Haze in the Grand Canyon An Evaluation of the Winter Haze Intensive Tracer Experiment (1990) / Chapter Skim
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Appendix 2: Selected Pages From the NPS-Whitex Report
Appendix 2: Selected Pages From the NPS-Whitex Report
Pages 45-94
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From page 45... ...
69 Tracer Mass Balance Regression (TMBR) Analysis (9-7)
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From page 46... ...
and measured total sulfur Chemical Mass Balance with Unique Tracer (6-33)
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~~ ~~ ~~ ~ ~7 Potential D^a[10= Tom ^ss~p[lons of Nonco~t~t Rc~es610n CoeGdonts e MOB Todd ~~ Gas Model Outputs ., (6B-6)
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From page 48... ...
1.2 Background The Colorado Plateau, with its many associated class I national park areas, was chosen as the location to implement a scoping study designed to evaluate the ability of a variety of receptor modeling approaches to attribute visibility impairment in a number of class I areas to emissions from a single point source, the Navajo Generating Station. The area, shown in Figure 1.3, is by most standards remote, undeveloped and sparsely populated.
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From page 49... ...
EXCERPTS FROM NPS-WNITEX · 49 \ 1 \ ~ U e g ~ 5 -O i 1 \ ~ e ~ ~ O J ~ v ` L o s ~ n g e I e s \ ~ " ,.~ | ~ ~ Power an~ I L g ~ s ~ _ . ~ 1 S ~ l t L ~ k e Ci tg ~P 0 ~ ~ r pl an t 14 ~ ~ a j 0 Phoen i x S ~ ~ I t e P 0 ~ e ~pl an t e.
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From page 50... ...
Specifically, various receptor and deterministic models were to be evaluated and intercompared as to their ability to link Navajo Generating Station emissions to visibility impairment at Grand Canyon and Canyonlands National Park and Glen Canyon National Recreation Area. Meeting this objective is a three tier process.
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From page 51... ...
The major focus of the WHITEX study is centered around the evaluation of receptor oriented approaches for linking NGS emissions to aerosol concentrations in Grand Canyon and Canyonlands National Parks and Glen Canyon National Recreation Area. In a receptor type model the atmosphere is treated as a black box through which source emissions are transferred to the receptor site.
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From page 52... ...
52 · APPENDIX 2 o ._ ~d o U3 ~o cd ~d .ca CO ~ C td ~ ~ ~C _, ~ ~o ~ ~o C oo o C)
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From page 53... ...
analysis where it is assumed that the relationships between atmospheric extinction, ban, and aerosol species mass concentrations, m', are represented by bar: = Hi |
From page 54... ...
Similarly, tracer (CD4) released over time can be used in a TMBR analysis to apportion sulfur and nitrate aerosols to NGS emissions, while DMB analysis will yield an independent estimation of NGS emission contribution to secondary aerosols at the receptor site.
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From page 56... ...
Table 1.2: List of the function associated with each of the monitoring sites. SITE SITE TYPE FUNCTION Glen Canyon National Recreation Area ~ Grand Canyon National Park Receptor site Canyonlands National Park ,, .
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IJ F`igure 1.3: Map of SCENES WHITEX study area.
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-* SFU ., Size Se'5re'5atin~s Trace Elements A Giant Particles (>10.0 A)
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From page 59... ...
Chemical mass balance, tracer mass balance and differential mass balance are quantitative models investigated while several non quantitative approaches are used to either confirm or negate quantitative calculations. The non quantitative procedures were also used to gain insight into physicochemical processes at work during the study period.
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From page 60... ...
Latimer, H Hogo, "Layered haze observed at Bryce Canyon National Park: A statistical evaluation of the phenomenon," In: Proceedings of the Air Pollution Control Association International Specialty Conference 'Visibility Protection: Research and Policy Aspects', September 8-10, 1986, Jackson Hole, Wyoming.
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From page 61... ...
Iyer, "Comparison of atmospheric extinction measurements made by a transmissometer, integrating nephelometer and teleradiometer with natural and artificial black target," 16: Proceedings of the Air Pollution Control Association International Specialty Conference 'Visibility Protection: Research and Policy Aspects', September 8-10, 1986, Jackson Hole, Wyoming.
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From page 62... ...
Eldred, W.C. Malm, "Size/time/composition data at Grand Canyon National Park and the role of ultrafine sulfur particles," In: Proceedings of the Air Pollution Control Association International Specialty Conference 'Invisibility Protection: Research and Policy Aspects', September 8-10, 1986, Jackson Hole, Wyoming.
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From page 63... ...
. Grand Canyon, Bryce Canyon, Capitol Reef, and Canyonlands National Parks, all within the WHITEX study area, are afforded such visibility protection Because NGS, a power plant without sulfur dioxide (SO2)
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From page 64... ...
NGS is determined from ambient concentrations of CD4 scaled to NGS sulfur emissions and accounting for oxidation and deposition. Without the tracer unique to NGS, WHITEX measurements of winds, spatial and temporal trends of ambient concentrations, and light extinction alone could be used to assess qualitatively the contribution of NGS.
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From page 65... ...
Light extinction budgets were developed for three WHITEX sites: Glen Canyon National Recreation Area (Page) , Grand Canyon National Park (Hopi Point)
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From page 66... ...
As a third special case of the GMB, the chemical mass balance formalism was used to estimate source contributions of primary aerosol species and to set an upper bound on NGS contributions. 9.4.1 Emissions Analysis Emission inventories and maps indicate that NGS is the largest single point source of 502 emissions in the vicinity of Grand Canyon National Park.
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From page 67... ...
These trajectories also suggest the possibility of long-range transport of copper smelter emissions from southern Arizona and northern Mexico into the WHITEX study region on Days 39-40. Upper-air winds at 300 and 600 m agl, measured three times per day at Page during WHITEX, were used as a basis for estimating the position and age of NGS plume parcels throughout the study region and study period.
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From page 68... ...
Thus, these analyses suggest that the prediction of NGS plume position was not far off target. 9.4.3 Spatial and Temporal Trends in Ambient Concentrations As previously mentioned, there is a statistically significant correlation between sulfate concentrations and predicted NGS plume "hits." One can also use spatial and temporal patterns of ambient sulfate concentrations to deduce whether this large, local source is a contributor or whether more distant sources contribute.
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From page 69... ...
9.4.5 Tracer Mass Balance Regression (TMBR) Analysis It is a simple statement of fact that the total ambient concentration of a given species (such as sulfate)
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From page 70... ...
Organic carbon and light-absorbing carbon were totally uncorrelated with tracer, as one might expect since these species are not emitted from NGS. A similar analysis was carried out for Glen Canyon National Recreation Area (Page, Arizona)
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From page 71... ...
The analyses suggested, within the considerable uncertainty in estimating plume age at Page, that essentially all of the sulfur in Page is attributable to NGS. The most physically realistic estimates of NGS contributions to SO2 and sulfate in Page were obtained when the average of the lower and upper bound of NGS plume age was used in the DMB calculations.
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From page 72... ...
For example if the RH value were underestimated, then the extinction due to NGS sulfate, other sulfate, and nitrate would all be underestimated. 9.4.8 Synthesis Differentiai Mass Balance and Tracer Mass Balance Regression are the two receptor oriented modeling approaches that were successfully exercised to yield quantitative attribution of sulfate aerosol concentrations.
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From page 73... ...
At Page the results from the too techniques are again quite similar. Best estimate of NGS contribution to sulfate are 75 ~ 2 percent while the DRIB calculation suggests NGS contribution to sulfate is between 60 and 100 percent depending on whether the average minimum air mass age is assumed to be 6 or 12 hours.
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From page 74... ...
Concentration fields of this nature under stable meteorology are suggestive of NGS emissions as being a significant contributor to ambient sulfate concentrations. Furthermore the strong correlation between predicted "hits" of the NGS plume and all time periods with elevated sulfate suggest a significant contribution to sulfate concentrations by NGS.
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From page 75... ...
The analysis of the samples is discussed in section 3.5 and in Appendices 3A and 3B. 3.3 Sample Collection A complete suite of measurements were made at the three receptor sites: Canyonlands National Park, Hopi Point (Grand Canyon National Park)
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at eight ~ lIITE.X receptor sites.
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From page 77... ...
of STD 90th SITE OBS DEV MAX PRCNTL 75th PRCNTL MEAN MED MIN GREEN RIVER PAGE CISCO MEXICAN HAT BITE BULLFROG CANYON LANDS MONTICELLO WUPATKI NAVAJO HOPI POINT MEADVIEW BRYCE CANYON _ .
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From page 78... ...
. Figure 5.4: Time traces of optical data and relative humidity at Hopi Point.
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From page 79... ...
and the fraction due to each component at Hopi Point. Extinction includes Rayleigh scattering.
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SITE .. LOCATION Apache Coronado NGS Springerville Cholla Cameo Craig Hayden Escalante Four Corners San Juan North Valmy Mohave Carbon Hunter Huntington Bridger Naughton Cohise, AZ St.
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From page 81... ...
Theoretical calculations suggest that the higher rates observed during WHITEX are indeed plausible. Figure 6.11 shows the sulfur oxidation rates as a function of droplet pH as a result of reactions with ozone (O3)
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, the NGS plume would be present with minor modifications of winds. WHITEX Study Period in 1987 Dater Hour Navajo GeDeratis~ Station Plume Age (hours)
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Period in 1987 CanyonlAnds Bullfrog Manna Dav Hour Page, Arizona Hopi Print ~ Monticello ~ Hite, Utah Green River, Utah Mexican Hat, Utah 28 17 6-12 (36)
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From page 84... ...
and fraction of ambient total sulfur due to NGS based on DMB analysis for Hopi Point. Ambient Julian S Day Concent Total Measured 5 Uncertainties NGS due to due to S K's Measmt Concent NGS Contribution to S Uncertainties due to due to K's Measmt Fraction Due to GIGS Uncertainties Ratio due to due to K's Measmt 13.8 0.25 0.04 0.04 1.40 0.47 0.18 5.63 1.90 1.28 14.3 1.50 0.11 0.11 3.31 1.12 0.31 2.21 0.75 0.24 14.8 0.71 0.05 0.05 0.66 0.38 0.11 0.93 0.53 0.17 15.3 0.38 0.05 0.05 1.39 0.44 0.13 3.65 1.16 0.66 15.8 0.33 0.04 0.04 0.76 0.38 0.28 2.34 1.18 0.93 16.2 0.59 0.04 0.04 0.77 0.42 0.11 1.30 0.71 0.20 16.7 0.78 0.05 0.05 0.57 0.37 0.04 0.72 0.47 0.06 17.2 0.57 0.04 0.04 0.57 0.47 0.17 1.01 0.83 0.32 17.7 0.34 0.04 0.04 0.40 0.37 0.14 1.20 1.11 0.47 18.2 0.20 0.04 0.04 1.23 0.42 0.24 6.19 2.12 1.90 32.2 0.08 0.03 0.03 0.06 0.10 0.01 0.78 1.26 0.76 32.7 0.07 0.03 0.03 0.22 0.17 0.09 2.90 2.23 2.52 33.2 0.09 0.03 0.03 0.05 0.10 0.01 0.57 1.10 0.38 33.7 0.12 0.03 0.03 0.15 0.16 0.10 1.24 1.36 0.89 34.2 1.01 0.06 0.06 0.09 0.11 0.02 0.09 0.11 0.02 34.7 0.50 0.04 0.04 0.12 0.06 0.09 0.24 0.11 0.19 35.2 4.42 0.33 0.33 0.59 0.29 0.10 0.13 0.06 0.03 35.7 0.61 0.05 0.05 1.24 0.39 0.29 2.05 0.64 0.53 36.2 0.91 0.07 0.07 0.16 0.23 0.01 0.17 0.26 0.02 36.7 1.33 0.10 0.10 1.66 0.57 0.46 1.25 0.43 0.36 37.2 0.75 0.06 0.06 1.08 0.37 0.11 1.43 0.49 0.19 37.7 0.71 0.06 0.06 0.72 0.24 0.13 1.02 0.35 0.22 38.2 0.55 0.05 0.05 0.24 0.31 0.02 0.43 0.56 0.06 38.7 0.24 0.03 0.03 0.26 0.24 0.07 1.10 0.98 0.35 39.2 ~ 0.34 0.04 0.04 0.11 0.11 0.07 0.31 0.31 0.22 39.7 0.55 0.04 0.04 0.19 0.07 0.24 0.35 0.12 0.43 40.2 0.79 0.06 0.06 0.10 0.07 0.04 0.13 0.09 0.06 40.7 0.65 0.05 0.05 0.10 0.06 0.08 0.16 0.08 0.13 41.2 0.49 0.04 0.04 0.20 0.06 0.14 0.42 0.13 0.30 41.7 0.27 0.04 0.04 0.69 0.21 0.41 2.60 0.78 1.67 42.2 0.54 0.04 0.04 0.93 0.39 0.14 1.71 0.71 0.29 42.7 0.46 0.04 0.04 0.98 0.29 0.33 2.12 0.63 0.79 43.2 0.40 0.04 0.04 1.22 0.38 0.12 3.05 0.96 0.41 43.7 0.25 0.04 0.04 0.46 0.27 0.21 1.79 1.06 0.90 44.2 0.16 0.03 0.03 0.02 0.01 0.03 0.12 0.09 0.21 44.7 0.15 0.03 0.03 0.17 0.10 0.05 1.14 0.70 0.50
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From page 85... ...
Chemical Mass Balance with Unique Tracer When there is a unique tracer associated with a source and when ratios of tracer to other emissions are known, Equation 6.9 can be used to estimate the upper limit of contributions to ambient aerosol species. For instance, ambient concentrations of total sulfur associated with NGS emissions can be calculated using ST,a = IST/CD4]
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From page 86... ...
Itio(lel and Tracer Mass Balance (TAB) Lioclel Overview The Tracer Mass Balance Regression Model is a multiple regression based model which may be used to apportion an aerosol species of interest measured at a receptor site to the various contributing sources.
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From page 87... ...
model when only a single trace element is used as a tracer for a particular source and all the remaining sources are accounted for by the intercept term in the model. When several trace elements are used in addition to the tracer for the distinguished source of interest, then the model is referred to as tracer mass balance regression (TMBR)
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From page 88... ...
The TMBR Model equations used in the application are: h Ck = To + ~ ~i~ci~k~uk u=1 where: C,` = concentration of sulfate sulfur or total sulfur for time period k Ci,,k = concentration of trace element in for time period k yin = regression coefficient associated with trace element is (9) ,0 = intercept representing the mean background concentration of the species being apportioned, due to all sources not accounted for explicitly.
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From page 89... ...
. When other trace elements are used in addition to CD4 then the model is referred to as tracer mass balance regression (TAlBR)
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From page 90... ...
The mean fraction Fu of the sulfur attributed to each source is estimated by the mean sulfur concentration Cu for that source divided by the mean total calculated sulfur C r ~ flu r — _ an— r v where l and and ( 17)
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From page 91... ...
The aerosol species used in the model are assumed to be tracers for nono~erlapping groups of sources. In particular, none of the species other than the tracer associated with the source of interest can be emitted by that source unless there is an independent method such as CMB modeling to partition the ambient species concentrations into components attributable to the various groups of sources.
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From page 92... ...
_ W 1 + 24{E, x} + ~ (29) where ~ = aE/a2 and /` is the difference between the estimated average NGS contribution and the true average FIGS contribution.
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From page 93... ...
Model Inputs. The model requires the following quantities as inputs: · The ambient concentrations of the aerosol species being apportioned, which is S04 in our application.
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