Containerships leave Lightning-Trails

Containerschiffe verändern das Wetter über den Ozeanen und erzeugen durch den erhöhten Abgas-Ausstoß auf den Routen Gewitter und hinterlassen dabei eine Spur aus Blitzen: Lightning storms triggered by exhaust from cargo ships. Das Anthropozän kann einiges.

When Joel Thornton at the University of Washington in Seattle and his colleagues looked at records of lightning strikes between 2005 and 2016 from the World Wide Lightning Location Network, they noticed there were significantly more strikes in certain regions of the east Indian Ocean and the South China Sea, compared with the surrounding areas. Unusually, they occurred along two straight lines in the open ocean, which coincided with two of the busiest shipping lanes in the world. Along these paths there were twice as many lightning strikes as in nearby areas. […]

Aerosol particles act as seeds, around which water vapour condenses into cloud droplets. In clean air there aren’t many seeds, so the cloud drops quickly grow and fall as rain. But when there are a lot of seeds, like over busy shipping routes, a greater number of small cloud drops form. Since these are light, they rise up high into the atmosphere and freeze, creating clouds rich in ice.

It is this that leads to more intense thunderstorms: lightning only occurs if clouds are electrically charged, and this only happens if there are lots of ice crystals.