Ground-based facilities for monitoring and studying condensation trails

Cloud formation can also result from human activity, as demonstrated by aircraft condensation trails, or contrails, created by the release of water vapor and soot. They rapidly change shape after formation and can persist in the atmosphere for varying lengths of time. Contrails persist in the atmosphere when the air is supersaturated with ice. They can evolve into cirrus clouds depending on atmospheric thermodynamic conditions. These cloud-like condensation trails therefore have environmental consequences and must be considered in climate models as non-CO2 contributions. These reasons motivated the study and monitoring of contrails and led to the installation of ground-based instruments in southern France, at the Haute-Provence Observatory (OHP). We will first present the currently installed and operational instrumentation for condensation trail monitoring. We will then use specific cases recorded at the OHP to illustrate the different processing steps, from detection to analysis.