The contribution of aviation NOx emissions to climate change: are we ignoring methodological flaws?

Grewe, Volker; Matthes, Sigrun; Dahlmann, Katrin

doi:10.1088/1748-9326/ab5dd7

Cited by 39 publications

(45 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The average temperature response provides a mean change of surface temperature over a selected time horizon. Recent studies have proposed novel concepts to overcome challenges for adequate representation of short-term effects [17,18], which can be integrated in the concept developed, as can significant updates to the calculation of the climate impact of non-CO 2 emissions [19,20].…”

Section: Performance and Robustness Assessment Of Climate-optimized Tmentioning

confidence: 99%

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

et al. 2020

Self Cite

View full text Add to dashboard Cite

Aviation can reduce its climate impact by controlling its CO2-emission and non-CO2 effects, e.g., aviation-induced contrail-cirrus and ozone caused by nitrogen oxide emissions. One option is the implementation of operational measures that aim to avoid those atmospheric regions that are in particular sensitive to non-CO2 aviation effects, e.g., where persistent contrails form. The quantitative estimates of mitigation potentials of such climate-optimized aircraft trajectories are required, when working towards sustainable aviation. The results are presented from a comprehensive modelling approach when aiming to identify such climate-optimized aircraft trajectories. The overall concept relies on a multi-dimensional environmental change function concept, which is capable of providing climate impact information to air traffic management (ATM). Estimates on overall climate impact reduction from a one-day case study are presented that rely on the best estimate for climate impact information. Specific weather situation that day, containing regions with high contrail impact, results in a potential reduction of total climate impact, by more than 40%, when considering CO2 and non-CO2 effects, associated with an increase of fuel by about 0.5%. The climate impact reduction per individual alternative trajectory shows a strong variation and, hence, also the mitigation potential for an analyzed city pair, depending on atmospheric characteristics along the flight corridor as well as flight altitude. The robustness of proposed climate-optimized trajectories is assessed by using a range of different climate metrics. A more sustainable ATM needs to integrate comprehensive environmental impacts and associated forecast uncertainties into route optimization in order to identify robust eco-efficient trajectories.

show abstract

Section: Performance and Robustness Assessment Of Climate-optimized Tmentioning

confidence: 99%

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…during model runtime) following the parameterization of Yienger and Levy (1995). The same applies for emissions of biogenic VOCs (volatile organic compounds), which are calculated following Guenther et al (1995), and emissions for lightning NO x for which the parameterization of Price and Rind (1994) is applied.…”

Section: Description Of the Model Systemmentioning

confidence: 99%

Attributing ozone and its precursors to land transport emissions in Europe and Germany

et al. 2020

Self Cite

View full text Add to dashboard Cite

Abstract. Land transport is an important emission source of nitrogen oxides, carbon monoxide, and volatile organic compounds. The emissions of nitrogen oxides affect air quality directly. Further, all of these emissions serve as a precursor for the formation of tropospheric ozone, thus leading to an indirect influence on air quality. In addition, ozone is radiatively active and its increase leads to a positive radiative forcing. Due to the strong non-linearity of the ozone chemistry, the contribution of emission sources to ozone cannot be calculated or measured directly. Instead, atmospheric chemistry models equipped with specific source attribution methods (e.g. tagging methods) are required. In this study we investigate the contribution of land transport emissions to ozone and ozone precursors using the MECO(n) model system (MESSy-fied ECHAM and COSMO models nested n times). This model system couples a global and a regional chemistry climate model and is equipped with a tagging diagnostic. We investigate the combined effect of long-range-transported ozone and ozone which is produced by European emissions by applying the tagging diagnostic simultaneously and consistently on the global and regional scale. We performed two simulations each covering 3 years with different anthropogenic emission inventories for Europe. We applied two regional refinements, i.e. one refinement covering Europe (50 km resolution) and one covering Germany (12 km resolution). The diagnosed absolute contributions of land transport emissions to reactive nitrogen (NOy) near ground level are in the range of 5 to 10 nmol mol−1. This corresponds to relative contributions of 50 % to 70 %. The largest absolute contributions appear around Paris, southern England, Moscow, the Po Valley, and western Germany. The absolute contributions to carbon monoxide range from 30 nmol mol−1 to more than 75 nmol mol−1 near emission hot-spots such as Paris or Moscow. The ozone which is attributed to land transport emissions shows a strong seasonal cycle with absolute contributions of 3 nmol mol−1 during winter and 5 to 10 nmol mol−1 during summer. This corresponds to relative contributions of 8 % to 10 % during winter and up to 16 % during summer. The largest values during summer are confined to the Po Valley, while the contributions in western Europe range from 12 % to 14 %. Only during summer are the ozone contributions slightly influenced by the anthropogenic emission inventory, but these differences are smaller than the range of the seasonal cycle of the contribution to land transport emissions. This cycle is caused by a complex interplay of seasonal cycles of other emissions (e.g. biogenic) and seasonal variations of the ozone regimes. In addition, our results suggest that during events with large ozone values the ozone contributions of land transport and biogenic emissions increase strongly. Here, the contribution of land transport emissions peaks up to 28 %. Hence, our model results suggest that land transport emissions are an important contributor during periods with large ozone values.

show abstract

“…For the present study, only steps 1-3 are important and will be further elaborated. Irvine et al (2013) identified that by simulating frequently occurring weather situations within a season, the global seasonal impact can be estimated. They analysed meteorological reanalysis data for 21 years for summer and winter.…”

Section: React4cmentioning

confidence: 99%

“…Due to the lower variability of the jet stream in summer, only three distinct weather situations were determined. The summer patterns occur 19 (SP1), 55 (SP2), and 18 (SP3) times per season and the winter patterns occur 17 (WP1 and WP2), 15 (WP3 and WP4), and 26 (WP5) times per season in the reanalysis data (Irvine et al, 2013). Analogously, REACT4C simulated 8 distinct model days, each representing one of these weather patterns.…”

Section: React4cmentioning

confidence: 99%

The impact of weather patterns and related transport processes on aviation's contribution to ozone and methane concentrations from NOx emissions

2020

Self Cite

View full text Add to dashboard Cite

Abstract. Aviation-attributed climate impact depends on a combination of composition changes in trace gases due to emissions of carbon dioxide (CO2) and non-CO2 species. Nitrogen oxides (NOx = NO + NO2) emissions induce an increase in ozone (O3) and a depletion of methane (CH4), leading to a climate warming and a cooling, respectively. In contrast to CO2, non-CO2 contributions to the atmospheric composition are short lived and are thus characterised by a high spatial and temporal variability. In this study, we investigate the influence of weather patterns and their related transport processes on composition changes caused by aviation-attributed NOx emissions. This is achieved by using the atmospheric chemistry model EMAC (ECHAM/MESSy). Representative weather situations were simulated in which unit NOx emissions are initialised in specific air parcels at typical flight altitudes over the North Atlantic flight sector. By explicitly calculating contributions to the O3 and CH4 concentrations induced by these emissions, interactions between trace gas composition changes and weather conditions along the trajectory of each air parcel are investigated. Previous studies showed a clear correlation between the prevailing weather situation at the time when the NOx emission occurs and the climate impact of the NOx emission. Here, we show that the aviation NOx contribution to ozone is characterised by the time and magnitude of its maximum and demonstrate that a high O3 maximum is only possible if the maximum occurs early after the emission. Early maxima occur only if the air parcel, in which the NOx emission occurred, is transported to lower altitudes, where the chemical activity is high. This downward transport is caused by subsidence in high-pressure systems. A high ozone magnitude only occurs if the air parcel is transported downward into a region in which the ozone production is efficient. This efficiency is limited by atmospheric NOx and HOx concentrations during summer and winter, respectively. We show that a large CH4 depletion is only possible if a strong formation of O3 occurs due to the NOx emission and if high atmospheric H2O concentrations are present along the air parcel's trajectory. Only air parcels, which are transported into tropical areas due to high-pressure systems, experience high concentrations of H2O and thus a large CH4 depletion. Avoiding climate-sensitive areas by rerouting aircraft flight tracks is currently computationally not feasible due to the long chemical simulations needed. The findings of this study form a basis of a better understanding of NOx climate-sensitive areas and through this will allow us to propose an alternative approach to estimate aviation's climate impact on a day-to-day basis, based on computationally cheaper meteorological simulations without computationally expensive chemistry. This comprises a step towards a climate impact assessment of individual flights, here with the contribution of aviation NOx emissions to climate change, ultimately enabling routings with a lower climate impact by avoiding climate-sensitive regions.

show abstract

The contribution of aviation NO_x emissions to climate change: are we ignoring methodological flaws?

Cited by 39 publications

References 35 publications

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

Attributing ozone and its precursors to land transport emissions in Europe and Germany

The impact of weather patterns and related transport processes on aviation's contribution to ozone and methane concentrations from NO<sub><i>x</i></sub> emissions

Contact Info

Product

Resources

About

The contribution of aviation NOx emissions to climate change: are we ignoring methodological flaws?

Cited by 39 publications

References 35 publications

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E

Attributing ozone and its precursors to land transport emissions in Europe and Germany

The impact of weather patterns and related transport processes on aviation's contribution to ozone and methane concentrations from NO&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt; emissions

Contact Info

Product

Resources

About

The contribution of aviation NO_x emissions to climate change: are we ignoring methodological flaws?

The impact of weather patterns and related transport processes on aviation's contribution to ozone and methane concentrations from NO<sub><i>x</i></sub> emissions