Articles | Volume 18, issue 1
https://doi.org/10.5194/amt-18-37-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-18-37-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Jan 2025
Research article |
| 07 Jan 2025
| 07 Jan 2025
Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations
Jade Low
Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
Roger Teoh
Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
Joel Ponsonby
Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
Edward Gryspeerdt
Grantham Institute for Climate Change and the Environment, Imperial College London, London, SW7 2AZ, UK
Marc Shapiro
Breakthrough Energy, 4110 Carillon Point, Kirkland, WA 98033, USA
Marc E. J. Stettler
CORRESPONDING AUTHOR
Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK
Related authors
No articles found.
Anna Tippett, Paul R. Field, and Edward Gryspeerdt
EGUsphere, https://doi.org/10.5194/egusphere-2025-3877, https://doi.org/10.5194/egusphere-2025-3877, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Clouds and their interactions with tiny particles in the air (aerosols) are a large source of uncertainty in climate models. To study Marine Cloud Brightening (MCB), we use ship tracks (changes to clouds from ship pollution). Comparing real ship track data with model results, we find the model struggles under rainy conditions and overestimates effects at high pollution levels, suggesting it needs improvement for reliable MCB simulations.
Oliver G. A. Driver, Marc E. J. Stettler, and Edward Gryspeerdt
EGUsphere, https://doi.org/10.5194/egusphere-2025-2737, https://doi.org/10.5194/egusphere-2025-2737, 2025
Short summary
Short summary
Contrails are ice clouds caused by planes. In humid (ice supersaturated) regions ice crystals are stable, and clouds persist. Contrails have a warming effect, so it is important to model them. However, weather model data is unable to represent ice supersaturated regions well enough. We demonstrate that ice supersaturation modelling is structured by North Atlantic storm systems. We link the bias to underling processes being modelled, and gain insight into how the existing data could be used.
George Horner and Edward Gryspeerdt
Atmos. Chem. Phys., 25, 5617–5631, https://doi.org/10.5194/acp-25-5617-2025, https://doi.org/10.5194/acp-25-5617-2025, 2025
Short summary
Short summary
This work tracks the life cycle of thin cirrus clouds that flow out of tropical convective storms. These cirrus clouds are found to have a warming effect on the atmosphere over their whole lifetime. Thin cirrus that originate from land origin convection warm more than those of ocean origin. Moreover, if the lifetime of these cirrus clouds increase, the warming they exert over their whole lifetime also increases. These results help us understand how these clouds might change in a future climate.
Joel Ponsonby, Roger Teoh, Bernd Kärcher, and Marc Stettler
EGUsphere, https://doi.org/10.5194/egusphere-2025-1717, https://doi.org/10.5194/egusphere-2025-1717, 2025
Short summary
Short summary
Aerosol emissions from aircraft engines contribute to the formation of contrails, which have a climate impact comparable to that of aviation’s CO2 emissions. We show that emissions of volatile particulate matter – from fuel sulphur, unburned fuel, and lubrication oil – can increase the number of ice particles formed within a contrail, and therefore have an important role in the climate impacts of aviation. This has implications for emissions regulation and climate mitigation strategies.
Oliver G. A. Driver, Marc E. J. Stettler, and Edward Gryspeerdt
Atmos. Meas. Tech., 18, 1115–1134, https://doi.org/10.5194/amt-18-1115-2025, https://doi.org/10.5194/amt-18-1115-2025, 2025
Short summary
Short summary
Contrails (clouds caused by planes) play a large role in the climate warming caused by aviation. Satellites are a good tool to validate modelled impact estimates. Many contrails are either too narrow or too disperse to detect. This work shows that only around half of contrails are observable but that the most climatically important are easier to detect. It supports the use of satellites for contrail observation but highlights the need for observability considerations for specific applications.
Harri Kokkola, Juha Tonttila, Silvia M. Calderón, Sami Romakkaniemi, Antti Lipponen, Aapo Peräkorpi, Tero Mielonen, Edward Gryspeerdt, Timo Henrik Virtanen, Pekka Kolmonen, and Antti Arola
Atmos. Chem. Phys., 25, 1533–1543, https://doi.org/10.5194/acp-25-1533-2025, https://doi.org/10.5194/acp-25-1533-2025, 2025
Short summary
Short summary
Understanding how atmospheric aerosols affect clouds is a scientific challenge. One question is how aerosols affects the amount of cloud water. We used a cloud-scale model to study these effects on marine clouds. The study showed that variations in cloud properties and instrument noise can cause bias in satellite-derived cloud water content. However, our results suggest that for similar weather conditions with well-defined aerosol concentrations, satellite data can reliably track these effects.
Zebediah Engberg, Roger Teoh, Tristan Abbott, Thomas Dean, Marc E. J. Stettler, and Marc L. Shapiro
Geosci. Model Dev., 18, 253–286, https://doi.org/10.5194/gmd-18-253-2025, https://doi.org/10.5194/gmd-18-253-2025, 2025
Short summary
Short summary
Contrails forming in some atmospheric conditions may persist and become strongly warming cirrus, while in other conditions may be neutral or cooling. We develop a contrail forecast model to predict contrail climate forcing for any arbitrary point in space and time and explore integration into flight planning and air traffic management. This approach enables contrail interventions to target high-probability high-climate-impact regions and reduce unintended consequences of contrail management.
Anna Tippett, Edward Gryspeerdt, Peter Manshausen, Philip Stier, and Tristan W. P. Smith
Atmos. Chem. Phys., 24, 13269–13283, https://doi.org/10.5194/acp-24-13269-2024, https://doi.org/10.5194/acp-24-13269-2024, 2024
Short summary
Short summary
Ship emissions can form artificially brightened clouds, known as ship tracks, and provide us with an opportunity to investigate how aerosols interact with clouds. Previous studies that used ship tracks suggest that clouds can experience large increases in the amount of water (LWP) from aerosols. Here, we show that there is a bias in previous research and that, when we account for this bias, the LWP response to aerosols is much weaker than previously reported.
Rebecca J. Murray-Watson and Edward Gryspeerdt
Atmos. Chem. Phys., 24, 11115–11132, https://doi.org/10.5194/acp-24-11115-2024, https://doi.org/10.5194/acp-24-11115-2024, 2024
Short summary
Short summary
The formation of mixed-phase clouds during marine cold-air outbreaks is not well understood. Our study, using satellite data and Lagrangian trajectories, reveals that the occurrence of these clouds depends on both time and temperature, influenced partly by the presence of biological ice-nucleating particles. This highlights the importance of comprehending local aerosol dynamics for precise modelling of cloud-phase transitions in the Arctic.
Audran Borella, Olivier Boucher, Keith P. Shine, Marc Stettler, Katsumasa Tanaka, Roger Teoh, and Nicolas Bellouin
Atmos. Chem. Phys., 24, 9401–9417, https://doi.org/10.5194/acp-24-9401-2024, https://doi.org/10.5194/acp-24-9401-2024, 2024
Short summary
Short summary
This work studies how to compare the climate impact of the CO2 emitted and contrails formed by a flight. This is applied to contrail avoidance strategies that would decrease climate impact of flights by changing the trajectory of aircraft to avoid persistent contrail formation, at the risk of increasing CO2 emissions. We find that different comparison methods lead to different quantification of the total climate impact of a flight but lead to similar decisions of whether to reroute an aircraft.
Johannes Mülmenstädt, Edward Gryspeerdt, Sudhakar Dipu, Johannes Quaas, Andrew S. Ackerman, Ann M. Fridlind, Florian Tornow, Susanne E. Bauer, Andrew Gettelman, Yi Ming, Youtong Zheng, Po-Lun Ma, Hailong Wang, Kai Zhang, Matthew W. Christensen, Adam C. Varble, L. Ruby Leung, Xiaohong Liu, David Neubauer, Daniel G. Partridge, Philip Stier, and Toshihiko Takemura
Atmos. Chem. Phys., 24, 7331–7345, https://doi.org/10.5194/acp-24-7331-2024, https://doi.org/10.5194/acp-24-7331-2024, 2024
Short summary
Short summary
Human activities release copious amounts of small particles called aerosols into the atmosphere. These particles change how much sunlight clouds reflect to space, an important human perturbation of the climate, whose magnitude is highly uncertain. We found that the latest climate models show a negative correlation but a positive causal relationship between aerosols and cloud water. This means we need to be very careful when we interpret observational studies that can only see correlation.
Roger Teoh, Zebediah Engberg, Ulrich Schumann, Christiane Voigt, Marc Shapiro, Susanne Rohs, and Marc E. J. Stettler
Atmos. Chem. Phys., 24, 6071–6093, https://doi.org/10.5194/acp-24-6071-2024, https://doi.org/10.5194/acp-24-6071-2024, 2024
Short summary
Short summary
The radiative forcing (RF) due to aviation contrails is comparable to that caused by CO2. We estimate that global contrail net RF in 2019 was 62.1 mW m−2. This is ~1/2 the previous best estimate for 2018. Contrail RF varies regionally due to differences in conditions required for persistent contrails. COVID-19 reduced contrail RF by 54% in 2020 relative to 2019. Globally, 2 % of all flights account for 80 % of the annual contrail energy forcing, suggesting a opportunity to mitigate contrail RF.
Joel Ponsonby, Leon King, Benjamin J. Murray, and Marc E. J. Stettler
Atmos. Chem. Phys., 24, 2045–2058, https://doi.org/10.5194/acp-24-2045-2024, https://doi.org/10.5194/acp-24-2045-2024, 2024
Short summary
Short summary
Aerosol emissions from aircraft engines contribute to the formation of contrails, which have a climate impact as important as that of aviation’s CO2 emissions. For the first time, we experimentally investigate the freezing behaviour of water droplets formed on jet lubrication oil aerosol. We show that they can activate to form water droplets and discuss their potential impact on contrail formation. Our study has implications for contrails produced by future aircraft engine and fuel technologies.
Roger Teoh, Zebediah Engberg, Marc Shapiro, Lynnette Dray, and Marc E. J. Stettler
Atmos. Chem. Phys., 24, 725–744, https://doi.org/10.5194/acp-24-725-2024, https://doi.org/10.5194/acp-24-725-2024, 2024
Short summary
Short summary
Emissions from aircraft contribute to climate change and degrade air quality. We describe an up-to-date 4D emissions inventory of global aviation from 2019 to 2021 based on actual flown trajectories. In 2019, 40.2 million flights collectively travelled 61 billion kilometres using 283 Tg of fuel. Long-haul flights were responsible for 43 % of CO2. The emissions inventory is made available for use in future studies to evaluate the negative externalities arising from global aviation.
George Horner and Edward Gryspeerdt
Atmos. Chem. Phys., 23, 14239–14253, https://doi.org/10.5194/acp-23-14239-2023, https://doi.org/10.5194/acp-23-14239-2023, 2023
Short summary
Short summary
Tropical deep convective clouds, and the thin cirrus (ice) clouds that flow out from them, are important for modulating the energy budget of the tropical atmosphere. This work uses a new method to track the evolution of the properties of these clouds across their entire lifetimes. We find these clouds cool the atmosphere in the first 6 h before switching to a warming regime after the deep convective core has dissipated, which is sustained beyond 120 h from the initial convective event.
Rebecca J. Murray-Watson, Edward Gryspeerdt, and Tom Goren
Atmos. Chem. Phys., 23, 9365–9383, https://doi.org/10.5194/acp-23-9365-2023, https://doi.org/10.5194/acp-23-9365-2023, 2023
Short summary
Short summary
Clouds formed in Arctic marine cold air outbreaks undergo a distinct evolution, but the factors controlling their transition from high-coverage to broken cloud fields are poorly understood. We use satellite and reanalysis data to study how these clouds develop in time and the different influences on their evolution. The aerosol concentration is correlated with cloud break-up; more aerosol is linked to prolonged coverage and a stronger cooling effect, with implications for a more polluted Arctic.
Edward Gryspeerdt, Adam C. Povey, Roy G. Grainger, Otto Hasekamp, N. Christina Hsu, Jane P. Mulcahy, Andrew M. Sayer, and Armin Sorooshian
Atmos. Chem. Phys., 23, 4115–4122, https://doi.org/10.5194/acp-23-4115-2023, https://doi.org/10.5194/acp-23-4115-2023, 2023
Short summary
Short summary
The impact of aerosols on clouds is one of the largest uncertainties in the human forcing of the climate. Aerosol can increase the concentrations of droplets in clouds, but observational and model studies produce widely varying estimates of this effect. We show that these estimates can be reconciled if only polluted clouds are studied, but this is insufficient to constrain the climate impact of aerosol. The uncertainty in aerosol impact on clouds is currently driven by cases with little aerosol.
Edward Gryspeerdt, Franziska Glassmeier, Graham Feingold, Fabian Hoffmann, and Rebecca J. Murray-Watson
Atmos. Chem. Phys., 22, 11727–11738, https://doi.org/10.5194/acp-22-11727-2022, https://doi.org/10.5194/acp-22-11727-2022, 2022
Short summary
Short summary
The response of clouds to changes in aerosol remains a large uncertainty in our understanding of the climate. Studies typically look at aerosol and cloud processes in snapshot images, measuring all properties at the same time. Here we use multiple images to characterise how cloud temporal development responds to aerosol. We find a reduction in liquid water path with increasing aerosol, party due to feedbacks. This suggests the aerosol impact on cloud water may be weaker than in previous studies.
Roger Teoh, Ulrich Schumann, Edward Gryspeerdt, Marc Shapiro, Jarlath Molloy, George Koudis, Christiane Voigt, and Marc E. J. Stettler
Atmos. Chem. Phys., 22, 10919–10935, https://doi.org/10.5194/acp-22-10919-2022, https://doi.org/10.5194/acp-22-10919-2022, 2022
Short summary
Short summary
Aircraft condensation trails (contrails) contribute to over half of the climate forcing attributable to aviation. This study uses historical air traffic and weather data to simulate contrails in the North Atlantic over 5 years, from 2016 to 2021. We found large intra- and inter-year variability in contrail radiative forcing and observed a 66 % reduction due to COVID-19. Most warming contrails predominantly result from night-time flights in winter.
Edward Gryspeerdt, Daniel T. McCoy, Ewan Crosbie, Richard H. Moore, Graeme J. Nott, David Painemal, Jennifer Small-Griswold, Armin Sorooshian, and Luke Ziemba
Atmos. Meas. Tech., 15, 3875–3892, https://doi.org/10.5194/amt-15-3875-2022, https://doi.org/10.5194/amt-15-3875-2022, 2022
Short summary
Short summary
Droplet number concentration is a key property of clouds, influencing a variety of cloud processes. It is also used for estimating the cloud response to aerosols. The satellite retrieval depends on a number of assumptions – different sampling strategies are used to select cases where these assumptions are most likely to hold. Here we investigate the impact of these strategies on the agreement with in situ data, the droplet number climatology and estimates of the indirect radiative forcing.
Hailing Jia, Johannes Quaas, Edward Gryspeerdt, Christoph Böhm, and Odran Sourdeval
Atmos. Chem. Phys., 22, 7353–7372, https://doi.org/10.5194/acp-22-7353-2022, https://doi.org/10.5194/acp-22-7353-2022, 2022
Short summary
Short summary
Aerosol–cloud interaction is the most uncertain component of the anthropogenic forcing of the climate. By combining satellite and reanalysis data, we show that the strength of the Twomey effect (S) increases remarkably with vertical velocity. Both the confounding effect of aerosol–precipitation interaction and the lack of vertical co-location between aerosol and cloud are found to overestimate S, whereas the retrieval biases in aerosol and cloud appear to underestimate S.
Rebecca J. Murray-Watson and Edward Gryspeerdt
Atmos. Chem. Phys., 22, 5743–5756, https://doi.org/10.5194/acp-22-5743-2022, https://doi.org/10.5194/acp-22-5743-2022, 2022
Short summary
Short summary
Clouds are important to the Arctic surface energy budget, but the impact of aerosols on their properties is largely uncertain. This work shows that the response of liquid water path to cloud droplet number increases is strongly dependent on lower tropospheric stability (LTS), with weaker cooling effects in polluted clouds and at high LTS. LTS is projected to decrease in a warmer Arctic, reducing the cooling effect of aerosols and producing a positive, aerosol-dependent cloud feedback.
Matthew W. Christensen, Andrew Gettelman, Jan Cermak, Guy Dagan, Michael Diamond, Alyson Douglas, Graham Feingold, Franziska Glassmeier, Tom Goren, Daniel P. Grosvenor, Edward Gryspeerdt, Ralph Kahn, Zhanqing Li, Po-Lun Ma, Florent Malavelle, Isabel L. McCoy, Daniel T. McCoy, Greg McFarquhar, Johannes Mülmenstädt, Sandip Pal, Anna Possner, Adam Povey, Johannes Quaas, Daniel Rosenfeld, Anja Schmidt, Roland Schrödner, Armin Sorooshian, Philip Stier, Velle Toll, Duncan Watson-Parris, Robert Wood, Mingxi Yang, and Tianle Yuan
Atmos. Chem. Phys., 22, 641–674, https://doi.org/10.5194/acp-22-641-2022, https://doi.org/10.5194/acp-22-641-2022, 2022
Short summary
Short summary
Trace gases and aerosols (tiny airborne particles) are released from a variety of point sources around the globe. Examples include volcanoes, industrial chimneys, forest fires, and ship stacks. These sources provide opportunistic experiments with which to quantify the role of aerosols in modifying cloud properties. We review the current state of understanding on the influence of aerosol on climate built from the wide range of natural and anthropogenic laboratories investigated in recent decades.
Ulrich Schumann, Ian Poll, Roger Teoh, Rainer Koelle, Enrico Spinielli, Jarlath Molloy, George S. Koudis, Robert Baumann, Luca Bugliaro, Marc Stettler, and Christiane Voigt
Atmos. Chem. Phys., 21, 7429–7450, https://doi.org/10.5194/acp-21-7429-2021, https://doi.org/10.5194/acp-21-7429-2021, 2021
Short summary
Short summary
The roughly 70 % reduction of air traffic during the COVID-19 pandemic from March–August 2020 compared to 2019 provides a test case for the relationship between air traffic density, contrails, and their radiative forcing of climate change. This paper investigates the induced traffic and contrail changes in a model study. Besides strong weather changes, the model results indicate aviation-induced cirrus and top-of-the-atmosphere irradiance changes, which can be tested with observations.
Edward Gryspeerdt, Tom Goren, and Tristan W. P. Smith
Atmos. Chem. Phys., 21, 6093–6109, https://doi.org/10.5194/acp-21-6093-2021, https://doi.org/10.5194/acp-21-6093-2021, 2021
Short summary
Short summary
Cloud responses to aerosol are time-sensitive, but this development is rarely observed. This study uses isolated aerosol perturbations from ships to measure this development and shows that macrophysical (width, cloud fraction, detectability) and microphysical (droplet number) properties of ship tracks vary strongly with time since emission, background cloud and meteorological state. This temporal development should be considered when constraining aerosol–cloud interactions with observations.
Johannes Quaas, Antti Arola, Brian Cairns, Matthew Christensen, Hartwig Deneke, Annica M. L. Ekman, Graham Feingold, Ann Fridlind, Edward Gryspeerdt, Otto Hasekamp, Zhanqing Li, Antti Lipponen, Po-Lun Ma, Johannes Mülmenstädt, Athanasios Nenes, Joyce E. Penner, Daniel Rosenfeld, Roland Schrödner, Kenneth Sinclair, Odran Sourdeval, Philip Stier, Matthias Tesche, Bastiaan van Diedenhoven, and Manfred Wendisch
Atmos. Chem. Phys., 20, 15079–15099, https://doi.org/10.5194/acp-20-15079-2020, https://doi.org/10.5194/acp-20-15079-2020, 2020
Short summary
Short summary
Anthropogenic pollution particles – aerosols – serve as cloud condensation nuclei and thus increase cloud droplet concentration and the clouds' reflection of sunlight (a cooling effect on climate). This Twomey effect is poorly constrained by models and requires satellite data for better quantification. The review summarizes the challenges in properly doing so and outlines avenues for progress towards a better use of aerosol retrievals and better retrievals of droplet concentrations.
Cited articles
Agarwal, A., Meijer, V. R., Eastham, S. D., Speth, R. L., and Barrett, S. R. H.: Reanalysis-driven simulations may overestimate persistent contrail formation by 100–250 %, Environ. Res. Lett., 17, 1–14, https://doi.org/10.1088/1748-9326/AC38D9, 2022.
Bedka, S. T., Minnis, P., Duda, D. P., Chee, T. L., and Palikonda, R.: Properties of linear contrails in the Northern Hemisphere derived from 2006 Aqua MODIS observations, Geophys. Res. Lett., 40, 772–777, https://doi.org/10.1029/2012GL054363, 2013.
Bier, A. and Burkhardt, U.: Impact of Parametrizing Microphysical Processes in the Jet and Vortex Phase on Contrail Cirrus Properties and Radiative Forcing, J. Geophys. Res.-Atmos., 127, e2022JD036677, https://doi.org/10.1029/2022JD036677, 2022.
Bier, A., Unterstrasser, S., and Vancassel, X.: Box model trajectory studies of contrail formation using a particle-based cloud microphysics scheme, Atmos. Chem. Phys., 22, 823–845, https://doi.org/10.5194/acp-22-823-2022, 2022.
Boulanger, D., Bundke, U., Gallagher, M., Gerbig, C., Hermann, M., Nédélec, P., Rohs, S., Sauvage, B., Ziereis, H., Thouret, V., and Petzold, A.: IAGOS Time series, AERIS, https://doi.org/10.25326/06, 2022.
Bradski, G.: The OpenCV Library: Dr. Dobb's Journal of Software Tools, UBM Technology Group, 25, 120–125, https://www.proquest.com/docview/202684726?sourcetype=Trade Journals (last access: 17 December 2023), 2000.
Bräuer, T., Voigt, C., Sauer, D., Kaufmann, S., Hahn, V., Scheibe, M., Schlager, H., Diskin, G. S., Nowak, J. B., DiGangi, J. P., Huber, F., Moore, R. H., and Anderson, B. E.: Airborne Measurements of Contrail Ice Properties—Dependence on Temperature and Humidity, Geophys. Res. Lett., 48, e2020GL092166, https://doi.org/10.1029/2020GL092166, 2021.
Bresenham, J. E.: Algorithm for computer control of a digital plotter, IBM Syst. J., 4, 25–30, https://doi.org/10.1147/SJ.41.0025, 2010.
Burkhardt, U., Bock, L., and Bier, A.: Mitigating the contrail cirrus climate impact by reducing aircraft soot number emissions, npj Clim. Atmos. Sci., 1, 1–7, https://doi.org/10.1038/s41612-018-0046-4, 2018.
Caiazzo, F., Agarwal, A., Speth, R. L., and Barrett, S. R. H.: Impact of biofuels on contrail warming, Environ. Res. Lett., 12, 114013, https://doi.org/10.1088/1748-9326/aa893b, 2017.
Chen, C.-C. and Gettelman, A.: Simulated radiative forcing from contrails and contrail cirrus, Atmos. Chem. Phys., 13, 12525–12536, https://doi.org/10.5194/acp-13-12525-2013, 2013.
Dietmüller, S., Matthes, S., Dahlmann, K., Yamashita, H., Simorgh, A., Soler, M., Linke, F., Lührs, B., Meuser, M. M., Weder, C., Grewe, V., Yin, F., and Castino, F.: A Python library for computing individual and merged non−CO2 algorithmic climate change functions: CLIMaCCF V1.0, Geosci. Model Dev., 16, 4405–4425, https://doi.org/10.5194/gmd-16-4405-2023, 2023.
Driver, O. G. A., Stettler, M. E. J., and Gryspeerdt, E.: Factors limiting contrail detection in satellite imagery, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2024-2198, 2024.
Duda, D. P., Bedka, S. T., Minnis, P., Spangenberg, D., Khlopenkov, K., Chee, T., and Smith Jr., W. L.: Northern Hemisphere contrail properties derived from Terra and Aqua MODIS data for 2006 and 2012, Atmos. Chem. Phys., 19, 5313–5330, https://doi.org/10.5194/acp-19-5313-2019, 2019.
EASA: ICAO Aircraft Engine Emissions Databank (07/2021), EASA, https://www.easa.europa.eu/domains/environment/icao-aircraft-engine-emissions-databank (last access: 17 August 2021), 2021.
ECMWF: The Copernicus Programme: Climate Data Store, ECMWF, https://cds.climate.copernicus.eu/#!/home (last access: 15 February 2022), 2021.
EUROCONTROL: User Manual for the Base of Aircraft Data (BADA) Family 4, EEC Technical/Scientific Report No. 12/11/22-58, EUROCONTROL Experimental Centre (EEC), https://www.eurocontrol.int/model/bada (last access: 17 August 2021), 2016.
Feister, U., Möller, H., Sattler, T., Shields, J., Görsdorf, U., and Güldner, J.: Comparison of macroscopic cloud data from ground-based measurements using VIS/NIR and IR instruments at Lindenberg, Germany, Atmos. Res., 96, 395–407, https://doi.org/10.1016/J.ATMOSRES.2010.01.012, 2010.
Fuglestvedt, J. S., Shine, K. P., Berntsen, T., Cook, J., Lee, D. S., Stenke, A., Skeie, R. B., Velders, G. J. M., and Waitz, I. A.: Transport impacts on atmosphere and climate: Metrics, Atmos. Environ., 44, 4648–4677, https://doi.org/10.1016/j.atmosenv.2009.04.044, 2010.
Gierens, K., Braun-Unkhoff, M., Le Clercq, P., Plohr, M., Schlager, H., and Wolters, F.: Condensation trails from biofuels/kerosene blends scoping study, ENER/C2/2013-627, European Commission, 2016.
Gierens, K., Matthes, S., and Rohs, S.: How Well Can Persistent Contrails Be Predicted?, Aerospace, 7, 169, https://doi.org/10.3390/AEROSPACE7120169, 2020.
Grewe, V., Frömming, C., Matthes, S., Brinkop, S., Ponater, M., Dietmüller, S., Jöckel, P., Garny, H., Tsati, E., Dahlmann, K., Søvde, O. A., Fuglestvedt, J., Berntsen, T. K., Shine, K. P., Irvine, E. A., Champougny, T., and Hullah, P.: Aircraft routing with minimal climate impact: the REACT4C climate cost function modelling approach (V1.0), Geosci. Model Dev., 7, 175–201, https://doi.org/10.5194/gmd-7-175-2014, 2014.
Grewe, V., Matthes, S., Frömming, C., Brinkop, S., Jöckel, P., Gierens, K., Champougny, T., Fuglestvedt, J., Haslerud, A., and Irvine, E.: Feasibility of climate-optimized air traffic routing for trans-Atlantic flights, Environ. Res. Lett., 12, 34003, https://doi.org/10.1088/1748-9326/aa5ba0, 2017.
Gryspeerdt, E., Stettler, M. E. J., Teoh, R., Burkhardt, U., Delovski, T., Driver, O. G. A., and Painemal, D.: Operational differences lead to longer lifetimes of satellite detectable contrails from more fuel efficient aircraft, Environ. Res. Lett., 19, 084059, https://doi.org/10.1088/1748-9326/AD5B78, 2024.
Haywood, J. M., Allan, R. P., Bornemann, J., Forster, P. M., Francis, P. N., Milton, S., Rädel, G., Rap, A., Shine, K. P., and Thorpe, R.: A case study of the radiative forcing of persistent contrails evolving into contrail-induced cirrus, J. Geophys. Res.-Atmos., 114, D24201, https://doi.org/10.1029/2009JD012650, 2009.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J. N.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020.
Hoffmann, L., Günther, G., Li, D., Stein, O., Wu, X., Griessbach, S., Heng, Y., Konopka, P., Müller, R., Vogel, B., and Wright, J. S.: From ERA-Interim to ERA5: the considerable impact of ECMWF's next-generation reanalysis on Lagrangian transport simulations, Atmos. Chem. Phys., 19, 3097–3124, https://doi.org/10.5194/acp-19-3097-2019, 2019.
Holzapfel, F.: Probabilistic Two-Phase Wake Vortex Decay and Transport Model, J. Aircraft, 40, 323–331, https://doi.org/10.2514/2.3096, 2003.
Imperial College London: Breakthrough Energy, Low, J., Teoh, R., Gryspeerdt, E., Stettler, M., Ponsonby, J., and Shapiro, M.: Flight matched contrails in ground based camera imagery over London between November 2021 and April 2022, NERC EDS Centre for Environmental Data Analysis [data set], https://doi.org/10.5285/f45a1a95ddcc480784640da6f3001904, 2024.
Iwabuchi, H., Yang, P., Liou, K. N., and Minnis, P.: Physical and optical properties of persistent contrails: Climatology and interpretation, J. Geophys. Res.-Atmos., 117, D06215, https://doi.org/10.1029/2011JD017020, 2012.
Jensen, E. J., Toon, O. B., Kinne, S., Sachse, G. W., Anderson, B. E., Chan, K. R., Twohy, C. H., Gandrud, B., Heymsfield, A., and Miake-Lye, R. C.: Environmental conditions required for contrail formation and persistence, J. Geophys. Res.-Atmos., 103, 3929–3936, https://doi.org/10.1029/97JD02808, 1998a.
Jensen, E. J., Ackérman, A. S., Stevens, D. E., Toon, O. B., and Minnis, P.: Spreading and growth of contrails in a sheared environment, J. Geophys. Res.-Atmos., 103, 31557–31567, https://doi.org/10.1029/98JD02594, 1998b.
Jeßberger, P., Voigt, C., Schumann, U., Sölch, I., Schlager, H., Kaufmann, S., Petzold, A., Schäuble, D., and Gayet, J.-F.: Aircraft type influence on contrail properties, Atmos. Chem. Phys., 13, 11965–11984, https://doi.org/10.5194/acp-13-11965-2013, 2013.
Kärcher, B., Burkhardt, U., Unterstrasser, S., and Minnis, P.: Factors controlling contrail cirrus optical depth, Atmos. Chem. Phys., 9, 6229–6254, https://doi.org/10.5194/acp-9-6229-2009, 2009.
Kärcher, B., Burkhardt, U., Ponater, M., and Fromming, C.: Importance of representing optical depth variability for estimates of global line-shaped contrail radiative forcing, P. Natl. Acad. Sci. USA, 107, 19181–19184, https://doi.org/10.1073/pnas.1005555107, 2010.
Lee, D. S., Fahey, D. W., Skowron, A., Allen, M. R., Burkhardt, U., Chen, Q., Doherty, S. J., Freeman, S., Forster, P. M., Fuglestvedt, J., Gettelman, A., De León, R. R., Lim, L. L., Lund, M. T., Millar, R. J., Owen, B., Penner, J. E., Pitari, G., Prather, M. J., Sausen, R., and Wilcox, L. J.: The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018, Atmos. Environ., 244, 117834, https://doi.org/10.1016/J.ATMOSENV.2020.117834, 2021.
Lewellen, D. C.: Persistent contrails and contrail cirrus. Part II: Full lifetime behavior, J. Atmos. Sci., 71, 4420–4438, https://doi.org/10.1175/JAS-D-13-0317.1, 2014.
Lewellen, D. C. and Lewellen, W. S.: The Effects of Aircraft Wake Dynamics on Contrail Development, J. Atmos. Sci., 58, 390–406, https://doi.org/10.1175/1520-0469(2001)058<0390:TEOAWD>2.0.CO;2, 2001.
Lewellen, D. C., Meza, O., Huebsch, W. W., Lewellen, D. C., Meza, O., and Huebsch, W. W.: Persistent Contrails and Contrail Cirrus. Part I: Large-Eddy Simulations from Inception to Demise, J. Atmos. Sci., 71, 4399–4419, https://doi.org/10.1175/JAS-D-13-0316.1, 2014.
Long, C. N., Sabburg, J. M., Calbó, J., and Pagès, D.: Retrieving Cloud Characteristics from Ground-Based Daytime Color All-Sky Images, J. Atmos. Ocean. Tech., 23, 633–652, https://doi.org/10.1175/JTECH1875.1, 2006.
Mannstein, H., Brömser, A., and Bugliaro, L.: Ground-based observations for the validation of contrails and cirrus detection in satellite imagery, Atmos. Meas. Tech., 3, 655–669, https://doi.org/10.5194/amt-3-655-2010, 2010.
Marjani, S., Tesche, M., Bräuer, P., Sourdeval, O., and Quaas, J.: Satellite Observations of the Impact of Individual Aircraft on Ice Crystal Number in Thin Cirrus Clouds, Geophys. Res. Lett., 49, e2021GL096173, https://doi.org/10.1029/2021GL096173, 2022.
Märkl, R. S., Voigt, C., Sauer, D., Dischl, R. K., Kaufmann, S., Harlaß, T., Hahn, V., Roiger, A., Weiß-Rehm, C., Burkhardt, U., Schumann, U., Marsing, A., Scheibe, M., Dörnbrack, A., Renard, C., Gauthier, M., Swann, P., Madden, P., Luff, D., Sallinen, R., Schripp, T., and Le Clercq, P.: Powering aircraft with 100 % sustainable aviation fuel reduces ice crystals in contrails, Atmos. Chem. Phys., 24, 3813–3837, https://doi.org/10.5194/acp-24-3813-2024, 2024.
Martin Frias, A., Shapiro, M., Engberg, Z., Zopp, R., Soler, M., and Stettler, M. E. J.: Feasibility of contrail avoidance in a commercial flight planning system: an operational analysis, Environmental Research: Infrastructure and Sustainability, 4, 015013, https://doi.org/10.1088/2634-4505/ad310c, 2024.
Meerkötter, R., Schumann, U., Doelling, D. R., Minnis, P., Nakajima, T., and Tsushima, Y.: Radiative forcing by contrails, Ann. Geophys., 17, 1080–1094, https://doi.org/10.1007/s00585-999-1080-7, 1999.
Meijer, V. R., Kulik, L., Eastham, S. D., Allroggen, F., Speth, R. L., Karaman, S., and Barrett, S. R. H.: Contrail coverage over the United States before and during the COVID-19 pandemic, Environ. Res. Lett., 17, 034039, https://doi.org/10.1088/1748-9326/AC26F0, 2022.
Paugam, R., Paoli, R., and Cariolle, D.: Influence of vortex dynamics and atmospheric turbulence on the early evolution of a contrail, Atmos. Chem. Phys., 10, 3933–3952, https://doi.org/10.5194/acp-10-3933-2010, 2010.
Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel, O., Blondel, M., Prettenhofer, P., Weiss, R., Dubourg, V., Vanderplas, J., Passos, A., Cournapeau, D., Brucher, M., Perrot, M., and Duchesnay, É.: Scikit-learn: Machine Learning in Python, J. Mach. Learn. Res., 12, 2825–2830, https://arxiv.org/abs/1201.0490v4 (last access: 7 September 2023), 2012.
Petzold, A., Thouret, V., Gerbig, C., Zahn, A., Brenninkmeijer, C. A. M., Gallagher, M., Hermann, M., Pontaud, M., Ziereis, H., Boulanger, D., Marshall, J., NéDélec, P., Smit, H. G. J., Friess, U., Flaud, J. M., Wahner, A., Cammas, J. P., Volz-Thomas, A., Thomas, K., Rohs, S., Bundke, U., Neis, P., Berkes, F., Houben, N., Berg, M., Tappertzhofen, M., Blomel, T., Pätz, W., Filges, A., Boschetti, F., Verma, S., Baum, S., Athier, G., Cousin, J. M., Sauvage, B., Blot, R., Clark, H., Gaudel, A., Gressent, A., Auby, A., Fontaine, A., Gautron, B., Bennouna, Y., Petetin, H., Karcher, F., Abonnel, C., Dandin, P., Beswick, K., Wang, K. Y., Rauthe-Schöch, A., Baker, A. K., Riede, H., Gromov, S., Zimmermann, P., Thorenz, U., Scharffe, D., Koeppel, C., Slemr, F., Schuck, T. J., Umezawa, T., Ditas, J., Cheng, Y., Schneider, J., Williams, J., Neumaier, M., Christner, E., Fischbeck, G., Safadi, L., Petrelli, A., Gehrlein, T., Heger, S., Dyroff, C., Weber, S., Assmann, D., Rubach, F., Weigelt, A., Stratmann, G., Stock, P., Penth, L., Walter, D., Heue, K. P., Allouche, Y., Marizy, C., Hermira, J., Bringtown, S., Saueressig, G., Seidel, N., Huf, M., Waibel, A., Franke, H., Klaus, C., Stosius, R., Baumgardner, D., Braathen, G., Paulin, M., and Garnett, N.: Global-scale atmosphere monitoring by in-service aircraft – current achievements and future prospects of the European Research Infrastructure IAGOS, Tellus B, 67, 1–24, https://doi.org/10.3402/TELLUSB.V67.28452, 2015.
Quaas, J., Gryspeerdt, E., Vautard, R., and Boucher, O.: Climate impact of aircraft-induced cirrus assessed from satellite observations before and during COVID-19, Environ. Res. Lett., 16, 064051, https://doi.org/10.1088/1748-9326/ABF686, 2021.
Raspberry Pi: Accessories: Camera, https://www.raspberrypi.com/documentation/accessories/camera.html (last access: 16 August 2023), 2023.
Reutter, P., Neis, P., Rohs, S., and Sauvage, B.: Ice supersaturated regions: properties and validation of ERA-Interim reanalysis with IAGOS in situ water vapour measurements, Atmos. Chem. Phys., 20, 787–804, https://doi.org/10.5194/acp-20-787-2020, 2020.
Rosenow, J., Hospodka, J., Lán, S., and Fricke, H.: Validation of a Contrail Life-Cycle Model in Central Europe, Sustainability, 15, 8669, https://doi.org/10.3390/SU15118669, 2023.
Schumann, U.: On conditions for contrail formation from aircraft exhausts, Meteorol. Z., 5, 4–23, https://doi.org/10.1127/metz/5/1996/4, 1996.
Schumann, U.: A contrail cirrus prediction model, Geosci. Model Dev., 5, 543–580, https://doi.org/10.5194/gmd-5-543-2012, 2012.
Schumann, U., Graf, K., and Mannstein, H.: Potential to reduce the climate impact of aviation by flight level changes, in: 3rd AIAA Atmospheric Space Environments Conference, 27 June 2011–30 June 2011, Honolulu, Hawaii, American Institute of Aeronautics and Astronautics, https://doi.org/10.2514/6.2011-3376, 2011.
Schumann, U., Hempel, R., Flentje, H., Garhammer, M., Graf, K., Kox, S., Lösslein, H., and Mayer, B.: Contrail study with ground-based cameras, Atmos. Meas. Tech., 6, 3597–3612, https://doi.org/10.5194/amt-6-3597-2013, 2013.
Schumann, U., Penner, J. E., Chen, Y., Zhou, C., and Graf, K.: Dehydration effects from contrails in a coupled contrail–climate model, Atmos. Chem. Phys., 15, 11179–11199, https://doi.org/10.5194/acp-15-11179-2015, 2015.
Schumann, U., Baumann, R., Baumgardner, D., Bedka, S. T., Duda, D. P., Freudenthaler, V., Gayet, J.-F., Heymsfield, A. J., Minnis, P., Quante, M., Raschke, E., Schlager, H., Vázquez-Navarro, M., Voigt, C., and Wang, Z.: Properties of individual contrails: a compilation of observations and some comparisons, Atmos. Chem. Phys., 17, 403–438, https://doi.org/10.5194/acp-17-403-2017, 2017.
Schumann, U., Poll, I., Teoh, R., Koelle, R., Spinielli, E., Molloy, J., Koudis, G. S., Baumann, R., Bugliaro, L., Stettler, M., and Voigt, C.: Air traffic and contrail changes over Europe during COVID-19: a model study, Atmos. Chem. Phys., 21, 7429–7450, https://doi.org/10.5194/acp-21-7429-2021, 2021.
Segrin, M. S., Coakley, J. A., and Tahnk, W. R.: MODIS Observations of Ship Tracks in Summertime Stratus off the West Coast of the United States, J. Atmos. Sci., 64, 4330–4345, https://doi.org/10.1175/2007JAS2308.1, 2007.
Seiz, G., Shields, J., Feister, U., Baltsavias, E. P., and Gruen, A.: Cloud mapping with ground-based photogrammetric cameras, Int. J. Remote Sens., 28, 2001–2032, https://doi.org/10.1080/01431160600641822, 2007.
Shapiro, M., Engberg, Z., Teoh, R., Stettler, M., Dean, T., and Abbott, T.: pycontrails: Python library for modeling aviation climate impacts (v0.52.2), Zenodo [code], https://doi.org/10.5281/zenodo.13151570, 2024.
Shields, J. E., Karr, M. E., Johnson, R. W., and Burden, A. R.: Day/night whole sky imagers for 24-h cloud and sky assessment: history and overview, Appl. Optics, 52, 1605–1616, https://doi.org/10.1364/AO.52.001605, 2013.
Sussmann, R. and Gierens, K. M.: Lidar and numerical studies on the different evolution of vortex pair and secondary wake in young contrails, J. Geophys. Res.-Atmos., 104, 2131–2142, https://doi.org/10.1029/1998JD200034, 1999.
Teoh, R., Schumann, U., Majumdar, A., and Stettler, M. E. J.: Mitigating the Climate Forcing of Aircraft Contrails by Small-Scale Diversions and Technology Adoption, Environ. Sci. Technol., 54, 2941–2950, https://doi.org/10.1021/acs.est.9b05608, 2020.
Teoh, R., Schumann, U., Gryspeerdt, E., Shapiro, M., Molloy, J., Koudis, G., Voigt, C., and Stettler, M. E. J.: Aviation contrail climate effects in the North Atlantic from 2016 to 2021, Atmos. Chem. Phys., 22, 10919–10935, https://doi.org/10.5194/acp-22-10919-2022, 2022a.
Teoh, R., Schumann, U., Voigt, C., Schripp, T., Shapiro, M., Engberg, Z., Molloy, J., Koudis, G., and Stettler, M. E. J.: Targeted Use of Sustainable Aviation Fuel to Maximise Climate Benefits, Environ. Sci. Technol,. 56, 17246–17255, https://doi.org/10.1021/acs.est.2c05781, 2022b.
Teoh, R., Engberg, Z., Schumann, U., Voigt, C., Shapiro, M., Rohs, S., and Stettler, M. E. J.: Global aviation contrail climate effects from 2019 to 2021, Atmos. Chem. Phys., 24, 6071–6093, https://doi.org/10.5194/acp-24-6071-2024, 2024a.
Teoh, R., Engberg, Z., Shapiro, M., Dray, L., and Stettler, M. E. J.: The high-resolution Global Aviation emissions Inventory based on ADS-B (GAIA) for 2019–2021, Atmos. Chem. Phys., 24, 725–744, https://doi.org/10.5194/acp-24-725-2024, 2024b.
Tesche, M., Achtert, P., Glantz, P., and Noone, K. J.: Aviation effects on already-existing cirrus clouds, Nat. Commun., 7, 1–6, https://doi.org/10.1038/ncomms12016, 2016.
Tsai, R. Y.: A Versatile Camera Calibration Technique for High-Accuracy 3D Machine Vision Metrology Using Off-the-Shelf TV Cameras and Lenses, IEEE Journal on Robotics and Automation, 3, 323–344, https://doi.org/10.1109/JRA.1987.1087109, 1987.
Unterstrasser, S.: Properties of young contrails – a parametrisation based on large-eddy simulations, Atmos. Chem. Phys., 16, 2059–2082, https://doi.org/10.5194/acp-16-2059-2016, 2016.
Unterstrasser, S. and Gierens, K.: Numerical simulations of contrail-to-cirrus transition – Part 1: An extensive parametric study, Atmos. Chem. Phys., 10, 2017–2036, https://doi.org/10.5194/acp-10-2017-2010, 2010.
Vázquez-Navarro, M., Mannstein, H., and Kox, S.: Contrail life cycle and properties from 1 year of MSG/SEVIRI rapid-scan images, Atmos Chem Phys, 15, 8739–8749, https://doi.org/10.5194/acp-15-8739-2015, 2015.
Wolf, K., Bellouin, N., and Boucher, O.: Distribution and morphology of non-persistent contrail and persistent contrail formation areas in ERA5, Atmos. Chem. Phys., 24, 5009–5024, https://doi.org/10.5194/acp-24-5009-2024, 2024.
World Meteorological Organization: International Cloud Atlas: Aircraft condensation trails, WMO, https://cloudatlas.wmo.int/en/aircraft-condensation-trails.html (last access: 13 May 2023), 2017.
Wu, Y., Jiang, S., Xu, Z., Zhu, S., and Cao, D.: Lens distortion correction based on one chessboard pattern image, Frontiers of Optoelectronics, 8, 319–328, https://doi.org/10.1007/S12200-015-0453-7, 2015.
Short summary
The radiative forcing due to contrails is of the same order of magnitude as aviation CO2 emissions but has a higher uncertainty. Observations are vital to improve our understanding of the contrail lifecycle, improve models, and measure the effect of mitigation action. Here, we use ground-based cameras combined with flight telemetry to track visible contrails and measure their lifetime and width. We evaluate model predictions and demonstrate the capability of this approach.
The radiative forcing due to contrails is of the same order of magnitude as aviation CO2...
