Atmospheric Basics

Earth According to Science Early Earth was comprised of CH4 (methane), NH3 (Amonia), H2 (Hydrogen Gas), Water Vapor and He (Helium).

Atmosphere Today 99% is N2 and O2. 1% is a mixture of Argon, Co2, Water Vapor and other trace gases. Water Vapor, Ozone (O3), and Co2 amounts can vary and influence how much energy gets absorbed by the atmosphere and returned back to Earth.

Water Vapor, CO2, & Ozone Water Vapor is the gaseous form of water. Amounts Vary with Seasons, Altitude, and properties underneath the air mass (Land or Water). CO2 is cycled through organisms, oceans and rocks. CO2 levels have risen from 0.028 to 0.038 over the last 150 years as a result of burning fossil fuels.

Burning fossil fuels produces sulfur dioxide and nitrogen oxide which cause Acid Rain, respiratory problems, and other environmental issues.

Ozone Ozone is formed by adding an atom of oxygen to an oxygen molecule to form CO3. Most is found 20 – 50 km above Earth’s surface. Often measured in Antarctica., Recently Ozone amounts have decreased as a result of Chlorofluorocarbons, which break down ozone.

Ozone (O3)

Other Particles Our atmosphere also consist of tiny particles like salt, dust and ice. Airborne microorganisms like fungi and bacteria can attach to microscopic dust.

Atmospheric Layers Atmospheric Layer Components Troposphere Layer closest to Earth’s surface, ends at the Tropopause Stratosphere Layer above Troposphere , contains Ozone layer, and ends at stratopause. Mesosphere Layer above the stratosphere, ends at the mesopause Thermosphere Layer above mesosphere, absorbs solar radiation. Exosphere Outermost part of Earth’s atmosphere, transitional space between Earth’s atmosphere and outer space.

Troposphere This is where weather takes place. El Nino effects or La Nina. Temperature decrease as altitude increases. Temperatures stop decreasing at the tropopause.

Stratosphere Temperatures increase with altitude. Contains Ozone layer. Below the Ozone layer, temperatures stay constant. Temps increase above the layer as a result of Ozone absorbing ultraviolet radiation. Temperatures stop rising at the Stratopause.

Mesosphere Air temperatures decrease with altitude due to very little amounts of solar radiation being absorbed.

Thermosphere Low density air causes temperatures to rise up to 2000 degrees Celcius. Contains the Ionosphere which is made up of electrically charged particles.

Energy Transfer In the Atmosphere All materials are made of particles (atoms). Random Motion is where particles are moving even if the object is not moving. These moving particles have Kinetic Energy (E in motion). Thermal Energy is the total amount of energy due to their random motion. Thermal Energy gets transferred by Radiation, Conduction, and Convection.

Radiation Radiation is the transfer of thermal energy by electromagnetic waves. Think of a heat lamp - Thermal energy carried in electromagnetic waves heats things up. The sun gives off solar radiation which is absorbed by Earth in the form of visible light. About 30% is reflected back into space, 20% is absorbed by clouds and the atmosphere. The remaining 50% is absorbed to heat the Earth.

Rates of Absorption The rate absorption varies by location. Ex. Water heats and cools faster than land. Dark areas such as black asphalt heats faster than white concrete.

Conduction Conduction is the transfer of thermal energy between objects when their atoms or molecules collide. This is easier between solids and liquids.

Convection Convection is the transfer of thermal energy by the movement of heated material from one place to another.