tt.nee {flux}

Medium frequency concentration data and fluxes from non-steady state closed chamber measurements

Description

The data comes from the Trebeltal / Northeastern Germany and has been recorded with flexible transparent and opaque non-steady state closed chambers in 2011.

Usage

data(tt.nee)
data(tt.flux)

Format

tt.nee is a data.frame with 18 variables representing 14388 CO2 concentration measurements from 104 chamber placements.

tt.flux is a results table representing fluxes estimated with fluxx from tt.nee with 28 columns and 104 rows (= number of chamber placements in tt.nee). Contains many variables from tt.nee.

date

Factor giving the date of field sampling, format is "%Y-%m-%d".

time

Factor giving the time of measurement in the field, format is "%H:%M:%S".

session

(Unique) Session number identifying one chamber placement. Integer.

record

Integer, running number of concentration measurement within one session.

spot

Factor identifying the field measurement location.

PAR

Numeric. Photosynthetic photon flux density (PPFD).

t.cham

Numeric. Temperature logged inside chamber during concentration measurements

NEE

Numeric. CO2 concentration in chamber headspace.

t.air

Numeric. Air temperature outside chamber.

t.soil2

Numeric. Soil temperature at 2cm depth.

t.soil5

Numeric. Soil temperature at 5cm depth.

t.soil10

Numeric. Soil temperature at 10cm depth.

area

Numeric. Chamber area.

height

Numeric. Chamber height.

kind

Integer. Chamber kind. 1 = transparent chamber, 3 = transparent chamber with measurement before sun rise, 5 = opaque chamber

volume

Numeric. Chamber volume.

datetime

POSIXlt. Time stamp.

plot

Factor identifying the field plot (all TY1).

all

Factor. Combined unique identifier for chamber placement.

CO2.pv

Numeric. p.value of the fitted regression for the flux estimation.

CO2.r2.f

Logical numeric (0 | 1) giving the r2 flag. See fluxx for details.

CO2.range.f

Logical numeric (0 | 1) giving the range flag. See fluxx for details.

CO2.nrmse.f

Logical numeric (0 | 1) giving the nrmse flag. See fluxx for details.

CO2.ghg

Character. Greenhouse gas as submitted to fluxx via var.par.

CO2.unit

Character. Ouput unit of the flux as specified via out.unit in fluxx.

CO2.flux

Numeric. Flux

CO2.r2

Numeric. R2 of the model that has been used for flux estimation.

CO2.nrmse

Numeric. NRMSE of the model that has been used for flux estimation.

CO2.nomba.f

Numeric. Number of concentration measurements below ambient.

CO2.podpu

Numeric between 0 and 1. Propórtion of data points used.

Details

tt.nee contains medium frequency (measured online) CO2 concentration data from 3 spots with Typha angustifolia and includes data needed for modelling gpp/nne measured with transparent chamber and reco measured with opaque chamber. tt.flux contains fluxes estimated from tt.nee using fluxx.

Source

unpublished preliminary data

Examples

## see examples at fluxx and gpp.