Evening star., 1927-04-25
RADIO is AFFECTED
BY SUN RADIATION
Long Distance Reception
Rests on Solar Variation,
Says Abbot.

The strength of reception Of long
distance radio appears to be almost
wholly function OF the variation in
the suns radiation, according to DIR.
G.. G. Abbot, acting secretary of the
Smithsonian Institution, who in a
Smithsonian publication given out to-
day, sums up the startling recent de-
velopments in his Investigations of the
SUMS heat changes. This radio discov-
cry was made by DIR. l.. w Austin
of the United States Bureau Of Stand
ards, who made a three-year study of
radio reception and compared his re-
suIting curves with Smit hsonian
curves for solar radiation over the
same period. The curves correspond
almost exactly.
The paper in which this result ap-
pears is studded with significant de-
velopments in one of the most vital
scientific Investigations of the present
day and abundantly justities the %
years already spent on solar investi-
cation by the Smithsonian.
Suns Radiation Varies.
The publication presents indisput-
able proof of the fact that the suns
radiation varies; it reveals a 2525
months periodicity in this variation,
which gives promise of forecasting
that length of time in advance; it
shows a deviation in barometric pres
sures for the cities of Winnipeg, Chi
cago and New York, which correspond
closely with deviations in the solar
constant, suggesting q definite re-
sponse in the earth's weather to
changes in the suns $ radiation.
During the % years in which the
Smithsonian aStrophysiciSts have been
developing. proofs that the SUMS radi-
alton varies from day to day as well
as from year to year, the majority of
the scientific world has doubted the
truth of such variation. DIR. Abbot
now presents further proof of his con-
tention. Expressed in the simplest
FORM this proof consists in negativ-
ing the effect of the earth's atmos-
phere on the suns rays by selecting
days for comparison on which atmos-
pheric conditions are the same. The
resulting curve for the same months
during several years parallels the
curve already published by the Smith
sonian for the suns radiation outside
of the eafth'S atmosphere during the
same months. Thus the truth of vari-
alton is proved and also the approx
mate correctness of Smithsonian meas
urements. Furthermore, both curves
compare very favorably with the
curve for spots on the sun during the
same period, showing a definite rela-
ton between radiation and sun spots.
Weather Is Influenced.
AS to the matter of the 2525 month
periodicity, measurements over a
period Of six and one-half years
show regular recurrence of similar
values for the solar constant in these
time periods. Proof of the exactitude
of this periodicity was given by the
celebrated machines for harmonic
analysis and synthesis of curves in
vented by DIR. Dayton G. Miller. The
Importance of this periodicity is two
fold. In the first place, this funda-
mental period of nearly two years
and two months has been mentioned
by many authors as associated with
weather and crop harvests. This fact
gives strong confirmation of the
Smithsonian hypothesis that solar
variation influences weather.
In the second place, with his ma
chine DIR. Miller built up DIR. Abbot's
curve for several months beyond the
data furnished to him., Thus far the
values for solar radiation received
from the Smithsonian solar observa-
tory in Chile have agreed well with
this forecast Of DIR. Miller, which
foretold a sharp rise in the solar con-
stant