nsrdb.all_sky.all_sky.all_sky

all_sky(alpha, aod, asymmetry, cloud_type, cld_opd_dcomp, cld_reff_dcomp, ozone, solar_zenith_angle, ssa, surface_albedo, surface_pressure, time_index, total_precipitable_water, cloud_fill_flag=None, variability_kwargs=None, scale_outputs=True, disc_on=False)[source]

Calculate the all-sky irradiance. Updated by Yu Xie on 3/29/2023 to compute DNI by FARMS-DNI.

Variables

dni_farmsdni: np.ndarray

DNI computed by FARMS-DNI (Wm-2).

dni0: np.ndarray
DNI computed by the Lambert law (Wm-2). It only includes the narrow

beam in the circumsolar region.

Updated by Yu Xie on 3/29/2023 to compute DNI by FARMS-DNI.

Variables

dni_farmsdni: np.ndarray

DNI computed by FARMS-DNI (Wm-2).

Parameters:

  • alpha (np.ndarray) – Angstrom wavelength exponent, ideally obtained by linear regression of all available spectral AODs between 380 and 1020 nm. Input value will be tested for compliance with the mandatory interval [0, 2.5], and corrected if necessary.

  • aod (np.ndarray) – Array of aerosol optical depth (AOD) values.

  • asymmetry (np.ndarray) – Aerosol asymmetry parameter. Since it tends to vary with wavelength and alpha, use a representative value for a wavelength of about 700 nm and alpha about 1. Will default to 0.7 if a NEGATIVE value is input (when exact value is unknown).

  • cloud_type (np.ndarray) – Array of integer cloud types.

  • cloud_opd_dcomp (np.ndarray) – Array of cloud optical depths. Expected range is 0 - 160 with missing values <= 0.

  • cld_reff_dcomp (np.ndarray) – Array of cloud effective partical radii. Expected range is 0 - 160 with missing values <= 0.

  • ozone (np.ndarray) – reduced ozone vertical pathlength (atm-cm) [Note: 1 atm-cm = 1000 DU]

  • solar_zenith_angle (np.ndarray) – Solar zenith angle (degrees). Must represent the average value over the integration period (e.g. hourly) under scrutiny.

  • ssa (np.ndarray) – aerosol single-scattering albedo at a representative wavelength of about 700 nm. Use -9.99 or any other NEGATIVE value if unknown (will default to 0.92 if a negative value is input)

  • surface_albedo (np.ndarray) – Ground albedo.

  • surface_pressure (np.ndarray) – Surface pressure (mbar).(mbar is same as hPa)

  • time_index (pd.DatetimeIndex) – Time index.

  • total_precipitable_water (np.ndarray) – Total precip. water (cm).

  • cloud_fill_flag (None | np.ndarray) – Integer array of flags showing what data was previously filled and why. None will create a new fill flag initialized as all zeros. An array input will be interpreted as flags showing which cloud properties have already been filled.

  • variability_kwargs (NoneType | dict) – Variability key word args to apply to GHI. Provides synthetic variability for cloudy irradiance when downscaling data. See nsrdb.all_sky.utilities.cloud_variability for kwarg definitions.

  • scale_outputs (bool) – Flag to safely scale and dtype convert output arrays.

  • disc_on (bool) – Compute cloudy-sky DNI using FARMS-DNI (False) or DISC (True).

returns:

output (dict) – Namespace of all-sky irradiance output variables with the following keys:

‘clearsky_dhi’ ‘clearsky_dni’ ‘clearsky_ghi’ ‘dhi’ ‘dni’ ‘ghi’ ‘fill_flag’