1
|
Zhao B, Gu Y, Liou KN, Wang Y, Liu X, Huang L, Jiang JH, Su H. Type-Dependent Responses of Ice Cloud Properties to Aerosols From Satellite Retrievals. GEOPHYSICAL RESEARCH LETTERS 2018; 45:3297-3306. [PMID: 31631917 PMCID: PMC6800730 DOI: 10.1002/2018gl077261] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/24/2018] [Indexed: 05/25/2023]
Abstract
Aerosol-cloud interactions represent one of the largest uncertainties in external forcings on our climate system. Compared with liquid clouds, the observational evidence for the aerosol impact on ice clouds is much more limited and shows conflicting results, partly because the distinct features of different ice cloud and aerosol types were seldom considered. Using 9-year satellite retrievals, we find that, for convection-generated (anvil) ice clouds, cloud optical thickness, cloud thickness, and cloud fraction increase with small-to-moderate aerosol loadings (<0.3 aerosol optical depth) and decrease with further aerosol increase. For in situ formed ice clouds, however, these cloud properties increase monotonically and more sharply with aerosol loadings. An increase in loading of smoke aerosols generally reduces cloud optical thickness of convection-generated ice clouds, while the reverse is true for dust and anthropogenic pollution aerosols. These relationships between different cloud/aerosol types provide valuable constraints on the modeling assessment of aerosol-ice cloud radiative forcing.
Collapse
Affiliation(s)
- Bin Zhao
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Yu Gu
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
| | - Kuo-Nan Liou
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
| | - Yuan Wang
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Xiaohong Liu
- Department of Atmospheric Science, University of Wyoming, Laramie, WY, USA
| | - Lei Huang
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Jonathan H Jiang
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - Hui Su
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| |
Collapse
|
2
|
Zhao B, Liou KN, Gu Y, Jiang JH, Li Q, Fu R, Huang L, Liu X, Shi X, Su H, He C. Impact of aerosols on ice crystal size. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018; 18:1065-1078. [PMID: 31534446 PMCID: PMC6750036 DOI: 10.5194/acp-18-1065-2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The interactions between aerosols and ice clouds represent one of the largest uncertainties in global radiative forcing from pre-industrial time to the present. In particular, the impact of aerosols on ice crystal effective radius (R ei), which is a key parameter determining ice clouds' net radiative effect, is highly uncertain due to limited and conflicting observational evidence. Here we investigate the effects of aerosols on R ei under different meteorological conditions using 9-year satellite observations. We find that the responses of R ei to aerosol loadings are modulated by water vapor amount in conjunction with several other meteorological parameters. While there is a significant negative correlation between R ei and aerosol loading in moist conditions, consistent with the "Twomey effect" for liquid clouds, a strong positive correlation between the two occurs in dry conditions. Simulations based on a cloud parcel model suggest that water vapor modulates the relative importance of different ice nucleation modes, leading to the opposite aerosol impacts between moist and dry conditions. When ice clouds are decomposed into those generated from deep convection and formed in situ, the water vapor modulation remains in effect for both ice cloud types, although the sensitivities of R ei to aerosols differ noticeably between them due to distinct formation mechanisms. The water vapor modulation can largely explain the difference in the responses of R ei to aerosol loadings in various seasons. A proper representation of the water vapor modulation is essential for an accurate estimate of aerosol-cloud radiative forcing produced by ice clouds.
Collapse
Affiliation(s)
- Bin Zhao
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| | - Kuo-Nan Liou
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| | - Yu Gu
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| | - Jonathan H. Jiang
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Qinbin Li
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| | - Rong Fu
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| | - Lei Huang
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Xiaohong Liu
- Department of Atmospheric Science, University of Wyoming, Laramie, Wyoming 82071, USA
| | - Xiangjun Shi
- Department of Atmospheric Science, University of Wyoming, Laramie, Wyoming 82071, USA
| | - Hui Su
- Jet propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
| | - Cenlin He
- Joint Institute for Regional Earth System Science and Engineering and Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California 90095, USA
| |
Collapse
|
3
|
Kallos G, Solomos S, Kushta J, Mitsakou C, Spyrou C, Bartsotas N, Kalogeri C. Natural and anthropogenic aerosols in the Eastern Mediterranean and Middle East: possible impacts. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 488-489:389-97. [PMID: 24630589 DOI: 10.1016/j.scitotenv.2014.02.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/10/2013] [Accepted: 02/07/2014] [Indexed: 05/26/2023]
Abstract
The physical and chemical properties of airborne particles have significant implications on the microphysical cloud processes. Maritime clouds have different properties than polluted ones and the final amounts and types of precipitation are different. Mixed phase aerosols that contain soluble matter are efficient cloud condensation nuclei (CCN) and enhance the liquid condensate spectrum in warm and mixed phase clouds. Insoluble particles such as mineral dust and black carbon are also important because of their ability to act as efficient ice nuclei (IN) through heterogeneous ice nucleation mechanisms. The relative contribution of aerosol concentrations, size distributions and chemical compositions on cloud structure and precipitation is discussed in the framework of RAMS/ICLAMS model. Analysis of model results and comparison with measurements reveals the complexity of the above links. Taking into account anthropogenic emissions and all available aerosol-cloud interactions the model precipitation bias was reduced by 50% for a storm simulation over eastern Mediterranean.
Collapse
Affiliation(s)
- G Kallos
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece.
| | - S Solomos
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| | - J Kushta
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| | - C Mitsakou
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| | - C Spyrou
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| | - N Bartsotas
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| | - C Kalogeri
- University of Athens, Division of Physics of Environment - Meteorology, Atmospheric Modeling and Weather Forecasting Group (AM&WFG), University Campus, Building PHYSICS V, Athens 15784, Greece
| |
Collapse
|
4
|
Aamaas B, Peters GP, Fuglestvedt JS. Simple emission metrics for climate impacts. EARTH SYSTEM DYNAMICS 2013. [PMID: 0 DOI: 10.5194/esd-4-145-2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Abstract. In the context of climate change, emissions of different species (e.g., carbon dioxide and methane) are not directly comparable since they have different radiative efficiencies and lifetimes. Since comparisons via detailed climate models are computationally expensive and complex, emission metrics were developed to allow a simple and straightforward comparison of the estimated climate impacts of emissions of different species. Emission metrics are not unique and variety of different emission metrics has been proposed, with key choices being the climate impacts and time horizon to use for comparisons. In this paper, we present analytical expressions and describe how to calculate common emission metrics for different species. We include the climate metrics radiative forcing, integrated radiative forcing, temperature change and integrated temperature change in both absolute form and normalised to a reference gas. We consider pulse emissions, sustained emissions and emission scenarios. The species are separated into three types: CO2 which has a complex decay over time, species with a simple exponential decay, and ozone precursors (NOx, CO, VOC) which indirectly effect climate via various chemical interactions. We also discuss deriving Impulse Response Functions, radiative efficiency, regional dependencies, consistency within and between metrics and uncertainties. We perform various applications to highlight key applications of emission metrics, which show that emissions of CO2 are important regardless of what metric and time horizon is used, but that the importance of short lived climate forcers varies greatly depending on the metric choices made. Further, the ranking of countries by emissions changes very little with different metrics despite large differences in metric values, except for the shortest time horizons (GWP20).
Collapse
|
5
|
Gettelman A, Liu X, Barahona D, Lohmann U, Chen C. Climate impacts of ice nucleation. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017950] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
6
|
Hendricks J, Kärcher B, Lohmann U. Effects of ice nuclei on cirrus clouds in a global climate model. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd015302] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
7
|
Holmes CD, Tang Q, Prather MJ. Uncertainties in climate assessment for the case of aviation NO. Proc Natl Acad Sci U S A 2011; 108:10997-1002. [PMID: 21690364 PMCID: PMC3131318 DOI: 10.1073/pnas.1101458108] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nitrogen oxides emitted from aircraft engines alter the chemistry of the atmosphere, perturbing the greenhouse gases methane (CH(4)) and ozone (O(3)). We quantify uncertainties in radiative forcing (RF) due to short-lived increases in O(3), long-lived decreases in CH(4) and O(3), and their net effect, using the ensemble of published models and a factor decomposition of each forcing. The decomposition captures major features of the ensemble, and also shows which processes drive the total uncertainty in several climate metrics. Aviation-specific factors drive most of the uncertainty for the short-lived O(3) and long-lived CH(4) RFs, but a nonaviation factor dominates for long-lived O(3). The model ensemble shows strong anticorrelation between the short-lived and long-lived RF perturbations (R(2)=0.87). Uncertainty in the net RF is highly sensitive to this correlation. We reproduce the correlation and ensemble spread in one model, showing that processes controlling the background tropospheric abundance of nitrogen oxides are likely responsible for the modeling uncertainty in climate impacts from aviation.
Collapse
Affiliation(s)
- Christopher D Holmes
- Department of Earth System Science, University of California, Irvine, CA 92697-3100, USA.
| | | | | |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|