Minimizing contrail formation by rerouting around dynamic ice-supersaturated regions

Abstract

Today, the European airspace is already faced with airspace capacity constraints, especially during business driven peak periods of the day in central European air traffic control sectors. This capacity bottleneck will cause a challenging number of severe difficulties in future flight planning and airport ground handling. Additionally, the growing public awareness and the increasing scientific knowledge of the aviation environmental impact urges air traffic stakeholders to reduce the aviation induced global warming to an acceptable level. These efforts should include both the prevention of unnecessary fuel burn due to detours and the avoidance of passing ice-supersaturated regions during cruise to prevent contrail formation. Therewith, conflicting goals have to be considered in trajectory optimization. The induced contrails influence the radiation budget of the Earth atmosphere, which depend on the dynamic size and location of the ice-supersaturated regions. However, contrail avoidance can lead to unsolvable high requirements on airspace capacity in dry and warm air spaces, where contrails are not induced. Furthermore, contrail avoidance procedures can lead to large detours, which in turn cause more fuel burn and an increased impact on the environment due to the emission of additional radiative active substances. In this paper, the Air Traffic Control Fast Time Simulator and Air Traffic Optimizer AirTOp is used to simulate one day of Europeans air traffic and to reduce the radiative forcing of contrails by minimizing the number of flight hours through dynamic ice-supersaturated regions. Rerouting the affected flights does this, so that separation requirements are still fulfilled and each aircraft still reaches its destination. In this paper the following measures are assessed without and with contrail involved rerouting: the decrease of airspace capacity, the additional distance flown, the additional fuel burn and the contrail induced environmental impact. We found, that rerouting on this special day would have caused higher additional fuel and time costs, than saved reduced contrail costs.