Chapter 8 Contrails and contrail cirrus - The Truth Denied 8 Contrails and contrail cirrus. 8.1...
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Transcript of Chapter 8 Contrails and contrail cirrus - The Truth Denied 8 Contrails and contrail cirrus. 8.1...
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
Gayet, 2008, A380
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Detection of the contrail of an A380
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Introduction
Contrails develop at lower relative humidity than natural cirrus and therefore can modify high cloudiness.
Contrails change the radiation budget and the upper tropospheric moisture budget significantly.
Georgia 13 October 2004 NASA
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Introduction 2
Aircraft influence high clouds directly by producing line-shaped contrails.
Contrails can persist and spread in ice-supersaturated air. The resulting clusters of contrail-cirrus can be observed on regional scales, sometimes also in regions without significant air traffic, because they are advected with the wind field over large distances.
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Introduction 3
Contrails predominantly form when aircraft fly through preexisting cirrus clouds, sometimes accompanied by the formation of distrails. The main effect seems to be the formation of a localized 'cloud hole':
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Contrail-cirrus can exert an indirect effect on their own. Cirrus may have different properties because they nucleate in regions with preexisting ice and share the available water.
Aircraft influence high clouds indirectly by injecting aerosol particles that may act as heterogeneous ice nuclei at some point after emission. In the absence of aircraft emissions, a cirrus cloud would not have formed or the resulting cirrus would have different properties.
It is important to recognize that a strong coupling may exist between the pure direct and indirect effects.
Introduction 4
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
Gayet, 2008, A380
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
7.7.1 Formation conditions of contrails
Contrails consist of ice particles that nucleate primarily on aerosols emitted or formed in the plume.
At initial stage contrails grow by deposition of exhaust water vapor.
Later during their life cycle contrails grow by deposition of entrained ambient water vapor.
Formation of contrails due to increase in RHI during isobaric mixing of the hot and humid exhaust gases with colder and less humid ambient air.
Contrail formation within ~ a wingspan distance behind the aircraft when S with respect to water is reached.
Threshold temperatures and humidities for contrail formation at a given flight level are directly specified by thermodynamic relations.
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.2 Contrail formation conditions
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.3 Homogeneous nucleation of contrails in volatile aerosol
Krcher, 1999
Volatile and soot exhaust aerosol are processed by rapid uptake of H2O and H2SO4 in contrails. Ice crystals that scavenged sulfate aerosols release larger sulfate droplets upon evaporation.
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.3 Heterogeneous nucleation of contrails on soot
Krcher, 1998
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.3 Heterogeneous nucleation of contrails on soot and volatile aerosol
after Krcher and Yu, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.3 Heterogeneous nucleation of contrails on soot and volatile aerosol
Krcher and Yu, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.4 Indirect effect of soot on cirrus
Krcher et al., ACP, 2007
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.4 Indirect effect of soot on cirrus
Hendricks et al., GRL, 2005
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.5 Growth of ice crystals in contrails
Schrder et al., 1999
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.5 Growth of ice crystals in contrails - transition into contrail cirrus
Schrder et al., 1999
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.5 Growth of ice crystals in contrails - transition into contrail cirrus
Schrder et al., 1999
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.5 Transition of contrails into contrail cirrus
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
line-shaped
process
based
all process
based
line-shaped
scaled
line-shaped
process
based
b ~ Dyn(T, RH, 4h)
b ~ Dyn(T, RH, )
logarithmic scale
b ~ C x T x RH
b ~ Dyn(T, RH, 4h)
linear scaleBurkhardt and Krcher, JGR, 2009
8.5 Simulation of contrail cirrus coverage
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
visible all visible allline-shaped contrails contrail cirrus
new scheme 0.05 0.10 0.50 1.14
Increase in coverage due to ageing contrails regionally very variable
Increase depends on visibility threshold and overlap assumptions
8.5 Simulation of contrail cirrus coverage
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.6 Variability of contrail cirrus properties-
Interannual variability of contrail coverage
observations
model realizations
model average
Burkhardt and Krcher, JGR, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.6 Variability of contrail cirrus optical depth
Krcher et al., ACPD, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.6 Variability of contrail cirrus properties
Krcher et al., ACPD, 2009
Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field.
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Krcher et al., ACPD, 2009
8.6 Variability of contrail cirrus properties
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.6 Variability of contrail cirrus optical depth
Krcher et al., ACPD, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.7 Heterogeneous chemistry on contrailsOzone changes due to aircraft emissions
Meilinger et al., ACP, 2005
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.7 Heterogeneous chemistry on contrailsPotential of aircraft aerosols and contrails to produce or destroy ozone
Meilinger et al., ACP, 2005
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Chapter 8Contrails and contrail cirrus8.1 Introduction - Terminology8.2 Contrail formation conditions8.3 Heterogeneous nucleation on volatile aerosol and soot8.4 Indirect effect of soot on cirrus8.5 Contrail cirrus8.6 Variability of contrail properties8.7 Heterogeneous chemistry on contrails8.8 Aerodynamic contrails
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.8 Aerodynamic contrails
Gierens et al., JAS, 2009, Krcher et al., JAS, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.8 Aerodynamic contrails
Gierens et al., JAS, 2009, Krcher et al., JAS, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
8.8 Aerodynamic contrails
Gierens et al., JAS, 2009, Krcher et al., JAS, 2009
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Chapter 8 - Contrails J. Schneider & Chr. Voigt - Physics and Chemistry of Aerosols and Ice Clouds
Foliennummer 1Detection of the contrail of an A380Foliennummer 4Foliennummer 5Foliennummer 6Foliennummer 7Foliennummer 8Foliennummer 9Foliennummer 11Foliennummer 12Foliennummer 13Foliennummer 14Foliennummer 15Foliennummer 16Foliennummer 17Foliennummer 18Foliennummer 19Foliennummer 22Foliennummer 23Foliennummer 24Foliennummer 25Foliennummer 26Foliennummer 28Foliennummer 31Foliennummer 32Foliennummer 33Foliennummer 34Foliennummer 35Foliennummer 36Foliennummer 38Foliennummer 39Foliennummer 40Foliennummer 41Foliennummer 42Foliennummer 45Foliennummer 46Foliennummer 47Foliennummer 49Foliennummer 50