Dear DSSAT Members,

    I have access to daily solar radiation data but there are five
different types of radiation listed.  I was wondering if anyone knows
which type is appropriate for DSSAT.  The options are listed below
with a description.  Any information would be great.

1.) Extraterrestrial Horizontal Radiation -- Amount of solar radiation
in Wh/m2 received on a horizontal surface at the top of the atmosphere
2.) Extraterrestrial Direct Normal Radiation -- Amount of solar
radiation in Wh/m2 received on a surface normal to the sun at the top
of the atmosphere
3.) Global Horizontal Radiation -- Total amount of direct and diffuse
solar radiation in Wh/m2 received on a horizontal surface
4.) Direct Normal Radiation -- Amount of solar radiation in Wh/m2
received within a 5.7 degree field of view centered on the sun
5.) Diffuse Horizontal Radiation -- Amount of solar radiation in Wh/m2
received from the sky (excluding the solar disk) on a horizontal
surface

Thanks,
--
Jordan Shockley
University of Kentucky
Department of Agricultural Economics
331 C.E. Barnhart Building
Lexington, KY 40546-0276
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