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AmeriFlux Standardized Level 2 Data FilesMay 2014
Recognizing the need and convenience for some users to be able to easily obtain data
files containing long-term records from AmeriFlux sites in a common, standardized
format, the AmeriFlux data activity within the Carbon Dioxide Information AnalysisCenter CDIAC! at "a# Ridge $ational %aboratory &roduces the standard files &resented
here' (hese files contain data &rovided by individual site investigators for individual
years that have been chec#ed and reformatted by CDIAC' (hese %evel ) %)! filescontain the same data available from the CDIAC AmeriFlux *ite and Data +x&loration
*ystem htt&ameriflux'ornl'gov!'
.hen using these files /%+A*+ adhere to the AmeriFlux fair-use data &olicy listed on
each data file as &art of the standard header record' If you have 0uestions about the
content, use, or citation of these data, &lease contact (om 1oden bodenta2ornl'gov! or
1ai 3ang yangb2ornl'gov!'
For some sites e'g', 4aira Ranch, California! both ga&-filled files and files with &eriods
of missing data are furnished' *e&arate directories are &rovided for ga&-filledga&5filled! and non ga&-filled with5ga&s! records' (he basic file naming convention
is 6A7F5CCFID5yyyy5%)58854999'csv: or 6A7F5CCFID5yyyy5%)58854999'nc:'
A7F denotes the files are from the AmeriFlux networ#' CC is a two-character countrycode e'g', ;* for the ;nited *tates, CA for Canada!' FID is a uni0ue, three-character
site identifier assigned to all flux sites worldwide e'g', D#< is assigned to the Du#e
Forest loblolly &ine site!' A com&lete list of the AmeriFlux sites and their country code-
site identifiers are &rovided at htt&ameriflux'lbl'govAmeriFlux*ites/ages*ite-7a&'as&x' yyyy is the sam&ling year A'D' or C'+' e'g', =>>?!' %) reflects the AmeriFlux
&roduct level i'e', %evel )!' 88 identifies whether the file contains records with ga&s.@! or offers ga&-filled @F! records' 4999 denotes the release version for this&articular site e'g', 4B re&resents the seventh release of a new set of %) files for site
FID!' (he %) files are &rovided as A*CII text files with each variable se&arated by
commasi'e', comma-se&arated value or 'csv files! or in $etCDF format 'nc files!' +verycsv file contains a =B-line header record followed by data records' (he basic content of
the header record and the order of the variables &resented in the data records are identical
for each file, regardless of whether the files are ga&-filled or not' 7issing values orvalues set to missing by CDIAC during their AC chec#s are denoted by ->>>>'
/arameters not re&orted by the site investigator are denoted by ->>>'
Content and Format of Header Records
%ine = *itename
%ine ) %ocation including latitude and longitude coordinates decimal degrees,$ E + hemis&heres have &ositive values, * E . hemis&heres have
negative values! and elevation masl!
%ine < /rinci&al investigator name%ine +cosystem ty&e according to I@1/ classifications
http://ameriflux.ornl.gov/mailto:[email protected]://ameriflux.lbl.gov/AmeriFluxSites/Pages/Site-Map.aspxhttp://ameriflux.lbl.gov/AmeriFluxSites/Pages/Site-Map.aspxhttp://ameriflux.ornl.gov/mailto:[email protected]://ameriflux.lbl.gov/AmeriFluxSites/Pages/Site-Map.aspxhttp://ameriflux.lbl.gov/AmeriFluxSites/Pages/Site-Map.aspx8/11/2019 L2 Lecture Note
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%ine G File creation date
%ines -=< AmeriFlux fair-use data &olicy
%ines =-= File origin and bac#ground%ine =B +-mail contact for 0uestions
%ine =? %isting of the variables and order for each data record
%ine => ;nits for each variable listed in line =G%ine ) *ummary record that identifies the &ercentage of non-missing values for
each column
Content and Format of Data Records
Variable Name Description and Units
3+AR 3ears A'D' or C'+', values range from =>>= to )='
@A/ Indicator used to identify whether C") flux estimates FC! arefurnished for a &articular recordH denotes an FC measurement is
&resent and -= denotes no FC measurement is &resent' *ummaryfiles sitename'html! are also &rovided in each subdirectory to aid
users in determining the availability of data for s&ecific sites and
variables'
D(I7+ %ocal standard time of dayH each half-hour e0uals ')?
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(*) *oil tem&erature ex&ressed in degrees C'
(*)de&th) 7easurement de&th for (*), ex&ressed in cm'
/R+C (otal rainfall or wintertime &reci&itation within the measurement&eriod ex&ressed in mm'
RJ Relative humidity of air, ex&ressed as a &ercentage, measured Lustabove the cano&y'
/R+** 1arometric &ressure ex&ressed in #/a'
C") C") concentration ex&ressed in umolmol'
4/D 4a&or &ressure deficit, as the difference between the saturation
water va&or &ressure and the measured water va&or &ressure,ex&ressed in #/a' 4/D is calculated from relative humidity RJ!
and air tem&erature (A! or from water va&or concentrationJ)"!, (A, and barometric &ressure /R+**!'
*.C= *oil water content, based on time-domain measurement methodssensitive to dielectric &ermittivity, at de&th = ex&ressed as a
&ercentage'
*.C) *oil water content, based on time-domain measurement methodssensitive to dielectric &ermittivity, at de&th ) ex&ressed as a
&ercentage'
7easurement de&ths and column de&ths in cm for *.C= and
*.C) are &rovided in a table at the bottom of this document'
Rn $et radiation ex&ressed in .m)' /ositive values denote
downwards'
/AR Incoming &hotosynthetically active radiation i'e', radiation in the' to 'B micrometer waveband!, measured above the cano&y, and
ex&ressed in umolm)s'
Rg Incoming global solar radiation shortwave radiation, '=G to '
micrometer waveband! including both direct radiation and diffuse
radiation, measured above the cano&y, and ex&ressed in .m)'
Rgdif Incoming diffuse global solar radiation including reflected and
scattered radiation from all &ortions of the s#y, measured above the
cano&y, and ex&ressed in .m)'
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/ARout Reflected &hotosynthetically active radiation ex&ressed inumolm)s'
Rg"ut "utgoing global solar radiation shortwave radiation, '=G to '
micrometer waveband!, measured above the cano&y, ex&ressed in.m)'
Rgl Incoming longwave radiation i'e', radiation in the to =micrometer waveband!, measured above the cano&y, ex&ressed in
.m)'
Rgl"ut "utgoing longwave radiation, measured above the cano&y,ex&ressed in .m)'
J)" .ater va&or concentration above the cano&y ex&ressed in
mmolmol'
R+ (otal ecosystem res&iration ex&ressed in umolm)s'
@// @ross &rimary &roduction, including total ecosystem res&iration
R+! and net ecosystem exchange $++!, ex&ressed in umolm)s'@// is calculated as @// K R+ - $++
C")to& If more than one concentration is re&orted by the site investigator
the measurement closest to the surface is &resented above as C")and the measurement from the highest sam&ling &oint is re&orted
here as C")to& in umolmol'
C")height Indicates the height of the C")to& measurement ex&ressed in
meters'
A/AR (he amount of &hotosynthetically active radiation /AR!
assimilated by the cano&y and understory as determined by the
difference between above-cano&y /AR measurements and ground-
level /AR measurements' A/AR values are ex&ressed inumolm)s'
/ARdif Incoming diffuse &hotosynthetically active radiation i'e', radiationin the ' to 'B micrometer waveband!, measured above the
cano&y, and ex&ressed in umolm)s' Diffuse /AR includes
reflected and scattered radiation in the ' to 'B micrometerwavebands from all &ortions of the s#y'
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A/AR&ct (he &ercentage of incoming &hotosynthetically active radiation
/AR! assimilated by the cano&y and understory' A/AR&ct values
are ex&ressed as &ercentages'
M% Atmos&heric stability &arameter calculated from M% where M is
the measurement height and % is the 7onin-"bu#hov length' M%is unitless'
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Measurement heights expressed in meters !or the edd"#covariance s"stems$
Site name Measurement height %m&
Ai#en )G'
Ana#tuvu# River moderate burn site )'BAna#tuvu# River severe burn site )'B)
Ana#tuvu# River unburned site )'G
AR7 *@/ site ')?
AR7 burn site G
At0asu# )'
Audubon @rasslands '
Austin Cary
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Flagstaff managed forest site )'Jarvard Forest hemloc# site )B'
Jeritage %and Conservancy >'
Jowland east tower harvest site )>'
Jowland main )>'
Jowland west tower site )>'
Imnavait Cree# heath tundra
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;CI =>>? burn site '
;CI )< burn site '
;71* '
;71* Disturbance
.alnut River )'=
.illow Cree# )>'
.ind River B'
.isconsin Clearcut Red /ine '
.isconsin Clearcut 3oung Jardwoods '
.isconsin 7ature Jardwoods )'
.isconsin 7ature Red /ine )
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Measurement depths and integration depths expressed in cm !or S()* and
S()2' $A denotes cases where only one soil moisture value was re&orted by the
&rinci&al investigator'
Site name S()* S()2
Ana#tuvu# River moderate burn site )'G $AAna#tuvu# River severe burn site )'G $A
Ana#tuvu# River unburned site )'G $A
AR7 *@/ site = G before
=
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Florida +verglades (aylor *lough short
hydro&eriod marsh
-=G $A
Fort /ec# G )-
)?! =)
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"hio "a# "&enings - wet burn site )G ?= burn site > $A
;CI =>?> burn site = $A
;CI =>>? burn site == >
;71* -