Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-02-06
SUN VARIATIONS
BASIS OF WEATHER
Or. Abbot Presents Evidence
Challenging Theory of
ForecaSterS.

The basic theory of meteorology -
upon which the United States Weather
Bureau and practically all other fore
casting stations In the world base their
predictions-was challenged today by
DR.. Charles G. Abbot, secretary of the
Smithsonian Institution.
In what members of the Smithsonian
staff consider a revolutionary document
in the history of science, DR.. Abbot pre-
sented direct evidence of variations in
temperature and barometric pressure in
one part of the world Enthusiastically cor
related with variations in the radiation
OF the sun measured several thousand
miles away.
He found that flve-day rises in the
solar constant measured at the Smith
sonian observing station in Chile were
followed by five-day drops of tempera-
ture and corresponding pressure changes
at washington. while decreases in
the constant were followed by warmer
weather at the National Capital The
solar constant is defined as the amount
of heat which a black body of the di
mansions of a cubic centimeter would
absorb in one second from the sun If
placed in open space the mean dis
lance of the earth away from the sun.
New Evidence Presented.
Meteorologists have hitherto believed
that weather, which is defined as de-
partures from regularity in climate, de-
ponds principally on the irregularities
of the earths surface and, like rough
water in a stream over rocky bed,
is essentially unpredictable for any con-
siderable time in advance. But DR.
Abbot saws q statement issued by the
Smithsonian, presents evidence to
show on the contrary that weather is
caused chiefly by the frequent inter
ventions of actual changes of the ennis
sion of radiation within the sun itself.
These changes in solar radiation are
periodic and promise to be predicted
long in advance; weather appears to
respond directly to them, although
there are notifications due to local
conditions. The net conclusion Is that
long-range weather forecasting is pos
sible and even probable.
"The evidence from which DR.. Abbot
draws these momentous conclusions
consists of the daily measurements OF
solar recitation made by the Astro-
physical Observatory of the Smlthso-
MAN Institution at Montezuma, Chile.
from 1924 to the present From this
great number of observations DR.. Abbot
has selected III instances in which
the solar constant showed continu-
GUS rise for five consecutive days and
106 instances in which the solar con-
slant showed a continuous fall Tor
five consecutive days He then plot
ted the mean temperature and baro-
metric pressure at Washington. d. c..
for the periods associated with these
rises and falls of the solar constant.
In every instance the curves OF tempera-
ture and barometric pressure corre-
spending respectively, to rising and
TO falling solar radiation showed
marked opposition to each other. That
is, when the suns radiation increased,
as shown by measurements in Chile,
the temperature and barometric press
ure at Washington pursued an opposite
course to that which they followed
after falling radiation. A similar OPP
position of weather effects after OPP
posite solar causes prevailed at VIII
liston, NJ Oak, and at Yuma, Ariz.
Short Period Effects.
Furthermore. whereas the changes
in solar radiation averaged only 0.S
per cent. the temperature changes aver
aged S degrees Fahrenheit That Is to
to say writes Dr. Abbot, major changes
in weather are due TO Short-period
changes in the sun. So revolutionary
is this conclusion for meteorology, that
I hesitated to publish it until the
unanimous approval of many competent
critics encouraged me-
buI SLSDlS0Ulenk VI a ASldblOiLoiAlP
between solar radiation changes and
weather is not in itself sufficient to
make weather forecasting possible; the
radiation changes must themselves first
be practicable And this would be pos
sible only if the same conditions recur
periodically DR.. Abbot has found such
periodicities in the last 10 years OF
solar radiation changes. He has found
five in all. for periods of 9, IL, Is,
as and SO months, respectively. SO
good is the fit to the original observa-
tions Of the compound curve of these
periodicities. that DR.. Abbot has vent
ured to predict what the solar radl-
alton will be for 1881 and 1882. In
other words. he believes that radiation
values are practicable.
But If the weather is dependent on
solar variation and If solar variation
shows five periodicities over term OF
years. then the same periodicities ought
TO show in the weather. DR.. Abbot
has found that they do appear. Dis
crepancies do occur at several times
n prevent a perfect approximation of
the weather curve with the radiation
e.trva l,ttt fhe SIMILARITY Is striking