lecture 3 - the global energy system Flashcards
Today’s Atmosphere
Pure, dry air consists mainly of
nitrogen, about 78% by volume, and oxygen, about 21%.
Dusts and other fine particles are present, some of which play an important role in the formation of precipitation by acting as
condensation nuclei
Ozone protects plants and animals from its harmful effects by absorbing
UV radiation
Dobson unit (DU),
to measure the density of ozone in a column of atmosphere above a specified area of the Earth’s surface
Greenhouse gases are able to trap
long-wave radiation, and cause global warming.
Electromagnetic radiation
the principal form in which energy is transported from the sun to the Earth) is characterized by its wavelength () and frequency (f).
Electromagnetic waves
of different wavelengths and frequencies form the electromagnetic spectrum (gamma rays to radio waves).
visible light portion of the electromagnetic spectrum corresponds to
the wavelength range 400-700 nanometres (nm).
The intensity of a flow of the sun’s radiant energy that reaches the top of Earth’s atmosphere is 1,367 Watts per square metre (Wm-2).
1367 Wm-2 is the
total solar irradiance
