partitionNEEGL: partitionNEEGL

In REddyProc: Post Processing of (Half-)Hourly Eddy-Covariance Measurements

partitionNEEGL

Description

Partition NEE fluxes into GP and Reco using the daytime method.

Usage

partitionNEEGL(ds, NEEVar = if (!missing(NEEVar.s)) NEEVar.s else paste0("NEE", 
    suffixDash, "_f"), TempVar = if (!missing(TempVar.s)) TempVar.s else "Tair_f", 
    VPDVar = if (!missing(VPDVar.s)) VPDVar.s else "VPD_f", 
    RadVar = if (!missing(RadVar.s)) RadVar.s else "Rg_f", 
    suffix = if (!missing(Suffix.s)) Suffix.s else "", 
    NEEVar.s, TempVar.s, VPDVar.s, RadVar.s, 
    Suffix.s, ..., controlGLPart = partGLControl(), 
    isVerbose = TRUE, nRecInDay = 48L, lrcFitter = RectangularLRCFitter())

Arguments

ds	dataset with all the specified input columns and full days in equidistant times
NEEVar	Variable of NEE
TempVar	Filled air or soil temperature variable (degC)
VPDVar	Filled Vapor Pressure Deficit - VPD - (hPa)
RadVar	Filled radiation variable
suffix	string inserted into column names before identifier for NEE column defaults (see sEddyProc_sMDSGapFillAfterUstar).
NEEVar.s	deprecated
TempVar.s	deprecated
VPDVar.s	deprecated
RadVar.s	deprecated
Suffix.s	deprecated identifier for NEE column defaults (see sEddyProc_sMDSGapFillAfterUstar).
...	further arguments to partGLExtractStandardData, such as PotRadVar
controlGLPart	further default parameters, see partGLControl
isVerbose	set to FALSE to suppress output messages
nRecInDay	number of records within one day (for half-hourly data its 48)
lrcFitter	R5 class instance responsible for fitting the light response curve. Current possibilities are RectangularLRCFitter(), NonrectangularLRCFitter(), and LogisticSigmoidLRCFitter().

Details

Daytime-based partitioning of measured net ecosystem fluxes into gross primary production (GPP) and ecosystem respiration (Reco)

The fit to the light-response-curve is done by default using the Rectangular hyperbolic function, as in Lasslop et al. (2010) Alternative fittings can be used by providing the corresponding subclass of LightResponseCurveFitter-class to lrcFitter argument. (see LightResponseCurveFitter_predictGPP)

While the extrapolation uses filled data, the parameter optimization may use only measured data, i.e. with specified quality flag. Even with using filled VPD, there may be large gaps that have not been filled. With the common case where VPD is missing for fitting the LRC, by default (with controlGLPart$isRefitMissingVPDWithNeglectVPDEffect = TRUE) is to redo the estimation of LRC parameters with neglecting the VPD-effect. Next, in the predictions (rows) with missing VPD are then replaced with predictions based on LRC-fits that neglected the VPD effect.

Value

Reco_DT_<suffix>	predicted ecosystem respiration: mumol CO2/m2/s
GPP_DT_<suffix>	predicted gross primary production mumol CO2/m2/s
<LRC>	Further light response curve (LRC) parameters and their standard deviation depend on the used LRC (e.g. for the non-rectangular LRC see NonrectangularLRCFitter_getParameterNames). They are estimated for windows and are reported with the first record of the window
FP_VARnight	NEE filtered for nighttime records (others NA)
FP_VARday	NEE filtered for daytime records (others NA)
NEW_FP_Temp	temperature after filtering for quality flag degree Celsius
NEW_FP_VPD	vapour pressure deficit after filtering for quality flag, hPa
FP_RRef_Night	basal respiration estimated from nighttime (W / m2)
FP_qc	quality flag: 0: good parameter fit, 1: some parameters out of range, required refit, 2: next parameter estimate is more than two weeks away
FP_dRecPar	records until or after closest record that has a parameter estimate associated
FP_errorcode	information why LRC-fit was not successful or was rejected, see result of LightResponseCurveFitter_fitLRC
FP_GPP2000	predicted GPP at VPD = 0 and PAR = 2000: a surrogate for maximum photosynthetic capacity
FP_OPT_VPD	list object of fitting results including iOpt and covParms
FP_OPT_NoVPD	same as FP_OPT_VPD holding optimization results with fit neglecting the VPD effect

Author(s)

TW Department for Biogeochemical Integration at MPI-BGC, Jena, Germany <[e-mail]> [cph], Thomas Wutzler <[e-mail]> [aut, cre], Markus Reichstein <[e-mail]> [aut], Antje Maria Moffat <[e-mail]> [aut, trl], Olaf Menzer <[e-mail]> [ctb], Mirco Migliavacca <[e-mail]> [aut], Kerstin Sickel <[e-mail]> [ctb, trl], Ladislav <U+0160>igut <[e-mail]> [ctb]

References

Lasslop G, Reichstein M, Papale D, et al. (2010) Separation of net ecosystem exchange into assimilation and respiration using a light response curve approach: critical issues and global evaluation. Global Change Biology, Volume 16, Issue 1, Pages 187-208

See Also

partGLFitNightTimeTRespSens

partGLFitLRCWindows

partGLInterpolateFluxes

REddyProc documentation built on May 29, 2024, 12:10 p.m.