photo #4798974

A contrail and a distrail are two sides of the same coin. The first, short for ‘condensation trail’, is a line of cloud created from the water vapour in the exhaust gasses of an aircraft, like this one spotted by Christoph Geiss (Cloud Appreciation Society Member 47,439), forming a swoosh across the Altocumulus stratiformis cloud over an athletic field in Hartford, Connecticut, US. A distrail is short for ‘dissipation trail’ and is often more subtle and hard to spot. It is a hole or line cut from a cloud where a plane passed through, the disturbance having caused the cloud’s droplets to freeze, fall, and evaporate away in the drier air below. Can you spot the distrail in Christoph’s cloud? Remember, we said it’s subtle!