Estimating the Climate Effect of Contrails in Mid-Latitudes Using a Lagrangian Framework in the EMAC Model

Optimizing flight trajectories to reduce the climate effect of non-CO₂ aviation emissions - particularly by avoiding contrails and contrail cirrus - represents a promising strategy for mitigating aviation's environmental footprint. This approach depends on detailed knowledge of how localized aviation emissions affect the climate. Previous research has examined the influence of different meteorological conditions on aviation emissions and identified regions particularly sensitive to these effects. Tools like 4-dimensional climate change functions (CCFs) have been developed to assist sustainable air traffic management (ATM) in designing flight trajectories that minimize climate effects. However, these tools have so far been limited to specific regions, seasons, or weather scenarios [1,2].

In this study, we expand the geographic scope of the CCFs by conducting Lagrangian simulations across different extratropical regions of the northern hemisphere. Using the modular ECHAM5/MESSy atmospheric chemistry model (EMAC), we analyze contrail evolution along Lagrangian trajectories, offering insights into the temporal dynamics of contrail formation parameters and their radiative forcing effects. This approach allows for a detailed examination of the physical processes driving contrail-climate interactions, as well as their spatial and temporal variability.

A key advancement over previous CCFs studies is the application of an improved interpolation method, which transforms meteorological parameters from grid boxes onto Lagrangian trajectories with higher precision. Preliminary results indicate that this method enhances the accuracy of contrail property estimates, revealing regional differences in contrail persistence and radiative forcing that were previously unresolved. Our findings highlight the importance of refining modeling techniques to better assess contrail effects on climate at regional and global scales.

This study was funded by the European SESAR programme under Grant Agreement No. 101114785 (CONCERTO) and the German LuFo Project Dkult (Grant Agreement No. 20M2111A). High-performance supercomputing resources were provided by the German CARA Cluster in Dresden and the DKRZ Cluster in Hamburg.

References:  

[1] Matthes, S., Lührs, B., Dahlmann, K., Grewe, V., Linke, F., Yin, F., Klingaman, E. and Shine, K. P.: Climate-Optimized Trajectories and Robust Mitigation Potential: Flying ATM4E, Aerospace 7(11), 156, 2020.

[2]  Frömming, C., Grewe, V., Brinkop, S., Jöckel, P., Haslerud, A. S., Rosanka, S., van Manen, J., and Matthes, S.: Influence of weather situation on non-CO₂ aviation climate effects: the REACT4C climate change functions, Atmos. Chem. Phys., 21, 9151–9172, https://doi.org/10.5194/acp-21-9151-2021, 2021.