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

Stratospheric Absorption 2 Tropospheric absorption 17 Global shortwave radiation cascade (source Pidwirney online) Albedo 30 Radiation from Sun 100 units Reflected by Clouds 20 clouds Scattered 6 Surface reflection 4 Direct Diffused 23 28 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 space 6 Atmospheric longwave emmission lost to space 64 Atmospheric absorption of surface emission Emission by atmosphere and clouds 160 Latent heat 23 111 Surface longwave emission 117 Atmospheric longwave emission to Earth 96 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