Real-time contrail formation conditions across 42 countries and 235 cities. Powered by atmospheric science and live weather data.
For each tracked city, ChemTracker fetches atmospheric data from Open-Meteo at 8 pressure levels (150–400 hPa), covering the full range of jet cruising altitudes from approximately 23,000 ft to 45,000 ft.
At each pressure level, the system applies the Schmidt-Appleman criterion: it calculates the critical temperature for contrail formation based on ambient pressure, relative humidity, and engine efficiency (default 0.3). If the actual temperature is below the critical threshold and relative humidity with respect to ice (RH-ice) exceeds 70%, the level is flagged as favorable for contrail formation.
Data is refreshed every 30 minutes via Incremental Static Regeneration, ensuring conditions are current without overloading the weather API.
The app goes beyond this index. See live ADS-B data for every aircraft, get alerts when trail-producing planes are overhead, and explore 8 pressure levels in real time.
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