Supercooled water droplets can remain in liquid form at temperatures as low as what?

Supercooled water droplets can remain in liquid form at temperatures as low as -40°C. This phenomenon occurs because water droplets can remain in a liquid state even below their typical freezing point. The presence of impurities or a lack of nucleation sites can allow these droplets to avoid crystallization, resulting in supercooled liquid water at low temperatures.

The primary reason this is significant in aviation is that supercooled droplets can pose a risk to aircraft during flight, particularly in clouds where temperatures are well below freezing. Understanding the behavior of these droplets helps pilots and engineers develop strategies to mitigate icing risks.

Other temperature options, such as -30°C, -20°C, and -10°C, represent higher temperatures where supercooled droplets can exist but do not reach the extreme limit that -40°C indicates. At these higher temperatures, it is more common for the droplets to eventually freeze and form ice.