parameter, description
time, timestamp in format "YYYY-mm-dd HH:MM:SS"
incPPFD, Incoming Photosynthetic photon flux density in μmol.m-2.s-1
bcPPFD_1, First below canopy PPFD in μmol.m-2.s-1; averaged with bcPPFD_2 to get the averaged bcPPFD for trees
bcPPFD_2, Second below canopy PPFD in μmol.m-2.s-1; averaged with bcPPFD_1 to get the averaged bcPPFD for trees
naPPFD, non-absorbed PPFD by grass in  μmol.m-2.s-1
frac_grass, fraction of absorbed PPFD for grass; unitless
frac_trees, fraction of absorbed PPFD for trees; unitless
frac, weighted average of frac_grass and frac_trees using weights of 0.7 and 0.3 respectively to account for the relative cover of grass and trees; unitless
VPD, Vapor pressure deficit in hPa
GPP, Gross primary production in gC.m-2.30min-1 (scaled to 30min from average per second)
SWC, Soil water content in the forest, in m3.m-3
Rg, Global radiation per 30min in MJ.m-2.30min-1
PAR, Photosynthetically active radiation obtained from Rg using a factor of 0.45; same unit as Rg; MJ.m-2.30min-1
APAR, Absorbed PAR obtained by multiplying PAR by frac; same unit as Rg and PAR MJ.m-2.30min-1
uncloudy, binary variable (0/1) characterizing days without cloud or with negligible clouds; obtained by fitting the downward quadratic function "y=x+x²" to the incoming half-hourly PPFD from 7am to 3pm. Uncloudy days have r²>0.95