GPPFourier: Calculate GPP from O2 time series

In GPPFourier: Calculate Gross Primary Production (GPP) from O2 Time Series

Description

This is the workhorse to calculate aquatic Gross Primary Production from high frequency dissolved oxygen data. It will often be more convenient to use the higher level functions WindowGPPFourier and WindowGPPFourier.gts

Usage

GPPFourier(x, dt = NULL, units = c("days", "hours", "mins"), Nfilt = NULL,
  fDL = NULL, filtcorrect = FALSE, phi = NULL, lambda = NULL, ...)

Arguments

x	Regularly sampled O2 time series. x can be a dataframe with time (POSIXt) in first column and O2 concentrations in second column or a vector of concentrations sampled with time step = dt
dt	Sampling time step. Not used when x is a data frame, then dt is calculated #' from the time spacing between the first two samples. Either a difftime object or a numerical value. When dt is given as a numerical value, units have to be provided.
units	Unit of sampling time step
Nfilt	Moving average filter width
fDL	Relative fraction of light hours during the day. When x is a data frame, and no value for fDL is provided, fDL is calculated with fDLfun
filtcorrect	Logical controlling whether GPP estimate is corrected for signal falsely removed by filtering
phi	Optional: Lattitude. Only used when fDL=NULL and daylength is calculated with fDLfun
lambda	Optional: Lattitude. Only used when fDL=NULL and daylength is calculated with fDLfun
...	Other parameters to be passed to GPPFourierPreprocess

Details

no details

Value

Volume specific average gross primary production in units of oxgen as in x. per time unit (unit of dt, given by units). Specifically: if O2 concentrations are in mg/L, and units = days, calculated GPP has units mg/L/day. If surface specific primary production (e.g. per m2) is desired, this number has to be multiplied by the depth of the water body.

Author(s)

Tom Cox <[e-mail]>

References

Cox T.J.S. et al. (2015) 'Estimating primary production from oxygen time series: a novel approach in the frequency domain', Limnology And Oceanography:Methods 13, 529-552. DOI: 10.1002/lom3.10046

See Also

GPPFourierPreprocess, GPPFourier_t, WindowGPPFourier, WindowGPPFourier.gts

Examples

DO <- Kruibeke[Kruibeke$time>="2010-06-03"&Kruibeke$time<="2010-06-13",]
dt <- as.numeric(difftime(DO$time[2],DO$time[1],units="days"))
DL <- fDLfun(DO$time[1], phi=51.176, lambda=4.326) 
GPP <- GPPFourier(DO$O2,dt=dt,Nfilt=100,fDL=DL)

GPPFourier documentation built on Sept. 22, 2017, 5:06 p.m.