Simulates the light macro environment

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

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.