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Schulze BC, Charan SM, Kenseth CM, Kong W, Bates KH, Williams W, Metcalf AR, Jonsson HH, Woods R, Sorooshian A, Flagan RC, Seinfeld JH. Characterization of Aerosol Hygroscopicity Over the Northeast Pacific Ocean: Impacts on Prediction of CCN and Stratocumulus Cloud Droplet Number Concentrations. Earth Space Sci 2020; 7:e2020EA001098. [PMID: 33225018 PMCID: PMC7676499 DOI: 10.1029/2020ea001098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
During the Marine Aerosol Cloud and Wildfire Study (MACAWS) in June and July of 2018, aerosol composition and cloud condensation nuclei (CCN) properties were measured over the N.E. Pacific to characterize the influence of aerosol hygroscopicity on predictions of ambient CCN and stratocumulus cloud droplet number concentrations (CDNC). Three vertical regions were characterized, corresponding to the marine boundary layer (MBL), an above-cloud organic aerosol layer (AC-OAL), and the free troposphere (FT) above the AC-OAL. The aerosol hygroscopicity parameter (κ) was calculated from CCN measurements (κ CCN) and bulk aerosol mass spectrometer (AMS) measurements (κ AMS). Within the MBL, measured hygroscopicities varied between values typical of both continental environments (~0.2) and remote marine locations (~0.7). For most flights, CCN closure was achieved within 20% in the MBL. For five of the seven flights, assuming a constant aerosol size distribution produced similar or better CCN closure than assuming a constant "marine" hygroscopicity (κ = 0.72). An aerosol-cloud parcel model was used to characterize the sensitivity of predicted stratocumulus CDNC to aerosol hygroscopicity, size distribution properties, and updraft velocity. Average CDNC sensitivity to accumulation mode aerosol hygroscopicity is 39% as large as the sensitivity to the geometric median diameter in this environment. Simulations suggest CDNC sensitivity to hygroscopicity is largest in marine stratocumulus with low updraft velocities (<0.2 m s-1), where accumulation mode particles are most relevant to CDNC, and in marine stratocumulus or cumulus with large updraft velocities (>0.6 m s-1), where hygroscopic properties of the Aitken mode dominate hygroscopicity sensitivity.
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Affiliation(s)
- B. C. Schulze
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA, USA
| | - S. M. Charan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - C. M. Kenseth
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - W. Kong
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - K. H. Bates
- Center for the Environment, Harvard University, Cambridge, MA, USA
| | - W. Williams
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, USA
| | - A. R. Metcalf
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, USA
| | | | - R. Woods
- Naval Postgraduate School, Monterey, CA, USA
| | - A. Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - R. C. Flagan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA
| | - J. H. Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA
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Youn JS, Crosbie E, Maudlin L, Wang Z, Sorooshian A. Dimethylamine as a major alkyl amine species in particles and cloud water: Observations in semi-arid and coastal regions. Atmos Environ (1994) 2015; 122:250-258. [PMID: 26807039 PMCID: PMC4719122 DOI: 10.1016/j.atmosenv.2015.09.061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal aerosol mass size distribution with a dominant peak between 0.18 and 0.56 μm. Particulate DMA concentrations increase as a function of marine biogenic emissions, sulfate, BVOC emissions, and aerosol-phase water. Such data supports biogenic sources of DMA, aminium salt formation, and partitioning of DMA to condensed phases. DMA concentrations exhibit positive correlations with various trace elements and most especially vanadium, which warrants additional investigation. Cloud water DMA levels are enhanced significantly during wildfire periods unlike particulate DMA levels, including in droplet residual particles, due to effective dissolution of DMA into cloud water and probably DMA volatilization after drop evaporation. DMA:NH+4 molar ratios peak between 0.18 and 1.0 μm depending on the site and time of year, suggesting that DMA competes better with NH3 in those sizes in terms of reactive uptake by particles.
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Affiliation(s)
- J.-S. Youn
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - E. Crosbie
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - L.C. Maudlin
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Z. Wang
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - A. Sorooshian
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Corresponding author. PO Box 210011, Tucson, AZ, 85721, USA. (A. Sorooshian)
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Crosbie E, Youn JS, Balch B, Wonaschütz A, Shingler T, Wang Z, Conant WC, Betterton EA, Sorooshian A. On the competition among aerosol number, size and composition in predicting CCN variability: a multi-annual field study in an urbanized desert. Atmos Chem Phys 2015; 15:6943-6958. [PMID: 26316879 PMCID: PMC4548966 DOI: 10.5194/acp-15-6943-2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A 2-year data set of measured CCN (cloud condensation nuclei) concentrations at 0.2 % supersaturation is combined with aerosol size distribution and aerosol composition data to probe the effects of aerosol number concentrations, size distribution and composition on CCN patterns. Data were collected over a period of 2 years (2012-2014) in central Tucson, Arizona: a significant urban area surrounded by a sparsely populated desert. Average CCN concentrations are typically lowest in spring (233 cm-3), highest in winter (430 cm-3) and have a secondary peak during the North American monsoon season (July to September; 372 cm-3). There is significant variability outside of seasonal patterns, with extreme concentrations (1 and 99 % levels) ranging from 56 to 1945 cm-3 as measured during the winter, the season with highest variability. Modeled CCN concentrations based on fixed chemical composition achieve better closure in winter, with size and number alone able to predict 82% of the variance in CCN concentration. Changes in aerosol chemical composition are typically aligned with changes in size and aerosol number, such that hygroscopicity can be parameterized even though it is still variable. In summer, models based on fixed chemical composition explain at best only 41% (pre-monsoon) and 36% (monsoon) of the variance. This is attributed to the effects of secondary organic aerosol (SOA) production, the competition between new particle formation and condensational growth, the complex interaction of meteorology, regional and local emissions and multi-phase chemistry during the North American monsoon. Chemical composition is found to be an important factor for improving predictability in spring and on longer timescales in winter. Parameterized models typically exhibit improved predictive skill when there are strong relationships between CCN concentrations and the prevailing meteorology and dominant aerosol physicochemical processes, suggesting that similar findings could be possible in other locations with comparable climates and geography.
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Affiliation(s)
- E. Crosbie
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - J.-S. Youn
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - B. Balch
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - A. Wonaschütz
- University of Vienna, Faculty of Physics, Vienna, Austria
| | - T. Shingler
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Z. Wang
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - W. C. Conant
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - E. A. Betterton
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - A. Sorooshian
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
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Hersey SP, Garland RM, Crosbie E, Shingler T, Sorooshian A, Piketh S, Burger R. An overview of regional and local characteristics of aerosols in South Africa using satellite, ground, and modeling data. Atmos Chem Phys 2015; 15:4259-4278. [PMID: 26312061 PMCID: PMC4547400 DOI: 10.5194/acp-15-4259-2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present a comprehensive overview of particulate air quality across the five major metropolitan areas of South Africa (Cape Town, Bloemfontein, Johannesburg and Tshwane (Gauteng Province), the Industrial Highveld Air Quality Priority Area (HVAPA), and Durban), based on a decadal (1 January 2000 to 31 December 2009) aerosol climatology from multiple satellite platforms and detailed analysis of ground-based data from 19 sites throughout Gauteng Province. Satellite analysis was based on aerosol optical depth (AOD) from MODIS Aqua and Terra (550 nm) and MISR (555 nm) platforms, Ångström Exponent (α) from MODIS Aqua (550/865 nm) and Terra (470/660 nm), ultraviolet aerosol index (UVAI) from TOMS, and results from the Goddard Ozone Chemistry Aerosol Radiation and Transport (GOCART) model. At continentally influenced sites, AOD, α, and UVAI reach maxima (0.12-0.20, 1.0-1.8, and 1.0-1.2, respectively) during austral spring (September-October), coinciding with a period of enhanced dust generation and the maximum integrated intensity of close-proximity and subtropical fires identified by MODIS Fire Information for Resource Management System (FIRMS). Minima in AOD, α, and UVAI occur during winter. Results from ground monitoring indicate that low-income township sites experience by far the worst particulate air quality in South Africa, with seasonally averaged PM10 concentrations as much as 136 % higher in townships that in industrial areas. We report poor agreement between satellite and ground aerosol measurements, with maximum surface aerosol concentrations coinciding with minima in AOD, α, and UVAI. This result suggests that remotely sensed data are not an appropriate surrogate for ground air quality in metropolitan South Africa.
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Affiliation(s)
- S. P. Hersey
- Department of Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- Now at Franklin W. Olin College of Engineering, Needham, MA, USA
| | - R. M. Garland
- Now at Franklin W. Olin College of Engineering, Needham, MA, USA
- Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa
| | - E. Crosbie
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - T. Shingler
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - A. Sorooshian
- Department of Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - S. Piketh
- Department of Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - R. Burger
- Department of Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
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Sorooshian A, Shingler T, Harpold A, Feagles CW, Meixner T, Brooks PD. Aerosol and precipitation chemistry in the southwestern United States: spatiotemporal trends and interrelationships. Atmos Chem Phys 2013; 13:7361-7379. [PMID: 24432030 PMCID: PMC3890361 DOI: 10.5194/acp-13-7361-2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
This study characterizes the spatial and temporal patterns of aerosol and precipitation composition at six sites across the United States Southwest between 1995 and 2010. Precipitation accumulation occurs mostly during the wintertime (December-February) and during the monsoon season (July-September). Rain and snow pH levels are usually between 5-6, with crustal-derived species playing a major role in acid neutralization. These species (Ca2+, Mg2+, K+, Na+) exhibit their highest concentrations between March and June in both PM2.5 and precipitation due mostly to dust. Crustal-derived species concentrations in precipitation exhibit positive relationships with [Formula: see text], [Formula: see text], and Cl-, suggesting that acidic gases likely react with and partition to either crustal particles or hydrometeors enriched with crustal constituents. Concentrations of particulate [Formula: see text] show a statistically significant correlation with rain [Formula: see text] unlike snow [Formula: see text], which may be related to some combination of the vertical distribution of [Formula: see text] (and precursors) and the varying degree to which [Formula: see text]-enriched particles act as cloud condensation nuclei versus ice nuclei in the region. The coarse : fine aerosol mass ratio was correlated with crustal species concentrations in snow unlike rain, suggestive of a preferential role of coarse particles (mainly dust) as ice nuclei in the region. Precipitation [Formula: see text] : [Formula: see text] ratios exhibit the following features with potential explanations discussed: (i) they are higher in precipitation as compared to PM2.5; (ii) they exhibit the opposite annual cycle compared to particulate [Formula: see text] : [Formula: see text] ratios; and (iii) they are higher in snow relative to rain during the wintertime. Long-term trend analysis for the monsoon season shows that the [Formula: see text] : [Formula: see text] ratio in rain increased at the majority of sites due mostly to air pollution regulations of [Formula: see text] precursors.
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Affiliation(s)
- A. Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA
- Department of Atmospheric Sciences, University of Arizona, Tucson, Arizona, USA
| | - T. Shingler
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA
| | - A. Harpold
- Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona, USA
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, Colorado, USA
| | - C. W. Feagles
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona, USA
| | - T. Meixner
- Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona, USA
| | - P. D. Brooks
- Department of Hydrology and Water Resources, University of Arizona, Tucson, Arizona, USA
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Metcalf AR, Craven JS, Ensberg JJ, Brioude J, Angevine W, Sorooshian A, Duong HT, Jonsson HH, Flagan RC, Seinfeld JH. Black carbon aerosol over the Los Angeles Basin during CalNex. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd017255] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Sorooshian A, Ashwani R, Choi H, Moinpour M, Oehler A, Tregub A. Effect of Particle Interaction on Agglomeration of Silica-Based CMP Slurries. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-816-k4.9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractChemical Mechanical Planarization has become a method of choice for planarization of metal and oxide layers in microelectronics industry. A CMP process includes up to 16 variables that need to be controlled to achieve a stable CMP process [1]. One of the major variables in CMP is related to slurry compositions. In particularly, a uniform distribution of the sizes of the abrasive particle in slurry is crucial for a stable CMP performance. The agglomerates can be unstable, since their size depends on addition of chemical additives and shearing during the CMP process.In this work, the authors studied agglomeration of the fumed and colloidal silica-based slurries using dynamic rheometry, zeta potential tests, and an accusizer.Slurry viscosity, determined using a steady state rheometry, was correlated to the particle charge, characterized by zeta potential, and to the particle sizes obtained using the particle size analyzer. Additionally, rheometer was used for slurry shearing to study effect of shear on slurry characteristics. Particle agglomeration due to slurry shearing and storage was observed and corroborated using rheometry, zeta potential, and particle size measurements.
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Gilardoni S, Russell LM, Sorooshian A, Flagan RC, Seinfeld JH, Bates TS, Quinn PK, Allan JD, Williams B, Goldstein AH, Onasch TB, Worsnop DR. Regional variation of organic functional groups in aerosol particles on four U.S. east coast platforms during the International Consortium for Atmospheric Research on Transport and Transformation 2004 campaign. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007737] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S. Gilardoni
- Scripps Institution of Oceanography; University of California; San Diego, La Jolla California USA
| | - L. M. Russell
- Scripps Institution of Oceanography; University of California; San Diego, La Jolla California USA
| | - A. Sorooshian
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - R. C. Flagan
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - J. H. Seinfeld
- Department of Chemical Engineering; California Institute of Technology; Pasadena California USA
| | - T. S. Bates
- Pacific Marine Environmental Laboratory; NOAA; Seattle Washington USA
| | - P. K. Quinn
- Pacific Marine Environmental Laboratory; NOAA; Seattle Washington USA
| | - J. D. Allan
- School of Earth, Atmospheric and Environmental Science; University of Manchester; Manchester UK
| | - B. Williams
- Department of Environmental Sciences, Policy and Management; University of California; Berkeley California USA
| | - A. H. Goldstein
- Department of Environmental Sciences, Policy and Management; University of California; Berkeley California USA
| | - T. B. Onasch
- Aerodyne Research, Inc.; Billerica Massachusetts USA
| | - D. R. Worsnop
- Aerodyne Research, Inc.; Billerica Massachusetts USA
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