Atmospheric issues. Atmosphere. Importance. A blanket of air surrounding the lithosphere

Transcription

1 Atmospheric issues Atmosphere A blanket of air surrounding the lithosphere Atmosphere held to Earth s surface by gravity Dynamic (changing): currents and circulation cells constantly moving Importance Insulator Equalizes temperature and pressure across earth s surface by transfer of heat, energy, and moisture Shield (against meteors, ultraviolet radiation) Enables travel of sound waves, aircraft Without the atmosphere: cold, quiet, cratered place 1

2 mi 400 Air molecules Altitude (km) Air density 100 Mt. Everest Air pressure 90% in first 10 mi 62 mi 10 mi Atmospheric composition: Permanent Gases All invisible Nitrogen 78% Plant life Oxygen 20.9% Living creatures Argon 0.9% Inert Variable gases Water vapor Humidity Clouds Precipitation Varies between 4% to less than 1% Lower water vapor in drier areas Carbon dioxide Absorbs infrared radiation ~0.04% 2

3 Atmospheric Profile Atmosphere extends to 32,000 km (20,000 mi) from surface Three criteria to examine atmosphere Thermal (temperature) Composition Function Thermal layers: Troposphere Where we live contains 90% of the mass of the atmosphere decrease of mass with altitude temperature decreases with height clouds / weather layer Thermal layers: Stratosphere Layer directly above troposphere Decrease in amount of gases with altitude Temperatures increase with altitude Because of ozone layer within stratosphere Ozone absorbing ultraviolet light 3

4 Thermal layers: Mesosphere Layer above stratosphere Temperatures dropping with altitude Mesopause altitude where the temperatures stops dropping Thermal layers: Thermosphere Very thin air little mass Temperature increases because receiving ultraviolet light After thermosphere: Exosphere 4

5 Compositional layers Heterosphere Gases separated & layered Homosphere Gases mixed Functional Layers Stratosphere Ozone layer Atmosphere Dynamic constantly moving and changing Problem with pollution and atmosphere doesn t stay within state or country boundaries - wind 5

6 Wind Differences in atmospheric pressure cause wind Horizontal movement of air (advection) Wind flows from high towards low pressure areas Local: land-sea breezes Global: westerlies Land-sea breezes Global winds Persistent winds Trade winds - ~5-25º N & S Westerlies - ~35-55º N & S Easterlies - ~55-75º N & S Important in understanding where pollutants will travel 6

7 Vertical Temperature Patterns Temperature changes as altitude increases Without changes to anything else, temperature decreases at an average rate Environmental lapse rate (average) observed trend in vertical temperature change Major issues Air pollution Smog/air pollutants Acid rain Ozone(ground-level) Ozone thinning Climate change ENSO (El Niño /La Niña) related issues Environmental Regulation EPA founded 1970; combined several smaller agencies into one to regulate pollutants for both the environment and human health Charged to protect human health and the environment, by writing and enforcing regulations based on laws passed by Congress Administers the Clean Air Act Coincided with the first Earth Day 7

8 Clean Air Act st national legislation for air pollution Provided grants to assist states but preserved state s rights to set goals 1970 amendments set clean air goals, identified critical pollutants Primary standards protect human health Secondary standards protect crops, visibility, materials Bad air Original 7 pollutants regulated by Clean Air Act Sulfur compounds fossil fuel burning, industry Nitrogen compounds fossil fuel & biomass burning Carbon monoxide biomass burning, automobiles Particulate material biomass burning, smoke Metals and halogens industry, manufacturing Volatile organic compounds (VOCs) - plants Photochemical oxidants chemical reactions Air toxins industry (hazardous air pollutants) Sulfur compounds Carbon monoxide 8

9 What happens to air pollution? Pollutes air breathing problems Pollutes water consumption issues Pollutes soil breathing and consumption High concentrations of mercury and lead often found near old industrial sites downwind of industry Asbestos, diesel also found in soil How is it cleaned up? Improve the filtering of industrial sites, cars, and manufacturing plants to stop airborne pollutants Change technology so filtering is not necessary Afterward: wait for airborne particulates to settle, then clean up Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) Clean up releases or threatened releases of hazardous substances that may endanger public health or the environment EPA designate sites that are extremely polluted (hazardous waste) so that special attention is paid to clean them up may receive governments funds Will first try to determine Potentially Responsible Party (PRP) to have them clean up site Could be former site owner, current site owner, person who arranged for disposal of contaminant, person who transported contaminant 9

10 Clean up Sites ranged from old military bases to old paper mill sites Types of cleanup/response: Removal typically short term, remove threat Remedial clean up site, monitor, long term Sites where clean up is remedial is conducted under National Priorities List (NPL) NPL - Superfund Sites Hazard ranking system (HRS) identifies the threat level to public and environment of each sites Scale is from 0 to 100 Score of 28.5 gets a site on the NPL list, eligible for cleanup Site can be proposed, listed, and deleted Superfund has support of states, tribes and communities NPL Approx. 1,280 sites currently on list 10

11 Regional superfund sites In our region, 7,000 hazardous waste sites identified. Of these, 239 sites have been placed on the National Priorities List and have been or are being cleaned up under EPA's authority. 11