The Logan County banner. [volume] (Logan, W. Va.) 1889-1903, 1890-06-12
METEOROLOGICAL FACTS.


The Dlncrcnt Movements 81 the Atmosphere
and Tfieif Gasscs.
Solar heat Is the prfwam mobQ~ Of al
atmospheric movements But while
this enormous force Is all-peryading and
cver-present there arc others which
hare an influence that can not be neg
lected
Il is now generally acknowledged in
the dynamics Of meteorology that there
are four principal forces which must be
taken into account IN correct theory
81 the Winds The first arises from the
greater specific gravity Of the atmo-
sphere in some places than others on
account OF its condition as to tempcra-
ture and the dew point; for whom II be-
comes heated in any place or charged
with vapor to q greater degree than at
others, 1t becomes specifically lighter;
hence the equilibrium Is destroyed;
there is flowing together there Of tho
heavier air on all sides, which displaces
the lighter air, and causes 1t to rise up
and to flow out in contrary direction.
A second force arises from the ten
dency which the atmosphere has under
the influence Of gravity, when from any
cause 1t has risen above the. general
level to fow 70 places Of q lower level.
These two forces generally produce
counter currents
Again, when from any cause particle
Of air has been put in motion toward
the N. or s. the combination Of this
motion with the rotatory motion of the
earth produces third force, which
causes detection OF the motion to the
E. when this motion is toward the
NJ and DETECTION to the w.
when it is toward the S. This Is the
same as one OF the forces contained In
La Places general equations of the
tides, the analytical expression Of which
is sin cos nur; being the latitude,
the motion Of the earth at the equator,
. the velocity Of the particle N. or s.,
and the radius Of the earth.
The fourth or last force arises from
the com animation Of relative E. or W..
motion Of the atmosphere with the
rotatory motion of the earth. In con-
sequence Of the atmosphere revolving
on common axis with that Of the earth,
each particle is impressed with a centri-
fugal force, which, being resolved into
vertical and horizontal force, the latter
causes it to assume a spheroidal form,
conformingsto the figure of the earth.
But If the rotatory motion Of any part
OF the atmosphere Is greater than that
OF the surface Of the earth, or, in other
words, If any part Of the atmosphere has
a relative easterly motion with regard
tSsthe earth's surface, this force is in
creased, and ii 1t has relative westerly
motion, 1t is diminished; and this differ
ence gives rise to disturbing force
which prevents the atmosphere from
being in state Of equilibrium with o
figure conforming to that Of the earth's
surface, but causes an accumulation Of
the atmosphere at certain attitudes and
depression at others; and the conse-
quent difference In the pressures Of the
atmosphere at these latitudes very ma
terially influence It's motions. This
force is also Expressed by one of the
terms OF La Places equations, the ana
lytical expression Of which is . sin ] n v
r, being the relative eastern and west
ern velocity Of the atmosphere. What
ever direction body moves on the sur
face of the earth, there is force arising
from the earth's rotation which defects
it to the right the northen hemisphere,
but to the left in the southern.
Among the effects Of these forces are
the development of the well-lnown
Highs and Lows, as shown on the daily
weather map. Also the well-established
fact that all storms move from west to
east in the northern hemisphere and
that the general tend Of the paths Of all
Lows is northeasterly. Also, that the
circulation of the air about Low in the
northern hemisphere is from right to
left. and the. contrary in the case of a
High. In the southern hemisphere
these motions are reversed. Ma tional