jgrass-newage swrb

Bancheri and Formetta

LINKERS

JGrass-NewAge: SWRB componentMarialaura Bancheri*†

and Giuseppe Formetta†

*Correspondence:

[email protected]

Dipartimento di Ingegneria Civile

Ambientale e Meccanica, Trento,

Mesiano di Povo, Trento, IT

Full list of author information is

available at the end of the article†Code Author

Abstract

These pages teach how to run the ShortWave Radiation Balance (SWRB) componentinside the OMS 3 console. Some preliminary knowledge and installation of OMS ismandatory (see @Also useful). The SWRB component deals with the calculation of theshortwave incident radiation on complex topography settings. It accounts for elevationslope, aspect, shadow of the sites, and uses suitable parameterization for obtaining thecloudless irradiance.The SWRB component is a part of the larger system,JGrass-NewAge, and it can be used seamlessly with the various modeling solutionsavailable like, for example, the estimation of long wave radiation, evapotranspiration,and snow melting, as well as standalone components to just estimate shortwaveradiation for various uses.

@Version:0.1

@License:GPL v. 3

@Inputs:• Air temperature (◦C);• Relative humidity (%);• Digital Elevation Model (DEM);• Skyview factor (-);• Current date (String);• Ozone layer thickness (pCmO3) (cm);• Visibility (km);• Albedo (m).• Vector file containing the coordinates of the station.

@Outputs:• Direct radiation (W/m2)• Diffuse radiation (W/m2)• Radiation at the top of the atmosphere (W/m2)

@Doc Author: Marialaura Bancheri

@References:• See References section below

Keywords: OMS; JGrass-NewAGE Component Description; Shortwave radiationestimation

mailto:[email protected]

Bancheri and Formetta of 8

Code Information

Executables

This link points to the jar file that, once downloaded can be used in the OMS console:

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/lib

Developer Info

This link points to useful information for the developers, i.e. information about the code

internals, algorithms and the source code

https://github.com/geoframecomponents

Also useful

To run JGrass-NewAGE it is necessary to know how to use the OMS console. Information

at: ”How to install and run the OMS console”,

https://alm.engr.colostate.edu/cb/project/oms).

JGrasstools are required for preparing some input data (information at:

http://abouthydrology.blogspot.it/2012/11/udig-jgrasstools-resources-in-italian.

html

To visualize results you need a GIS. Use your preferred GIS, following its installation

instructions. To make statistics on the results, you can probably get benefits from R:

http://www.r-project.org/ and follow its installation instruction.

To whom address questions

[email protected]

Authors of documentation

Marialaura Bancheri ([email protected])

This documentation is released under Creative Commons 4.0 Attribution International

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/lib

https://github.com/geoframecomponents

https://alm.engr.colostate.edu/cb/project/oms

http://abouthydrology.blogspot.it/2012/11/udig-jgrasstools-resources-in-italian.html

http://abouthydrology.blogspot.it/2012/11/udig-jgrasstools-resources-in-italian.html

http://www.r-project.org/


Component DescriptionThe incident shortwave (S ↓) on an arbitrary sloping surface in a point under cloudless

sky conditions is given by (1):

S ↓= C1 · Isc · E0 · cos(θs) · (Ts+ βs) · ψ (1)

in which:

• C1 = 0.9751 is the fraction of solar radiation that is included between 0.3 and 3.0

µm wavelengths;

• E0 [–] is a correction factor related to Earth’s orbit eccentricity computed according

to Spencer (1971);

• Ts [–] is the product of the atmospheric transmittance:

Ts = τr · τ0 · τg · τw · τa (2)

where the τ functions are the transmittance functions for Rayleigh scattering, ozone,

uniformly mixed gases,water vapor, and aerosols, respectively;

• βs[m] is a correction factor for increased transmittance with elevation z [m] defined

according to Corripio (2002);

• θs [rad] is the angle between the Sun vector and the surface plane ((2));

• ψ is the shadows index that accounts for the sun or shadow of the point under

analysis, Eq. (6), and is modeled according to (2).

The modeling of the diffuse component of solar radiation, d ↓ , follows (1):

d ↓= (d ↓r +d ↓a +d ↓m) · Vs, (3)

where d ↓r, d ↓a and d ↓m are the diffuse irradiance components after the first pass

through the atmosphere due to the Rayleigh scattering, the aerosol scattering and multiple

reflection,respectively. Finally Vs is the sky view factor, i.e., the fraction of sky visible in

a point, computed using the algorithm presented in Corripio (2002).

A more detailed description of the component is in (3).

Detailed Inputs description

General description

The input file is a .csv file containing a header and one or more time series of input data,

depending on the number of stations involved. Each column of the file is associated to a

different station.

The file must have the following header:

• The first 3 rows with general information such as the date of the creation of the file

and the author;

• the fourth and fifth rows contain the IDs of the stations (e.g. station number 8:

value 8, ID, ,8);

• the sixth row contains the information about the type of the input data (in this

case, one column with the date and one column with double values);

• the seventh row specifies the date format (YYYY-MM-dd HH:mm).

All the previous information shown in the figure 1.


Figure 1 Heading of the .csv input file

Air temperature

The air temperature is given in time series or raster maps of (◦C) values. The conversion

in (◦K) is directly done by the component.

Relative humidity measures

The relative humidity is given in time series or raster maps of (% ) values.

DEM

DEM is the digital elevation model of the HRU considered.

Sky view factor

The sky view factor is a raster map of adimensional values in the interval [0,1] at the

given point. It is the fraction of visible sky in the upper hemisphere and it is obtained

from the digital elevation model using the JGrasstools.

Current date

The current date is given as a string and is required to compute the correction factor

related to Earth’s orbit eccentricity (EO)

Ozone layer thickness

Ozone layer thickness is a double value in (cm) and usually varies in the interval [0.4,

0.6].

Visibility

Visibility is a double value in (km) and it depends on aerosol attenuation. It usually varies

in the interval [5, 180 ] km.

Albedo

Albedo is the double value of the ground albedo.

Vector file containing the coordinates of the station

This shapefile should contain all the information about the stations involved in the sim-

ulation. It is required to obtain the station IDs and to determine their coordinates. The

name of the field containing the IDs of the stations must be specified as a string in the

sim file at the field ”fStationid”


Detailed Outputs description

S ↓

The S ↓ output is given as a time series at a given point or as raster maps. The components

in the two cases are different (respectively SwrbPointCase and SwrbRasterCase). Its units

are (W ·m−2). Figure 2 shows the results of a S ↓ simulation obtained using data from

a station in the the Posina River basin, Italy:

0 5000 10000 15000

0200

400

600

800

ShortWave Radiation Balance: Direct radiation

Time[h]

Dire

ct [W

/m2]

Figure 2 Time series of direct shortwave radiation.

d ↓

The d ↓ output is given as a time series at a given point or as raster maps. Its units are

(W ·m−2) . Figure 3 shows the results of a S ↓ simulation obtained using data from a

station in the the Posina River basin, Italy:

0 5000 10000 15000

050

100

150

ShortWave Radiation Balance: Diffuse radiation

Time[h]

Diff

use

[W/m

2]

Figure 3 Time series of diffuse shortwave radiation.


Top atmosphere radiation]

The radiation at top atmosphere is given as a time series at a given point or as raster

maps. Its units are [W/m2]. Figure 4 shows the results of a simulation obtained using

data from a station in the the Posina River basin , Italy:

0 5000 10000 15000

0200

600

1000

ShortWave Radiation Balance: top atmosphere radiation

Time[h]

TopA

TM [W

/m2]

Figure 4 Time series of top atmosphere shortwave radiation.

ExamplesThe following .sim file is customized for the use of the SWRB component. The .sim file

can be downloaded from here:

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/simulation

import static oms3.SimBuilder.instance as OMS3def home = oms_prj// start and end date of the simulation

def startDate= "1994 -01 -01 00:00"def endDate="1994 -02 -01 00:00"OMS3.sim {

resource "$oms_prj/lib"

model(while : "reader_data_airT.doProcess" ) {components {

// components to be called: reader input data , swrb and writeroutput data

"reader_data_airT" "org.jgrasstools.gears.io.timedependent.OmsTimeSeriesIteratorReader"

"reader_dem" "org.jgrasstools.gears.io.rasterreader.OmsRasterReader"

"reader_sky" "org.jgrasstools.gears.io.rasterreader.OmsRasterReader"

"vreader_station" "org.jgrasstools.gears.io.shapefile.OmsShapefileFeatureReader"

"swrb" "swrbPointCase.ShortwaveRadiationBalancePointCase"

"writer_direct" "org.jgrasstools.gears.io.timedependent.OmsTimeSeriesIteratorWriter"

"writer_diffuse" "org.jgrasstools.gears.io.timedependent.OmsTimeSeriesIteratorWriter"

"writer_topATM" "org.jgrasstools.gears.io.timedependent.OmsTimeSeriesIteratorWriter"

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/simulation


}

parameter{

// parameter of the reader components"reader_data_airT.file" "${home}/data/Temperature.csv""reader_data_airT.idfield" "ID""reader_data_airT.tStart" "${startDate}""reader_data_airT.tEnd" "${endDate}""reader_data_airT.tTimestep" 60"reader_data_airT.fileNovalue" " -9999"

"reader_dem.file" "${home}/data/dem.asc""reader_sky.file" "${home}/data/skyview.asc""vreader_station.file" "${home}/data/stations.shp

"

// parameter of the swrb component , (see "Detailed inputDescription " section for further info)

"swrb.fStationsid" "netnum""swrb.tStartDate" "${startDate}""swrb.doHourly" true"swrb.pCmO3" 0.6"swrb.pAlphag" 0.9"swrb.pVisibility" 80

// parameter of the writing component"writer_direct.file" "${home}/ output/DIRETTA.csv

""writer_direct.tStart" "${startDate}""writer_direct.tTimestep" 60

"writer_diffuse.file" "${home}/ output/DIFFUSA.csv"

"writer_diffuse.tStart" "${startDate}""writer_diffuse.tTimestep" 60

"writer_topATM.file" "${home}/ output/TOPATM.csv""writer_topATM.tStart" "${startDate}""writer_topATM.tTimestep" 60

}connect {

"reader_data_airT.outData" "swrb.inTemperatureValues"

"reader_dem.outRaster" "swrb.inDem""reader_sky.outRaster" "swrb.inSkyview""vreader_station.geodata" "swrb.inStations"

"swrb.outHMdirect" "writer_direct.inData""swrb.outHMdiffuse" "writer_diffuse.inData""swrb.outHMtopatm" "writer_topATM.inData"

}

}}

Data and ProjectThe following link is for the download of the input data necessaries to execute the SWRB

component (as shown in the .sim file in the previous section ) :

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/data

The following link is for the download of the OMS project for SWRB component:

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB

%

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB/tree/master/data

https://github.com/GEOframeOMSProjects/OMS_Project_SWRB


References1. Corripio, J.G.: Modelling the energy balance of high altitude glacierised basins in the central andes. PhD thesis,

University of Edinburgh (2002)

2. Corripio, J.G.: Vectorial algebra algorithms for calculating terrain parameters from dems and solar radiation modelling in

mountainous terrain. International Journal of Geographical Information Science 17(1), 1–23 (2003)

3. Formetta, G., Rigon, R., Chavez, J., David, O.: Modeling shortwave solar radiation using the jgrass-newage system.

Geoscientific Model Development 6(4), 915–928 (2013)