Coarse particle speciation at selected locations in the rural continental United States

Malm, William C.; Pitchford, Marc; McDade, Charles E.; Ashbaugh, Lowell L.

doi:10.1016/j.atmosenv.2006.10.077

Cited by 55 publications

(44 citation statements)

References 17 publications

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“…We caution that these two stations were < 150 km away from the metropolitan regions, indicating that urban emissions may also contribute to CM there. Additional contributions may result from sea salt or sodium nitrate resulting from reactions of nitric acid with sea salt, as mentioned in their study (Malm et al, 2007). Therefore, to minimize the contributions of other aerosols to CM, we do not use the stations in or near the metropolitan regions or near the coast for the validation of dust concentration.…”

Section: Observationsmentioning

confidence: 99%

“…In reality, in addition to dust, CM may also contain other aerosols such as sulfate, nitrate, organic and elemental carbon, and sea salt. However, according to the study of Malm et al (2007), who analyzed the speciation of coarse particles collected at nine selected rural IMPROVE stations in 2004, the contributions of dust to CM are above 70 % (74-90 %) at the three stations in the inland western US. In their study, lower contributions of dust to CM (34 and 65 %) were 517°°°°°°°°°°°°°°°°°°°°F igure 4.…”

Section: Observationsmentioning

confidence: 99%

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Impacts of absorbing aerosol deposition on snowpack and hydrologic cycle in the Rocky Mountain region based on variable-resolution CESM (VR-CESM) simulations

Liu

Lin

et al. 2018

Atmos. Chem. Phys.

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Abstract. The deposition of light-absorbing aerosols (LAAs), such as black carbon (BC) and dust, onto snow cover has been suggested to reduce the snow albedo and modulate the snowpack and consequent hydrologic cycle. In this study we use the variable-resolution Community Earth System Model (VR-CESM) with a regionally refined highresolution (0.125 • ) grid to quantify the impacts of LAAs in snow in the Rocky Mountain region during the period 1981-2005. We first evaluate the model simulation of LAA concentrations both near the surface and in snow and then investigate the snowpack and runoff changes induced by LAAs in snow. The model simulates similar magnitudes of near-surface atmospheric dust concentrations as observations in the Rocky Mountain region. Although the model underestimates near-surface atmospheric BC concentrations, the model overestimates BC-in-snow concentrations by 35 % on average. The regional mean surface radiative effect (SRE) due to LAAs in snow reaches up to 0.6-1.7 W m −2 in spring, and dust contributes to about 21-42 % of total SRE. Due to positive snow albedo feedbacks induced by the LAA SRE, snow water equivalent is reduced by 2-50 mm and snow cover fraction by 5-20 % in the two regions around the mountains (eastern Snake River Plain and southwestern Wyoming), corresponding to an increase in surface air temperature by 0.9-1.1 • C. During the snow melting period, LAAs accelerate the hydrologic cycle with monthly runoff increases of 0.15-1.00 mm day −1 in April-May and reductions of 0.04-0.18 mm day −1 in June-July in the mountainous regions. Of all the mountainous regions, the Southern Rockies experience the largest reduction of total runoff by 15 % during the later stage of snowmelt (i.e., June and July). Compared to previous studies based on field observations, our estimation of dust-induced SRE is generally 1 order of magnitude smaller in the Southern Rockies, which is ascribed to the omission of larger dust particles (with the diameter > 10 µm) in the model. This calls for the inclusion of larger dust particles in the model to reduce the discrepancies. Overall these results highlight the potentially important role of LAA interactions with snowpack and the subsequent impacts on the hydrologic cycles across the Rocky Mountains.

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Section: Observationsmentioning

confidence: 99%

Section: Observationsmentioning

confidence: 99%

Impacts of absorbing aerosol deposition on snowpack and hydrologic cycle in the Rocky Mountain region based on variable-resolution CESM (VR-CESM) simulations

Liu

Lin

et al. 2018

Atmos. Chem. Phys.

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“…One such region is the arid desert of the southwestern United States (US), including Arizona. A recent study estimated that resuspended dust accounts for as much as 20% of PM 2.5 and 76% of PM c in the southwestern US (Malm et al, 2007). Pinal County, in central Arizona, is an area that frequently exceeds the PM 10 NAAQS (U.S. EPA AirData, 2012).…”

Section: Introductionmentioning

confidence: 99%

Size-Differentiated Chemical Composition of Re-Suspended Soil Dust from the Desert Southwest United States

Upadhyay

Clements

Fraser

et al. 2015

Aerosol Air Qual. Res.

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As part of the Desert Southwest Coarse Particulate Matter Study which characterized the composition of fine and coarse particulate matter in Pinal County, AZ during 2010-2011, several source samples were collected from several different soil types to assist in source apportionment analysis of the study results. Soil types included native desert soils, agricultural soils (crop farming), dirt-road material adjacent to agricultural areas, paved road dusts, dirt road material from within and adjacent to a cattle feedlot, and material from an active cattle feedlot. Following laboratory resuspension of the soil, sizesegregated PM 2.5 and PM 10 fractions for each source type were collected on filters and characterized for mass, ions, OC, EC, and trace elements. While there are unique chemical compositions of soils in the region (e.g., high As and Sb) that reiterate the importance of using local source profiles (e.g., native soils) as compared to Upper Continental Crust or soil profiles from other regions in receptor modeling studies. The study also provides new insights into the impact of land-use modification on source emission profiles. Specifically, high OC and PO 4 3-are found in material representative of local cattle feedlot activities while elevated Cu, Sb and Zn are found from sources impacted by motor vehicle traffic. Results of the study indicate that the local native soil composition is only slightly modified by agricultural activities and this study provides the chemical composition of both native and agricultural soil for source apportionment studies in the Desert Southwest.

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“…This distribution of aerosol species between PM 2.5 and PM 10 is typical. 22 Here, a differentiation is made between wind-entrained soil dust and soil-related elements emitted during the burning Notes: The number of data points is 742 in spring and 642 in summer. of carbonaceous material, whether it be coal-or forest/ agriculture-related material.…”

Section: Comparison Of Average Fine and Coarse Particle Density Derivmentioning

confidence: 99%

Using High Time Resolution Aerosol and Number Size Distribution Measurements to Estimate Atmospheric Extinction

Malm

McMeeking

Kreidenweis

et al. 2009

Journal of the Air & Waste Management Association

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Rocky Mountain National Park is experiencing reduced visibility and changes in ecosystem function due to increasing levels of oxidized and reduced nitrogen. The Rocky Mountain Atmospheric Nitrogen and Sulfur (Ro-MANS) study was initiated to better understand the origins of sulfur and nitrogen species as well as the complex chemistry occurring during transport from source to receptor. As part of the study, a monitoring program was initiated for two 1-month time periods-one during the spring and the other during late summer/fall. The monitoring program included intensive high time resolution concentration measurements of aerosol number size distribution, inorganic anions, and cations, and 24-hr time resolution of PM 2.5 and PM 10 mass, sulfate, nitrate, carbon, and soil-related elements concentrations. These data are combined to estimate high time resolution concentrations of PM 2.5 and PM 10 aerosol mass and fine mass species estimates of ammoniated sulfate, nitrate, and organic and elemental carbon. Hour-by-hour extinction budgets are calculated by using these species concentration estimates and measurements of size distribution and assuming internal and external particle mixtures. Summer extinction was on average about 3 times higher than spring extinction. During spring months, sulfates, nitrates, carbon mass, and PM 10 Ϫ PM 2.5 mass contributed approximately equal amounts of extinction, whereas during the summer months, carbonaceous material extinction was 2-3 times higher than other species. INTRODUCTIONAtmospheric nitrogen and sulfur species can cause several deleterious effects, including visibility impairment and changes in ecosystem function and surface water chemistry from atmospheric deposition. In Rocky Mountain National Park (RMNP), the most recent 12-yr-average winter fractional contributions of nitrates and sulfates to visibility impairment are 18 and 36%, respectively. However, during some days, nitrates can contribute over 50%, whereas on other days sulfates contribute over 60% to particle light extinction. Although atmospheric concentrations of sulfur species have decreased in recent years, nitrogen concentrations have not. In fact, ambient nitrate concentrations have increased by approximately 10 -20% over the past 10 yr. Nitrate wet deposition has increased by approximately the same amount, and ammonium wet deposition has increased by approximately 50%.The Rocky Mountain Atmospheric Nitrogen and Sulfur study (RoMANS) was initiated to better understand the origins and physical, chemical, and optical characteristics of sulfur and nitrogen species, as well as the complex chemistry occurring during transport from source to receptor.As part of the study, a monitoring program was conducted over two time periods-one in the spring and the other during late summer/fall-that were approximately 1

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Coarse particle speciation at selected locations in the rural continental United States

Cited by 55 publications

References 17 publications

Impacts of absorbing aerosol deposition on snowpack and hydrologic cycle in the Rocky Mountain region based on variable-resolution CESM (VR-CESM) simulations

Impacts of absorbing aerosol deposition on snowpack and hydrologic cycle in the Rocky Mountain region based on variable-resolution CESM (VR-CESM) simulations

Size-Differentiated Chemical Composition of Re-Suspended Soil Dust from the Desert Southwest United States

Using High Time Resolution Aerosol and Number Size Distribution Measurements to Estimate Atmospheric Extinction

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