The weekly times-record. (Valley City, N.D.) 1912-1922, 1912-11-14
Geography Instructor
On Weather Condition
BRIEF EXPLANATION OF LOCAL
ATMOSPHERIC PHENOMENA
TIMELY GIVEN.
(By Prof. j. E. Switzer)

! (By Prof. j. E. SWltZer)
There is no subject so much talked
about, or that forms so large par
of general conversation as the topic
, of weather Yet it is also true tha
most of US really know less about il
than about most topics we discuss
with more thought. 1T is the purpose
of this article, and one or two sue
ceeding ones, to call attention to some
of the laws governing the weather
conditions of North Dakota.
AS the question of temperature is
the one to be of greatest interest fol
the next few months, we shall con
slider the factors of its control first
The source of practically all of our
heat is the sun. This heat, or heat
energy, is radiated from the sun at q
very nearly constant rate throughout
the year. Then why our great range
of temperature? r.
In the first place, the temperature
of the body at any given time is the
balance between the amount OF heat
it has received and the amount given
of. AS soon as the body is warmer
than its surrounding medium. it be-
gins to give of its heat, and will be-
come warmer or cooler to just the OK
tent that it receives more or less heat
than it is giving off. The amount of
heat received from the sun depends
primarily upon two factors, i. e., the
hours Of sunshine and the angle of
the suns ray. The higher the sun
is in the sky, the more heat will reach
the earth, because (1) the rays will
pass through fewer miles of atmos-
phere which will absorb some of the
heat and CD more rays will fall upon
a given area.
The unequal length of day and the
variation in the angle of the suns
rays are due to the fact that our earth
is rotating on an exis always paral-
lei to it's former position, inclined
twenty three and half degrees from
the plane of its orbit, and revolving
around the sun. ---.
Water absorbs heat more slowly
than does the land, but retains it long
err, and it therefore follows that land
near large bodies of water will have
more even temperature than that
far inland. Also, the rate of radiation
will be greater in a region where the
amount of moisture in the atmosphe ere
is small, because the moisture con
tent acts as a blanket and retards ra'
diation.
Another factor is the topographic
situation, or the relation of position to
the surrounding highlands and low
lands. On the west are the high
rockies, but of them We will speak
later, To the east, north and south
is an almost unbroken plain stretching
for more than fifteen hundred miles
From across these plains come our
warming winds from the south, and
damp chilling winds from the east and
the cold blizzard winds from the north
and the northwest.
To sum up briefly, we have our
rather extreme winter conditions be-
cause we have the long nights and
short days with the angle of the sun
low, and our position far inland. Our
summers with the long periods Of sun
shine and the sun at much higher
angle, but cool nights because of the
rapid radiation due to relatively dry
atmosphere. f
Now just word about temperature
as it seems and as it really is. We
do not feel the heat of the summer
as do the people of the more humid
climates, because the moisture from
the body evaporates much more rapid
ly in our dry atmosphere than in a
moist one. Evaporation uses up heat
Neither do we feel the extreme cold
temperatures that are felt in more
humid sections with even higher Their.
mometer readings. Moist air is bet:
ter conductor of heat than dry all
and for that reason when We do have
moist wind we feel the effects OF
the body heat being conducted away
Ito be conrln1ed.)
~