Radiation Energy from the sun

Presentation on theme: "Radiation Energy from the sun"— Presentation transcript:

1 Radiation Energy from the sun
All forms of energy that travel through space in waves Travel at 300,000 km/s or 186,000 mi/s

2 Electromagnetic Sectrum
Full range of all radiation One wavelength is the dist from the crest of one wave to another. Shorter wavelength = higher energy

3 Where does all the radiation go?
Many of the shorter wavelength (higher energy) radiation is absorbed by the atm. N2 & O2 absorb x-rays and gamma rays UV rays absorbed in stratosphere

4 Longer wavelengths IR radiation is absorbed by carbon dioxide and water vapor in the troposphere.

5 Scattering Incoming radiation can be scattered by water droplets, dust or gas molecules Blue light is scattered in the atmosphere an makes the sky blue Scattering makes the sun appear red or orange at sunrise.

6 Reflection of Solar Radiation
Incoming radiation 20% absorbed by atm 30% scattered or refl. 50% absorbed by Earth Reflection and absorption at the surface depends on the medium

7 Albedo The fraction of solar radiation reflected by a particular surface

8 What’s the greenhouse effect?
greenhouse gases in the atmosphere trap heat at the Earth’s surface and prevent it from escaping. These gases include: Carbon dioxide CO2 Methane CH4 Nitrous oxide N2O Chlorofluorocarbons Water vapor H2O (this is the most important one, by far!)

9 The greenhouse effect occurs naturally...
A moderate greenhouse: On Earth, the atmosphere contains about 360 parts per million CO2, and the surface temperature is about 16°C (60 F). Without greenhouse gases, the Earth would be a frozen snowball! A runaway greenhouse: On Venus, the atmosphere is nearly all carbon dioxide, and the temperature is about 400°C (752 F).

10 Changes in atmospheric CO2 induced by humans
Mainly, we burn fossil fuels - coal, oil, and gas. 80% of the CO2 increase 20% of the CO2 increase Secondarily, we cut down forests (particularly in the tropics)

11 CO2 changes in the last 300 yr 70 ppm Industrial Revolution

12 Other greenhouse gases are also increasing

13 Sources of CO2 Natural Man Made Respiration Vegetation
Fossil Fuel Combustion Deforestation

14 Sources of Methane Natural Man Made Agriculture Decomposition
Landfills Mining Burning Biomass

15 Continue notes from chapter
Finish notes from 23.2 Do P , complete sentences