#---------------------------------------------------------------------------------------- Eddy-covariance measurements of CO2 and H2O at km 67 tower site, Tapajos National Forest Contacts: Steve Wofsy (wofsy@fas.harvard.edu) Lucy Hutyra (lhutyra@fas.harvard.edu) Elaine Gottlieb (gottlieb@deas.harvard.edu) * * * * * FAIR USE * * * * * * * PLEASE READ CAREFULLY * * The data contained on this site is freely available and we encourage others to use it. Kindly keep us informed of how you are using our data and of any publication plans. Please acknowledge the data source as a citation, or in the acknowledgments if the data have not yet been published. If we feel that we should be offered participation as authors, we will let you know and we assume that an agreement on such matters will be reached prior to publishing the data. If your work directly competes with our analysis we may ask that we have the opportunity to submit a manuscript before you submit one that uses unpublished data. These data may be updated or reprocessed from time to time, and it is your responsibility to insure that your publication contains the most recent revision of the data. In order to maintain these measurements we periodically need to demonstrate progress to our sponsoring agencies. In addition to informing us of your plans, we kindly request that you help us by providing preprints and updates on publication status. By downloading this data, you agree to the terms of our fair use policy Known Problems: These data are subject to ongoing error-correction and quality-assurance testing, and are subject to change. Some of the main known problems/issues in this dataset include: 1. Wind-direction by wind vane sensor (column 15) has uncalibrated offset, and directionality reversed. Use the sonic-derived wind-direction for now. 2. There are occasional individual points that are bad, but which for one reason or another, have not yet been removed. #---------------------------------------------------------------------------------------- #---------------------------------------------------------------------------------------- output in km67.eddyflux.2002.2006.txt.gz: 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 [,5] "Tamb" # ambient temp at 58m (level 1 eddy) from chilled mirror sensor [,6] "Tdew" # ambient dew point temperature @ 58m [,7] "Tson" # sonic temp (deg C, unadjusted for moisture @ 57.8m) [,8] "Tasp" # distance weighted aspirated ambient temperature from thermistors [,9] "fheat" # heat flux (degC m/sec) [,10] "fmom" # momentum flux [,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/m^2 [,18] "LHdry" # Latent heat flux W/m^2 [relative to dry air] [,19] "ustar" # friction velocity, sqrt(-) (m/sec), # where w,u are the rotated wind components [,20] "ppm2umol" # density conversion factor for fluxes mol/m^3 [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 [,24] "par" # PAR (umol/m2/sec) level 1 (63.6 m) [,25] "sPAR1up" # std deviation on hourly mean [,26] "PAR2up" # PAR (umol/m2/sec) level 2 (15.09 m) [,27] "sPAR2up" # std deviation on hourly mean [,28] "PAR1dn" # downward PAR (umol/m2/sec) level 1 (63.6 m) [,29] "sPAR1dn" # std deviation on hourly mean [,30] "Tair1" # Temp (via thermistor) at profile level 1 (61.94 m) [,31] "Tair2" # Temp (via thermistor) at profile level 2 (49.75 m) [,32] "WS1" # cup anemometer #1 (m/sec, 64.1 m) [,33] "sWS1" # std deviation on hourly mean [,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 courtecy 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/m^2), 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