Systematic atmospheric observation began in the 19th century with weather stations and balloon soundings. Today it encompasses satellite imagery, ground-based radar, aircraft-mounted sensors, and community-operated ADS-B networks that track every transponder-equipped aircraft in real time.

What changes when anyone can watch

The democratization of observation tools — flight trackers, public weather APIs, open government databases — means that patterns once visible only to specialists are now accessible to anyone willing to look consistently and carefully.