# Potential Incoming Solar Radiation

O.Conrad (c) 2010
Calculation of potential incoming solar radiation (insolation).
References:

- Boehner, J., Antonic, O. (2009): Land Surface Parameters Specific to Topo-Climatology. in Hengl, T. & Reuter, H.I. [Eds.]: Geomorphometry - Concepts, Software, Applications.
- Oke, T.R. (1988): Boundary Layer Climates. London, Taylor & Francis.
- Wilson, J.P., Gallant, J.C. [Eds.] (2000): Terrain Analysis - Principles and Applications. New York, John Wiley & Sons, Inc.

*) Most options should do well, but TAPES-G based diffuse irradiance calculation ('Atmospheric Effects' methods 2 and 3) needs further revision!

## Parameters

Grid system
Grid system
  Grid system
Elevation
Input Grid
Sky View Factor
Input Grid
Water Vapour Pressure [mbar]
Input Grid
Latitude [degree]
Input Grid
Longitude [degree]
Input Grid
Direct Insolation
Output Grid
Diffuse Insolation
Output Grid
Total Insolation
Output Grid
  Total insolation, the sum of direct and diffuse incoming solar radiation.
Direct to Diffuse Ratio
Output Grid
Duration of Insolation
Output Grid
Sunrise
Output Grid
  time of sunrise/sunset is only calculated if time span is set to single day
Sunset
Output Grid
  time of sunrise/sunset is only calculated if time span is set to single day
Solar Constant [W / m²]
Floating point
Local Sky View Factor
Boolean
  Use sky view factor based on local slope (after Oke 1988), if no sky viev factor grid is given.
Units
Choice
  Units for output radiation values.
  Available choices: kWh / m², kJ / m², J / cm²
Location
Node
Latitude
Degree
  Minimum: -90.0; Maximum: 90.0
Planetary Bending
Parameters
Time
Node
Time Period
Choice
  Available choices: moment, day, range of days
Moment [h]
Floating point
  Maximum: 24.0
Time Span [h]
Value range
  Time span used for the calculation of daily radiation sums.
  Minimum: 1.39579710889e-316; Maximum: 1.395734659e-316
Time Resolution [h]: Day
Floating point
  Time step size for a day's calculation given in hours.
  Maximum: 24.0
Time Resolution [d]: Range of Days
Integer
  Time step size for a range of days calculation given in days.
  Minimum: 1.0
Update
Choice
  show direct insolation for each time step.
  Available choices: do not update, update, colour stretch for each time step, update, fixed colour stretch
Day of Year
Node
Day of Month
Choice
  Available choices: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31
Month
Choice
  Available choices: January, February, March, April, May, June, July, August, September, October, November, December
Day of Year (End of Range)
Node
Day of Month
Choice
  Available choices: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31
Month
Choice
  Available choices: January, February, March, April, May, June, July, August, September, October, November, December
Atmospheric Effects
Node
Atmospheric Effects
Choice
  Available choices: Height of Atmosphere and Vapour Pressure, Air Pressure, Water and Dust Content, Lumped Atmospheric Transmittance
Height of Atmosphere and Vapour Pressure
Node
Height of Atmosphere [m]
Floating point
Water Vapour Pressure [mbar]
Floating point
  This value is used as constant if no vapour pressure grid is given.
Air Pressure, Water and Dust Content
Node
Atmospheric Pressure [mbar]
Floating point
Water Content [cm]
Floating point
  Water content of a vertical slice of atmosphere in cm: 1.5 to 1.7, average=1.68
Dust [ppm]
Floating point
  Dust factor: 100 ppm (standard)
Lumped Atmospheric Transmittance
Node
Lumped Atmospheric Transmittance [Percent]
Floating point
  The transmittance of the atmosphere, usually between 60 and 80 percent.
  Maximum: 100.0