The variables are as follows:
time_EEST POSIXct Local time according to EET coordinates.
UTC POSIXct Local time according to UTC.
ppfd_tot_mean numeric (umol m-2 m-2)
ppfd_tot_min numeric (umol m-2 m-2)
ppfd_tot_max numeric (umol m-2 m-2)
ppfd_tot_sd numeric (umol m-2 m-2)
ppfd_diff_mean numeric (umol m-2 m-2)
ppfd_diff_min numeric (umol m-2 m-2)
ppfd_diff_max numeric (umol m-2 m-2)
ppfd_diff_sd numeric (umol m-2 m-2)
These data are part of a much larger data set (Aphalo, 2023).
Instrument used: Delta-T BF5 "quantum sensor" , mounted on tripod at
approximately 2 m height. Data collected with a Campbell Scientific CR6
datalogger, using analogue outputs from the sensor. Wavelength sensitivity
range of the quantum sensor is 400 nm to 700 nm, but response is not
proportional to energy quanta across wavelengths. Sensor calibrated in site
for sunlight. Location: Viikki campus of the University of Helsinki,
Finland. Coordinates: 60.226803 N, 25.019205 E.