fRegrE0fromShortTerm: Estimation of the temperature sensitivity E_0

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

Description

Estimation of the temperature sensitivity E_0 from regression of fLloydTaylor for short periods

Usage

fRegrE0fromShortTerm(NightFlux.V.n, TempVar.V.n, DayCounter.V.i, 
    WinDays.i = 7, DayStep.i = 5, TempRange.n = 5, 
    Trim.n = 5, NumE_0.n = 3, MinE_0.n = 30, MaxE_0.n = 450, 
    T_ref.n, CallFunction.s = "", optimAlgorithm = "default")

Arguments

NightFlux.V.n	(Original) nighttime ecosystem carbon flux, i.e. respiration vector
TempVar.V.n	(Original) air or soil temperature vector (degC)
DayCounter.V.i	Integer specifying the day of each record
WinDays.i	Window size for fLloydTaylor regression in days
DayStep.i	Window step for fLloydTaylor regression in days
TempRange.n	Threshold temperature range to start regression (#! Could be larger for Tair)
Trim.n	Percentile to trim residual (%)
NumE_0.n	Number of best E_0's to average over
MinE_0.n	Minimum E0 for validity check
MaxE_0.n	Maximum E0 for validity check
T_ref.n
CallFunction.s	Name of function called from
optimAlgorithm	optimization algorithm used (see nls ) or 'LM' for Levenberg-Marquard (see nlsLM from package minpack.lm)

Details

The coefficient E0 is estimated for windows with a length of WinDays.i days, for successive periods in steps of DayStep.i days. Only those windows with a sufficient number or records and with a sufficient temperature range TempRange.n are used for the fLloydTaylor regression of E0 using the optimization fOptimSingleE0. Unreasonable estimates are discarded (95% confidence interval inside MinE_0.n and MaxE_0.n and the others are ordered by their standard deviations. The mean across the best (=lowest standard deviation) E0 estimates is reported with NumE_0.n defining the number of best estimates to use.

Take average of the three E_0 with lowest standard deviation

Value

Estimated scalar temperature sensitivity (E_0, degK)

Author(s)

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

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