AIR QUALITYGLOBAL ENVIRONMENTAL ISSUES

The atmosphere of Earth; Ocean currents

Upwellings are caused by winds pushing surface waters away from a shoreline. Deep waters rise to replace the moved away waters. Upwelling bring nutrients, especially phosphorus, form the deep sediments, that become available to photosynthetic algae. Upwelling regions are highly productive.

El Nio (Spanish, Christ child) refers to the failing of the upwellings of Peru and it has large-scale climatic effects.

Astronomy cyclesObliquity cycle:41,000 yearsEccentricity cycle:100,000 years

Precession cycle:23,000 years

Solar Radiation and Earth Atmosphere

GREENHOUSE GASES

Methane, CH460% relates to anthropogenic activities (agriculture, fossil fuel, waste disposal)Bacterial fermentation under anaerobic conditions in swamps, marshes, rice paddies, landfills, digestive trucks 3.5 billion years ago, there was 1,000 times more CH4. Earliest CH4 formed by volcanoes and ancient bacteria that converted H2 and CO2 into CH4 and H2O

Nitrous Oxide, N2OGlobally N2O increased 10% since 1880; 0.2-0.3% per yearIn stratosphere, it helps destroy ozoneSources:- Coal burning- Forest fires- Bacterial activity Halocarbons, CFCsSources: Refrigeration and air conditioning Aerosols Blowing agent in plastic foams Solvent for cleaning electronic parts Some fire extinguishers

Ozone, O3Ozone: 10% in troposphere and 90% in stratosphereLifespan: hours to daysSources: Photochemical chemistry & industrial processes.

Extreme conditions: very low temperature inside the vortex ~-80C; the vortex lasts for a few months during Antarctic winter period.

FORMATION AND DISSOCIATION OF OZONE IN ATMOSPHERE:

O + O2 + M O3 + M

O3 + hv O2 + O-------------------------------

X + O3 XO + O2XO + O X + O2------------------------------O + O3 2 O2 X=Cl, Br, H, OH, NO

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