sEstUstarThresholdDistribution: sEstUstarThresholdDistribution

In REddyProc: Data processing and plotting utilities of (half-)hourly eddy-covariance measurements

Description

Estimating the distribution of u* threshold by bootstrapping over data

Usage

sEstUstarThresholdDistribution(ctrlUstarEst.l = usControlUstarEst(), 
    ctrlUstarSub.l = usControlUstarSubsetting(), UstarColName = "Ustar", 
    NEEColName = "NEE", TempColName = "Tair", RgColName = "Rg", 
    ..., seasonFactor.v = usCreateSeasonFactorMonth(sDATA$sDateTime), 
    seasonFactorsYear = usGetYearOfSeason(seasonFactor.v, 
        ds$sDateTime), nSample = 100L, probs = c(0.05, 
        0.5, 0.95), verbose.b = TRUE)

Arguments

ctrlUstarEst.l	control parameters for estimating uStar on a single binned series, see usControlUstarEst
ctrlUstarSub.l	control parameters for subsetting time series (number of temperature and Ustar classes ...), see usControlUstarSubsetting
UstarColName	column name for UStar
NEEColName	column name for NEE
TempColName	column name for air temperature
RgColName	column name for solar radiation for omitting night time data
...	further arguments to sEstUstarThreshold
seasonFactor.v	factor of seasons to split (data is resampled only within the seasons)
seasonFactorsYear	named integer vector: for each seasonFactor level, get the year that this season belongs to
nSample	the number of repetitions in the bootstrap
probs	the quantiles of the bootstrap sample to return. Default is the 5%, median and 95% of the bootstrap
verbose.b	set to FALSE to omit printing progress

Details

The choice of the criterion for sufficiently turbulent conditions (u* > choosen threshold) introduces large uncertainties in calculations based on gap-filled Eddy data. Hence, it is good practice to compare derived quantities based on gap-filled data using a range of u* threshold estimates.

Quality Assurance

If more than ctrlUstarEst.l$minValidBootProp (default 40%) did not report a treshold, no quantiles (i.e. NA) are reported.

Value

A data.frame with columns aggregationMode, year, and UStar estimate based on the unresampled data. The other columns correpond to the quantiles of Ustar estimate for given probabilities (argument probs based on the distribution of estimates using resampled the data.

Author(s)

TW (Department for Biogeochemical Integration at MPI-BGC, Jena, Germany)

See Also

sEstUstarThreshold, sMDSGapFillAfterUStarDistr

REddyProc documentation built on May 2, 2019, 5:19 p.m.