March 26, 2004 EAS 4/8803 1 EAS 4/8803: Experimental Methods in AQ Week 11: Air Quality Management (AQM) Clean Air Act (History, Objectives, NAAQS) Emissions and Atmospheric Trends (Links) Principal Measurement Techniques (NOx, CO, SO 2 ) Measurement of CO (Exp 5) NDIR Method (Interferences, Stability, DL, Precision, Accuracy) Controlling O 3 and PM 2.5 Principal Measurement Techniques (O 3 , PM 2.5 ) Atmospheric Transport & Photochemistry (NOx vs VOC, SOA) Controlling O 3 , Emissions and Trends (GA) Measurement of O 3 (Exp 6) UV Absorption (Interferences, Stability, DL, Precision, Accuracy)
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March 26, 2004EAS 4/88031 EAS 4/8803: Experimental Methods in AQ Week 11: Air Quality Management (AQM) Clean Air Act (History, Objectives, NAAQS) Emissions.
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March 26, 2004 EAS 4/8803 1
EAS 4/8803: Experimental Methods in AQWeek 11:
Air Quality Management (AQM)Clean Air Act (History, Objectives, NAAQS)Emissions and Atmospheric Trends (Links)Principal Measurement Techniques (NOx, CO, SO2)
Measurement of CO (Exp 5)NDIR Method (Interferences, Stability, DL, Precision, Accuracy)
Controlling O3 and PM2.5
Principal Measurement Techniques (O3, PM2.5)Atmospheric Transport & Photochemistry (NOx vs VOC, SOA)Controlling O3, Emissions and Trends (GA)
Ozone IsoplethsArea of effective VOC control (most often highly populated areas)
Volatile Organic Compounds (VOC)
Nitr
ogen
Oxi
des
(NO
x) Constant [O3]
Low [O3]
High [O3]
NOx control effective(areas with high biogenics)
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NOx Sources in Columbus MSA (2000)Total: 42 tons per day
March 26, 2004 EAS 4/8803 12
Implementation of NOx Controls Since 2000,Full Implementation Expected by 2007
• Annual, stricter vehicle emissions inspections• Open burning ban in 45 counties• Georgia Power phasing in NOx controls• 30 ppm sulfur gasoline in 45 counties • GA Power plants achieve NOx reduction in 45 counties• Stricter peaking generator rule• Large industrial source NOx reductions
March 26, 2004 EAS 4/8803 13
2007 NOx Emissions in Georgia by Region
0
50
100
150
200
250
300
NO
x em
issi
ons
(tons
/day
) MOBILEPOINT
AREANONROAD
MOBILE 277.4 36.7 22.5 14.9 90.1 135.0 57.6
POINT 126.6 16.8 15.8 0.6 34.0 96.5 23.7 142.2
AREA 61.5 3.0 2.7 2.5 11.6 19.8 7.9
NONROAD 134.2 11.9 8.2 5.2 29.6 70.1 21.3
Atlanta Macon Augusta Columbus N. Georgia S. Georgia C. Georgia Scherer (92) + Branch (50)
2007 NOx Emissions in GA by Region and SourceIf Fully Implemented
Georgia Total: 1480 tons/day
Alabama Total (not shown): 998 tons/day
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Significant improvements in regional air quality by 2007with no additional controls (current SIP fully implemented)
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Estimated Change in Regional Peak 8-hour Surface Ozone from August 17th, 2000 to 2007 under the Existing Federal Control Strategies (ppbv)
Region Atlanta Augusta Columbus Macon
Observed 139 111 114 134
4-km grid 132 118 100 89 108 96 143 128
% reduction 11% 11% 11% 10%
Region Maximum Daily Peak 8-hour OzoneObserved / Simulated 2000 2007
But will these existing controls be enough?
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0.0880.086 0.087
0.085
0.089
0.094
0.090
0.060
0.070
0.080
0.090
0.100
1981 1984 1987 1990 1993 1996 1999 2002Year
Thre
e Ye
ar A
vera
ge o
f 4th
Max
for O
zone
(ppm
v)The State of the Air in Columbus, Georgia
8-hour Average Ozone Design Values
Attain“Good”
NAAQS
Nonattain“Bad”
March 26, 2004 EAS 4/8803 17
0.0880.086 0.087
0.085
0.089
0.094
0.090
0.060
0.070
0.080
0.090
0.100
1981 1984 1987 1990 1993 1996 1999 2002Year
Thre
e Ye
ar A
vera
ge o
f 4th
Max
for O
zone
(ppm
v)The State of the Air in Columbus, Georgia
8-hour Average Ozone Design Values and Theoretical 10% Improvement
3.2 Discuss jNO2 Diurnal ProfileThe photolysis rate coefficients (jNO2) provided here exemplarily, were calculated using a radiative transfer model (Zeng et al., 1996), which is based upon the Stamnes discrete ordinates model modified to solve the radiative transfer equation in pseudo-spherical coordinates. The discrete ordinates code was run with eight streams. The surface albedo was assumed to be 5%, and the total aerosol optical depth was parameterized in terms of visual range. The model assumes a constant visual range of 25 km for the lowest 2 km, a logarithmically decreasing aerosol optical depth above this, as well as a single scattering albedo of 0.99 and an asymmetry parameter of 0.61, which are both wavelength-independent. The jNO2 values were then scaled linearly by the flat-plate Eppley-UV (290-385 nm) measurements and by their ratio to the radiative transfer model clear-sky irradiance to account for the actual cloud and aerosol effects on jNO2. This scaling helps to correct for any errors made by the visual range assumptions.