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| Main Authors: | , , |
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| Format: | Recurso digital |
| Language: | |
| Published: |
Zenodo
2025
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| Online Access: | https://doi.org/10.5281/zenodo.15643030 |
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Table of Contents:
- <p>Aviation-induced clouds, especially persistent contrails and contrail cirrus, contribute significantly to anthropogenic climate forcing, often surpassing the short-term impact of aviation CO2 emissions. These clouds form in ice-supersaturated regions, where they trap outgoing longwave radiation and warm the climate. On 25 November 2023, widespread ice-supersaturated layers over eastern Canada and the USA led to extensive contrail formation. Persistent contrails, particularly over Lake Ontario, were confirmed by GOES-16 satellite imagery and ground-based photography. Atmospheric conditions were characterized using ceilometer data from Toronto Pearson International Airport and radiosonde soundings from multiple stations.</p> <p>High-resolution numerical simulations were conducted using the Global Environmental Multiscale (GEM) model with the Predicted Particle Properties (P3) microphysics scheme. The Contrail Avoidance Tool (CoAT), incorporating Schmidt-Appleman Criteria (SAC) and a wake vortex model, was employed to simulate persistent contrail formation and properties. Sensitivity tests modulating ice depositional growth rates were performed to evaluate their impact on ice supersaturation representation. Results indicate that the control (CNTL) simulation underestimated relative humidity with respect to ice (RHi), a common limitation in atmospheric models where moisture is depleted too rapidly. Reduced depositional growth rates improved RHi forecasts and the extent of contrail-forming regions. However, GEM-CoAT underestimated contrail depth and ice number concentration in very shallow high-RHi layers. Additionally, CoAT simulations revealed that SAC alone is insufficient for predicting persistent contrails, as wake vortex dynamics can induce adiabatic warming, leading to complete ice particle sublimation. </p> <p>Further analysis examined the formation of the contrails for two types of aircraft (A321 and B747). The B747 generated deeper wake vortices, enhancing adiabatic heating and reducing contrail ice number concentrations by 27% in sensitivity simulations and 78% in the CNTL simulations, suggesting that heavier aircraft may inhibit contrail formation. Our findings indicate that without modulating the depositional growth rate of ice to better represent ice supersaturation, GEM-CoAT was unable to accurately simulate contrail formation and persistence on the observed day.</p>