Simulates the light macro environment — lightME • PEcAn.data.atmosphere

Simulates light macro environment based on latitude, day of the year. Other coefficients can be adjusted.

Usage

lightME(lat = 40, DOY = 190, t.d = 12, t.sn = 12, atm.P = 1e+05, alpha = 0.85)

Arguments

lat: the latitude, default is 40 (Urbana, IL, U.S.).
DOY: the day of the year (1–365), default 190.
t.d: time of the day in hours (0–23), default 12.
t.sn: time of solar noon, default 12.
atm.P: atmospheric pressure, default 1e5 (kPa).
alpha: atmospheric transmittance, default 0.85.

Value

a list structure with components:

'I.dir': Direct radiation (\(\mu\) mol \(m^{-2}s^{-1}\)
'I.diff': Indirect (diffuse) radiation (\(\mu\) mol\(m^{-2}s^{-1}\)
'cos.th': cosine of \(\theta\), solar zenith angle.
'propIdir': proportion of direct radiation.
'propIdiff': proportion of indirect (diffuse) radiation.