Names of cloud families traced to English
chemist
By Jan Null
When many people look at clouds they say things like, ``Look at those puffy
white clouds over the hills,'' or ``Here come the usual night and morning
low clouds.'' The more astute readers of this column may know that the puffy
clouds are cumulus and the usual low clouds around the Bay Area are stratus
clouds. But who named the clouds?
Most of the credit goes to an English chemist and pharmacist named Luke
Howard who devised a classification system in 1802 that is still in use.
Howard presented a paper to the Askesian Society titled ``On the
Modification of Clouds'' which described three basic categories or families
of clouds. He used Latin root words to describe them, following the
18th-century methodology of Carl von Linne, who gave us the Latin-based
classification systems for plants and animals.
Howard describes clouds with conical shapes increasing upward from a flat
base as ``cumulus'' from the Latin term for ``heap.'' A bit more colorfully,
he also described them as ``wool bag clouds.'' Our ``stratus'' clouds derive
from the Latin term for ``layer or sheet'' and their appearance is indeed
one of a flat horizontal sheet. Howard's third family of clouds was
``cirrus'' which he took from the Latin word of ``curl of hair,'' and these
are the thin, wispy ice-crystal clouds high in the atmosphere. To the three
families he added the ``nimbus'' category, from the term for ``rain.''
He also reasoned that clouds could combine their form and change shape to
become amalgamations like ``cumulostratus,'' ``cirro-stratus'' and
``cirrocumulus.''
Despite huge strides in meteorology over the past two centuries, Howard's
system remains the foundation for cloud naming.
Want more information about the clouds? Read ``The Invention of Clouds'' by
Richard Hamblyn or John Day's ``The Book of Clouds.'' On the Web, an
excellent resource is www.cloudman .com/.
Q I heard a weathercaster from a Midwest
TV station say that ``meteorological winter'' was ending. What is
meteorological winter and how does it differ from the usual meaning of
winter? Sal Murillo - Gilroy
A ``Meteorological winter'' is defined
as the three coldest months of the year: December, January and February.
Using whole months makes it easier from a statistical point of view to keep
track of weather data.
Q My sister-in-law, who lives in Newport
Beach, says that storms pick up moisture from the ocean and deposit it on
land. My question is, if this is true, what happens to the salt picked up
from the ocean? Tom Brown - San Jose
A Yes, storms that move over water do
pick up additional moisture. This is especially true over the relatively
warmer waters off the Southern California coast. The moisture that gets
pulled into storm systems is water vapor that has evaporated from the ocean.
When water evaporates it leaves behind the heavier salt in the ocean.
Q I had always heard that there was
nitrogen in snow, that it was good for the farmer's crops. In fact,
sometimes they would plow under the first snowfall, calling it ``poor man's
fertilizer.'' My daughter is a meteorologist and said that I am telling old
wives' tales, and that there is only water and particulate matter in snow.
Who is right? - Diana Hulbert
Morrice, Mich.
A You are both right! It's not just the
first snowfall that has nitrogen. Any snow (and rain) brings at least trace
amounts of nitrogen compounds that are suspended in the air. The water
content, of course, would also be beneficial.
The suspended nitrogen acts just like the nitrogen fertilizer that you buy
at local garden store. It is estimated that 2 to 12 pounds of nitrogen are
deposited per acre. The amount of nitrogen compounds in the air has
increased due to industrialization and the burning of fossil fuels.