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Losey DJ, Sihvonen SK, Veghte DP, Chong E, Freedman MA. Acidic processing of fly ash: chemical characterization, morphology, and immersion freezing. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2018; 20:1581-1592. [PMID: 30339168 DOI: 10.1039/c8em00319j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Fly ash can undergo aging in the atmosphere through interactions with sulfuric acid and water. These reactions could result in chemical and physical changes that could affect the cloud condensation or ice nucleation activity of fly ash particles. To explore this process, different water and acid treated fly ash types were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), electron dispersive spectroscopy (EDS), selected area diffraction (SAED), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Then, their immersion freezing activity was assessed. With water and acid treatment, a wide variety of metals were leached, depending on the starting composition of the fly ash. Acid treatment resulted in the formation of gypsum, Ca(SO4)·2H2O, for fly ash containing Ca as well as morphological changes. The immersion freezing activity was also assessed for each fly ash system to compare the effects of water and acid processing. Our results support the assertion that fly ash can serve as a cloud condensation or ice nucleus to affect climate.
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Affiliation(s)
- Delanie J Losey
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA.
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Barahona D, Molod A, Kalesse H. Direct estimation of the global distribution of vertical velocity within cirrus clouds. Sci Rep 2017; 7:6840. [PMID: 28754986 PMCID: PMC5533806 DOI: 10.1038/s41598-017-07038-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/21/2017] [Indexed: 12/03/2022] Open
Abstract
Cirrus clouds determine the radiative balance of the upper troposphere and the transport of water vapor across the tropopause. The representation of vertical wind velocity, W, in atmospheric models constitutes the largest source of uncertainty in the calculation of the cirrus formation rate. Using global atmospheric simulations with a spatial resolution of 7 km we obtain for the first time a direct estimate of the distribution of W at the scale relevant for cirrus formation, validated against long-term observations at two different ground sites. The standard deviation in W, σw, varies widely over the globe with the highest values resulting from orographic uplift and convection, and the lowest occurring in the Arctic. Globally about 90% of the simulated σw values are below 0.1 m s−1 and about one in 104 cloud formation events occur in environments with σw > 0.8 m s−1. Combining our estimate with reanalysis products and an advanced cloud formation scheme results in lower homogeneous ice nucleation frequency than previously reported, and a decreasing average ice crystal concentration with decreasing temperature. These features are in agreement with observations and suggest that the correct parameterization of σw is critical to simulate realistic cirrus properties.
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Affiliation(s)
- Donifan Barahona
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, USA.
| | - Andrea Molod
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Heike Kalesse
- Leibniz Institute for Tropospheric Research, Leipzig, Germany
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Lee D, Pitari G, Grewe V, Gierens K, Penner J, Petzold A, Prather M, Schumann U, Bais A, Berntsen T, Iachetti D, Lim L, Sausen R. Transport impacts on atmosphere and climate: Aviation. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2010; 44:4678-4734. [PMID: 32288556 PMCID: PMC7110594 DOI: 10.1016/j.atmosenv.2009.06.005] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 05/30/2009] [Accepted: 06/02/2009] [Indexed: 05/04/2023]
Abstract
Aviation alters the composition of the atmosphere globally and can thus drive climate change and ozone depletion. The last major international assessment of these impacts was made by the Intergovernmental Panel on Climate Change (IPCC) in 1999. Here, a comprehensive updated assessment of aviation is provided. Scientific advances since the 1999 assessment have reduced key uncertainties, sharpening the quantitative evaluation, yet the basic conclusions remain the same. The climate impact of aviation is driven by long-term impacts from CO2 emissions and shorter-term impacts from non-CO2 emissions and effects, which include the emissions of water vapour, particles and nitrogen oxides (NO x ). The present-day radiative forcing from aviation (2005) is estimated to be 55 mW m-2 (excluding cirrus cloud enhancement), which represents some 3.5% (range 1.3-10%, 90% likelihood range) of current anthropogenic forcing, or 78 mW m-2 including cirrus cloud enhancement, representing 4.9% of current forcing (range 2-14%, 90% likelihood range). According to two SRES-compatible scenarios, future forcings may increase by factors of 3-4 over 2000 levels, in 2050. The effects of aviation emissions of CO2 on global mean surface temperature last for many hundreds of years (in common with other sources), whilst its non-CO2 effects on temperature last for decades. Much progress has been made in the last ten years on characterizing emissions, although major uncertainties remain over the nature of particles. Emissions of NO x result in production of ozone, a climate warming gas, and the reduction of ambient methane (a cooling effect) although the overall balance is warming, based upon current understanding. These NO x emissions from current subsonic aviation do not appear to deplete stratospheric ozone. Despite the progress made on modelling aviation's impacts on tropospheric chemistry, there remains a significant spread in model results. The knowledge of aviation's impacts on cloudiness has also improved: a limited number of studies have demonstrated an increase in cirrus cloud attributable to aviation although the magnitude varies: however, these trend analyses may be impacted by satellite artefacts. The effect of aviation particles on clouds (with and without contrails) may give rise to either a positive forcing or a negative forcing: the modelling and the underlying processes are highly uncertain, although the overall effect of contrails and enhanced cloudiness is considered to be a positive forcing and could be substantial, compared with other effects. The debate over quantification of aviation impacts has also progressed towards studying potential mitigation and the technological and atmospheric tradeoffs. Current studies are still relatively immature and more work is required to determine optimal technological development paths, which is an aspect that atmospheric science has much to contribute. In terms of alternative fuels, liquid hydrogen represents a possibility and may reduce some of aviation's impacts on climate if the fuel is produced in a carbon-neutral way: such fuel is unlikely to be utilized until a 'hydrogen economy' develops. The introduction of biofuels as a means of reducing CO2 impacts represents a future possibility. However, even over and above land-use concerns and greenhouse gas budget issues, aviation fuels require strict adherence to safety standards and thus require extra processing compared with biofuels destined for other sectors, where the uptake of such fuel may be more beneficial in the first instance.
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Affiliation(s)
- D.S. Lee
- Dalton Research Institute, Department of Environmental and Geographical Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
- Corresponding author. Tel.: +44 161 247 3663.
| | - G. Pitari
- Dipartimento di Fisica, University of L'Aquila, Vio Vetoio Località Coppito, 67100 l'Aquila, Italy
| | - V. Grewe
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany
| | - K. Gierens
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany
| | - J.E. Penner
- Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward St., Ann Arbor, MI 48109-2143, USA
| | - A. Petzold
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany
| | - M.J. Prather
- Department of Earth System Science, University of California, Irvine, 3329 Croull Hall, CA 92697-3100, USA
| | - U. Schumann
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany
| | - A. Bais
- Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - T. Berntsen
- Department of Geosciences, University of Oslo, PO Box 1022 Blindern, 0315, Oslo, Norway
| | - D. Iachetti
- Dipartimento di Fisica, University of L'Aquila, Vio Vetoio Località Coppito, 67100 l'Aquila, Italy
| | - L.L. Lim
- Dalton Research Institute, Department of Environmental and Geographical Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - R. Sausen
- Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany
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Koehler KA, DeMott PJ, Kreidenweis SM, Popovicheva OB, Petters MD, Carrico CM, Kireeva ED, Khokhlova TD, Shonija NK. Cloud condensation nuclei and ice nucleation activity of hydrophobic and hydrophilic soot particles. Phys Chem Chem Phys 2009; 11:7906-20. [DOI: 10.1039/b905334b] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Prenni AJ, DeMott PJ, Twohy C, Poellot MR, Kreidenweis SM, Rogers DC, Brooks SD, Richardson MS, Heymsfield AJ. Examinations of ice formation processes in Florida cumuli using ice nuclei measurements of anvil ice crystal particle residues. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007549] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anthony J. Prenni
- Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
| | - Paul J. DeMott
- Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
| | - Cynthia Twohy
- College of Oceanic and Atmospheric Sciences; Oregon State University; Corvallis Oregon USA
| | - Michael R. Poellot
- Department of Atmospheric Science; University of North Dakota; Grand Forks North Dakota USA
| | - Sonia M. Kreidenweis
- Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
| | - David C. Rogers
- National Center for Atmospheric Research; Boulder Colorado USA
| | - Sarah D. Brooks
- Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
| | - Mathews S. Richardson
- Department of Atmospheric Science; Colorado State University; Fort Collins Colorado USA
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Richardson MS, DeMott PJ, Kreidenweis SM, Cziczo DJ, Dunlea EJ, Jimenez JL, Thomson DS, Ashbaugh LL, Borys RD, Westphal DL, Casuccio GS, Lersch TL. Measurements of heterogeneous ice nuclei in the western United States in springtime and their relation to aerosol characteristics. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007500] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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