Seasonal variation of solar radiation receipt
(Source: Pidwirny (online)
Please consult Pidwirny Fundamentals of Physical Geography
@ http://www.physicalgeography.net/fundamentals/contents.html
and answer the following questions
• How has the sun’s output of energy changed over
the last 3.5 billion years? (5d)
• How has the Earth’s temperature changed over its
history? (5d))
• What is the present temperature of the sun? (6d)
• The sun emits most of its radiation through what
wavelength band? (6f)
Day length
Solar radiation received
Source: Pidwirny (online)
Helions
Source: Pidwirny (online )
What is solar energy received at
the Earth’s surface used for?
• Heating the earth’s surface and lower
atmosphere
• Melting ice and evaporating water
• Photosynthesis in plants
Global shortwave radiation cascade
(source Pidwirney online)
Radiation from Sun
100 units
Albedo
30
Reflected by
Clouds
20
clouds
Stratospheric
Absorption 2
Tropospheric
absorption 17
Scattered
6
Direct
28
Surface
reflection
4
Diffused 23
Energy absorbed by Earth’s surface
Annual (1987) reflectivity of the Earth's
surface
Source: Pidwirney online
•Albedo of the Earth’s
surface
•Dry sand 35 to 45 %
•Broadleaf deciduous
forest 5 to 10 %
•Needleleaf coniferous
forest 10 to 20 %
•Grass type vegetation
15 to 25 %
•Fresh snow 90%
Global longwave radiation cascade
(source Pidwirney online)
Surface longwave
emmission lost to
6
space
Atmospheric
absorption of
surface emission
111
Surface longwave
emission 117
Atmospheric
longwave emmission
lost to space 64
Emission by
atmosphere and
clouds 160
Atmospheric
longwave emission
to Earth
96
Latent heat
23
evaporation
Energy released by Earth’s surface
Sensible heat
7
Conduction &
convection
The annual pattern of solar radiation absorption at
the Earth's surface for the year 1987
Source: Pidwirney online
Redistribution of global energy - winds
• Energy absorption
Heating of the Earth’s surface
Heating of the atmosphere
Development of pressure cells
Development of wind systems
Lower atmosphere wind systems
Upper atmosphere wind systems
Lower atmosphere
Upper atmosphere
Atmospheric
circulation
Upper atmosphere
Ocean currents
Subsurface currents
Red is near
subsurface
currents
Blue is lower
cold currents