tahm ja tema olulisus - globe
TRANSCRIPT
6.10.2011 Comenius
Sisukord
• 1. Õhusaaste • 2.Miks oluline • 3. Tahm ja tema roll • 4. Tulemuste tähtsus
6.10.2011 Comenius
Õhu koostis
N2 – 78.1%, O2 – 20.9%, Ar – 0.9%, tihedus 1,25 kg kuupmeetri kohta
• Muud osised tühised • Enamus olulisi efekti tingitud väikestest
koostisosadest
6.10.2011 Comenius
Miks õhu kvaliteet oluline 1. AINERINGLUS - ca 20 kg, vaid ca 2 kg of
toit ja vedelik !!! 2. Valikuvõimalused !!! 3. Õppeosa 4. ENAMUS ÕHUSAASTEST MEIE
IGAPÄEVATEGEVUSTEST
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ÕHUSAASTEST TINGITUD PROBLEEMID
1) global – climate change, ozone layer depletion 2) regional – acid rain, elevated levels of ozone and
particles, 3) local – air quality issues in cities and industrial
areas, toxic compounds 4) today different scales more and more mixed
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VIIMASED MUUTUSED (IPCC, 2007)
• Increase in GHG ca 1/3 for CO2, 4/3 for CH4, 1/5 for N2O
• Levels much higher than during last millenium
• Changes accelerating during last century
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EU limit values - mainly for gases
In particles (PM10) also As, Cd, Ni as yearly average, correspondingly 6, 5, 20 ng m-3
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Formation of pollution
• Energy demand of mankind increased during last century 10 times
Main reasons – transport on fossil fuels (oil production increase 100 times), growth of mankind and social pressure
• When most of particles formed naturally (10 times more than by mankind), then their radiative influence almost equal (due to black carbon)
Pollution formation during combustion
• Non-efficient combustion mainly occurring in smaller engines – cars, domestic heating
• Black carbon formation similar to CO, especially marked in IPCC reports
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Pollution distribution - houses, trees etc diminish horisontal mixing several times
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What to measure?
• List of pollutants measured and measurements frequency related to problem involved
• Global issues mainly require long-living compounds, exceptions particles remaining in dynamic equilibrium
• Thus also when we diminish release of particles, influence can be quick
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Siting of measurements (Sivertsen, 1997)
The quicker we measure the less stations
The more polluted the more required measurements
Important also for making analysis – until which area you can say something
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BC or EC measurements
• Measurements in few places, usually temporarily during scientific campaigns
• Not required directly by directives, can help to determine sources and manage air quality
• Can easily be linked with local human activities – driving, domestic heating (but not with natural gas)