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Date: | Tue, 23 Apr 2002 09:47:07 -0400 |
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Mr. Asif:
Extra-terrestial solar radiation is solar radiation received above
atmosphere before the sunlight
goes through the atmosphere to reach the earth. it can be calculated by
following formula:
Ra=[(86400)(1360)/3.1416] * (dm/d)^2 *
[(Hs)*sin(a)*sin(b)+cos(a)*cos(b)*sin(Hs)]
Where:
Ra: extra-terrestrial solar radiation (MJm-2day-1)
Hs: solar angle at solar noon,
Hs = (90 - a + b) * 3.14159 / 180
a: is latitude of local station,
b: is solar declination, it varies from -23.5 to 23.5 for
each year. it can be calculated or simply given in
a table. contact me if you need the table.
dm: is the mean distance from the Sun to the Earth during
a year, and
d is the distance from the Sun to the Earth on daily basis.
I also have table contains dm and d values for recent years, contact me
if you need them.
Good luck!
**************************************************
Zhisheng (Jason) Qing
PhD Candidate & Research Assistant
Agricultural and Biological Engineering Department
Clemson University
Clemson, SC 29631
Voice: 864 656 4079
Email: [log in to unmask]
Fax: 864 656 0338
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