Interpretation of Trends of PM<sub>25</sub> and Reconstructed Visibility from the IMPROVE Network

Sisler, James F.; Malm, William C.

doi:10.1080/10473289.2000.10464127

Cited by 65 publications

(54 citation statements)

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“…The VR data were calculated by Sisler from IMPROVE monitoring data. 5 The dotted lines in Figure 2 compare the lengths of the longest lines in the parks with VR, and the solid lines compare the estimated lengths of the longest sight paths within the parks with VR.…”

Section: Protection Of Views Outside Class I Areasmentioning

confidence: 99%

Use of the Deciview Haze Index as an Indicator for Regional Haze

Richards

1999

Journal of the Air & Waste Management Association

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The U.S. Environmental Protection Agency (EPA) Notice of Proposed Rulemaking (NPR) for regional haze uses the deciview haze index (dv) as the indicator for visibility impairment and proposes a change of 1 dv as "a small but noticeable change in haziness under most circumstances." All previous visibility rules have specified human perception as the indicator for visibility impairment. This article examines the technical basis cited in the NPR for this new indicator for visibility impairment and for the perception threshold of approximately 1 dv. Derivations based on the assumptions and approximations cited in the NPR show that the deciview haze index does not have the correct functional form to relate changes in haze within federal Class I areas to the visual perception of those changes. The just-noticeable change in light extinction is, in most cases, inversely proportional to the sight path length instead of proportional to the light-extinction coefficient. These derivations also indicate that a 1-dv change in haziness is typically too small to be perceived in most Class I areas.

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Section: Protection Of Views Outside Class I Areasmentioning

confidence: 99%

Use of the Deciview Haze Index as an Indicator for Regional Haze

Richards

1999

Journal of the Air & Waste Management Association

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“…We excluded the contribution of coarse mass and NO 2 due to their insignificant contribution to b ext (Cheung et al, 2005;Jung et al, 2009;Gao et al, 2015). A constant 10 Mm -1 is assigned to b Rayleigh (Sisler and Malm, 2000;Hand et al, 2011).…”

Section: Reconstruction Of Pm 25 and Light Extinctionmentioning

confidence: 99%

Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

Chen

Lai

Gao

et al. 2016

Aerosol Air Qual. Res.

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A one-year campaign was conducted to collected PM 2.5 samples in the rural area of Guangzhou, the largest megacity in South China, from March 2012 to February 2013. Mass concentration of PM 2.5 , carbonaceous fractions (i.e., organic carbon (OC) and elemental carbon (EC)) and 6 water-soluble ions were analyzed. Light extinction coefficient (b ext ) of fine particulate matter was reconstructed using the revised IMPROVE formula at the site. (NH 4 ) 2 SO 4 (AS) made a dominant contribution to the light extinction budget, accounting for 61.3% (155.6 ± 108.5 Mm -1 ) annually, with highest in autumn (68.0%) and lowest in winter (55.2%). Organic matter (OM) was the second largest contributor accounting for 20.5% (52.2 ± 42.7 Mm -1 ) with highest in winter (23.4%) and lowest in spring (18.0%). The relationship between reconstructed b ext and measured b ext was investigated under the influence of seasonality, visibility and PM 2.5 concentration. We found that b ext could be reconstructed using revised IMPROVE formula in high PM 2.5 days (threshold value of ~60 µg m -3 ). On other hand, the performance of formula was unsatisfactory for b ext reconstruction of in low PM 2.5 days, when meteorological conditions could have significant impact on visibility.

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“…Our focus on sulfate aerosols stems from studies which show that this is the dominant anthropogenic aerosol component in the eastern United States [e.g., Sisler and Malm, 2000]. We present a detailed evaluation of model performance by comparing simulated particle mass and number concentrations, size parameters (effective radius, mass mean radius, and number mean radius), and surrogates to the underlying size distributions with observations.…”

Section: Introductionmentioning

confidence: 99%

“…Most of these models have simulated only the mass concentration of sulfate aerosol and not size distributions. However, representing the microphysical properties of aerosols (i.e., their intensive properties [Ogren, 1995]) in addition to their mass concentrations (extensive properties) and understanding the influence of aerosol microphysical processes on properties of tropospheric aerosols are important because environmental effects of aerosols such as atmospheric visibility, climate change, acid deposition, and health effects depend not just on the mass concentration but also on the size distribution and chemical composition of these particles [Sisler and Malm, 2000;Yu et al, 2000Yu et al, , 2001Schwartz, 1996;Penner et al, 2002;Ghan et al, 2001]. Additionally, the mass loading of aerosols is itself influenced by processes whose rates depend on particle size.…”

Section: Introductionmentioning

confidence: 99%

Moment‐based simulation of microphysical properties of sulfate aerosols in the eastern United States: Model description, evaluation, and regional analysis

Kasibhatla

Wright

et al. 2003

J. Geophys. Res.

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[1] A six-moment microphysics module for sulfate aerosols based on the quadrature method of moments has been incorporated in a host 3-D regional model, the Multiscale Air Quality Simulation Platform. Model performance was examined and evaluated by comparison with in situ observations over the eastern United States for a 40-day period from 19 July to 28 August 1995. The model generally reproduces the spatial patterns (sulfate mixing ratios and wet deposition) over the eastern United States and time series variations of sulfate mass concentrations. The model successfully captured the observed size distribution in the accumulation mode (radius 0.1-0.5 mm), in which the sulfate is predominately located, while underestimating the nucleation and coarse modes on the basis of the size distributions retrieved from the modeled six moments at the Great Smoky Mountains (GSM). This is consistent with better model performance on the effective radius (ratio of third to second moment, important for light scattering) than on numbermean and mass-mean radii. However, the model did not predict some of the moments well, especially the higher moments and during the dust events. Aerosol components other than sulfate such as dust and organics appear to have contributed substantially to the observed aerosol loading at GSM. The model underpredicted sulfate mixing ratios by 13% with about 50% of observations simulated to within a factor of 2. One of the reasons for this underestimation may be overprediction of sulfate wet deposition. Sulfate mass concentrations and number concentrations were high in the source-rich Ohio River valley, but number concentrations were also high over the mid-Atlantic coast (New Jersey area). Most (77%) sulfate amount was below 2.6 km, whereas most sulfate number (>52%) was above 2.6 km except over Ohio River valley (41%). These results demonstrate the accuracy, utility, practicality, and efficiency of moment-based methods for representing aerosol microphysical processes in large-scale chemical transport models.

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Interpretation of Trends of PM₂₅ and Reconstructed Visibility from the IMPROVE Network

Cited by 65 publications

References 1 publication

Use of the Deciview Haze Index as an Indicator for Regional Haze

Use of the Deciview Haze Index as an Indicator for Regional Haze

Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

Moment‐based simulation of microphysical properties of sulfate aerosols in the eastern United States: Model description, evaluation, and regional analysis

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Interpretation of Trends of PM25 and Reconstructed Visibility from the IMPROVE Network

Cited by 65 publications

References 1 publication

Use of the Deciview Haze Index as an Indicator for Regional Haze

Use of the Deciview Haze Index as an Indicator for Regional Haze

Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China

Moment‐based simulation of microphysical properties of sulfate aerosols in the eastern United States: Model description, evaluation, and regional analysis

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Interpretation of Trends of PM₂₅ and Reconstructed Visibility from the IMPROVE Network