This module calculates the radiative transfer of SW radiation in snow-covered terrain. It can take into account anisotropic reflection of light on snow (forward scattering) and multiple reflections in the terrain. More...

#include <TerrainRadiationComplex.h>

Public Member Functions
	TerrainRadiationComplex (const mio::Config &cfg, const mio::DEMObject &dem_in, const std::string &method)

	~TerrainRadiationComplex ()

virtual void	getRadiation (mio::Array2D< double > &direct, mio::Array2D< double > &diffuse, mio::Array2D< double > &terrain, const mio::Array2D< double > &direct_unshaded_horizontal, const mio::Array2D< double > &total_ilwr, mio::Array2D< double > &sky_ilwr, mio::Array2D< double > &terrain_ilwr, double solarAzimuth, double solarElevation)
	Computes direct, diffuse and terrain radiation for each gridpoint. Terrain radiation. More...

virtual void	setMeteo (const mio::Array2D< double > &albedo, const mio::Array2D< double > &ta)

void	getSkyViewFactor (mio::Array2D< double > &o_sky_vf)

void	setSP (const mio::Date timestamp, const double solarAzimuth, const double solarElevation)

void	writeSP (const unsigned int max_steps)

Public Member Functions inherited from TerrainRadiationAlgorithm
	TerrainRadiationAlgorithm (const std::string &i_algo)

virtual	~TerrainRadiationAlgorithm ()

bool	hasSP ()

virtual void	getRadiation (mio::Array2D< double > &direct, mio::Array2D< double > &diffuse, mio::Array2D< double > &terrain, const mio::Array2D< double > &direct_unshaded_horizontal, const mio::Array2D< double > &total_ilwr, mio::Array2D< double > &sky_ilwr, mio::Array2D< double > &terrain_ilwr, double solarAzimuth, double solarElevation)=0

virtual void	setMeteo (const mio::Array2D< double > &albedo, const mio::Array2D< double > &ta)=0

virtual void	setSP (const mio::Date, const double, const double)

virtual void	writeSP (const unsigned int)

virtual void	getSkyViewFactor (mio::Array2D< double > &o_sky_vf)=0

Additional Inherited Members
Public Attributes inherited from TerrainRadiationAlgorithm
const std::string	algo

Protected Attributes inherited from TerrainRadiationAlgorithm
bool	_hasSP

Detailed Description

This module calculates the radiative transfer of SW radiation in snow-covered terrain. It can take into account anisotropic reflection of light on snow (forward scattering) and multiple reflections in the terrain.

The price for this complexity is high: The initialization time is extremely long (for a DEM with 30'000 pixels it can be 12 hours. However, if a ViewList-file is generated during the initialization, it can be bypassed in later simulations. ) In the main computation loop, the effort is considerable too and may dominate the simulation time in many cases. Therefore, this module is recommended for explicit radiation investigations based on relatively small, high-resolution DEM's. It can also be coupled to the SolarPanel-module for precise simulation of radiation on photovoltaic panels.

The algorithm is described in F. von Rütte et al., "How Forward-Scattering Snow and Terrain Change the Alpine Radiation Balance With Application to Solar Panels", Journal of Geophysical Research: Atmospheres 126.15 (2021), 10.1029/2020JD034333 or in the master thesis of Felix von Rütte (under the supervision of M. Lehning), entitled "Radiative Transfer Model for Snowy Mountains" (in the comments, it is often referred to by the abbreviation "MT").

This algorithm is configured with the following ini keys:

COMPLEX_ANISOTROPY: Whether a snow BRDF should be included. False means isotropic scattering (true or false);
COMPLEX_MULTIPLE : Whether multiple scattering in the terrain should be taken into account (true or false);
COMPLEX_WRITE_VIEWLIST : Whether the initialization data should be written to file (it requires an already existing "output" folder); (true or false);
COMPLEX_READ_VIEWLIST : Whether an existing initialization file should be read in; bypassing the initialization (true or false);
COMPLEX_VIEWLISTFILE : Path and filename to the ViewList file if existing, for example "../input/surface-grids/ViewList_Totalp_30x30.rad", ()

[EBalance]
TERRAIN_RADIATION = TRUE
TERRAIN_RADIATION_METHOD = COMPLEX
 
COMPLEX_ANISOTROPY      = TRUE
COMPLEX_MULTIPLE        = TRUE
COMPLEX_WRITE_VIEWLIST  = FALSE
COMPLEX_READ_VIEWLIST   = TRUE
COMPLEX_VIEWLISTFILE = ../input/surface-grids/ViewList_Totalp_30x30.rad

Constructor & Destructor Documentation

◆ TerrainRadiationComplex()

TerrainRadiationComplex::TerrainRadiationComplex	(	const mio::Config &	cfg,
		const mio::DEMObject &	dem_in,
		const std::string &	method
	)

◆ ~TerrainRadiationComplex()

TerrainRadiationComplex::~TerrainRadiationComplex ( )

Member Function Documentation

◆ getRadiation()

void TerrainRadiationComplex::getRadiation	(	mio::Array2D< double > &	direct,
		mio::Array2D< double > &	diffuse,
		mio::Array2D< double > &	terrain,
		const mio::Array2D< double > &	direct_unshaded_horizontal,
		const mio::Array2D< double > &	total_ilwr,
		mio::Array2D< double > &	sky_ilwr,
		mio::Array2D< double > &	terrain_ilwr,
		double	solarAzimuth,
		double	solarElevation
	)

virtual

Computes direct, diffuse and terrain radiation for each gridpoint. Terrain radiation.

Parameters

[out]	direct	Direct short wave radiation component
[out]	diffuse	Diffuse short wave radiation component
[out]	terrain	Terrain reflected short wave radiation component
[in]	total_ilwr	Total Incoming Long Wave radiation (unused)
[in]	sky_ilwr	Incoming Long Wave radiation coming from the sky (unused)
[in]	terrain_ilwr	Incoming Long Wave radiation emitted by the terrain (unused)
[in]	solarAzimuth	Azimuth of the Sun in the sky
[in]	solarElevation	Elevation of the Sun in the sky