The Leon reporter. (Leon, Iowa) 1887-1930, 1911-02-02
DqDl -
THE ORIGIN OF COLD WAVES.
Every One Surely Knows What it is
But Few Can Explain the Cause
of the Phenomena.

Leon Citizens know what a "cold
wave" is, but it is possible that not
very many know the cause of that
, climatic phenomena. The following
! is a description given by one of the
government forecasters.
There are few greater wonders in
the real of nature than the cold waves
of North America, which are the Sc
verest, the most widespread in the
world. They are invariably associ-
ated with anti-cyclones or "highs"
as they are designated ON the wealth
err map. These highs are character
lied by high barometer and outflow
ing winds, and their opposites, the
flows" by low barometer and in
flowing winds. The highs, great areas
of clear, cold, heavy air, are often
two thousand or three thousand
miles in diameter. AS rule the cold
waves are first located by the wealth
err bureau north of the Dakotas or in
Manitoba. Indeed, nature provides
in the interior of Canada an ideal
climate for the development of cold
waves. This region is so far north
and the winter days are so short that
the slanting rays of the sun cannot
produce a high temperature.
Even the tempering winds from
the ocean are felt very little, if at
then, that a high wind which comes
from such region should frequent
ly possess temperature thirty or
forty degrees below zero. The Sc
we're winter climate of the Canadian
northwest, however, is not the only
cause of excessively low temperature
within a high, for lows frequently
come from the same region in winter,
accompanied by comparatively high
temperature. The structure of char
acter of the high itself must there
fore account to some extent for it's
ability to assume a frigid tempera-
ture of the frozen north.
Observations with balloons have
shown that the temperature a few
miles above the surface of the earth
is exceedingly cold even in summer
Since the lower air always blows out
of high, the heavy cold air from
higher levels is permitted to descend
to take its place. AS result of
this downdraft of air, and also be-
cause the WINDS are blowing from a
cold toward warm region, the skies
are prevailing clear. This absence
of clouds permits rapid loss of
heat by radiation from the ground
during the long winter nights, there
by chilling the lower layers of the
atmosphere within a night still more
These are some of the factors that
produce the cold wave in the north
west, and when there is a low to the
southwark moving rapidly eastward,
the cold wave is drawn southwark
and eastward, and often overspreads
the entire country.
The duration of a cold wave is sell
dom long, for soon after the center of
the high passes a place the winds
again begin to blow from the south,
1t is worthy of remark that the cold
waves of winter and the cool waves
OF summer are caused by similar
conditions. The cold wave CT Feb
rurary, 1899, was the severest ever
recorded by the weather bureau, and
the line of zero temperatures ex-
tended southwark to within twenty
five or fifty miles of the Gulf coast.
Cold waves must not be considered
an unmftigated evil, in spite of the
damage and discomforts which they
occasion. The cool, clear days that
often follow the period of severe
cold are wonderfully invigorating
and even the disagreeable wind by
replacing the contaminated air of
our cities with the pure air of the
north, is natures method of cleans
ing the atmosphere.