Fog Formation and Latent Heat
Is there a correlation between latent heat and fog formations?
Latent heat refers to energy used to evaporate water.
Most fogs form because the temperature drops
below the temperature at which the air becomes saturated
with water, droplets of water form, and either clouds or fog
However, there is something called an evaporation fog (normally
referred to as steam fog), where cold air passes over warmer water,
warmer wet ground, or "wet" snow. The cold (and typically drier,
both in the absolute and relative sense) air causes an enhancement
of evaporation from the water, ground, or snow and cools the
humidified air, producing a shallow fog. This can often been seen
over lakes and rivers especially during cold air outbreaks in the
Autumn, or after a warm spell partially melts snow during winter.
David R. Cook
Climate Research Section
Environmental Science Division
Argonne National Laboratory
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Update: June 2012