albedo net radiation #sgtuniversity solal radiation

1. ALBEDO & NET
RADIATION
VIKASH 191101039
BECHLOR OF SCIENCE IN AGRICULTURE
2ND YEAR
TO DR. ROHIT KUMAR , FASE, SGT UNIVERSITY

2. CONTENT
• Solar constant
• Albedo
• Eaeth’s albedo
• Solar radiation
• Net radiation
• Net radiation example

3. SOLAR
CONSTANT
The solar constant is the amount of the incoming solar radiation per unit
area, measured on the outer surface of Earth’s atmosphere, in a plane
perpendicular to the rays.
• Solar Constant for earth S= 1350 W/m2

4. ALBEDO
• Albedo is a fraction of sunlight which is reflected off a planet.
• When an object reflects most of the light that hits it, it looks bright and
it has a high Albedo.
• When an object absorbs most of the light that hits it, it looks dark.
Dark objects have low Albedo.

5. EARTH’S ALBEDO
• The average albedo of the earth is about 0.30.
• That means that about a third of the solar energy that gets the Earth is
reflected out to space and about two thirds is absorbed.

6. SOLAR RADIATIONS
• Solar radiation, often called the solar resource or just sunlight, is a
general term for the electromagnetic radiation emitted by the
sun. Solar radiation can be captured and turned into useful forms of
energy, such as heat and electricity, using a variety of technologies.

7. NET RADIATION
The net radiation is the difference between the
radiant energy absorbed and the radiant energy
emitted.

8. NET RADIATION EXAMPLE
• From atmosphere 300 W/m2
From surface 600 W/m2
From sun 80 W/m2
Net Radiation 380 W/m2 at surface