METO 637 Lesson 19. NO x emission inventory VOC Emissions.
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Transcript of METO 637 Lesson 19. NO x emission inventory VOC Emissions.
METO 637
Lesson 19
NOx emission inventory
28%
13%
5%30%
19%
5%Fuel Combustion- Electric Utility
Fuel Combustion- Industrial
Fuel Combustion- Other
On-RoadVehicles
Non-RoadVehicles
All Other
VOC Emissions
33%
7%
29%
13%
18% SolventUtilization
Storage &Transport
On-RoadVehicles
Non-RoadVehicles
All Other
Sulfur Dioxide emissions
67%
17%
4%
3%2%
7%
Fuel Combustion- Electric Utility
Fuel Combustion- Industrial
Fuel Combustion- Other
MetalsProcessing
Non-RoadVehicles
All Other
A Typical Day in a Pollution Episode
•A common severe pollution weather pattern occurs when high pressure is centered just west of the Mid Atlantic region.
•Circulation around the high pressure center moves pollution from points west into the mid-Atlantic.
H
Fort Meade profile 6/19/2001
After Sunrise Ozone Levels Increase Sharply
• The ground heats up and the warm air above it erodes the inversion.
• Ozone and other compounds above the inversion layer mix with the pollution under the layer.
• This causes a dramatic increase in ground-level ozone, beginning around 10 AM.
Temperature
Alt
itu
de
Sub. inv.
Noct. inv.
Ozone Levels Reach a Maximum in the Afternoon
Temperature
Alt
itu
de
Sub. inv.
Temperature
Alt
itu
de
Sub. inv.
Noct. inv.
After Sunset• If the weather remains
the same, the temperature inversion forms again after dark.
• Ozone concentrations above the inversion remain at a constant, relatively, high level.
• Ozone trapped under the inversion reacts with other pollutants, and the surface; the ozone concentration diminishes. Ozone concentration
remaining constant
Ozone concentration diminishing
Temperature Inversion
Temperature
Alt
itu
de
Westerly transport is often present when the highest ozone is observed in the mid-Atlantic.
24 hr. Back-trajectories on days of 1-hr. ozone exceedances from 1997 through 2002, Baltimore area
Aircraft measurements of ozone
Aircraft measurements of Sulfur Dioxide
Upper level windsUpper level windsfrom the west…from the west…
……are turned by theare turned by thelee side troughlee side trough
Lee Side T
rough
daytimedaytime
Low Level Jet
nighttimenighttime
Air pollution from the southwest…Air pollution from the southwest…
……comes into Maryland overnightcomes into Maryland overnight
Plot of low-level winds from the Fort Meade, MD wind profiler during a high ozone episode
LLJLLJ LLJ
9:00 PM 11:00 PM 01:00 AM
03:00 AM 05:00 AM 07:00 AM
Rapid Update Cycle (RUC)
model depiction of
the LLJduring a high ozone period
(high wind speeds in red).
All three modes of transport are important when the highest pollution values are observed in the mid-Atlantic.
•Large scale ~ 800 km (~70-100 ppbv)(Much of the Eastern US)
•Medium scale ~ 200- 800 km(Carolinas to New England Region)
•Small scale ~ 100 km(N. Virginia to Baltimore,Research Triangle to NC/VA border)
Modes of Transport
Sources
• Different types of transport imply different types of sources– Local transport Cars, industry, and other
sources in the local area– Long distance transport Primarily power plants to
W, though plumes from cities certainly contribute.
– Low level jet Primarily cars and other
low level sources; moves from SW to NE
Effects of the August 15, 2003 Blackout on Air Quality
Compared with Aug 4, 2002
Coming soon to GRL
Selinsgrove, PA
Effects of the 2003 Blackout on Air Quality
CEM data indicatereductions of 60-80%
L. Marufu, B. Taubman, B. Doddridge et al.
Effects of the 2003 Blackout on Air Quality
In summary
• It isn’t all transport…• It isn’t all local…• It isn’t all power plants…• It isn’t all automobiles…• The problem will not be solved by addressing
any one of these problems individually. ALL of these will have to show significant reductions for us to breathe clean air.