pyet.rad_utils.calc_rad_net

pyet.rad_utils.calc_rad_net(tmean, rn=None, rs=None, lat=None, n=None, nn=None, tmax=None, tmin=None, rhmax=None, rhmin=None, rh=None, elevation=None, rso=None, a=1.35, b=-0.35, ea=None, albedo=0.23, as1=0.25, bs1=0.5, kab=None)

Net radiation [MJ m-2 d-1].

Parameters:

• tmean (pandas.Series/xarray.DataArray) – average day temperature [°C].

• rn (float or pandas.Series or xarray.DataArray, optional) – net radiation [MJ m-2 d-1].

• rs (float or pandas.Series or xarray.DataArray, optional) – incoming solar radiation [MJ m-2 d-1].

• lat (float/xarray.DataArray, optional) – the site latitude [rad].

• n (float or pandas.Series or xarray.DataArray, optional) – actual duration of sunshine [hour].

• nn (float or pandas.Series or xarray.DataArray, optional) – maximum possible duration of sunshine or daylight hours [hour].

• tmax (float or pandas.Series or xarray.DataArray, optional) – maximum day temperature [°C].

• tmin (float or pandas.Series or xarray.DataArray, optional) – minimum day temperature [°C].

• rhmax (float or pandas.Series or xarray.DataArray, optional) – maximum daily relative humidity [%].

• rhmin (float or pandas.Series or xarray.DataArray, optional) – mainimum daily relative humidity [%].

• rh (float or pandas.Series or xarray.DataArray, optional) – mean daily relative humidity [%].

• elevation (float/xarray.DataArray, optional) – the site elevation [m].

• rso (float or pandas.Series or xarray.DataArray, optional) – clear-sky solar radiation [MJ m-2 day-1].

• a (float, optional) – empirical coefficient for Net Long-Wave radiation [-].

• b (float, optional) – empirical coefficient for Net Long-Wave radiation [-].

• ea (float or pandas.Series or xarray.DataArray, optional) – actual vapor pressure [kPa].

• albedo (float, optional) – surface albedo [-]

• as1 (float, optional) – regression constant, expressing the fraction of extraterrestrial reaching the earth on overcast days (n = 0) [-]

• bs1 (float, optional) – empirical coefficient for extraterrestrial radiation [-]

• kab (float, optional) – coefficient derived from as1, bs1 for estimating clear-sky radiation [degrees].

Returns:

• float or pandas.Series or xarray.DataArray, optional containing the calculated net

• shortwave radiation.

Notes

Based on equation 40 in Allen et al. (1998).