mlclouds.tdisc.tdisc

tdisc(ghi, sza, doy, pressure=101325, sza_lim=89.0)[source]

Estimate DNI from GHI using the DISC model.

*Warning: should only be used for cloudy FARMS data.

The DISC algorithm converts global horizontal irradiance to direct normal irradiance through empirical relationships between the global and direct clearness indices.

Parameters:

  • ghi (np.ndarray) – Global horizontal irradiance in W/m2.

  • sza (np.ndarray) – Solar zenith angle in degrees.

  • doy (np.ndarray) – Day of year (array of integers).

  • pressure (np.ndarray) – Pressure in mbar (same as hPa).

  • sza_lim (float | int) – Upper limit for solar zenith angle in degrees. SZA values greater than this will be truncated at this value.

Returns:

DNI (np.ndarray) – Estimated direct normal irradiance in W/m2.