Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations
<p>Observations of contrails are vital for improving our understanding of the contrail formation and life cycle, informing models, and assessing mitigation strategies. Here, we developed a methodology that utilises ground-based cameras for tracking and analysing young contrails (<span class...
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Copernicus Publications
2025-01-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/18/37/2025/amt-18-37-2025.pdf |
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| author | J. Low R. Teoh J. Ponsonby E. Gryspeerdt M. Shapiro M. E. J. Stettler |
| author_facet | J. Low R. Teoh J. Ponsonby E. Gryspeerdt M. Shapiro M. E. J. Stettler |
| author_sort | J. Low |
| collection | DOAJ |
| description | <p>Observations of contrails are vital for improving our understanding of the contrail formation and life cycle, informing models, and assessing mitigation strategies. Here, we developed a methodology that utilises ground-based cameras for tracking and analysing young contrails (<span class="inline-formula"><</span> 35 <span class="inline-formula">min</span>) formed under clear-sky conditions, comparing these observations against reanalysis meteorology and simulations from the contrail cirrus prediction model (CoCiP) with actual flight trajectories. Our observations consist of 14 <span class="inline-formula">h</span> of video footage recorded over 5 different days in Central London, capturing 1582 flight waypoints from 281 flights. The simulation correctly predicted contrail formation and absence for around 75 % of these waypoints, with incorrect contrail predictions occurring at warmer temperatures than those with true-positive predictions (7.8 <span class="inline-formula">K</span> vs. 12.8 <span class="inline-formula">K</span> below the Schmidt–Appleman criterion threshold temperature). When evaluating contrails with observed lifetimes of at least 2 <span class="inline-formula">min</span>, the simulation's correct prediction rate for contrail formation increases to over 85 %. Among all waypoints with contrail observations, 78 % of short-lived contrails (observed lifetimes <span class="inline-formula"><</span> 2 <span class="inline-formula">min</span>) formed under ice-subsaturated conditions, whereas 75 % of persistent contrails (observed lifetimes <span class="inline-formula">></span> 10 <span class="inline-formula">min</span>) formed under ice-supersaturated conditions. On average, the simulated contrail geometric width was around 100 <span class="inline-formula">m</span> smaller than the observed (visible) width over its observed lifetime, with the mean underestimation reaching up to 280 <span class="inline-formula">m</span> within the first 5 min. Discrepancies between the observed and simulated contrail formation, lifetime, and width can be associated with uncertainties in reanalysis meteorology due to known model limitations and sub-grid-scale variabilities, contrail model simplifications, uncertainties in aircraft performance estimates, and observational challenges, among other possible factors. Overall, this study demonstrates the potential of ground-based cameras to create essential observational and benchmark datasets for validating and improving existing weather and contrail models.</p> |
| format | Article |
| id | doaj-art-20bcf1d36ce4475aa5252e998fbc0b81 |
| institution | Kabale University |
| issn | 1867-1381 1867-8548 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj-art-20bcf1d36ce4475aa5252e998fbc0b812025-01-07T09:37:11ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482025-01-0118375610.5194/amt-18-37-2025Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulationsJ. Low0R. Teoh1J. Ponsonby2E. Gryspeerdt3M. Shapiro4M. E. J. Stettler5Department of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UKDepartment of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UKDepartment of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UKGrantham Institute for Climate Change and the Environment, Imperial College London, London, SW7 2AZ, UKBreakthrough Energy, 4110 Carillon Point, Kirkland, WA 98033, USADepartment of Civil and Environmental Engineering, Imperial College London, London, SW7 2AZ, UK<p>Observations of contrails are vital for improving our understanding of the contrail formation and life cycle, informing models, and assessing mitigation strategies. Here, we developed a methodology that utilises ground-based cameras for tracking and analysing young contrails (<span class="inline-formula"><</span> 35 <span class="inline-formula">min</span>) formed under clear-sky conditions, comparing these observations against reanalysis meteorology and simulations from the contrail cirrus prediction model (CoCiP) with actual flight trajectories. Our observations consist of 14 <span class="inline-formula">h</span> of video footage recorded over 5 different days in Central London, capturing 1582 flight waypoints from 281 flights. The simulation correctly predicted contrail formation and absence for around 75 % of these waypoints, with incorrect contrail predictions occurring at warmer temperatures than those with true-positive predictions (7.8 <span class="inline-formula">K</span> vs. 12.8 <span class="inline-formula">K</span> below the Schmidt–Appleman criterion threshold temperature). When evaluating contrails with observed lifetimes of at least 2 <span class="inline-formula">min</span>, the simulation's correct prediction rate for contrail formation increases to over 85 %. Among all waypoints with contrail observations, 78 % of short-lived contrails (observed lifetimes <span class="inline-formula"><</span> 2 <span class="inline-formula">min</span>) formed under ice-subsaturated conditions, whereas 75 % of persistent contrails (observed lifetimes <span class="inline-formula">></span> 10 <span class="inline-formula">min</span>) formed under ice-supersaturated conditions. On average, the simulated contrail geometric width was around 100 <span class="inline-formula">m</span> smaller than the observed (visible) width over its observed lifetime, with the mean underestimation reaching up to 280 <span class="inline-formula">m</span> within the first 5 min. Discrepancies between the observed and simulated contrail formation, lifetime, and width can be associated with uncertainties in reanalysis meteorology due to known model limitations and sub-grid-scale variabilities, contrail model simplifications, uncertainties in aircraft performance estimates, and observational challenges, among other possible factors. Overall, this study demonstrates the potential of ground-based cameras to create essential observational and benchmark datasets for validating and improving existing weather and contrail models.</p>https://amt.copernicus.org/articles/18/37/2025/amt-18-37-2025.pdf |
| spellingShingle | J. Low R. Teoh J. Ponsonby E. Gryspeerdt M. Shapiro M. E. J. Stettler Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations Atmospheric Measurement Techniques |
| title | Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations |
| title_full | Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations |
| title_fullStr | Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations |
| title_full_unstemmed | Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations |
| title_short | Ground-based contrail observations: comparisons with reanalysis weather data and contrail model simulations |
| title_sort | ground based contrail observations comparisons with reanalysis weather data and contrail model simulations |
| url | https://amt.copernicus.org/articles/18/37/2025/amt-18-37-2025.pdf |
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