Atmosphere and Change Learning objectives: To be able to understand the external factors that affect the energy balance.

Recap From memory sketch the global energy balance

What questions could you ask about this data?

Key terms Solar radiation Albedo Milankovich cycles Global brightenning Global dimming

External forcings Cause Description Impact on the energy balance Change in eccentricity / obliquity / precision Change in solar activity Volcanic activity

Orbital oscillations –more or less sunlight reaching the Earth.

Eccentricity Cycle of about 100 000 years Ranges from 0%- 5% eccentricity Changes the distance the SW radiation must travel from the Sun to reach the Earth This changes the amount of radiation at different seasons

Current tilt of the Earth is 23.5 degrees Accounts for the seasons A greater tilt = greater range in the seasons

Sun spot activity P147 Paul Guinness Read and makes notes on the causes and effects of sunspot activity

Albedo of the atmosphere The proportion of the solar energy reflected from the Earth back into space Use p148 to consider the albedo at each biome

Volcanic activity

Changes in long wave radiation returned to space