Tradeoff Between Contrail Reduction and Emissions in United States National Airspace

Abstract

This paper describes a class of strategies for reducing persistent contrail formation with the capability of trading o between contrails and aircraft induced emissions. The concept of contrail frequency index is dened and used to quantify the contrail activities. The contrail reduction strategies reduce the contrail frequency index by altering aircraft’s cruising altitude with consideration to extra emissions. The strategies use a user-dened factor to trade o between contrail reduction and extra emissions. The analysis shows that contrails can be reduced with extra emissions and without adding congestion to airspace. For a day with high contrail activities, the results show that the maximal contrail reduction strategy can achieve a contrail reduction of 88%. When a trade-o factor is used, the strategy can achieve less contrail reduction while emitting less emissions compared to the maximal contrail reduction strategy. The user-dened trade-o factor provides a exible way to trade o between contrail reduction and extra emissions. Better understanding of the trade-os between contrails and emissions and their impact on the climate need to be developed to fully utilize this class of contrail reduction strategies. The strategies provide a starting point for developing operational policies to reduce the impact of aviation on climate.