Aircraft Emission

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O A Sovde - One of the best experts on this subject based on the ideXlab platform.

  • Aircraft Emission mitigation by changing route altitude a multi model estimate of Aircraft nox Emission impact on o3 photochemistry
    Atmospheric Environment, 2014
    Co-Authors: O A Sovde, G. Pitari, D. Iachetti, Sigrun Matthes, Agnieszka Skowron, Ling L Lim, Bethan Owen, Oivind Hodnebrog, Glauco Di Genova, David S Lee
    Abstract:

    The atmospheric impact of Aircraft NOx Emissions are studied using updated Aircraft inventories for the year 2006, in order to estimate the photochemistry-related mitigation potential of shifting cruise altitudes higher or lower by 2000 ft. Applying three chemistry-transport models (CTM) and two climatechemistry models (CCM) in CTM mode, all including detailed tropospheric and stratospheric chemistry, we estimate the short-lived radiative forcing (RF) from O3 to range between 16.4 and 23.5 mW m 2, with a mean value of 19.5 mW m 2. Including the long-lived RF caused by changes in CH4, the total NOxrelated RF is estimated to about 5 mW m 2, ranging 1e8 mW m 2. Cruising at 2000 ft higher altitude increases the total RF due to Aircraft NOx Emissions by 2 ± 1 mW m 2, while cruising at 2000 ft lower altitude reduces RF by 2 ± 1 mWm 2. This change is mainly controlled by short-lived O3 and show that chemical NOx impact of contrail avoiding measures is likely small.

  • Aircraft pollution – a futuristic view
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet are investigated using the Oslo CTM2, with Emissions provided through the EU project SCENIC. The Aircraft Emission scenarios consist of Emissions from subsonic and supersonic Aircraft. In particular it is shown that aerosol Emissions from such an Aircraft fleet can have a relatively large impact on ozone, and possibly reduce the total atmospheric NOx by more than what is emitted by Aircraft. Without aerosol Emissions this Aircraft fleet leads to similar NOx increases for subsonic (at 11–12 km) and supersonic (at 18–20 km) Emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. Tropospheric ozone increases are about 10 ppbv in the Northern Hemisphere due to Emissions from subsonic Aircraft. Increased ozone loss from supersonic Aircraft at higher altitudes leads to ozone reductions of about 39 ppbv in the Northern Hemisphere and 22 ppbv in the Southern Hemisphere. The latter reduction is a result of transport of ozone depleted air from northern latitudes. When including Aircraft aerosol Emissions, NOx is reduced due to heterogeneous chemistry. The reduced NOx seems to counterweight the reduction of ozone from Emissions of NOx and H2O above 20 km. At these altitudes the NOx (and thus ozone loss) reduction is large enough to give an Aircraft Emissions induced increase in ozone. In the height range 11–20 km altitude, however, ozone production is reduced. Heterogeneous reactions and reduced NOx enhances ClO, further enhancing ozone loss in the lower stratosphere. This results in a 14 ppbv additional reduction of ozone. Although supersonic Aircraft have opposite effects on ozone in the upper and lower stratosphere, the change in ozone columns is clearly dominated by the upper stratospheric loss, thus supersonic Aircraft aerosol Emissions lead to enhanced ozone columns. The largest increase in the ozone column due to aerosol Emissions is therefore seen in the Northern Hemispheric autumn and winter, giving a column increase of 4.5 DU. It is further found that at high northern latitudes during spring the heterogeneous chemistry on PSCs is particularly efficient, thereby increasing the ozone loss.

  • Aircraft pollution: a futuristic view
    Atmospheric Chemistry and Physics Discussions, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet, provided in the EU project SCENIC, are investigated using the Oslo CTM2, a 3-D chemical transport model including comprehensive chemistry for the stratosphere and the troposphere. The Aircraft Emission scenarios comprise Emissions from subsonic and supersonic Aircraft. The increases in NOy due to Emissions from the mixed fleet are comparable for subsonic (at 11–12 km) and supersonic (at 18–20 km) Aircraft, with annual zonal means of 1.35 ppbv and 0.83 ppbv, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. The Aircraft Emissions increase tropospheric ozone by about 10 ppbv in the Northern Hemisphere due to increased ozone production, mainly because of subsonic Aircraft. Supersonic Aircraft contribute to a reduction of stratospheric ozone due to increased ozone loss at higher altitudes. In the Northern Hemisphere the reduction is about 39 ppbv, but also in the Southern Hemisphere a 22 ppbv stratospheric decrease is modeled due to transport of supersonic Aircraft Emissions and ozone depleted air. The total ozone column is increased in lower and Northern mid-latitudes, otherwise the increase of ozone loss contributes to a decrease of the total ozone column. Two exceptions are the Northern Hemispheric spring, where the ozone loss increase is small due to transport processes, and tropical latitudes during summer where the effect of subsonic Aircraft is low due to a high tropopause. Aerosol particles emitted by Aircraft reduce both Aircraft and background NOx, more than counterweighting the effect of NOx and H2O Aircraft Emissions in the stratosphere. Above about 20 km altitude, the NOx (and thus ozone loss) reduction is large enough to give an increase in ozone due to Aircraft Emissions. This effect is comparable in the Northern and Southern Hemisphere. At 11–20 km altitude, however, ozone production is reduced due to less NOx. Also ClONO2 is increased at this altitude due to enhanced heterogeneous reactions (lowered HCl), and ClO is increased due to less NOx, further enhancing ozone loss in this region. This results in a 14 ppbv further reduction of ozone. Mainly, this results in an increase of the total ozone column due to a decrease in ozone loss caused by the NOx cycle (at the highest altitudes). At the lowermost latitudes, the reduced loss due to the NOx cycle is small. However, ozone production at lower altitudes is reduced and the loss due to ClO is increased, giving a decrease in the total ozone column. Also, at high latitudes during spring the heterogeneous chemistry is more efficient on PSCs, increasing the ozone loss.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics, 2006
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen and ozone. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated, taking into account effects of flight route changes on fuel consumption and Emissions. In a reference case including both civil and military Aircraft the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. Enhanced use of polar routes implies substantially larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increases in the lower stratosphere and upper troposphere, and to larger ozone increases at altitudes below. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the contribution from higher altitudes dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics Discussions, 2005
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen, ozone, and the chemical lifetime of methane. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated. In the reference case the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. The lifetime of methane is calculated to decrease by 0.71%, inducing a radiative forcing of ?6.4 mW/m2. Enhanced use of polar routes implies significantly larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increase in the lower stratosphere and upper troposphere, and to larger ozone increase at lower altitudes. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the stratospheric decrease dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.

C. Marizy - One of the best experts on this subject based on the ideXlab platform.

  • Radiative forcing from particle Emissions by future supersonic Aircraft
    Atmospheric Chemistry and Physics Discussions, 2008
    Co-Authors: G. Pitari, D. Iachetti, E. Mancini, V. Montanaro, C. Marizy, O. Dessens, H. Rogers, J. Pyle, V. Grewe, A. Stenke
    Abstract:

    In this work we focus on the direct radiative forcing (RF) of black carbon (BC) and sulphuric acid particles emitted by future supersonic Aircraft, as well as on the ozone RF due to changes produced by Emissions of both gas species (NOx, H2O) and aerosol particles capable of affecting stratospheric ozone chemistry. Heterogeneous chemical reactions on the surface of sulphuric acid stratospheric particles (SSA-SAD) are the main link between ozone chemistry and supersonic Aircraft Emissions of sulphur precursors (SO2) and particles (H2O-H2SO4). Photochemical O3 changes are compared from four independent 3-D atmosphere-chemistry models (ACMs), using as input the perturbation of SSA-SAD calculated in the University of L'Aquila model, which includes on-line a microphysics code for aerosol formation and growth. The ACMs in this study use Aircraft Emission scenarios for the year 2050 developed by AIRBUS as a part of the EU project SCENIC, assessing options for fleet size, engine technology (NOx Emission index), Mach number, range and cruising altitude. From our baseline modelling simulation, the impact of supersonic Aircraft on sulphuric acid aerosol and BC mass burdens is 53 and 1.5 µg/m2, respectively, with a direct RF of -11.4 and 4.6 mW/m2 (net RF=-6.8 mW/m2). This paper discusses the similarities and differences amongst the participating models in terms of O3 precursors changes due to Aircraft Emissions (NOx, HOx,Clx,Brx) and stratospheric ozone sensitivity to them. In the baseline case, the calculated global ozone change is -0.4±0.3 DU, with a net radiative forcing (IR+UV) of -2.5±2 mW/m2. The fraction of this O3-RF attributable to SSA-SAD changes is, however, highly variable among the models, depending on the NOx removal efficiency from the Aircraft Emission regions by large scale transport.

  • Aircraft pollution – a futuristic view
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet are investigated using the Oslo CTM2, with Emissions provided through the EU project SCENIC. The Aircraft Emission scenarios consist of Emissions from subsonic and supersonic Aircraft. In particular it is shown that aerosol Emissions from such an Aircraft fleet can have a relatively large impact on ozone, and possibly reduce the total atmospheric NOx by more than what is emitted by Aircraft. Without aerosol Emissions this Aircraft fleet leads to similar NOx increases for subsonic (at 11–12 km) and supersonic (at 18–20 km) Emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. Tropospheric ozone increases are about 10 ppbv in the Northern Hemisphere due to Emissions from subsonic Aircraft. Increased ozone loss from supersonic Aircraft at higher altitudes leads to ozone reductions of about 39 ppbv in the Northern Hemisphere and 22 ppbv in the Southern Hemisphere. The latter reduction is a result of transport of ozone depleted air from northern latitudes. When including Aircraft aerosol Emissions, NOx is reduced due to heterogeneous chemistry. The reduced NOx seems to counterweight the reduction of ozone from Emissions of NOx and H2O above 20 km. At these altitudes the NOx (and thus ozone loss) reduction is large enough to give an Aircraft Emissions induced increase in ozone. In the height range 11–20 km altitude, however, ozone production is reduced. Heterogeneous reactions and reduced NOx enhances ClO, further enhancing ozone loss in the lower stratosphere. This results in a 14 ppbv additional reduction of ozone. Although supersonic Aircraft have opposite effects on ozone in the upper and lower stratosphere, the change in ozone columns is clearly dominated by the upper stratospheric loss, thus supersonic Aircraft aerosol Emissions lead to enhanced ozone columns. The largest increase in the ozone column due to aerosol Emissions is therefore seen in the Northern Hemispheric autumn and winter, giving a column increase of 4.5 DU. It is further found that at high northern latitudes during spring the heterogeneous chemistry on PSCs is particularly efficient, thereby increasing the ozone loss.

  • Aircraft pollution: a futuristic view
    Atmospheric Chemistry and Physics Discussions, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet, provided in the EU project SCENIC, are investigated using the Oslo CTM2, a 3-D chemical transport model including comprehensive chemistry for the stratosphere and the troposphere. The Aircraft Emission scenarios comprise Emissions from subsonic and supersonic Aircraft. The increases in NOy due to Emissions from the mixed fleet are comparable for subsonic (at 11–12 km) and supersonic (at 18–20 km) Aircraft, with annual zonal means of 1.35 ppbv and 0.83 ppbv, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. The Aircraft Emissions increase tropospheric ozone by about 10 ppbv in the Northern Hemisphere due to increased ozone production, mainly because of subsonic Aircraft. Supersonic Aircraft contribute to a reduction of stratospheric ozone due to increased ozone loss at higher altitudes. In the Northern Hemisphere the reduction is about 39 ppbv, but also in the Southern Hemisphere a 22 ppbv stratospheric decrease is modeled due to transport of supersonic Aircraft Emissions and ozone depleted air. The total ozone column is increased in lower and Northern mid-latitudes, otherwise the increase of ozone loss contributes to a decrease of the total ozone column. Two exceptions are the Northern Hemispheric spring, where the ozone loss increase is small due to transport processes, and tropical latitudes during summer where the effect of subsonic Aircraft is low due to a high tropopause. Aerosol particles emitted by Aircraft reduce both Aircraft and background NOx, more than counterweighting the effect of NOx and H2O Aircraft Emissions in the stratosphere. Above about 20 km altitude, the NOx (and thus ozone loss) reduction is large enough to give an increase in ozone due to Aircraft Emissions. This effect is comparable in the Northern and Southern Hemisphere. At 11–20 km altitude, however, ozone production is reduced due to less NOx. Also ClONO2 is increased at this altitude due to enhanced heterogeneous reactions (lowered HCl), and ClO is increased due to less NOx, further enhancing ozone loss in this region. This results in a 14 ppbv further reduction of ozone. Mainly, this results in an increase of the total ozone column due to a decrease in ozone loss caused by the NOx cycle (at the highest altitudes). At the lowermost latitudes, the reduced loss due to the NOx cycle is small. However, ozone production at lower altitudes is reduced and the loss due to ClO is increased, giving a decrease in the total ozone column. Also, at high latitudes during spring the heterogeneous chemistry is more efficient on PSCs, increasing the ozone loss.

G. Pitari - One of the best experts on this subject based on the ideXlab platform.

  • Aircraft Emission mitigation by changing route altitude a multi model estimate of Aircraft nox Emission impact on o3 photochemistry
    Atmospheric Environment, 2014
    Co-Authors: O A Sovde, G. Pitari, D. Iachetti, Sigrun Matthes, Agnieszka Skowron, Ling L Lim, Bethan Owen, Oivind Hodnebrog, Glauco Di Genova, David S Lee
    Abstract:

    The atmospheric impact of Aircraft NOx Emissions are studied using updated Aircraft inventories for the year 2006, in order to estimate the photochemistry-related mitigation potential of shifting cruise altitudes higher or lower by 2000 ft. Applying three chemistry-transport models (CTM) and two climatechemistry models (CCM) in CTM mode, all including detailed tropospheric and stratospheric chemistry, we estimate the short-lived radiative forcing (RF) from O3 to range between 16.4 and 23.5 mW m 2, with a mean value of 19.5 mW m 2. Including the long-lived RF caused by changes in CH4, the total NOxrelated RF is estimated to about 5 mW m 2, ranging 1e8 mW m 2. Cruising at 2000 ft higher altitude increases the total RF due to Aircraft NOx Emissions by 2 ± 1 mW m 2, while cruising at 2000 ft lower altitude reduces RF by 2 ± 1 mWm 2. This change is mainly controlled by short-lived O3 and show that chemical NOx impact of contrail avoiding measures is likely small.

  • Radiative forcing from particle Emissions by future supersonic Aircraft
    Atmospheric Chemistry and Physics Discussions, 2008
    Co-Authors: G. Pitari, D. Iachetti, E. Mancini, V. Montanaro, C. Marizy, O. Dessens, H. Rogers, J. Pyle, V. Grewe, A. Stenke
    Abstract:

    In this work we focus on the direct radiative forcing (RF) of black carbon (BC) and sulphuric acid particles emitted by future supersonic Aircraft, as well as on the ozone RF due to changes produced by Emissions of both gas species (NOx, H2O) and aerosol particles capable of affecting stratospheric ozone chemistry. Heterogeneous chemical reactions on the surface of sulphuric acid stratospheric particles (SSA-SAD) are the main link between ozone chemistry and supersonic Aircraft Emissions of sulphur precursors (SO2) and particles (H2O-H2SO4). Photochemical O3 changes are compared from four independent 3-D atmosphere-chemistry models (ACMs), using as input the perturbation of SSA-SAD calculated in the University of L'Aquila model, which includes on-line a microphysics code for aerosol formation and growth. The ACMs in this study use Aircraft Emission scenarios for the year 2050 developed by AIRBUS as a part of the EU project SCENIC, assessing options for fleet size, engine technology (NOx Emission index), Mach number, range and cruising altitude. From our baseline modelling simulation, the impact of supersonic Aircraft on sulphuric acid aerosol and BC mass burdens is 53 and 1.5 µg/m2, respectively, with a direct RF of -11.4 and 4.6 mW/m2 (net RF=-6.8 mW/m2). This paper discusses the similarities and differences amongst the participating models in terms of O3 precursors changes due to Aircraft Emissions (NOx, HOx,Clx,Brx) and stratospheric ozone sensitivity to them. In the baseline case, the calculated global ozone change is -0.4±0.3 DU, with a net radiative forcing (IR+UV) of -2.5±2 mW/m2. The fraction of this O3-RF attributable to SSA-SAD changes is, however, highly variable among the models, depending on the NOx removal efficiency from the Aircraft Emission regions by large scale transport.

  • Aircraft pollution – a futuristic view
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet are investigated using the Oslo CTM2, with Emissions provided through the EU project SCENIC. The Aircraft Emission scenarios consist of Emissions from subsonic and supersonic Aircraft. In particular it is shown that aerosol Emissions from such an Aircraft fleet can have a relatively large impact on ozone, and possibly reduce the total atmospheric NOx by more than what is emitted by Aircraft. Without aerosol Emissions this Aircraft fleet leads to similar NOx increases for subsonic (at 11–12 km) and supersonic (at 18–20 km) Emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. Tropospheric ozone increases are about 10 ppbv in the Northern Hemisphere due to Emissions from subsonic Aircraft. Increased ozone loss from supersonic Aircraft at higher altitudes leads to ozone reductions of about 39 ppbv in the Northern Hemisphere and 22 ppbv in the Southern Hemisphere. The latter reduction is a result of transport of ozone depleted air from northern latitudes. When including Aircraft aerosol Emissions, NOx is reduced due to heterogeneous chemistry. The reduced NOx seems to counterweight the reduction of ozone from Emissions of NOx and H2O above 20 km. At these altitudes the NOx (and thus ozone loss) reduction is large enough to give an Aircraft Emissions induced increase in ozone. In the height range 11–20 km altitude, however, ozone production is reduced. Heterogeneous reactions and reduced NOx enhances ClO, further enhancing ozone loss in the lower stratosphere. This results in a 14 ppbv additional reduction of ozone. Although supersonic Aircraft have opposite effects on ozone in the upper and lower stratosphere, the change in ozone columns is clearly dominated by the upper stratospheric loss, thus supersonic Aircraft aerosol Emissions lead to enhanced ozone columns. The largest increase in the ozone column due to aerosol Emissions is therefore seen in the Northern Hemispheric autumn and winter, giving a column increase of 4.5 DU. It is further found that at high northern latitudes during spring the heterogeneous chemistry on PSCs is particularly efficient, thereby increasing the ozone loss.

  • Aircraft pollution: a futuristic view
    Atmospheric Chemistry and Physics Discussions, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet, provided in the EU project SCENIC, are investigated using the Oslo CTM2, a 3-D chemical transport model including comprehensive chemistry for the stratosphere and the troposphere. The Aircraft Emission scenarios comprise Emissions from subsonic and supersonic Aircraft. The increases in NOy due to Emissions from the mixed fleet are comparable for subsonic (at 11–12 km) and supersonic (at 18–20 km) Aircraft, with annual zonal means of 1.35 ppbv and 0.83 ppbv, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. The Aircraft Emissions increase tropospheric ozone by about 10 ppbv in the Northern Hemisphere due to increased ozone production, mainly because of subsonic Aircraft. Supersonic Aircraft contribute to a reduction of stratospheric ozone due to increased ozone loss at higher altitudes. In the Northern Hemisphere the reduction is about 39 ppbv, but also in the Southern Hemisphere a 22 ppbv stratospheric decrease is modeled due to transport of supersonic Aircraft Emissions and ozone depleted air. The total ozone column is increased in lower and Northern mid-latitudes, otherwise the increase of ozone loss contributes to a decrease of the total ozone column. Two exceptions are the Northern Hemispheric spring, where the ozone loss increase is small due to transport processes, and tropical latitudes during summer where the effect of subsonic Aircraft is low due to a high tropopause. Aerosol particles emitted by Aircraft reduce both Aircraft and background NOx, more than counterweighting the effect of NOx and H2O Aircraft Emissions in the stratosphere. Above about 20 km altitude, the NOx (and thus ozone loss) reduction is large enough to give an increase in ozone due to Aircraft Emissions. This effect is comparable in the Northern and Southern Hemisphere. At 11–20 km altitude, however, ozone production is reduced due to less NOx. Also ClONO2 is increased at this altitude due to enhanced heterogeneous reactions (lowered HCl), and ClO is increased due to less NOx, further enhancing ozone loss in this region. This results in a 14 ppbv further reduction of ozone. Mainly, this results in an increase of the total ozone column due to a decrease in ozone loss caused by the NOx cycle (at the highest altitudes). At the lowermost latitudes, the reduced loss due to the NOx cycle is small. However, ozone production at lower altitudes is reduced and the loss due to ClO is increased, giving a decrease in the total ozone column. Also, at high latitudes during spring the heterogeneous chemistry is more efficient on PSCs, increasing the ozone loss.

M. Gauss - One of the best experts on this subject based on the ideXlab platform.

  • Aircraft pollution – a futuristic view
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet are investigated using the Oslo CTM2, with Emissions provided through the EU project SCENIC. The Aircraft Emission scenarios consist of Emissions from subsonic and supersonic Aircraft. In particular it is shown that aerosol Emissions from such an Aircraft fleet can have a relatively large impact on ozone, and possibly reduce the total atmospheric NOx by more than what is emitted by Aircraft. Without aerosol Emissions this Aircraft fleet leads to similar NOx increases for subsonic (at 11–12 km) and supersonic (at 18–20 km) Emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. Tropospheric ozone increases are about 10 ppbv in the Northern Hemisphere due to Emissions from subsonic Aircraft. Increased ozone loss from supersonic Aircraft at higher altitudes leads to ozone reductions of about 39 ppbv in the Northern Hemisphere and 22 ppbv in the Southern Hemisphere. The latter reduction is a result of transport of ozone depleted air from northern latitudes. When including Aircraft aerosol Emissions, NOx is reduced due to heterogeneous chemistry. The reduced NOx seems to counterweight the reduction of ozone from Emissions of NOx and H2O above 20 km. At these altitudes the NOx (and thus ozone loss) reduction is large enough to give an Aircraft Emissions induced increase in ozone. In the height range 11–20 km altitude, however, ozone production is reduced. Heterogeneous reactions and reduced NOx enhances ClO, further enhancing ozone loss in the lower stratosphere. This results in a 14 ppbv additional reduction of ozone. Although supersonic Aircraft have opposite effects on ozone in the upper and lower stratosphere, the change in ozone columns is clearly dominated by the upper stratospheric loss, thus supersonic Aircraft aerosol Emissions lead to enhanced ozone columns. The largest increase in the ozone column due to aerosol Emissions is therefore seen in the Northern Hemispheric autumn and winter, giving a column increase of 4.5 DU. It is further found that at high northern latitudes during spring the heterogeneous chemistry on PSCs is particularly efficient, thereby increasing the ozone loss.

  • Aircraft pollution: a futuristic view
    Atmospheric Chemistry and Physics Discussions, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet, provided in the EU project SCENIC, are investigated using the Oslo CTM2, a 3-D chemical transport model including comprehensive chemistry for the stratosphere and the troposphere. The Aircraft Emission scenarios comprise Emissions from subsonic and supersonic Aircraft. The increases in NOy due to Emissions from the mixed fleet are comparable for subsonic (at 11–12 km) and supersonic (at 18–20 km) Aircraft, with annual zonal means of 1.35 ppbv and 0.83 ppbv, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. The Aircraft Emissions increase tropospheric ozone by about 10 ppbv in the Northern Hemisphere due to increased ozone production, mainly because of subsonic Aircraft. Supersonic Aircraft contribute to a reduction of stratospheric ozone due to increased ozone loss at higher altitudes. In the Northern Hemisphere the reduction is about 39 ppbv, but also in the Southern Hemisphere a 22 ppbv stratospheric decrease is modeled due to transport of supersonic Aircraft Emissions and ozone depleted air. The total ozone column is increased in lower and Northern mid-latitudes, otherwise the increase of ozone loss contributes to a decrease of the total ozone column. Two exceptions are the Northern Hemispheric spring, where the ozone loss increase is small due to transport processes, and tropical latitudes during summer where the effect of subsonic Aircraft is low due to a high tropopause. Aerosol particles emitted by Aircraft reduce both Aircraft and background NOx, more than counterweighting the effect of NOx and H2O Aircraft Emissions in the stratosphere. Above about 20 km altitude, the NOx (and thus ozone loss) reduction is large enough to give an increase in ozone due to Aircraft Emissions. This effect is comparable in the Northern and Southern Hemisphere. At 11–20 km altitude, however, ozone production is reduced due to less NOx. Also ClONO2 is increased at this altitude due to enhanced heterogeneous reactions (lowered HCl), and ClO is increased due to less NOx, further enhancing ozone loss in this region. This results in a 14 ppbv further reduction of ozone. Mainly, this results in an increase of the total ozone column due to a decrease in ozone loss caused by the NOx cycle (at the highest altitudes). At the lowermost latitudes, the reduced loss due to the NOx cycle is small. However, ozone production at lower altitudes is reduced and the loss due to ClO is increased, giving a decrease in the total ozone column. Also, at high latitudes during spring the heterogeneous chemistry is more efficient on PSCs, increasing the ozone loss.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics, 2006
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen and ozone. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated, taking into account effects of flight route changes on fuel consumption and Emissions. In a reference case including both civil and military Aircraft the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. Enhanced use of polar routes implies substantially larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increases in the lower stratosphere and upper troposphere, and to larger ozone increases at altitudes below. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the contribution from higher altitudes dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics Discussions, 2005
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen, ozone, and the chemical lifetime of methane. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated. In the reference case the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. The lifetime of methane is calculated to decrease by 0.71%, inducing a radiative forcing of ?6.4 mW/m2. Enhanced use of polar routes implies significantly larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increase in the lower stratosphere and upper troposphere, and to larger ozone increase at lower altitudes. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the stratospheric decrease dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.

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  • Aircraft pollution – a futuristic view
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet are investigated using the Oslo CTM2, with Emissions provided through the EU project SCENIC. The Aircraft Emission scenarios consist of Emissions from subsonic and supersonic Aircraft. In particular it is shown that aerosol Emissions from such an Aircraft fleet can have a relatively large impact on ozone, and possibly reduce the total atmospheric NOx by more than what is emitted by Aircraft. Without aerosol Emissions this Aircraft fleet leads to similar NOx increases for subsonic (at 11–12 km) and supersonic (at 18–20 km) Emissions, 1.35 ppbv and 0.83 ppbv as annual zonal means, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. Tropospheric ozone increases are about 10 ppbv in the Northern Hemisphere due to Emissions from subsonic Aircraft. Increased ozone loss from supersonic Aircraft at higher altitudes leads to ozone reductions of about 39 ppbv in the Northern Hemisphere and 22 ppbv in the Southern Hemisphere. The latter reduction is a result of transport of ozone depleted air from northern latitudes. When including Aircraft aerosol Emissions, NOx is reduced due to heterogeneous chemistry. The reduced NOx seems to counterweight the reduction of ozone from Emissions of NOx and H2O above 20 km. At these altitudes the NOx (and thus ozone loss) reduction is large enough to give an Aircraft Emissions induced increase in ozone. In the height range 11–20 km altitude, however, ozone production is reduced. Heterogeneous reactions and reduced NOx enhances ClO, further enhancing ozone loss in the lower stratosphere. This results in a 14 ppbv additional reduction of ozone. Although supersonic Aircraft have opposite effects on ozone in the upper and lower stratosphere, the change in ozone columns is clearly dominated by the upper stratospheric loss, thus supersonic Aircraft aerosol Emissions lead to enhanced ozone columns. The largest increase in the ozone column due to aerosol Emissions is therefore seen in the Northern Hemispheric autumn and winter, giving a column increase of 4.5 DU. It is further found that at high northern latitudes during spring the heterogeneous chemistry on PSCs is particularly efficient, thereby increasing the ozone loss.

  • Aircraft pollution: a futuristic view
    Atmospheric Chemistry and Physics Discussions, 2007
    Co-Authors: O A Sovde, G. Pitari, M. Gauss, I.s.a. Isaksen, C. Marizy
    Abstract:

    Impacts of NOx, H2O and aerosol Emissions from a projected 2050 Aircraft fleet, provided in the EU project SCENIC, are investigated using the Oslo CTM2, a 3-D chemical transport model including comprehensive chemistry for the stratosphere and the troposphere. The Aircraft Emission scenarios comprise Emissions from subsonic and supersonic Aircraft. The increases in NOy due to Emissions from the mixed fleet are comparable for subsonic (at 11–12 km) and supersonic (at 18–20 km) Aircraft, with annual zonal means of 1.35 ppbv and 0.83 ppbv, respectively. H2O increases are also comparable at these altitudes: 630 and 599 ppbv, respectively. The Aircraft Emissions increase tropospheric ozone by about 10 ppbv in the Northern Hemisphere due to increased ozone production, mainly because of subsonic Aircraft. Supersonic Aircraft contribute to a reduction of stratospheric ozone due to increased ozone loss at higher altitudes. In the Northern Hemisphere the reduction is about 39 ppbv, but also in the Southern Hemisphere a 22 ppbv stratospheric decrease is modeled due to transport of supersonic Aircraft Emissions and ozone depleted air. The total ozone column is increased in lower and Northern mid-latitudes, otherwise the increase of ozone loss contributes to a decrease of the total ozone column. Two exceptions are the Northern Hemispheric spring, where the ozone loss increase is small due to transport processes, and tropical latitudes during summer where the effect of subsonic Aircraft is low due to a high tropopause. Aerosol particles emitted by Aircraft reduce both Aircraft and background NOx, more than counterweighting the effect of NOx and H2O Aircraft Emissions in the stratosphere. Above about 20 km altitude, the NOx (and thus ozone loss) reduction is large enough to give an increase in ozone due to Aircraft Emissions. This effect is comparable in the Northern and Southern Hemisphere. At 11–20 km altitude, however, ozone production is reduced due to less NOx. Also ClONO2 is increased at this altitude due to enhanced heterogeneous reactions (lowered HCl), and ClO is increased due to less NOx, further enhancing ozone loss in this region. This results in a 14 ppbv further reduction of ozone. Mainly, this results in an increase of the total ozone column due to a decrease in ozone loss caused by the NOx cycle (at the highest altitudes). At the lowermost latitudes, the reduced loss due to the NOx cycle is small. However, ozone production at lower altitudes is reduced and the loss due to ClO is increased, giving a decrease in the total ozone column. Also, at high latitudes during spring the heterogeneous chemistry is more efficient on PSCs, increasing the ozone loss.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics, 2006
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen and ozone. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated, taking into account effects of flight route changes on fuel consumption and Emissions. In a reference case including both civil and military Aircraft the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. Enhanced use of polar routes implies substantially larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increases in the lower stratosphere and upper troposphere, and to larger ozone increases at altitudes below. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the contribution from higher altitudes dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.

  • Impact of Aircraft NOx Emissions on the atmosphere ? tradeoffs to reduce the impact
    Atmospheric Chemistry and Physics Discussions, 2005
    Co-Authors: M. Gauss, I.s.a. Isaksen, D. S. Lee, O A Sovde
    Abstract:

    Within the EU-project TRADEOFF, the impact of NOx (=NO+NO2) Emissions from subsonic aviation upon the chemical composition of the atmosphere has been calculated with focus on changes in reactive nitrogen, ozone, and the chemical lifetime of methane. We apply a 3-D chemical transport model that includes comprehensive chemistry for both the troposphere and the stratosphere and uses various Aircraft Emission scenarios developed during TRADEOFF for the year 2000. The environmental effects of enhanced air traffic along polar routes and of possible changes in cruising altitude are investigated. In the reference case the model predicts Aircraft-induced maximum increases of zonal-mean NOy (=total reactive nitrogen) between 156 pptv (August) and 322 pptv (May) in the tropopause region of the Northern Hemisphere. Resulting maximum increases in zonal-mean ozone vary between 3.1 ppbv in September and 7.7 ppbv in June. The lifetime of methane is calculated to decrease by 0.71%, inducing a radiative forcing of ?6.4 mW/m2. Enhanced use of polar routes implies significantly larger zonal-mean ozone increases in high Northern latitudes during summer, while the effect is negligible in winter. Lowering the flight altitude leads to smaller ozone increase in the lower stratosphere and upper troposphere, and to larger ozone increase at lower altitudes. Regarding total ozone change, the degree of cancellation between these two effects depends on latitude and season, but annually and globally averaged the stratospheric decrease dominates, mainly due to washout of NOy in the troposphere, which weakens the tropospheric increase. Raising flight altitudes increases the ozone burden both in the troposphere and the lower stratosphere, primarily due to a more efficient accumulation of pollutants in the stratosphere.