Detailed Description

Station data including all information on snowpack layers (elements and nodes) and on canopy
This is the PRIMARY data structure of the SNOWPACK program
It is used extensively not only during the finite element solution but also to control the post-processing writes. It is initialized from SN_SNOWSOIL_DATA (at present).

#include <DataClasses.h>

Public Member Functions
	SnowStation (const bool &i_useCanopyModel=true, const bool &i_useSoilLayers=true)

	SnowStation (const SnowStation &c)

	~SnowStation ()

SnowStation &	operator= (const SnowStation &)
	Assignement operator. More...

void	initialize (const SN_SNOWSOIL_DATA &SSdata, const size_t &i_sector)
	This routine initializes the snow cover structure which contains all information about a station including element, nodal and canopy data Because you are working with layers, the first node is a special case; the rest can be generated in a loop .... The bottom temperature at the beginning of the computation is given by the temperature at the top of the lowest soil or snow layer IMPORTANT: it is very important for Alpine3D that Cdata.height is initialized even if CANOPY = 0, otherwise SnowInterface will not recognize the canopy grids (David 2007-06-25). More...

void	resize (const size_t &number_of_elements)
	Reallocate element and node data Edata and Ndata as well as nElems and nNodes are reallocated or reset, respectively. More...

void	reduceNumberOfElements (const size_t &rnE)
	Remove the upper "marked" element of two (snow only) Merging two elements: density is undefined take the uppermost node of both Removing melted or thin elements density is undefined AND length negative (*= -1.) as the latter will be used! keep upper node of lowest element. More...

void	combineElements (const size_t &number_top_elements, const bool &reduce_n_elements)
	If more than NUMBER_TOP_ELEMENTS snow elements exist, attempt to reduce their number in the FEM mesh, leaving NUMBER_TOP_ELEMENTS surface elements untouched Pairs of elements within the snow cover satisfying the conditions of combineCondition() are combined by placing everything in the lower element, setting the density of upper element to Constants::undefined, and getting rid of node in between. The elements being very similar and thus the microstructure parameters being approximately equal as defined in combineCondition(), simply average the microstructure properties NOTE that the condense element check is placed at the end of a time step, allowing elements do develop on their own. More...

void	combineElements (const size_t &number_top_elements, const bool &reduce_n_elements, const size_t &cond)

void	splitElement (const size_t &e)
	Split the element provided as first argument. More...

void	splitElements ()
	Split elements when they are near the top of the snowpack, when REDUCE_N_ELEMENTS is used. More...

void	compSnowpackMasses ()
	Computes the actual total masses of the snowpack (kg m-2) More...

void	compSnowpackInternalEnergyChange (const double &sn_dt)
	Computes the internal energy change of the snowpack during one computation time step (J m-2) More...

void	compSoilInternalEnergyChange (const double &sn_dt)
	Computes the internal energy change of the soil during one computation time step (J m-2) More...

double	getLiquidWaterIndex () const
	Computes the liquid water index defined as the ratio of total liquid water content (in mm w.e.) to calculated snow depth (in mm) divided by 0.03. Unit: (1) More...

double	getModelledTemperature (const double &z) const
	Returns modelled internal snow or/and soil temperature (instantaneous value; degC), at a given position z perpendicular to slope (m) z must be less than computed height (Xdata->cH), otherwise modeled temperature is set to Constants::undefined. More...

size_t	getNumberOfElements () const

size_t	getNumberOfNodes () const

bool	isGlacier (const bool &hydro=false) const
	returns if a snow profile can be considered as a glacier. Practically, the hydrological criteria is that if a pixel contains more than 2 m of pure ice anywhere, it is considered to be glaciated. The standard criteria is that if the top 5 layers are made of pure ice, the pixel is glaciated. Therefore, a glacier covered by seasonal snow is glaciated in regard to the hydrological criteria but non-glaciated in regard to the standard criteria. More...

bool	hasSoilLayers () const

size_t	find_tag (const size_t &tag) const
	Find element with corresponding tag or return IOUtils::npos if not found. More...

const std::string	toString () const

Static Public Member Functions
static bool	combineCondition (const ElementData &Edata0, const ElementData &Edata1, const double &depth, const bool &reduce_n_elements)
	Boolean routine to check whether two snow elements can be combined. More...

static void	mergeElements (ElementData &Edata0, const ElementData &Edata1, const bool &merge, const bool &topElement)
	Merging two elements. More...

Public Attributes
mio::StationData	meta
	Station meta data. More...

double	cos_sl
	Cosinus of slope angle, initialized once! More...

size_t	sector
	current slope sector of width 360./max(1, nSlopes-1) More...

CanopyData	Cdata
	Pointer to canopy data. More...

double	pAlbedo
	Parameterized snow albedo. More...

double	Albedo
	Snow albedo used by the model. More...

double	SoilAlb
	Soil albedo. More...

double	BareSoil_z0
	Bare soil roughness in m. More...

size_t	SoilNode
	The top soil node, 0 in case of SNP_SOIL == 0. More...

double	Ground
	The ground height – meaning the height of the top soil node. More...

double	cH
	The CALCULATED height, including soil depth if SNP_SOIL == 1. More...

double	mH
	The MEASURED height, including soil depth if SNP_SOIL == 1. More...

double	mass_sum
	Total mass summing mass of snow elements. More...

double	swe
	Total mass summing snow water equivalent of elements. More...

double	lwc_sum
	Total liquid water in snowpack. More...

double	hn
	Depth of new snow to be used on slopes. More...

double	rho_hn
	Density of new snow to be used on slopes. More...

size_t	ErosionLevel
	Element where snow erosion stopped previously for the drift index. More...

double	ErosionMass
	Eroded mass either real or virtually (storage if less than one element) More...

char	S_class1
	Stability class based on hand hardness, grain class ... More...

char	S_class2
	Stability class based on hand hardness, grain class ... More...

double	S_d
	Minimum Direct Action Stability Index ... More...

double	z_S_d
	Depth of Minimum Direct Action Stability. More...

double	S_n
	Minimum Natural Stability Index. More...

double	z_S_n
	Depth of Minimum Natural Stability. More...

double	S_s
	Minimum Skier Stability Index (SSI) More...

double	z_S_s
	Depth of Minimum SSI. More...

double	S_4
	stab_index4 More...

double	z_S_4
	Depth of stab_index4. More...

double	S_5
	stab_index5 More...

double	z_S_5
	Depth of stab_index5. More...

std::vector< NodeData >	Ndata
	pointer to nodal data array (e.g. T, z, u, etc..) More...

std::vector< ElementData >	Edata
	pointer to element data array (e.g. Te, L, Rho, etc..) More...

void *	Kt
	Pointer to pseudo-conductivity and stiffnes matrix. More...

double	ColdContent
	Cold content of snowpack (J m-2) More...

double	ColdContentSoil
	Cold content of soil (J m-2) More...

double	dIntEnergy
	Internal energy change of snowpack (J m-2) More...

double	dIntEnergySoil
	Internal energy change of soil (J m-2) More...

double	meltFreezeEnergy
	Melt freeze part of internal energy change of snowpack (J m-2) More...

double	meltFreezeEnergySoil
	Melt freeze part of internal energy change of soil (J m-2) More...

double	ReSolver_dt
	Last used RE time step in the previous SNOWPACK time step. More...

bool	windward
	True for windward (luv) slope. More...

double	WindScalingFactor
	Local scaling factor for wind at drift station. More...

double	TimeCountDeltaHS
	Time counter tracking erroneous settlement in operational mode. More...

Static Public Attributes
static const void *	Seaice = NULL
	dummy pointer for compatibility with the dev version More...

static const double	comb_thresh_l = 0.015
	Both elements must be smaller than COMB_THRESH_L (m) for an action to be taken. More...

static const double	comb_thresh_ice = 0.05
	Volumetric ice content (1), i.e., about 46 kg m-3. More...

static const double	comb_thresh_water = 0.01
	Water content (1) More...

static const double	comb_thresh_dd = 0.2
	Dendricity (1) More...

static const double	comb_thresh_sp = 0.05
	Sphericity (1) More...

static const double	comb_thresh_rg = 0.125
	Grain radius (mm) More...

static const double	thresh_moist_snow = 0.003
	Snow elements with a LWC above this threshold are considered at least to be moist. More...

static const double	thresh_moist_soil = 0.0001

static const size_t	number_top_elements = 5
	Number of top elements left untouched by the join functions. More...

static unsigned short	number_of_solutes = 0
	The model treats that number of solutes. More...

Friends
std::ostream &	operator<< (std::ostream &os, const SnowStation &data)

std::istream &	operator>> (std::istream &is, SnowStation &data)

Constructor & Destructor Documentation

◆ SnowStation() [1/2]

SnowStation::SnowStation	(	const bool &	i_useCanopyModel = `true`,
		const bool &	i_useSoilLayers = `true`
	)

explicit

◆ SnowStation() [2/2]

SnowStation::SnowStation ( const SnowStation & c )

◆ ~SnowStation()

SnowStation::~SnowStation ( )

Member Function Documentation

◆ combineCondition()

bool SnowStation::combineCondition	(	const ElementData &	Edata0,
		const ElementData &	Edata1,
		const double &	depth,
		const bool &	reduce_n_elements
	)

static

Boolean routine to check whether two snow elements can be combined.

no action will be taken if one of the two elements is
- a soil element
- larger than comb_thresh_l
- tagged
- dry surface hoar (mk=3)
- dendritic but not both
otherwise we use criteria for dendricity, sphericity, volumetric ice or water content, grain size and marker
Whatever type of thin elements are treated in WaterTransport::mergingElements()

Parameters

Edata0	Lower element
Edata1	Upper element
depth	Distance of the element from the snow surface
reduce_n_elements	Enable more "aggressive" combining for layers deeper in the snowpack, to reduce the number of elements and thus the computational load.

Returns: true if the two elements should be combined, false otherwise

◆ combineElements() [1/2]

void SnowStation::combineElements	(	const size_t &	i_number_top_elements,
		const bool &	reduce_n_elements
	)

If more than NUMBER_TOP_ELEMENTS snow elements exist, attempt to reduce their number in the FEM mesh, leaving NUMBER_TOP_ELEMENTS surface elements untouched
Pairs of elements within the snow cover satisfying the conditions of combineCondition() are combined by placing everything in the lower element, setting the density of upper element to Constants::undefined, and getting rid of node in between.
The elements being very similar and thus the microstructure parameters being approximately equal as defined in combineCondition(), simply average the microstructure properties
NOTE that the condense element check is placed at the end of a time step, allowing elements do develop on their own.

Parameters

i_number_top_elements	The number of surface elements to be left untouched
reduce_n_elements	Enable more "aggressive" combining for layers deeper in the snowpack

◆ combineElements() [2/2]

void SnowStation::combineElements	(	const size_t &	number_top_elements,
		const bool &	reduce_n_elements,
		const size_t &	cond
	)

◆ compSnowpackInternalEnergyChange()

void SnowStation::compSnowpackInternalEnergyChange ( const double & sn_dt )

Computes the internal energy change of the snowpack during one computation time step (J m-2)

◆ compSnowpackMasses()

void SnowStation::compSnowpackMasses ( )

Computes the actual total masses of the snowpack (kg m-2)

◆ compSoilInternalEnergyChange()

void SnowStation::compSoilInternalEnergyChange ( const double & sn_dt )

Computes the internal energy change of the soil during one computation time step (J m-2)

◆ find_tag()

size_t SnowStation::find_tag ( const size_t & tag ) const

Find element with corresponding tag or return IOUtils::npos if not found.

Parameters

tag	Tag to look for

Returns: Index of tagged element, IOUtils::npos if not found

◆ getLiquidWaterIndex()

double SnowStation::getLiquidWaterIndex ( ) const

Computes the liquid water index defined as the ratio of total liquid water content (in mm w.e.) to calculated snow depth (in mm) divided by 0.03. Unit: (1)

◆ getModelledTemperature()

double SnowStation::getModelledTemperature ( const double & z ) const

Returns modelled internal snow or/and soil temperature (instantaneous value; degC), at a given position z perpendicular to slope (m)
z must be less than computed height (Xdata->cH), otherwise modeled temperature is set to Constants::undefined.

Version: 11.03

Parameters

z	Sensor position perpendicular to slope (m)

◆ getNumberOfElements()

size_t SnowStation::getNumberOfElements ( ) const

◆ getNumberOfNodes()

size_t SnowStation::getNumberOfNodes ( ) const

◆ hasSoilLayers()

bool SnowStation::hasSoilLayers ( ) const

◆ initialize()

void SnowStation::initialize	(	const SN_SNOWSOIL_DATA &	SSdata,
		const size_t &	i_sector
	)

This routine initializes the snow cover structure which contains all information about a station including element, nodal and canopy data
Because you are working with layers, the first node is a special case; the rest can be generated in a loop .... The bottom temperature at the beginning of the computation is given by the temperature at the top of the lowest soil or snow layer
IMPORTANT: it is very important for Alpine3D that Cdata.height is initialized even if CANOPY = 0, otherwise SnowInterface will not recognize the canopy grids (David 2007-06-25).

Version: 10.02

Parameters

SSdata
i_sector	defines the exposition sector of the slope (width 360./number_slopes)

◆ isGlacier()

bool SnowStation::isGlacier ( const bool & hydro = false ) const

returns if a snow profile can be considered as a glacier. Practically, the hydrological criteria is that if a pixel contains more than 2 m of pure ice anywhere, it is considered to be glaciated. The standard criteria is that if the top 5 layers are made of pure ice, the pixel is glaciated. Therefore, a glacier covered by seasonal snow is glaciated in regard to the hydrological criteria but non-glaciated in regard to the standard criteria.

Parameters

hydro if true, use an hydrologist criteria (default: false)

Returns: true if the profile belongs to a glacier

◆ mergeElements()

void SnowStation::mergeElements	(	ElementData &	EdataLower,
		const ElementData &	EdataUpper,
		const bool &	merge,
		const bool &	topElement
	)

static

Merging two elements.

Joining:
- Keep the lower element, that is, the lowest snow element always survives!
- The properties of the upper and lower elements are (depth) averaged in an appropriate way.
- The new length is the sum of both
- Keep the birthday of the upper element
- Keep the tag of the upper element only if the lower is untagged (mk >= 100)
- Note
  Joining two elements may cause the tag (marker >= 100) to "jump" abruptly

Removing:

Remaining ice, liquid water, solutes, etc. are added to the lower element
The length of the lower element is kept

Keep the birthday of the lower element

Parameters

EdataLower	Properties of lower element
EdataUpper	Properties of upper element
merge	True if upper element is to be joined with lower one, false if upper element is to be removed
topElement	set to true if the upper element is at the very top of the snow pack

◆ operator=()

SnowStation & SnowStation::operator= ( const SnowStation & source )

Assignement operator.

◆ reduceNumberOfElements()

void SnowStation::reduceNumberOfElements ( const size_t & rnE )

Remove the upper "marked" element of two (snow only)

Merging two elements:
1. density is undefined
2. take the uppermost node of both
Removing melted or thin elements
1. density is undefined AND length negative (*= -1.) as the latter will be used!
2. keep upper node of lowest element.

Parameters

rnE	Reduced number of elements

◆ resize()

void SnowStation::resize ( const size_t & number_of_elements )

Reallocate element and node data
Edata and Ndata as well as nElems and nNodes are reallocated or reset, respectively.

Parameters

number_of_elements The new number of elements

◆ splitElement()

void SnowStation::splitElement ( const size_t & e )

Split the element provided as first argument.

◆ splitElements()

void SnowStation::splitElements ( )

Split elements when they are near the top of the snowpack, when REDUCE_N_ELEMENTS is used.

This function split elements when they are getting closer to the top of the snowpack. This is required when using the "aggressive" merging option (REDUCE_N_ELEMENTS). When snow melt brings elements back to the snow surface, smaller layer spacing is required to accurately describe temperature and moisture gradients.

◆ toString()

const std::string SnowStation::toString ( ) const

Friends And Related Function Documentation

◆ operator<<

std::ostream& operator<<	(	std::ostream &	os,
		const SnowStation &	data
	)

friend

◆ operator>>

std::istream& operator>>	(	std::istream &	is,
		SnowStation &	data
	)

friend

Member Data Documentation

◆ Albedo

double SnowStation::Albedo

Snow albedo used by the model.

◆ BareSoil_z0

double SnowStation::BareSoil_z0

Bare soil roughness in m.

◆ Cdata

CanopyData SnowStation::Cdata

Pointer to canopy data.

◆ cH

double SnowStation::cH

The CALCULATED height, including soil depth if SNP_SOIL == 1.

◆ ColdContent

double SnowStation::ColdContent

Cold content of snowpack (J m-2)

◆ ColdContentSoil

double SnowStation::ColdContentSoil

Cold content of soil (J m-2)

◆ comb_thresh_dd

const double SnowStation::comb_thresh_dd = 0.2

static

Dendricity (1)

◆ comb_thresh_ice

const double SnowStation::comb_thresh_ice = 0.05

static

Volumetric ice content (1), i.e., about 46 kg m-3.

◆ comb_thresh_l

const double SnowStation::comb_thresh_l = 0.015

static

Both elements must be smaller than COMB_THRESH_L (m) for an action to be taken.

◆ comb_thresh_rg

const double SnowStation::comb_thresh_rg = 0.125

static

Grain radius (mm)

◆ comb_thresh_sp

const double SnowStation::comb_thresh_sp = 0.05

static

Sphericity (1)

◆ comb_thresh_water

const double SnowStation::comb_thresh_water = 0.01

static

Water content (1)

◆ cos_sl

double SnowStation::cos_sl

Cosinus of slope angle, initialized once!

◆ dIntEnergy

double SnowStation::dIntEnergy

Internal energy change of snowpack (J m-2)

◆ dIntEnergySoil

double SnowStation::dIntEnergySoil

Internal energy change of soil (J m-2)

◆ Edata

std::vector<ElementData> SnowStation::Edata

pointer to element data array (e.g. Te, L, Rho, etc..)

◆ ErosionLevel

size_t SnowStation::ErosionLevel

Element where snow erosion stopped previously for the drift index.

◆ ErosionMass

double SnowStation::ErosionMass

Eroded mass either real or virtually (storage if less than one element)

◆ Ground

double SnowStation::Ground

The ground height – meaning the height of the top soil node.

◆ hn

double SnowStation::hn

Depth of new snow to be used on slopes.

◆ Kt

void* SnowStation::Kt

Pointer to pseudo-conductivity and stiffnes matrix.

◆ lwc_sum

double SnowStation::lwc_sum

Total liquid water in snowpack.

◆ mass_sum

double SnowStation::mass_sum

Total mass summing mass of snow elements.

◆ meltFreezeEnergy

double SnowStation::meltFreezeEnergy

Melt freeze part of internal energy change of snowpack (J m-2)

◆ meltFreezeEnergySoil

double SnowStation::meltFreezeEnergySoil

Melt freeze part of internal energy change of soil (J m-2)

◆ meta

mio::StationData SnowStation::meta

Station meta data.

◆ mH

double SnowStation::mH

The MEASURED height, including soil depth if SNP_SOIL == 1.

◆ Ndata

std::vector<NodeData> SnowStation::Ndata

pointer to nodal data array (e.g. T, z, u, etc..)

◆ number_of_solutes

unsigned short SnowStation::number_of_solutes = 0

static

The model treats that number of solutes.

◆ number_top_elements

const size_t SnowStation::number_top_elements = 5

static

Number of top elements left untouched by the join functions.

◆ pAlbedo

double SnowStation::pAlbedo

Parameterized snow albedo.

◆ ReSolver_dt

double SnowStation::ReSolver_dt

Last used RE time step in the previous SNOWPACK time step.

◆ rho_hn

double SnowStation::rho_hn

Density of new snow to be used on slopes.

◆ S_4

double SnowStation::S_4

stab_index4

◆ S_5

double SnowStation::S_5

stab_index5

◆ S_class1

char SnowStation::S_class1

Stability class based on hand hardness, grain class ...

◆ S_class2

char SnowStation::S_class2

Stability class based on hand hardness, grain class ...

◆ S_d

double SnowStation::S_d

Minimum Direct Action Stability Index ...

◆ S_n

double SnowStation::S_n

Minimum Natural Stability Index.

◆ S_s

double SnowStation::S_s

Minimum Skier Stability Index (SSI)

◆ Seaice

const void * SnowStation::Seaice = NULL

static

dummy pointer for compatibility with the dev version

◆ sector

size_t SnowStation::sector

current slope sector of width 360./max(1, nSlopes-1)

◆ SoilAlb

double SnowStation::SoilAlb

Soil albedo.

◆ SoilNode

size_t SnowStation::SoilNode

The top soil node, 0 in case of SNP_SOIL == 0.

◆ swe

double SnowStation::swe

Total mass summing snow water equivalent of elements.

◆ thresh_moist_snow

const double SnowStation::thresh_moist_snow = 0.003

static

Snow elements with a LWC above this threshold are considered at least to be moist.

◆ thresh_moist_soil

const double SnowStation::thresh_moist_soil = 0.0001

static

◆ TimeCountDeltaHS

double SnowStation::TimeCountDeltaHS

Time counter tracking erroneous settlement in operational mode.

◆ WindScalingFactor

double SnowStation::WindScalingFactor

Local scaling factor for wind at drift station.

◆ windward

bool SnowStation::windward

True for windward (luv) slope.

◆ z_S_4

double SnowStation::z_S_4

Depth of stab_index4.

◆ z_S_5

double SnowStation::z_S_5

Depth of stab_index5.

◆ z_S_d

double SnowStation::z_S_d

Depth of Minimum Direct Action Stability.

◆ z_S_n

double SnowStation::z_S_n

Depth of Minimum Natural Stability.

◆ z_S_s

double SnowStation::z_S_s

Depth of Minimum SSI.

The documentation for this class was generated from the following files:

Detailed Description

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Friends

Constructor & Destructor Documentation

◆ SnowStation() [1/2]

◆ SnowStation() [2/2]

◆ ~SnowStation()

Member Function Documentation

◆ combineCondition()

◆ combineElements() [1/2]

◆ combineElements() [2/2]

◆ compSnowpackInternalEnergyChange()

◆ compSnowpackMasses()

◆ compSoilInternalEnergyChange()

◆ find_tag()

◆ getLiquidWaterIndex()

◆ getModelledTemperature()

◆ getNumberOfElements()

◆ getNumberOfNodes()

◆ hasSoilLayers()

◆ initialize()

◆ isGlacier()

◆ mergeElements()

◆ operator=()

◆ reduceNumberOfElements()

◆ resize()

◆ splitElement()

◆ splitElements()

◆ toString()

Friends And Related Function Documentation

◆ operator<<

◆ operator>>

Member Data Documentation

◆ Albedo

◆ BareSoil_z0

◆ Cdata

◆ cH

◆ ColdContent

◆ ColdContentSoil

◆ comb_thresh_dd

◆ comb_thresh_ice

◆ comb_thresh_l

◆ comb_thresh_rg

◆ comb_thresh_sp

◆ comb_thresh_water

◆ cos_sl

◆ dIntEnergy

◆ dIntEnergySoil

◆ Edata

◆ ErosionLevel

◆ ErosionMass

◆ Ground

◆ hn

◆ Kt

◆ lwc_sum

◆ mass_sum

◆ meltFreezeEnergy

◆ meltFreezeEnergySoil

◆ meta

◆ mH

◆ Ndata

◆ number_of_solutes

◆ number_top_elements

◆ pAlbedo

◆ ReSolver_dt

◆ rho_hn

◆ S_4

◆ S_5

◆ S_class1

◆ S_class2

◆ S_d

◆ S_n

◆ S_s

◆ Seaice

◆ sector

◆ SoilAlb

◆ SoilNode