raidekalteudet

Raidekalteudet is a Finnish term that translates to "track coldness" or "rail coldness." It refers to a phenomenon where the temperature of railway tracks drops significantly below the ambient air temperature, particularly during clear, cold nights. This occurs due to radiative cooling, where the surface of the rail efficiently emits thermal radiation into the cold, clear sky. The absence of cloud cover prevents this emitted heat from being reflected back to the surface, leading to a substantial temperature difference.

The primary consequence of raidekalteudet is an increased risk of frost and ice formation on the rails. Even if the air temperature is slightly above freezing, the rail surface can become cold enough to freeze moisture present on the tracks. This ice can reduce traction for trains, potentially leading to delays, derailments, or the need for specialized de-icing operations. The effect is most pronounced in regions with cold climates and clear skies, such as Finland, where the term originates. Railway operators monitor track temperatures, especially during winter months, to anticipate and mitigate the effects of raidekalteudet. Strategies include using de-icing agents or adjusting train operations to maintain safety and efficiency.