CRC Report No. A-34 - Coordinating Research Council

More documents

Recommendations

Info

April 2005 samples. For Round 4, the CMB modelers had complete information about all sources present including the source composition profiles. Figure ES-1 compares the actual source category contribution to the sum of PAMS species in each air sample with the source contributions inferred by the CMB analysis. (a) Round 2b: Experiment 1 CMB vs. Actual Contribution, by Receptor 80 70 60 Van Nuys CMB Contribution (%) Anaheim Diamond Bar 50 LAX Hawthorn Long Beach Crestline 40 Lake Perris 30 Long Beach Lake Perris Crestline 23.23 Hawthorn Lake Perris 20 Crestline Diamond Bar Long Beach 10 Van Nuys Anaheim Diamond Anaheim LAX Bar Van Nuys Diamond Anaheim Bar Hawthorn Crestline Long Lake Beach Perris Anaheim Diamond Crestline Bar Hawthorn 0 Anaheim Diamond Lake Van Perris Nuys Bar 0 10 20 30 40 50 60 70 80 Actual Contribution (%) Gasoline Diesel Solvent Biogenic Backgd CNG and Aged LPG 1:1 (b) Round 4: Experiment 1 CMB vs. Actual Contribution, by Receptor 80 70 Long Beach 60 CMB Contribution (%) 50 40 30 Long Beach Crestline Van Nuys Hawthorn Diamond Bar Lake Perris Anaheim LAX LAX Anaheim Hawthorn Van Nuys Diamond Bar Lake Perris Crestline Gasoline Diesel Solvent Biogenic Backgd CNG and Aged LPG 1:1 20 Lake Perris Anaheim 10 Crestline Diamond Diamond Bar Bar Anaheim Crestline Hawthorn 0 Long Beach 0.00 Anaheim Diamond Lake Van Perris Diamond Van Hawthorn Crestline Lake Long Nuys Perris Beach Nuys Bar Bar Anaheim 0 10 20 30 40 50 60 70 80 Actual Contribution (%) Figure ES-1. Comparison of CMB contributions to actual contributions for experiment 1 at each receptor averaged over all hours in (a) Round 2b and (b) Round 4. H:\crca<strong>34</strong>-receptor\report\Final\ExecSum_r.doc ES-2
April 2005 Comparing the performance of CMB in Rounds 2b and 4 (Figure ES-1) lead to several findings: • In Round 2, the CMB analysis apportioned VOCs to categories called “CNG and Aged” and “LPG” that were not actually present in the samples, illustrating that CMB category names may describe chemical characteristics (fingerprints) rather than specific activities tracked in emission inventories. CNG is compressed natural gas and LPG is liquid petroleum gas. • CMB tended to over-estimate the contribution of gasoline emissions except when complete profile information was available in Round 4. • CMB performance for diesel was poorer in Round 4 than Round 2 because of a decision to exclude nonane, decane and undecane as CMB fitting species in Round 4 that resulted in partial colinearity between the diesel and gasoline source profiles. The results presented in Figure ES-1 show that CMB can achieve accurate results with adequate supporting information but that even with detailed supporting information, results can be biased by decisions made during the analysis. Consequently, it may be difficult to judge the accuracy of CMB results in each application. The comparisons presented in Figure ES-1 are based on the actual source contributions to VOCs present in air samples. However, CMB results are frequently interpreted as measures of emission inventories. There are at least two major reasons why actual contributions may differ from emission contributions; namely chemical reaction and spatial heterogeneity in emissions. The impacts of chemical reaction on source contributions are illustrated in Figure ES-2 for several source categories at a downwind receptor (Crestline). Figure ES-2 compares source category contributions from the photochemical model with and without chemical degradation included. Low reactivity VOCs (CNG/aged and LPG) are only slightly depleted by chemical degradation, whereas high reactivity VOCs (biogenics) are almost completely depleted during the night and highly depleted at day. Differences in VOC degradation rates introduce a bias toward low reactivity VOCs having higher contributions to actual concentrations than to emission inventories. H:\crca<strong>34</strong>-receptor\report\Final\ExecSum_r.doc ES-3
Page 1 and 2: International Corporation Air Scien
Page 3 and 4: April 2005 TABLE OF CONTENTS Page E
Page 5 and 6: April 2005 Table 4-1. Categories id
Page 7: April 2005 EXECUTIVE SUMMARY Recept
Page 11 and 12: April 2005 90 12 Anaheim 80 10 Cr e
Page 13 and 14: April 2005 This assumption is a mat
Page 15 and 16: April 2005 dissimilar from the loca
Page 17 and 18: April 2005 1.0 INTRODUCTION 1.1 STU
Page 19 and 20: April 2005 1.4 OVERVIEW OF PROJECT
Page 21 and 22: April 2005 Meteorological input dat
Page 23 and 24: April 2005 A-34 Num Short Name Full
Page 25 and 26: April 2005 Sunday 3-Aug-97 Monday 4
Page 27 and 28: April 2005 ARB ROG TOG ARB Profile
Page 29 and 30: April 2005 Industrial facilities fr
Page 31 and 32: April 2005 Figure 2-2. Comparison o
Page 33 and 34: April 2005 2.4 EXPERIMENTS FOR ROUN
Page 35 and 36: April 2005 Table 2-9. Source catego
Page 37 and 38: April 2005 Table 2-13. Replacement
Page 39 and 40: April 2005 from front to back is th
Page 41 and 42: April 2005 3. Set the average diese
Page 43 and 44: April 2005 Table 2-15. Model year d
Page 45 and 46: April 2005 Table 2-17. Fuel composi
Page 47 and 48: April 2005 3.0 RECEPTOR MODELING ME
Page 49 and 50: April 2005 Selection of Fitting Spe
Page 51 and 52: April 2005 samples. Spatial variati
Page 53 and 54: April 2005 • Removed ethane from
Page 55 and 56: April 2005 Table 3-2. Criteria for
Page 57 and 58: April 2005 Table 3-4 (continued). N
Page 59 and 60:
April 2005 120 100 80 60 40 20 0 no
Page 61 and 62:
April 2005 4.0 RESULTS This section
Page 63 and 64:
April 2005 (c) Round 4: Experiment
Page 65 and 66:
April 2005 emissions contributions,
Page 67 and 68:
April 2005 reactivity and found CMB
Page 69 and 70:
April 2005 (c) Round 4: Experiments
Page 71 and 72:
April 2005 (a) 6:00am to 9:00am 80
Page 73 and 74:
April 2005 (a) siteid Anaheim exp 1
Page 75 and 76:
April 2005 influence CMB performanc
Page 77 and 78:
April 2005 Round 3: Experiments 9-1
Page 79 and 80:
April 2005 Comparison of Source Con
Page 81 and 82:
April 2005 Table 4-2. Source catego
Page 83 and 84:
April 2005 contributions being diff
Page 85 and 86:
April 2005 to 2.4 over the A-34 sou
Page 87 and 88:
April 2005 Experiment 1: Base Case
Page 89 and 90:
April 2005 28. Spatial heterogeneit
Page 91 and 92:
April 2005 composition derived from
Page 93 and 94:
April 2005 species (CNG and LPG for
Page 95 and 96:
April 2005 REFERENCES Allen, P. 200
Page 97 and 98:
April 2005 Guenther, A., B. Baugh,
Page 99 and 100:
APPENDIX A Supplemental Modeling Re
Page 101 and 102:
SCC Description TOG %TOG Cumulative
Page 103 and 104:
SCC Description TOG %TOG Cumulative
Page 105 and 106:
ARB Profile Number TOG %Total % TOG
Page 107 and 108:
A-34 Number SCC Code SCC Descriptio
Page 109 and 110:
A-34 Number SCC Code SCC Descriptio
Page 111 and 112:
Table A-4 (continued). A-34 Source
Page 113 and 114:
Table A-5. Mean source profiles (PA
Page 115 and 116:
Table A-5 (concluded). A-34 Source
Page 117 and 118:
APPENDIX B CMB-Derived Source Contr
Page 119 and 120:
SCE (ppbC) SCE (ppbC) 18 16 14 12 1
Page 121 and 122:
Page 123 and 124:
SCE (ppbC) 14 12 10 8 6 4 2 0 6 5 C
Page 125 and 126:
Page 127 and 128:
SCE (ppbC) 12 10 8 6 4 2 0 6 5 Cons
Page 129 and 130:
SCE (ppbC) 10 9 8 7 6 5 4 3 2 1 0 6
Page 131 and 132:
SCE (ppbC) 6 5 4 3 2 1 0 Consumer P
Page 133 and 134:
SCE (ppbC) SCE (ppbC) SCE (ppbC) 4
Page 135 and 136:
Page 137 and 138:
SCE (ppbC) SCE (ppbC) 12 10 8 6 4 2
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
SCE (ppbC) SCE (ppbC) SCE (ppbC) 10
Page 145 and 146:
SCE (ppbC) 9 8 7 6 5 4 3 2 1 0 12 1
Page 147 and 148:
SCE (ppbC) SCE (ppbC) SCE (ppbC) SC
Page 149 and 150:
SCE (ppbC) 6 5 4 3 2 1 0 Consumer P
Page 151 and 152:
SCE (ppbC) 160 140 120 100 80 60 40
Page 153:
Diamond Bar - Source Category 14 Di
show all

CRC Report No. A-34 - Coordinating Research Council

Create successful ePaper yourself

Delete template?

Save as template?