David Parrish - NOAA Aeronomy Laboratory Review “Section 6.4: Evaluation of the strengths weaknesses of current inventories and models. Please feel free to provide critiques and feedback Today: Preview of NARSTO Emission Inventory Assessment EMIS Meeting, Portsmouth NH, August 3, 200
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David Parrish - NOAA Aeronomy Laboratory
• Review “Section 6.4: Evaluation of the strengths and weaknesses of current inventories and models.”
• Please feel free to provide critiques and feedback!!!
Today:
Preview of NARSTO Emission Inventory Assessment
EMIS Meeting, Portsmouth NH, August 3, 2004
1.0 Introduction
2.0 Overview of Emissions Inventories Provide an emissions inventory primer for decision makers
3.0 Vision for Future North American Emission Inventory Programs Set the target: define where we need to be in future years.
4.0 North American Emission Inventories List what currently exists
5.0 Inventory Tools Describe how are inventories constructed
6.0 Strengths and Weaknesses of Current Inventories and Models: Sensitivities, Uncertainties, and Applicability Describe how to evaluate Provide an evaluation of important sectors
7.0 Evolving Tools for Determining Emissions Describe advanced methods and methodologies
8.0 Roadmap for Future Emission Inventory Application and Development
Absolute NOx, SO2 and CO2 fluxes agree with CEMS data within the estimated uncertainty (±20% for optimum conditions).
CEMS data are accurate
Conclusions:
CEMS data are accurately integrated into the NEI
CO emissions can be more than a factor 10 higher than inventoried.
Evaluations of Power Plant Emissions:
emis
sion
tabu
late
d / f
lux
mea
sure
d
There are occasional significant discrepancies.
25
20
15
10
5
0NOx
,
ethene,
and
propene,
ppbv
12:52 PM8/27/00
12:56 PM 1:00 PM 1:04 PM
70
60
50
40
30
20
10
Ozone, ppbv
Sweeny FreeportChocolateBayou
Ethene
Propene
NOxavg
Isobutane
Inventory alkene emissions are low by the following factors:Sweeny Freeport Choc. Bayou
Ethene: 72 60 25 Propene 67 70 40
Coincident, highly elevated levels of NOx and reactive VOCs lead to rapid formation of high O3 levels. Models using inventoried emissions of VOCs fail.
Evaluation of Emissions from Texas Petrochemical Facilities
PM2.5 source apportionment from chemical mass balance compared to the emission inventory in Denver, CO
Showed nearly twice the fractional contribution from fugitive dust emissions. Did not include cold start gasoline vehicle exhaust, which makes a substantial contribution in the CMB analysis. Underrepresented high emitter (i.e. poorly-maintained) gasoline vehicles.
Compared to emission inventory, CMB showed:
Inverse modeling application to
ammonia emission inventory
Showed 40% lower average annual emissions with strong seasonal cycle. Dramatic improvement in aerosol nitrate simulation (not included in inverse optimization)
Compared to emission inventory, inverse modeling showed:
Conclusions
Recommendations
Challenge inventories with ambient measurements.
Increase interaction and feedback between inventory and measurement folks.
(Appropriate sites, measurement techniques, data analysis.)
“Top down” tests do provide valuable evaluations of current inventories.
It is not yet possible to develop “bottom up” inventories that are accurate enough for many scientific uses without support of direct measurements (e.g. CEMS)
Still, “bottom up” inventories are indispensable
Global CO Emissions Inventory Enigmas:
Compared to U.S., Western Europe emits factor of 2 less with 40% more population. Lifestyle!
Western Europe emissions decreasing significantly while U.S. emissions nearly constant?
Road transportation emissions in U.S.: ≈ 2/3 of total. Really increasing?
4
3
2
1
020001995199019851980
U.S. Western Europe
Total
RoadTransport
+0.5 %/year(1990-1995)
-1.8 %/year(1980-1995)
+2.0 %/year(1990-1995)
+0.2 %/year(1990-1995)
-2.3 %/year(1990-1995)
+0.2 %/year(1980-1995)
Total
RoadTransport
EDGAR 2.0
EDGAR 3.2CO Emissions
“Everyone knows” that CO emissions have decreased dramatically over the last couple of decades
“National Vehicle Emissions Policies and Practices and Declining US Carbon Monoxide-Related Mortality”, J.A. Mott et al., J. Amer. Med.
Assoc., 288, 988-995, 2002. ≈ 12,000 deaths avoided in U.S.
≈ 86% increase in vehicle miles traveled 1975-1998
Emissions ratios: from near-field aircraft transects in mixed layerslopes from multiple transects vary by ±2%combined instrumental uncertainties typ. ± 10%
Absolute emission rates: calculate flux across plume transect
White et al., Science, 194, 187-189, 1976.
Absolute emission rates: calculate flux across plume transect365
360
355
350
34520:287/7/99
20:29 20:30
20
10
0
60
50
40
30
20
10
0
Species Calculated Tabulated Flux Emissions
NOy 1.27 x 1025 1.24 x 1025
SO2 6.0 x 1024 5.6 x 1024
CO2 4.0 x 1027 4.3 x 1027
units: molec / s
Thomas Hill plantRandolph County, MO
July 7, 1999
20 km/1.5 hrs downwind
Estimated uncertainty of±20% in flux calculationunder optimal conditions
Application to CO emissions from power plants:
400
350
300
250
200
150
100
806040200
NOy, ppbv
440420400380360
CO2, ppmv
D
9/3/009/13/00
400
350
300
250
200
150
100
806040200
NOy, ppbv
440420400380360
CO2, ppmv
C
9/3/009/13/00
Power plant combustion is carefully monitored for maximum efficiency;most power plants emit undetectable amounts of CO, most of the time
Martin Lake (TX) Monticello (TX)
Three out of four lignite-coal-fueled power plants showed substantiallyenhanced CO emissions, up to factors of 30 greater than inventory values;also observed in bituminous- and gas-fired electric utility power plants.
J. Environ. Monit., 5, 35-39 (2003)
expectedslopes, frominventoryratios
Application to petrochemical industrial emissions: Houston, TX
Compare measured (alkene/NOx) to inventory (alkene/NOx) • Electra NOx and VOC measurements accurate to ±10%• 2000 PSDB inventory NOx data are accurate to ± 30%• any larger discrepancies in (alkene/NOx) comparison attributed to errors in the alkene emissions inventory
25
20
15
10
5
0NOx
,
ethene,
and
propene,
ppbv
12:52 PM8/27/00
12:56 PM 1:00 PM 1:04 PM
70
60
50
40
30
20
10
Ozone, ppbv
Sweeny FreeportChocolateBayou
Ethene
Propene
NOxavg
Isobutane
Application to petrochemical industrial emissions: Houston, TX
25
20
15
10
5
0NOx
,
ethene,
and
propene,
ppbv
12:52 PM8/27/00
12:56 PM 1:00 PM 1:04 PM
70
60
50
40
30
20
10
Ozone, ppbv
Sweeny FreeportChocolateBayou
Ethene
Propene
NOxavg
Isobutane
Inventory alkene emissions are low by the following factors:Sweeny Freeport Choc. Bayou