Ch.3 Introduction to the Atmosphere

Size and Composition of the Atmosphere

Air is a mixture of gases mostly 71% nitrogen and 21% oxygen and 2% of other items

Density decreases with Altitude

-most of the ocean’s air is held up due to gravity

– most of atmospheric mass found at very low altitudes

– atmosphere provides hospitable setting for life

Development of Earth Modern Atmosphere

Earth’s early atmosphere

-mix of gases altered by volcanic eruptions, arrival of comets, and the development of early life

-ancient Earth cooled, water vapor condensed out of the atmosphere, forming into a world ocean

-early bacteria and plants consumed 2CO then released oxygen as photosynthesis(we breath in oxygen and breath out co2 and photosynthesis is vice versa)

-transformed into an oxygen-rich atmosphere

Composition of dry air at lower altitudes is uniform

-made up of permanent gases

-Variable gases, particulates, and moisture in the air

vary from place to place and from time to time

Permanent Gases

-the two most abundant gases are Nitrogen and Oxygen

-both cycle through atmosphereic, organic, and inorganic processes

Water Vapor

-visible forms of solid and liquid

-varies by location more abundant over warm, moist surfaces

Carbon Dioxide

-fairly even distribution in lower atmospher

-effects climate

-incrreasing thorugh use of fossil fuel

Ozone

-filters ultraviolet radiation

Other Variable Gasses

-methane

-other from factory and auto emissions

Particulates(Aerosis)

Varying-sized nongaseous particles in air

-mainly liquid/ice water that forms clouds and percipation

Particulates or aerosols are solid and liquid particles small enough to be suspended in the air

Hygroscopic-

Condensation Nuclei-

Vertical structure of the atmosphere

Thermal Layers

-vertical temperature patterns are complex

-layers alternate between the increase or decrease of the temperature

Troposphere

-lowest layer in conctact with the surface

-depth varies by season, location, and latitude

-tempertaure decerases with increasing altitude

-80 percent of total mass of atmosphere

Stratosphere

-layred “stagnat air“

-location of ozone layer

-temperature increases with increasing altitude to stratopause

Upper thermal layers

Mesophere-temperature decreases with increasing altitude

Thermosphere-temperature increases with increasing altitued

Exosphere-transitions into interplantary space

Pressure

-force extered per unit area by molecules of atmosphere

-air pressure and density are highest at sea level, both decrease with increasing altitude

Compostion-principle gases uniform vertical distribution

Homosphere-

Heterosphere-

-aprser atmosphere above is layred by atomic weight

Ozone Layer-

-ozone is concerto

Stratosphereic Ozone Layer-

Ionosphere-deep layer of ions, electrically charged molecules or atoms

Weather and Climate

Weather

-short term atmospheric conditions at a specific time in a given area

Meterology-study of weather

Climate

-aggregate daily weather conditions over a long period of time, also encompasses variations and extremes

The elements of weather and climate

-temperature, moisture content, pressure, and wind

The controls of weather and climate

-influenced by a collection of semipermanent attributes

Latitude

-determines distribution of solar energy, more energy at the equator and less at the poles

-strongly influences temperature as warming/cooling

Distrubition of Land and Water

influences temperature and moisture characters

-oceans wam/cool slower than landmasses and add more atmospheric moisture

maritime climates

-milder temp and typically less humid

continental climates

-more extreme seasonal temperature rang, typically less humid

General circulation of the Atmosphere and Oceans

Atmosphere

-troposphere semipermanent wind and pressure systems

-greatly influences rest of elements

Oceans

-broad general pattern of semipermannet currents

-assist in energy transfer by moving warm/cool water

-minor influences on elements of weather and climate

Altitude

-distance away from earth surface

-temp, pressure, and moisture content all decrease with increasing altitude

-particular impacts on mountainous regions

Topographic Barries

-mountains and large hills divert wind flow

-affect temperature and moisture patterns

-pattern of windward and leeward microclimates

Windward-

Leeward-

-high pressure is pushing the air down

Storms

-vary in distribution, can be widespread or localized

-create specialized weather circumstances

The Coriolis effect

-results of earth rotation

-right in the northern hemisphere and left in the souther hemisphere

-greatest at the poles, zero at the equator

-deflection increases with fast moving objects

Human-Caused Atmospheric Change

Past century seen unintended and uncontrolled effects on atmosphere from increased human activity

-introduction of impurities at rapid pace and global scale

-impacts global climate and forms of life

Depletion of Ozone Layer

Natural Formation of Ozone

Diatomic Oxygen-

-reduces harmful exposure of UV to life in troposphere

The “Hole“ of the Ozone Layer

-thinning of stratosphere due to chlorofluorocarbons and other chemical substances

-linked with higher UV radiation at surface

Anatartic Polar Atmosphere

-extreme cooling during winter

-wind pattern known as polar vortex that isolates polar air

The Monteral Protocol

-group of countries banning CFCs

-no immediate recovery, but loss has been stabilized

The UV Index

-to inform public of intensity of UV radiation

Air Pollution

carbon monoxide-

-primary pollutant released directly into air

Nitrogen Compounds

-natural by product in water and soil

-most result of carbon based fuel use

Sulfur Compounds

-largely natural origin, increased with fossil fuel consumption

-hazardous to health as well as damaging to environment

Particulates

-primary sources are smoke from combustion and dust from industry

Photochemical Smog

-forming from reactions with UV in atmosphere are contaminants called secondary pollutants

-makeup of photochemical smog left behind particles and ground level ozon

-volatile organic compounds include nitrogen dioxide and hydrocarbons

Atmosphereic Conditions and Air Pollution

-impact of local conditions

-air movement disperses

-temperature inversions limiat air circulation

Consequences of Anthropogenic Air Pollution

-human and environmental disease, acid rain, and damage to crops and tressz

Energy Production and the Enviornment

-support for alternative energy

-growing demand for energy to power homes