Airplanes make clouds brighter

Contrails from airplanes make clouds brighter, shows new research. The researchers used a combination of flight tracking data and satellites equipped with sensitive lasers for detecting small changes in cloud optical thickness, i.e. the degree to which a cloud prevents light passing through it. When they looked at flight tracks from Honolulu to LA and Seattle to San Francisco, they found a significant increase in the optical thickness of the clouds close to the flight tracks compared to those further away.