Beyond Contrail Avoidance: Efficacy of Flight Altitude Changes to Minimise Contrail Climate Forcing
Abstract
:1. Introduction
2. Data and Methodology
2.1. Aircraft Activity and Emissions
2.2. Contrail Simulation and Uncertainty
2.3. Climate Forcing of Contrails and CO2
2.4. Contrail Mitigation
2.5. Loss of Separation
3. Results and Discussion
3.1. Efficacy of Flight Altitude Changes
3.1.1. Contrail Avoidance
3.1.2. Minimum Contrail RF’
3.1.3. Minimum EFcontrail
3.1.4. Minimum EFcontrail with No Fuel Penalty
3.1.5. Minimum EFtotal
3.2. Loss of Separation
4. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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Initial Contrail Length (109 m) | Mean Contrail Segment Age (h) | Mean Contrail RF’ (W m−2) | EFcontrail (1018 J) | Total Fuel Consumption, TFC a (108 kg) | a,b (1018 J) | EFtotal b (1018 J; Contrails + CO2) | ||
Baseline Scenario | 6.933 [6.813, 7.312] | 4.373 [4.126, 4.629] | 1.420 [0.940, 2.200] | 5.753 [4.119, 8.449] | 2.90716 [2.90710, 2.90721] | 3.4277 [1.7187, 5.0480] | 9.037 [6.468, 12.280] | |
% of Flights Diverted | Percentage Difference Relative to the Baseline Scenario | |||||||
Initial Contrail Length | Mean Contrail Segment Age | Mean Contrail RF’ | EFcontrail | Total Fuel Consumption, TFC | b | EFtotal b | ||
Min. Contrail Length | 12.9% [12.8, 13.2%] | −66.6% [−67.0, −65.8%] | −3.61% [−5.54, −0.59%] | −29.2% [−63.2, −12.4%] | −70.8% [−75.3, −66.0%] | +0.57% [+0.55, +0.59%] | +0.24% [+0.23, +0.24%] | −45.0% [−55.9, −38.6%] |
Min. Contrail RF’ | 15.0% [14.7, 15.3%] | −17.3% [−20.3, −13.5%] | −9.05% [−10.6, −7.21%] | −186% [−282, −122%] | −74.6% [−89.6, −65.4%] | +0.69% [+0.66, +0.72%] | +0.28% [+0.27, +0.30%] | −47.2% [−59.0, −40.5%] |
Min. EFcontrail | 15.3% [15.0, 15.7%] | −23.1% [−27.6, −17.4%] | −13.9% [−16.4, −11.4%] | −185% [−279, −121%] | −105% [−125, −91.8%] | +0.70% [+0.66, 0.73%] | +0.29% [+0.27, +0.30%] | −66.7% [−83.7, −57.2%] |
Min. EFcontrail (No Fuel Penalty) | 7.63% [7.47, 7.81%] | −8.64% [−10.7, −6.66%] | −4.90% [−6.06, −4.20%] | −75.7% [−119, −46.1%] | −52.1% [−60.8, −42.5%] | −0.86% [−0.88, −0.84%] | −0.36% [+0.27, +0.30%] | −32.4% [−41.7, −27.4%] |
Min. EFtotal (CO2 + Contrail) | 20.1% [19.9, 20.3%] | −23.2% [−27.7, −17.4%] | −13.7% [−16.3, −11.3%] | −183% [−275, −120%] | −105% [−125, −91.8%] | −0.40% [−0.47, −0.31%] | −0.17% [−0.20, −0.13%] | −66.8% [−83.9, −57.4%] |
Strategy | Total (and %) of Flights Diverted | Total No. of Aircraft Pairs in Conflict | Total No. of Flights in Conflict | Ratio of Flights in Conflict to the Total No. of Flights Diverted (%) |
---|---|---|---|---|
Small-scale diversions [28] | 2196 (1.47%) | 169 | 304 | 13.8% |
Min EFcontrail | 22696 (15.2%) | 1181 | 2056 | 9.06% |
Min EFcontrail (no fuel penalty) | 11386 (7.63%) | 678 | 1222 | 10.7% |
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Teoh, R.; Schumann, U.; Stettler, M.E.J. Beyond Contrail Avoidance: Efficacy of Flight Altitude Changes to Minimise Contrail Climate Forcing. Aerospace 2020, 7, 121. https://doi.org/10.3390/aerospace7090121
Teoh R, Schumann U, Stettler MEJ. Beyond Contrail Avoidance: Efficacy of Flight Altitude Changes to Minimise Contrail Climate Forcing. Aerospace. 2020; 7(9):121. https://doi.org/10.3390/aerospace7090121
Chicago/Turabian StyleTeoh, Roger, Ulrich Schumann, and Marc E. J. Stettler. 2020. "Beyond Contrail Avoidance: Efficacy of Flight Altitude Changes to Minimise Contrail Climate Forcing" Aerospace 7, no. 9: 121. https://doi.org/10.3390/aerospace7090121