Measurement of210Pb,210Po, and210Bi in Size-Fractionated Atmospheric Aerosols: An Estimate of Fine-Aerosol Residence Times

Marley, N. A.; Gaffney, J. S.; Drayton, P. J.; Cunningham, Mary M.; Orlandini, K.A.; Paode, Rajendra D.

doi:10.1080/027868200303489

Cited by 64 publications

(50 citation statements)

References 6 publications

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“…In general, the small aerosols are expected to have the longest atmospheric residence times and therefore have a larger percentage of older aerosols with atmospherically generated surface modi cations. The atmospheric residence times of the ne aerosols obtained at the UPRA and ANL sites, as determined by measuring the 210 Bi/ 210 Pb and 210 Po/ 210 Pb ratios, are 5-75 days (Marley et al 2000). The average lifetime at ANL was 36 days, where the average lifetime at UPRA was 41 days.…”

Section: Resultsmentioning

confidence: 99%

An Empirical Method for the Determination of the Complex Refractive Index of Size-Fractionated Atmospheric Aerosols for Radiative Transfer Calculations

Marley¹,

Gaffney²,

Baird³

et al. 2001

Aerosol Science and Technology

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To adequately assess the effects of atmospheric aerosols on climate, their optical constants (scattering and absorption coef cients) must be known. The absorption and scattering coef cients of the aerosols are derived from the real and imaginary parts of the complex refractive index and are dependent on their size and chemical composition. Because aerosol properties vary signi cantly with location, it is dif cult to assign values for the absorption and scattering of solar radiation by aerosols in models of global climate change. This study reports a new method of collecting size-fractionated atmospheric aerosol samples for the purpose of directly measuring their transmission and re ectance spectra followed by the determination of the complex refractive index across the entire atmospherically relevant spectral range. The samples were collected with a modi ed Sierra high-volume cascade impactor with the usual lter collection surfaces replaced with Te on sheets machined to hold quartz (ultraviolet [UV]/visible transparent) and/or silver chloride (infrared transparent) sample collection plates. Re ectance and transmission spectra can be obtained on the aerosol samples directly as a function of wavelength, from 280 nm to 2.5 m, with an integrating sphere coupled to an UV/visible or a Fourier transform infrared (FTIR) spectrophotometer. The effective real and imaginary components of the refractive index of the bulk sample material can then be approximated, as a function of wavelength, from the sample spectra. Preliminary results are presented for carbon soot samples generated in the laboratory and for standard diesel soot samples in the UV/visible spectral range. These are compared to results obtained for size-fractionated atmospheric aerosol samples collected near Pasco, WA, West Mesa, AZ, and Argonne, IL.

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Section: Resultsmentioning

confidence: 99%

An Empirical Method for the Determination of the Complex Refractive Index of Size-Fractionated Atmospheric Aerosols for Radiative Transfer Calculations

Marley¹,

Gaffney²,

Baird³

et al. 2001

Aerosol Science and Technology

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“…The aerosol absorption at T1 decreased slightly from 30 Mm −1 (range of 19-41 Mm −1 ) before the rainy period to 26 Mm −1 (range of 15-37 Mm −1 ) during the rainy period. Since a significant fraction of highly scattering nonabsorbing aerosols are primarily inorganic and hydrophilic, it is expected that they will wash out more readily during rain events than the freshly emitted absorbing BC aerosols that are more hydrophobic in nature (Marley et al, 2000;Gaffney and Marley, 2005;. However, as the BC aerosols become coated with SOA, they will become more hydrophilic in nature and their washout rates would be expected to increase.…”

Section: MMmentioning

confidence: 99%

“…Marley et al: Aerosol absorption and scattering in Mexico City 191 et al, 1999;Schnaiter et al, 2005). Aerosol distributions are also variable both spatially and temporally and although aerosol lifetimes are much shorter than those of the greenhouse gases, estimates of their atmospheric residence times range from less than a day to more than a month resulting in transport distances from a few miles to hemispheric scales (Marley et al, 2000;Williams et al, 2002). This variability in composition and distributions makes it difficult to quantify the aerosol impacts on climate and to represent these effects in climate models.…”

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confidence: 99%

Measurements of aerosol absorption and scattering in the Mexico City Metropolitan Area during the MILAGRO field campaign: a comparison of results from the T0 and T1 sites

Marley

Gaffney

Castro³

et al. 2009

Atmos. Chem. Phys.

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Abstract. In March 2006, a multiagency field campaign was undertaken in Mexico City called the Megacities Initiative: Local and Global Research Observations (MILAGRO). Two of the five field components of the MILAGRO study focused a major part of their efforts on atmospheric particulate emissions from the Mexico City basin and their effects on radiative balance as a function of time, location and processing conditions. As part of these two MILAGRO components, measurements of aerosol optical properties were obtained at a site located in the northern part of Mexico City (T0) and also at a site located 29 km northwest (T1) to estimate the regional effects of aerosol emissions from the basin.Measurements of aerosol absorption and scattering for fine mode aerosols were obtained at both sites. Aerosol absorption at 550 nm was similar at both sites, ranging from 7-107 Mm −1 at T0 and from 3-147 Mm −1 at T1. Aerosol scattering measured at 550 nm at T0 ranged from 16-344 Mm −1 while the aerosol scattering values at T1 were much lower than at T0 ranging from 2-136 Mm −1 . Aerosol single scattering albedos (SSAs) were calculated at 550 nm for the fine mode aerosols at both sites using these data. The SSAs at T0 ranged from 0.47-0.92 while SSAs at T1 ranged from 0.35-Correspondence to: J. S. Gaffney (jsgaffney@ualr.edu) 0.86. The presence of these highly absorbing fine aerosols in the lower atmosphere of the Mexico City area will result in a positive climate forcing and a local warming of the boundary layer in the region.Broadband UVB intensity was found to be higher at site T0, with an average of 64 µW/cm 2 at solar noon, than at site T1, which had an average of 54 µW/cm 2 at solar noon. Comparisons of clear-sky modeled UVB intensities with the simultaneous UVB measurements obtained at sites T0 and T1 for cloudless days indicate a larger diffuse radiation field at site T0 than at site T1. The determination of aerosolÅngstrom scattering coefficients at T0 suggests that this is due to the predominance of aerosols in the size range of 0.3 micron, which leads to scattering of UVB radiation peaked in the forward direction and to an enhanced UVB radiation observed at ground level. This enhancement of the UVB diffuse radiation field would explain the enhanced photochemistry observed in the Mexico City area despite the reduction in UVB anticipated from light absorbing species.

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“…Its short lived daughters are rapidly attached to the aerosol particles, and 210 Pb is found to be attached to the fine particulate matter and submicron particles [5]. Recently 210 Pb variation in atmospheric fine particulate matter with the diameter of less than 10μm, PM10, is collected because of its importance for air quality monitoring programs and is reported for some sites/regions.…”

Section: Introductionmentioning

confidence: 99%

Measurements of Lead-210 Activity Concentration in the Ground-Level Air in Finland and Bulgaria

Paatero¹,

Veleva²,

Hristova³

et al. 2017

RadJ

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Abstract. Airborne lead-210 is a useful tracer for studying air mass origin and transport. 210 Pb is produced in the atmosphere by the decay of the radioactive noble gas 222 Rn, emanating after 226 Ra decay from the earth crust. The results obtained for 210 Pb concentration in total suspended particulate (TSP) display seasonal pattern with maximum in the summer-autumn period. The TSP filters are collected within the scope of atmospheric radioactivity monitoring in NIMH, Bulgaria and were measured initially for short and long lived beta radionuclides. The methodology developed in FMI, Finland, based on gross alpha counting of 210 Po-the daughter of the combined aerosol filters samples collected in Sofia during the period 2001 -2003 and 2006-2007, is applied. The first results for 210 Pb in particulate matter, fraction below 10 μm (PM10), in February 2012 in Sofia are presented. The alpha counting methodology was successfully applied for daily PM10 quartz filters with the counting uncertainty value of ≤20%. Lead-210 daily concentration is compared to the PM10 mass concentration and elemental lead concentration, determined by EDXRF technique. The comparison between 210 Pb, elemental lead and PM10 mass concentration reveals a different time variation for days with cyclonic weather and mass transport from south-west and an anticyclone episode with increasing PM10, lead-210 and lead concentrations from day to day. An increase in the PM10/ 210 Pb ratio indicates local sources of the particulate mass.

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Measurement of²¹⁰Pb,²¹⁰Po, and²¹⁰Bi in Size-Fractionated Atmospheric Aerosols: An Estimate of Fine-Aerosol Residence Times

Cited by 64 publications

References 6 publications

An Empirical Method for the Determination of the Complex Refractive Index of Size-Fractionated Atmospheric Aerosols for Radiative Transfer Calculations

An Empirical Method for the Determination of the Complex Refractive Index of Size-Fractionated Atmospheric Aerosols for Radiative Transfer Calculations

Measurements of aerosol absorption and scattering in the Mexico City Metropolitan Area during the MILAGRO field campaign: a comparison of results from the T0 and T1 sites

Measurements of Lead-210 Activity Concentration in the Ground-Level Air in Finland and Bulgaria

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