Dear Tom,
You have mentioned that salt particles in the air act as condensation nuclei for cloud
formation. Where does that salt come from?
Joseph Mathias
Dear Joseph,
Every cloud that passes overhead is a visible collection of myriad particles
consisting of water droplets or ice crystals or both; and every cloud particle began its
life as a so-called condensation nucleus on which water molecules collected. The
collection process is called condensation when the resulting cloud particle is a water
droplet and sublimation when the resulting particle is a tiny ice crystal.
Chief among condensation nuclei are specks of sea salt, even thousands of miles into
the interior of continents. Droplets of salty ocean spray, when they evaporate, leave
their tiny burdens of salt floating in the air, to be disbursed through the atmosphere
and around the world.
