneath the flux sensors. Data are presented as values measured or calculated at 30 minute intervals as well as calculated daily (24 hour) and monthly (calendar) means.

 

Related Data Sets:

2. Data Characteristics:

Data are provided in three comma separated ASCII files:

CD04_km83_tower_fluxes_30_min.csv
CD04_km83_tower_fluxes_dailyavg.csv
CD04_km83_tower_fluxes_monthly_avg.csv

File 1: CD04_km83_tower_fluxes_30_min.csv 

There are 64992 records (rows), each corresponding to a 30 minute interval for a total 1354 days beginning June 29, 2000 and ending March 11, 2004. The timestamp corresponds to the beginning of the 30 minute interval. The first timestamp is experiment day 181, or June 29, 2000, where experiment day counts from 0 at 00:00 hours on January 1, 2000. The last timestamp is day 1535, or March 11, 2004, the day that a tree fell on the tower.

Data File Description:

Column # Heading Units Sensor Description
1 exp_day     experiment day (0 = January 1, 2000, 00:00 hours)
2 year yyyy   year
3 month mm   month
4 day dd   day
5 hr hh   hour at start of sampling period (GMT:24 hour clock)
6 min mm   minute at start of sampling period (GMT)
7 solar_in W/m2 Kipp & Zonen CM6B downward flux of solar radiation
8 solar out W/m2 Kipp & Zonen CM6B upward flux of solar radiation
9 long_in W/m2 Kipp & Zonen CG2 downward flux of long wave radiation
10 long_out W/m2 Kipp & Zonen CG2 upward flux of long wave radiation
11 par_in micromol/m2/s Li-Cor LI190 downward flux of photosynthetically active radiation
12 par_out micromol/m2/s Li-Cor LI190 upward flux of photosynthetically active radiation
13 rnet W/m2 Rebs Q*7 net radiation at 64 m height
14 T64 degrees C Campbell Scientific T107 air temperature at 64 m height
15 T40 degrees C Campbell Scientific T107 air temperature at 40 m height
16 T10 degrees C Campbell Scientific T107 air temperature at 10 m height
17 T2 degrees C Campbell Scientific T107 air temperature at 2 m height
18 press kPa Li-Cor LI7500 air pressure measured at 64 m height
19 h2o_64 mmol/mol Li-Cor LI7500 atmospheric water content measured at 64 m height
20 Usonic_64 m/s Campbell CSAT3 wind speed measured on the sonic anemometer at 64 m height
21 WD_64 degrees Campbell CSAT3 wind direction measured on the sonic anemometer at 64 m height
22 Ucup_64 m/s Met One 014 wind speed measured on the cup anemometer at 64 m height
23 Ucup_50 m/s Met One 014 wind speed measured on the cup anemometer at 50 m height
24 Ucup_40 m/s Met One 014 wind speed measured on the cup anemometer at 40 m height
25 rain mm Texas Electronics TE525 rainfall amount measured at 64 m height using a tipping bucket rain gauge during the 30 minute interval
26 Tsoil_10 degrees C Campbell Scientific T107 soil temperature at 10 cm depth
27 Tsoil_20 degrees C Campbell Scientific T107 soil temperature at 20 cm depth
28 Tsoil_50 degrees C Campbell Scientific T107 soil temperature at 50 cm depth
29 h2o_soil_10 m3/m3 Campbell Scientific CS615 soil moisture at 10 cm depth
30 h2o_soil_20 m3/m3 Campbell Scientific CS615 soil moisture at 20 cm depth
31 h2o_soil_40 m3/m3 Campbell Scientific CS615 soil moisture at 40 cm depth
32 hf_soil W/m2 REBS HFT 3.1 soil heat flux 10 cm depth
33 ustar m/s Campbell CSAT3 friction velocity 64 m height
34 hs W/m2 Campbell Scientific sensible heat flux measured at 64 m height
35 hl W/m2 Li-Cor LI7500 latent heat flux measured at 64 m height
36 co2_64 ppm Li-Cor LI7000 atmospheric CO2 concentration at 64 m height
37 fco2 umol/m2/s Li-Cor LI7000/LI7500 CO2 flux at 64 m height
38 ifco2     CO2 flux fill index ( 0= measured, 1= filled)
39 fstor umol/m2/s Li-Cor LI7000 CO2 storage below 64 m height
40 ifstor     CO2 storage fill index ( 0= measured, 1= filled)
41 nee_raw umol/m2/s   Net ecosystem exchange not u* corrected
42 inee_raw     NEE fill index ( 0= measured, 1= filled)
43 nee umol/m2/s   Net ecosystem exchange calculated as the sum of turbuant CO2 flux at 64 m and the change in the amount of CO2 stored in the air column below 64 m
44 ifilt     NEE u* filter index (1= u* filtered)
45 gpp umol/m2/s   gross primary productivity
46 igpp     GPP fill index ( 0= measured, 1= filled)
47 resp_meas umol/m2/s   respiration measured
48 resp_20_pts umol/m2/s   respiration smoothed using the nearest 20 pts
49 ndays_20_pts umol/m2/s   ndays respiration smoothed using the 20 nearest points
50 resp_par_40 umol/m2/s   respiration from PAR model PAR >0 and U* > 0.22
missing data are represented by -999


Example Data Records: CD04_km83_tower_fluxes_30_min.csv 

Header records omitted

exp_day,year,month,day,hr,min,solar_in,solar_out,long_in,long_out,par_in,par_out,rnet,T64,T40,T10,T2,press,h2o_64m,
Usonic_64,WD_64,Ucup_64,Ucup_50,Ucup_40,
rain,Tsoil_10,Tsoil_20,Tsoil_50,h2o_soil_10,h2o_soil_20,h2o_soil_40,
hf_soil,ustar,hs,hl,co2_64,fco2,ifco2,fstor,ifstor,nee_raw,inee_raw,nee,ifilt,gpp,igpp,resp_meas,resp_20_pts,ndays_20_pts,resp_par_40

181,2000,6,29,0,0,-999,-999,-999,-999,-999,-999,-999,24.71,23.02,23.49,22.83,98.71,27.66,3.03,61.04,1.97,1.18,0.45,0.00,-999,24.36,24.44,0.43,0.49,0.46,-5.99,0.55,-999,-999,389.84,3.78,0,7.06,0,10.84,0,10.84,0,-3.93,0,-999,6.910437,8.27,7.86,
181.020833,2000,6,29,0,30,-999,-999,-999,-999,-999,-999,-999,24.41,22.80,23.33,22.72,98.67,27.98,2.39,84.73,1.84,1.29,0.45,0.00,-999,24.37,24.44,0.43,0.49,0.46,-6.41,0.46,16.02,-999,389.07,5.92,0,1.45,0,7.37,0,7.37,0,-0.46,0,-999,6.910437,8.27,7.85,
...
1534.958333,2004,3,13,23,0,-0.21,-999,444.39,440.81,-0.44,-999,-999,-999,-999,-999,25.22,-999,19.06,-999,139.09,-999,-999,-999,0.00,24.95,24.98,24.94,0.44,-999,-999,-0.49,-999,-999,-999,402.39,-999,1,0.67,0,-999,1,-999,0,-999,1,-999,11.151,2.04,11.31,
1534.979167,2004,3,13,23,30,-0.24,-999,442.79,438.88,-0.50,-999,-999,-999,-999,-999,25.01,-999,18.62,2.07,137.23,-999,-999,-999,0.00,24.97,25.00,24.94,0.43,-999,-999,-1.27,-999,-999,-999,404.85,-999,1,5.92,0,-999,1,-999,0,-999,1,-999,11.151,2.04,11.32,

File 2: CD04_km83_tower_fluxes_dailyavg.csv

There are 1354 records (rows), each corresponding to a daily (24 hour) average of the 30 minute values.

Data File Description:

Column # Heading Units Sensor Description
1 exp_day     experiment day (0 = January 1, 2000, 00:00 hours)
2 year yyyy   year
3 month mm   month
4 day dd   day
5 solar_in W/m2 Kipp & Zonen CM6B mean daily downward flux of solar radiation
6 solar_out W/m2 Kipp & Zonen CM6B mean daily upward flux of solar radiation
7 long_in W/m2 Kipp & Zonen CG2 mean daily downward flux of long wave radiation
8 long_out W/m2 Kipp & Zonen CG2 mean daily upward flux of long wave radiation
9 par_in micromol/m2/s Li-Cor LI190 mean daily downward flux of photosynthetically active radiation
10 par_out micromol/m2/s Li-Cor LI190 mean daily upward flux of photosynthetically active radiation
11 rnet W/m2 Rebs Q*7 mean daily net radiation 64 m;
12 T64 degrees C Campbell Scientific T107 mean daily air temperature at 64 m height
13 T40 degrees C Campbell Scientific T107 mean daily air temperature at 40 m height
14 T10 degrees C Campbell Scientific T107 mean daily air temperature at 10 m height
15 T2 degrees C Campbell Scientific T107 mean daily air temperature at 2 m height
16 h2o_64 mmol/mol Li-Cor LI7500 mean daily atmospheric water content measured at 64 m height
17 press kPa Li-Cor LI7500 mean daily air pressure measured at 64m height
18 WS_64 m/s Campbell CSAT3 mean daily wind speed measured on the sonic anemometer at 64 m height
19 WD_64 degrees Campbell CSAT3 mean daily wind direction measured on the sonic anemometer at 64 m height
20 rain mm Texas Electronics TE525 total daily rainfall measured at 64 m height using a tipping bucket rain gauge
21 Tsoil_10 degrees C Campbell Scientific T107 mean daily soil temperature at 10 cm depth
22 Tsoil_20 degrees C Campbell Scientific T107 mean daily soil temperature at 20 cm depth
23 Tsoil_50 degrees C Campbell Scientific T107 mean daily soil temperature at 50 cm depth
24 h2o_soil_10 m3/m3 Campbell Scientific CS615 mean daily soil moisture at 10 cm depth
25 h2o_soil_20 m3/m3 Campbell Scientific CS615 mean daily soil moisture at 20 cm depth
26 h2o_soil_40 m3/m3 Campbell Scientific CS615 mean daily soil moisture at 40 cm depth
27 hf_soil W/m2 REBS HFT 3.1 mean daily soil heat flux 10 cm depth
28 ustar m/s Campbell CSAT3 mean daily friction velocity 64 m height
29 hs W/m2 Campbell Scientific mean daily sensible heat flux measured at 64 m height
30 hl W/m2 Li-Cor LI7500 mean daily latent heat flux measured at 64 m height
31 co2_64 ppm Li-Cor LI7000 mean daily atmospheric CO2 concentration at 64 m height
32 fco2 umol/m2/s Li-Cor LI7000/LI7500 mean daily CO2 flux at 64 m height
33 fstor umol/m2/s Li-Cor LI7000 mean daily CO2 storage below 64 m height
34 nee umol/m2/s   mean daily Net ecosystem exchange calculated as the sum of turbulent CO2 flux at 64 m and the change in the amount of CO2 stored in the air column below 64 m
35 resp umol/m2/s   mean daily ecosystem respiration
36 gpp umol/m2/s   mean daily gross primary productivity
missing data are represented by -999


Example Data Records: CD04_km83_tower_fluxes_dailyavg.csv

Header records omitted

exp_day,year,month,day,solar_in,solar_out,long_in,long_out,par_in,par_out,rnet,T64,T40,T10,T2,h2o_64,press,WS_64,WD_64,rain,
Tsoil_10,Tsoil_20,Tsoil_50,h2o_soil_10,h2o_soil_20,h2o_soil_40,hf_soil,ustar,hs,
hl,co2_64,fco2,fstor,nee,resp,gpp

181,2000,6,29,-999,-999,-999,-999,-999,-999,-999,26.12,24.54,24.28,23.62,-999,-999,-999,-999,0,-999,24.28,24.44,0.42,0.49,0.46,-1.06,-999,-999,-999,396.9,-999,0.04,-999,6.91,-999
182,2000,6,30,159.74,-999,-999,-999,333.26,10.7,105.05,26.39,24.64,24.32,23.74,27.73,98.67,2.09,-999,2.54,-999,24.36,24.43,0.42,0.49,0.45,-1.06,0.27,-999,-999,-999,-2.37,-999,-999,6.91,-999
...
1533,2004,3,12,-999,-999,-999,444.37,-999,-999,-999,-999,-999,-999,24.17,18.34,-999,1.72,147.13,1.27,24.72,24.75,24.9,0.45,-999,-999,-0.1,-999,-999,-999,392.92,-999,0.24,-999,11.15,-999
1534,2004,3,13,-999,-999,-999,445.18,-999,-999,-999,-999,-999,-999,24.48,18.49,-999,-999,141.5,0,24.84,24.88,24.92,0.44,-999,-999,-0.05,-999,-999,-999,411.82,-999,-0.33,-999,11.15,-999


File 3: CD04_km83_tower_fluxes_monthly_avg.csv

There are 44 records (rows), each corresponding to a monthly (calendar) average of the daily values. Months with some missing days were excluded. The experimental day for monthly average was set as a day near the end of the month. Fields are included that report the number of days used to calculate the various quantities.

Data File Description:


Column Heading Units Description
1 exp_day   experiment day (0 = January 1,2000, 00:00 hours)
2 year yyyy year
3 month mm month
4 solar_in W/m2 mean monthly downward flux of solar radiation
5 solar_out W/m2 mean monthly upward flux of solar radiation
6 long_in W/m2 mean monthly downward flux of long wave radiation
7 long_out W/m2 mean monthly upward flux of long wave radiation
8 par_in umol/m2/s mean monthly downward flux of photosynthetically active radiation
9 par_out umol/m2/s mean monthly upward flux of photosynthetically active radiation
10 rnet W/m2 mean monthly net radiation 64 m
11 T64 degrees C mean monthly air temperature at 64 m height
12 T40 degrees C mean monthly air temperature at 40 m height
13 T10 degrees C mean monthly air temperature at 10 m height
14 T2 degrees C mean monthly air temperature at 2 m height
15 h2o_64 mmol/mol mean monthly atmospheric water content measured at 64 m height
16 press kPa mean monthly air pressure measured at 64m height
17 WS_64 m/s mean monthly wind speed measured on the sonic anemometer at 64 m height
18 WD_64 degrees mean monthly wind direction measured on the sonic anemometer at 64 m height
19 rain mm total monthly rainfall measured at 64 m height using a tipping bucket rain gauge
20 Tsoil_10 degrees C mean monthly soil temperature at 10 cm depth
21 Tsoil_20 degrees C mean monthly soil temperature at 20 cm depth
22 Tsoil_50 degrees C mean monthly soil temperature at 50 cm depth
23 h2o_soil_10 m3/m3 mean monthly soil moisture at 10 cm depth
24 h2o_soil_20 m3/m3 mean monthly soil moisture at 20 cm depth
25 h2o_soil_40 m3/m3 mean monthly soil moisture at 40 cm depth
26 hf_soil W/m2 mean monthly soil heat flux 10 cm depth
27 ustar m/s mean monthly friction velocity 64 m height
28 hs W/m2 mean monthly sensible heat flux measured at 64 m height
29 hl W/m2 mean monthly latent heat flux measured at 64 m height
30 co2_64 ppm mean monthly atmospheric CO2 concentration at 64 m height
31 fco2 umol/m2/s mean monthly CO2 flux at 64 m height
32 fstor umol/m2/s mean monthly CO2 storage below 64 m height
33 nee umol/m2/s mean monthly Net ecosystem exchange calculated as the sum of turbulent CO2 flux at 64 m and the change in the amount of CO2 stored in the air column below 64 m
34 resp umol/m2/s mean monthly ecosystem respiration
35 resp_2 umol/m2/s mean monthly ecosystem respiration linear par model
36 resp_3 umol/m2/s mean monthly ecosystem respiration calculated using the par model
37 gpp umol/m2/s mean monthly gross primary productivity
38 CI_par_in umol/m2/s 95 percent confidence interval for par incoming 64 m
39 CI_par_out umol/m2/s 95 percent confidence interval for par outgoing 64 m
40 CI_rnet W/m2 95 percent confidence interval for net radiation 64 m
41 CI_T64 degrees C 95 percent confidence interval for air temperature 64 m
42 CI_h2o mmol/mol    95 percent confidence interval for h2o concentration 64 m
43 CI_WS m/s 95 percent confidence interval for wind speed sonic anemometer 64 m
44 CI_WD degrees 95 percent confidence interval for wind direction sonic anemometer 64 m
45 CI_ustar m/s 95 percent confidence interval for friction velocity
46 CI_hs W/m2 95 percent confidence interval for sensible heat flux 64 m
47 CI_hl W/m2 95 percent confidence interval for latent heat flux 64 m
48 CI_fco2 umol/m2/s 95 percent confidence interval for co2 flux 64 m
49 CI_fstor umol/m2/s 95 percent confidence interval for co2 storage below 64 m
50 CI_nee umol/m2/s 95 percent confidence interval for NEE
51 CI_resp umol/m2/s 95 percent confidence interval for respiration
52 CI_gpp umol/m2/s 95 percent confidence interval for GPP
53 Ndays   number of days included in the calendar month
54 Ndays_par_in   number of days included in the calculation of mean par_in
55 Ndays_par_out   number of days included in the calculation of mean par_out
56 Ndays_rnet   number of days included in the calculation of mean net radiation
57 Ndays_T64   number of days included in the calculation of mean air temperature at 64 m
58 Ndays_h2o   number of days included in the calculation of mean water concentration at 64 m
59 Ndays_co2   number of days included in the calculation of mean CO2 concentration at 64 m
60 Ndays_WS   number of days included in the calculation of mean wind speed
61 Ndays_WD   number of days included in the calculation of mean wind direction
62 Ndays_rain   number of days included in the calculation of total rainfall
63 Ndays_ustar   number of days included in the calculation of mean friction velocity
64 Ndays_hs   number of days included in the calculation of mean sensible heat flux
65 Ndays_hl   number of days included in the calculation of mean latent heat flux
66 Ndays_fco2   number of days included in the calculation of mean CO2 flux
67 Ndays_fstor   number of days included in the calculation of mean CO2 storage
68 Ndays_nee   number of days included in the calculation of mean net ecosystem exchange
69 Ndays_resp   number of days included in the calculation of mean respiration
70 Ndays_gpp   number of days included in the calculation of mean gross primary productivity
missing data are represented by -999



Example Data Records: CD04_km83_tower_fluxes_monthly_avg.csv

Header records omitted

exp_day,year,month,solar_in,solar_out,long_in,long_out,par_in,par_out,rnet,T64,T40,T10,T2,h2o_64,press,WS_64,WD_64,rain,
Tsoil_10,Tsoil_20,Tsoil_50,h2o_soil_10,h2o_soil_20,h2o_soil_40,hf_soil,ustar,hs,hl,co2_64,fco2,fstor,nee,resp,resp_2,resp_3,gpp,
CI_par_in,CI_par_out,CI_rnet,CI_T64,CI_h2o,CI_WS,CI_WD,CI_ustar,CI_hs,CI_hl,CI_fco2,CI_fstor,CI_nee,CI_resp,CI_gpp,
Ndays,Ndays_par_in,Ndays_par_out,Ndays_rnet,Ndays_T64,Ndays_h2o,Ndays_co2,Ndays_WS,Ndays_WD,Ndays_rain,
Ndays_ustar,Ndays_hs,Ndays_hl,Ndays_fco2,Ndays_fstor,Ndays_nee,Ndays_resp,Ndays_gpp

211.5,2000,7,204,-999,-999,-999,426.1,13.24,140.39,26.75,24.83,24.3,23.56,25.98,98.73,2.01,-999,162.56,
-999,24.21,24.32,0.43,0.49,0.45,-1.05,0.27,21.58,112.45,390.21,-1.46,-0.06,-0.12,7.66,5.55,6.52,8.26,
29.1,0.81,9.81,0.42,0.55,0.21,-999,0.02,3.71,8.23,0.49,0.19,0.57,1.58,0.52,
31,25,25,25,25,15,23,19,0,31,
25,17,14,23,23,21,86,21
242.5,2000,8,229,-999,-999,-999,478.21,14.01,154.76,26.43,25.86,25.15,24.45,26.55,98.54,2.24,95.79,62.48,
-999,25.07,24.91,0.42,0.48,0.45,-0.81,0.3,26.82,121.11,394.41,-1.63,0.04,0.35,9.38,6.79,9.1,9.34,
26.19,0.63,9.05,0.31,0.18,0.11,9.99,0.02,2.96,6.25,0.44,0.14,0.7,1.43,0.78,
31,29,29,29,27,27,23,28,23,31,
29,18,15,29,23,23,114,23
...
1490.5,2004,1,154,20.2,426.11,449.19,322.23,-999,108.27,24.69,24.91,24.48,24.26,16.62,98.53,2.12,126.1,154.18,
24.98,25.01,25.32,0.42,-999,-999,-1.19,0.28,23.93,108.94,406.97,-1.31,-0.01,-0.48,8.45,4.86,6.04,9.65,
43.48,-999,15.85,0.5,0.39,0.14,12.51,0.03,8.22,19.31,0.62,0.37,0.67,1.1,0.72,
31,21,0,21,24,20,20,20,20,31,
17,10,8,16,18,13,134,13
1520.5,2004,2,157,-999,431.35,444.36,327.67,-999,108.89,23.79,24.2,24.05,24.02,17.24,98.63,1.9,124.76,246.38,
24.59,24.66,24.87,0.44,-999,-999,-0.69,0.3,-999,-999,404.34,-0.95,-0.08,-1.11,8.2,7.02,8.97,9.61,
47.77,-999,17.07,0.35,0.25,0.17,15.7,0.03,-999,-999,0.82,0.14,0.98,0.95,0.72,
29,20,0,20,19,22,29,20,22,29,
17,0,0,16,28,16,190,16

Site boundaries: (All latitude and longitude given in degrees and fractions)

Site (Region) Westernmost Longitude Easternmost Longitude Northernmost Latitude Southernmost Latitude Geodetic Datum
Para Western (Santarem) - km 83 Logged Forest Tower (Para Western (Santarem)) -54.96889 -54.96889 -3.01806 -3.01806 World Geodetic System, 1984 (WGS-84)

Time period:

Platform/Sensor/Parameters measured include:

3. Data Application and Derivation:

Data Calculations

For the storage flux, molar densities of CO2 and H2O in the profile were determined using an IRGA. The amount of CO2 stored beneath the eddy flux sensors (64 m) was calculated by integrating the profile between 0 and 64 m. The storage flux was then calculated by differentiating this quantity with respect to time.

Net ecosystem exchange (NEE) was calculated for each half-hour interval as the sum of the turbulent CO2 flux at 64 m and the change in the amount of CO2 in the air column beneath 64 m (the storage flux). Ecosystem respiration was calculated from nighttime measurements of NEE during periods with sufficient vertical mixing; i.e., friction velocity ms-1 [Miller et al., 2004]. The necessary -threshold at this site was determined by comparing flux tower estimates of with several independent lines of evidence (scaled-up estimates of respiration components [Chambers et al., 2004b], and radon-based estimates of nocturnal mixing [Martens et al., 2004]. Uncertainties in the calculation of respiration and NEE at the Tapajos sites are discussed in detail in Saleska et al. [2003] and Miller et al. [2004].

Gross primary productivity was calculated by subtracting NEE from ecosystem respiration. Continuous 30-minute GPP were averaged to construct daily and monthly estimates of GPP. Uncertainty in monthly and annual GPP was calculated as the 95% confidence interval based on averaging daily GPP.

An additional estimate of respiration (R) was calculated as the intercept (PAR=0) of a non-linear least squares fit of a light curve model, NEE = R + (A*PAR)./(PAR+B), using measured PAR and NEE (when PAR>0 umol/m2/s and u*>0.22 m/s) , and A and B and R are the regression constants. For each day, the light model was applied to all available data within 20 days, thus a 40 day window.

Gap filling

Missing flux intervals in the yearly record were filled differently depending up on the length of the data gap and whether the gap was biased towards certain meteorological conditions. All gaps in NEE shorter than 2 hours were filled using linear interpolation. Longer gaps that were not considered biased to certain meteorological conditions were filled using mean diurnal variation (Falge et al. 2001). We used 20 days of reliable data nearest the missing interval to fill the gap. Missing intervals due to window obstruction of the open-path IRGA were distributed unevenly over the day. Daytime gaps were biased towards cloudy conditions and to account for that these gaps in NEE were filled using a light-curve model based on this data set.

Applications

Analysis of eddy covariance observations provides information useful for identifying which physiological and physical processes play dominant roles in controlling CO2 exchange. In turn, this information contributes to the development and improvement of models of ecosystem- atmosphere CO2 exchange and to understanding which processes are particularly sensitive to future change.

4. Quality Assessment:

Missing values or data that were flagged as unreliable either by an objective algorithm or subjective inspection have been given a value of -999. It is up to the end-user to fill these values if necessary. Separate columns are included for CO2 flux, storage, NEE, and GPP that indicate that the value was measured/calculated, or filled. These columns can be used by the end-user to substitute their own filling strategy.


5. Data Acquisition Materials and Methods:

Flux measurements were made from a 67 m tall tower, additional measurements were made on two 2 m tripods installed on the forest floor. The data acquisition computer and closed-path gas analyzers were located in an air-conditioned hut 8 m south of the tower base. Data acquisition and control systems were automated and data were downloaded weekly. Five data loggers connected by a coaxial network collected the instrument data in two types of files: slow files with 30 min statistics and fast files with 4- or 0.5 Hz observations which was then stored on the data acquisition computer. The turbulent fluxes of sensible heat, latent heat, CO2, and momentum at 64 m were determined with the eddy covariance technique. The signals directly required for flux calculation were digitized and stored at 4 Hz. Wind and temperature were measured with a 3-axis sonic anemometer pointed due east (Campbell Scientific, Logan UT). Winds from the east predominate at 64 m, accounting for about 85% of day and night intervals.

The molar densities of CO2 and H2O at 64 m were measured with two independent InfraRed Gas Analyzers (IRGAs).

The CO2 fluxes for both the open and closed path IRGAs were calculated as the 30-minute covariance of the vertical wind velocity (w) and the CO2 mixing ratio after subtracting the 30-minute mean (c'). The time lag for the closed path IRGA (typically 11 s) was determined by maximizing the correlation between w and c'. The fluxes were rotated to the plane with no mean vertical or cross wind.

A third IRGA (LI-COR LI7000 or, before Dec. 2000, a LI800, Lincoln NE) sequentially measured the molar densities of CO2 and H2O at 12 altitudes (0.1, 0.35, 0.7, 1.4, 3, 6, 10.7, 20, 35, 40, 50, 64 m above the ground) every 48 minutes. Four slpm of air was drawn through a 2 micron filter at each altitude, down 5.5-mm inner-diameter polyethylene lined tubing (Furon Dekabon 1300), through a solenoid manifold in an enclosure at the base of the tower (Parker General Valve, Fairfield NJ), into the equipment hut, and through the IRGA cell. The pressure in the IRGA cell was actively controlled at 83 kPa (MKS Instruments, Andover MA). The IRGA was calibrated for CO2 and water vapor daily by sequentially sampling purge air, CO2 standard in air (+-1% Scott Marin, Riverside CA), CO2 free air (Scott Marin, Riverside CA), and 16o C dew point air (LI-COR LI610, Lincoln NE).

Observations about the physical environment were archived at 0.5 Hz and all measurements were done at 64 m height unless otherwise noted. Precipitation was measured with a tipping bucket gauge (TE525: Texas Electronics Dallas). Atmospheric pressure was measured by the L17500. Incoming and reflected photosynthetically active photon flux density (PPFD) was measured with silicon quantum sensors (Li-Cor LI190). Net radiation was measured with a thermopile net radiometer (REBS Q*7.1: REBS). Incoming solar radiation was measured with a thermopile pyranometer (model CM6: Kipp and Xonene,
Delft, The Netherlands). Air temperatures at 64, 40, 10 and 2 m heights were measured with ventilated thermistors (model 076B, Met One). Horizontal wind speeds at 64, 50, and 40 m height were measured with cup anemometers (model 014; Met One). Soil temperatures at 19 locations at depths of 0.02 to 0.25 m were measured with copper constantan thermocouples (Omega Engineering) and soil heat flux at 2 cm depths was measured with 5 flux plates (REBS HFT3.1). Soil moisture at depths between 0.1 and 2.5 m across 20 locations was measured with water content reflectometers (Campbell Scientific CS615). Litter moisture was measured using 6 fuel moisture probes position immediately above the forest floor. 

Soil respiration was measured beginning in August 2001 with 15 automated chambers (Goulden and Crill 1997) located in intact forest approximately 50 m east of the tower and 50 m from the nearest logging-created gap. These chambers were sampled sequentially at 12 min intervals and soil respiration calculated from the increase in chamber CO2 concentrations over the sampling period.


6. Data Access:


This data is available through the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Data Archive Center:

Contact for Data Center Access Information:

E-mail: uso@daac.ornl.gov
Telephone: +1 (865) 241-3952

7. References:

Goulden M.L, and P.M. Crill. 1997. Automated measurements of CO2 exchange at the moss surface of a black spruce forest. Tree Physiology 17: 537-542.

Miller, S.D., M..L Goulden, M.C. Menton, H.R. da Rocha, H.C. de Freitas, A.M. Figueira and C.A.D. de Sousa. 2004. Biometric and micrometeorological measurements of tropical forest carbon balance. Ecological Applications 14: S114-S126. doi:10.1890/02-6005

Chambers, J.Q., E.S. Tribuzy, L.C. Toledo, B.F. Crispim, N. Higuchi, J. dos Santos, A.C. Araujo, B. Kruijt, A.D. Nobre, and S.E. Trumbore. 2004. Respiration from a tropical forest ecosystem: partitioning sources and low carbon use efficiency. Ecological Applications 14: S72-S88. doi:10.1890/01-6012

Falge, E., et al. 2001. Gap filling strategies for defensible annual sums of net ecosystem exchange. Agricultural and Forest Meteorology 107:43–69. doi:10.1016/S0168-1923(00)00225-2

Martens C.S., Shay T.J., H.P. Mendlovitz, D.M. Matross, S.R. Saleska, S.C. Wofsy, W.S. Woodward, M.C. Menton, J.M.S. De Moura, P.M. Crill, O.L.L. De Moraes, and R.L. Lima. 2004. Radon fluxes in tropical forest ecosystems of Brazilian Amazonia: night-time CO2 net ecosystem exchange derived from radon and eddy covariance methods. Global Change Biology 10: 618-629. doi:10.1111/j.1365-2486.2004.00764.x

Miller, S. D., M. L. Goulden, M. C. Menton, H. R. da Rocha, H. C. de Freitas, A. M. e Silva Figueira, and C. A. Dias de Sousa. 2004. Biometric and micrometeorological measurements of tropical forest carbon balance. Ecological Applications 14:S114–S126. doi:10.1890/02-6005

Saleska S.R., S.D. Miller, D.M. Matross, M.L. Goulden, S.C. Wofsy, .HR. 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, H. Silva . 2003. Carbon in amazon forests: Unexpected seasonal fluxes and disturbance-induced losses. Science 302:1554-1557.


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