The Washington times., 1923-08-30

Former" Dunn is one of the
| foremost aUeGther and DteteOrOlogi-
cal authorities in this country. He.
eOGs formerly chief of the u. S.
Weather Bureau at NeU York.
Has forecasts on numerous dis
GstroMs floods haze 4Co9s him an
usual tribute from scientists and
the press.
BY ELIAS b. FARMER DUNN,
Copyright. 1923. by Cosmopolitan
News Service.)
WEST ORANGE, NJ. J., Aug. 80.
What Is causing the climatic con-
vulsions?
There have been periods Of in
tense beat and drought In some
sections; intervals Of cold in SUM-.
mer months in others; frost in Au-
gust; violent thunder and electric
| storms; destructive windstorms;
cloudbursts, floods, tornadoes and
general storms; all within the.
present year. Again lives have
been lost, again property was de-
stroyed, and the crop condition be-
came disastrous in many sections.
The reason for the greater part
of those atmospheric Irregularities
we find to be due to mans handi-
work-his endeavor to turn the
arid land Of the west into O gar.
den OF flowers and wholesome pro-
ductivity.
Irrigation Is Cause.
Water for irrigation purposes
has been spread over $4,000, 900
acres from Montana and Washing
ton south to the Gulf Of California
and the Gulf Of Mexico. II al
great body of water were intro
duced into e. region Of extreme
heat, which before had been a. bar.
rem desert, there Is no doubt that
tremendous and permanent at
mospheric changes would result.
Therefore, It Is reasonable to ss.
sumo that the irrigation of q great
many square miles of land in tie
West has been accompanied by,
and been the cause Of changes in
weather conditions, not only local,
but widespread in influence.
Now, let US demonstrate how the
continuous performance Of main.
tanning 10000, 900 acres OF land In
a moist condition Is affecting cur
weather and general conditions.
Forty years ago the weather map
Issued by the Government showed |
that 20 per cent Of all storms en-
tered our country by way Of Oregon, /
washington and British Columbia;
about 20 per cent formed within
our borders, In or around the
central Rocky Mountain districts,
and the, balance developed in the
Gulf or South Atlantic States.
Part Of the storms from the
northwest would move almost due
0f oArOm0 Ln VA0ovfnno
pass out the st. Lawrence valley.
The others, mostly OF weak formae
tion,4 would drop southwark along
the east slope Of the Rocky Noun.
tains and, when in the vicinity OF
Wyoming or Colorado, turn north
east and head for the lake regions.
for moisture and rehabilitation and,
with greater energy, pass out the
st. Lawrence valley.
Few Of the storms that came IN
from the Pacific coast crossed di-
rectly over the Rocky Mountains.
When they did, all of their moisture
was precipitated upon the western
slope. Condensation took place be-
cause the air was forced into high
and colder elevation.
Seasons Were Evident.
In those years our winters were
cold and the summers warm. One
could easily tell when one season
left off and another began without
necessarily consulting a calendar.
What has irrigation done? It
has practically changed the place
Of development Of storms and their
course, which, in turn, has brought
about changes in our climate that
have entailed more frequent atmos-
pheric disturbances. Compare Gov
ernment weather charts with those
Of thirty, forty or fifty years ago,
for proof. One will find, now,
what are termed areas of low pres
sure, or cyclonic disturbances, en-
tering our country by way of the
South Pacific and over Southern
California, or developing over that |
section and the desert lands of
Arizona. The number of storms
that enter from the northwest is
greatly diminished.
Why? Because storms need heat
and moisture and there is no place
in the world that furnishes these
prime factors SO well as the south |
west, where the heat is intense in
the summer and moderate in the
winter and where evaporation is
extremely rapid.