Cavum Cloud

March 5, 2024

Scientists have long speculated about Cavum clouds, also called hole-punch clouds or fallstreak holes, but it’s now well understood that these odd cloud formations are caused by airplanes.
Formation
- Cavum clouds form when planes fly through banks of altocumulus clouds, mid-level clouds that have supercooled (below the freezing point of water but still liquid) water droplets.
- As air moves around the plane, a process called adiabatic expansion can make the droplets freeze into ice crystals.
- The ice crystals eventually grow heavy and fall out of the sky, leaving a hole in the cloud layer.
- The falling ice crystals are visible in the center of the holes as wispy trails of precipitation that never reach the ground – features called