Atmospheric Habitat

composition

nitrogen

oxygen

carbon dioxide

other gases

region

stratosphere

increasing temperature with height

location of 'good' ozone, limits uv light

extreme low temperature

lacking liquid water

mesophere

temperature decreasing with height

thermosphere

temperature increases with altitude

exosphere

extending into outer space

helium and H2 predominant

lonosphere

extreme low temperature

lacking liquid water

extreme uv and ionizing radiation levels

troposphere

nearest to the earth

characteristics

air temperature

atm pressure

conc. 02

organic carbon

water

Subtopic

other extreme environments

severe condition

high or low temperature

pH

irradiation

toxic chemicals

lack of nutrient, water availability

ionizing radiation

atmosphere

lower trophosphere contains high number of microbes

thermal gradient causes rapidmixing allowing for dispersal of microbes

air movement provide means of dispersal

precipitation aids deposition

example of micororganisms

sporea are better adapted to the atmosphere

low metabolic rate

produced in high number

thick cell wall-against dessication

some are pigmented

small size and low density

type

xenospores

forms that are primarily adapted to reproduction vs resistance to environmental stress

endospores

forms that are primarily adapted to resistance rather than production

physical features of the aerial environment

air movement in the troposphere

radiation

precipitation

dispersal of airbone particles

3 stages

liberation and take-off into the air

dispersion in air current

deposition