Environmental Compatible Flight Route Optimization

Background

Contrails and contrail cirrus are anthropogenic clouds. In the same way as natural clouds they have an impact on the earth radiation budget. If the ambient air is cold and moist enough, contrails are triggered by high flying aircrafts. According to the actual state of knowledge they account for 2 - 3% of the total anthropogenic warming. A contrail might be warming or cooling the earth-atmosphere system depending on the position of the sun, the surface properties and the state of the atmosphere. Only in limited areas temperature and water vapour content are favourable for the formation of contrails. Their life-time and spreading into cirrus decks are controlled by the atmospheric dynamics. Mainly at night, but also over bright surfaces or low clouds, contrails are warming. The basic idea of this project is to use weather forecast data in order to identify those regions which could lead to strongly warming contrails. This information will be included into the already existing routines for flight route optimisation to avoid those areas and flight levels if feasible. Within this project the feasibility and practicability of such an optimisation will be studied taking special care of the safety aspects and the cost effectiveness.

Kondensstreifen

Contrails and contrail cirrus over Southern Sweden (ENVISAT-AATSR)

Work packages

Modeling of the radiative forcing contrails and contrail cirrus based on trajectories derived from weather forecast data
Adaptation of existing weather forecast models to the special requirements for contrail formation and cirrus physics in the upper troposphere
Validation of the model and the contrail forecasts
Determination and calculation of a time and space dependent value, which describes the climate impact of potential contrails
Introduction of this value into the already existing flight optimisation routines
Feasibility studies, practicability under safety aspects, economic and climate impact
Concepts for air-borne measurements of humidity and contrail formation
Accompanying measures: public relations, promotion of this solution in an international framework