2.7 Module Input and Output
The solar model inputs are
1. The latitude and longitude of the location.
2. The Day-Of-the-Year (DOY) and hour of the day.
3. The land surface category.
4. Low, middle, and high fractional cloud amount. If all three cloud amounts are
missing, the low cloud amount is set equal to the global average cloud amount (0.54).
5. The low middle, and high cloud type. If missing, the model uses a set of default
conditions. The low cloud default is cumulus, the middle cloud type is altostratus, and
the high type is cirrus.
Items 1 and 2 are obtained from the meteorological data file, as are items 4 and 5 if they
are available. Item 3 is found in the FASST input file.
The model outputs are the downwelling, reflected and net shortwave flux (W/m2) at the
surface for the input conditions. If the input conditions are representative of some time
period, then the number of Joules/m2 for that period is given as the flux (W/m2) times the
length of the period in seconds.
2.8 References
NOAA (1979) SOLMET Vol. 2: Hourly Solar Radiation-Surface Meteorological
Observations, Final Report. D-9724, National Climatic Center, Asheville, NC.
through the Atmosphere, Applied Optics, V. 11, p. 760764.
Shapiro, R. (1982) Solar Radiative Flux Calculations from Standard Surface Meteoro-
logical Observations. AFGL-TR-82-0039, Air Force Geophysics Laboratory, Hanscom
AFB, MA.
Shapiro, R. (1987) A Simple Model for the Calculation of the Flux of Direct and Diffuse
Solar Radiation Through the Atmosphere. AFGL-TR-0200, Air Force Geophysics
Laboratory, Hanscom AFB, MA.
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