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Es 200 by sethi
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ES 200Second Half Semester
18+ Lectures
Professor Anurag GargProfessor Subhankar Karmakar
Professor Virendra SethiCESE
In Service of YOU
Professor Arcievala:
“Three things I learnt at Harvard:1. Quantification
2. Library work and
3. Apprenticeship”
Let’s Get Started
6
ES 200 Environmental Studies
Air Quality
Pre-course Quiz
not for grade
Phew !!!
Thank God for small mercies !!!
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What is Air Pollution ?
• Perception– Visible– Odour
• What is clean air ?– 78% Nitrogen + 21% Oxygen + 1% Trace– 340 ppm CO2 (0.034%) (YEAR ???)
• Water – Heat Released/Absorbed
9
Lifecycles/Statistics
• Capacity of the earth system as a sink– Feasibility (thermodynamics)– Proximity
• Characteristic times– Kinetics– Sulphur, Carbon, Nitrogen, Halogen Containing
Compounds Cycles
• Statistics
10
Scales
• Local > Regional > Global
• Earth : Apple :: Atmosphere : Skin
• Ambient : Indoor
• Dispersion and Mixing
11
Class Exercise
• Given : Regulatory Limit for SO2 in Ambient Air is – 80g/m3 (0.03 ppm) for annual average– 1300 g/m3 (0.5 ppm) for 3 hour average
• How many grams of Sulphur, if burnt in this lecture Hall, would pose a health risk to you ?
• S + O2 = SO2
• 32 gm S gives 64 gm of SO2
• X gm will give 2X gm
• Mixed in how much volume ? Will lead to exposure concentration…
Actual Question then is …
• What is the volume of air in this Hall
(in m3 ) ?
Prizes to be Won
DOUBLE DHAMAKA
Closest to Actual – 5 Star Chocolate
Closest to Average – 5 Star Chocolate
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Caution
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Results from Previous Year
1
10
100
1000
10000
100000
1000000
10000000
100000000
0 20 40 60 80 100 120 140 160 180
Students
Estim
ated
Vol
ume
of F
CK
ohli
Aud
itoriu
m (m
3)
Series1
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Results
• RANGE – 20 mg of Sulphur (panic buttons for no
reason)– 8 kg of Sulphur (dead people with Karma to
blame)
• Low Sulphur diesel YET ?
• Ships affecting coastal cities ?
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How do we manage Air Quality ?
• At the source itself– Industry– Vehicles– Dust– Home cooking
• After the source– Dispersion and Mixing
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Mixing/Dispersion
• Meteorology– Vertical
• Temperature– Lapse Rate
– Horizontal• Wind
– Speed – Direction
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Dispersion – Gaussian Plume
WIND
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Wind Rose
http://www.epa.gov/ttn/naaqs/ozone/areas/wind.htm#dlfi
1 knot = 1.82 km/hr
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• Wind roses are divided into 16 wind directions
• Each wind direction is divided into wind speeds
• As the percent of time the wind blows from a particular directions gets larger, the portion of the bar representing the wind speed gets larger both in length and width
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Mixing/Dispersion
• Meteorology– Vertical
• Temperature– Lapse Rate
– Horizontal• Wind
– Speed – Direction
30http://www.ldeo.columbia.edu/edu/dees/ees/climate/slides/atmprofile.gif
COMING SOON
Earth ki Kahani – Naam toh
Sunaa hoga !
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Lapse Rates
• Atmosphere cools with height– What rate ?
• Dry (Adiabatic) 10°C/km• Wet (Adiabatic) 6°C/km
– (Release of heat with condensation)
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ACTUAL
ADIABATIC (1°C/100 m)
1000 m (say)
20 °C19 °C18 °C
20 °C Air Parcel
19 °C Air Parcel at 1100 m
1100 m
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ADIABATIC (1°C/100 m)
1000 m (say)
20 °C 21°C 22 °C
20 °C Air Parcel
21 °C Air Parcel at 1100 m
1100 m
900 m
ACTUAL
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ADIABATIC (1°C/100 m)
1000 m (say)
20 °C19.5 °C19°C
20 °C Air Parcel
19 °C Air Parcel at 1100 m
1100 m
ACTUAL
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WIND
Adiabatic
Actual
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ScenariosAdiabatic
ActualH
eig
ht
Temperature
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ScenariosAdiabatic
ActualH
eig
ht
Temperature
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ScenariosAdiabatic
ActualH
eig
ht
Temperature
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Stability
http://www.tpub.com/content/aerographer/14312/css/14312_47.htm
Wet Lapse Rate
Dry Lapse Rate
Average
Unstable
Stable
Height
Temperature
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Match the Profile
Unstable
Stable
Plumes (a) (b) (c) (d)
(Adapted from Masters, 1997)
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Match the Profile
Unstable
Stable
Plumes (a) (b) (c) (d)
(Adapted from Masters, 1997)
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Review
Dispersion and Mixing Influenced by :• Wind
– Speed– Direction– Wind Rose
• Temperature Lapse Rates– Dry adiabatic– Wet Adiabatic– Stability
Contextual Communication
• Where to stand when participating in this course : – Good Citizen OR Decision Maker– How would this apply to my home city ?
• Grading :– 20 Questions : 20 Answers
Home Work
Please study the film
“An Inconvenient Truth”
(Al Gore)
before the March 21st Class
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