Atmosphere

Atmosphere

gaseous envelope surrounding celestial body, held by force of gravity

Earth Gas Composition

78% Nitrogen, 21% Oxygen, 1% (Ag, CO2, He, Ne, CH4, H)

Humidity

Measure of water vapour in solid, liquid form in the air

Water Vapour

0-5% of atmosphere Vol

Mainly found in Troposphere (lowest layer of atmosphere)

No water vapour = no weather

Large influence on weather

Release of latent heat (large amts of heat energy)

Warm air holds more WV than cold.

Layers of the Atmosphere

Troposphere

Stratosphere

Mesosphere

Thermosphere

Exosphere

Troposphere

Temp decreases with increase in altitude (environmental lapse rate)

Most weather found here

Stratosphere

Lack of change in temp, especially in lower layer

Temp of Strat rises in upper levels because of Ozone (In stratosphere)

Ozone absorbs harmful UV light from sun

Mesosphere

Temp cools through, atmospheres coldest at mesopause

Aurora clouds towards mesopause

Has meteoric dust particles

Thermosphere

Increase of temp in thermosphere due to UV radiation

Ionospshere positively charged molecules

Troposphere Characteristics

Higher you go, colder it gets

Most water vapour found here

Instability creates clouds and precipitation

Holds 70% of total mass due to air

Tropopause

Temperature is controlled by its height

Temperature is constant (isothermal)

Higher in summer, lower in winter