292 MONTHLY WEATHER REVIEW. JULY, 1905
spring grain were not injured. Corn, potatoes, and hops made satis- factory progress.-(2. N. Saliclbicry.
We& VirginCe.-Hot, showery weather prevailed during the first three weeks, and was very beneflcial for crop growth. The cuttiug of hay and
oats and the stackingof wheat were considerably delayed, but the fourth week was very favorable for this work. Corn made rapid gn bwth and was
very promising. Pastures and stock mere in flne coiitlition, AIiIlet. buckwheat, cowpeas, cabbages, and gardens were doing well.--E. C. Vow. Wkcomin.- The month was characterized by a deficiency or rainfall, moderate temperature, a good supply of sunshine, and severe local hail-
storms. Tobacco was damaged considerably by hail and grains were generally lodged by high winds. Hay was
well secured and was an unusually large crop, nothwithstanding damage
Corn macle rapid headway.
by adverse weather conditions earlier in the season. Spring grains made good progress. Pastures and meadows were in excellent condition. Fruits and berries were a heavy yield. Sugar bets continued in flne condition. The apple crop was not in satisfactory condition.-J. W. Bchneffer.
Wyoming.-The weather was faroralJle for the growth of grain and
gardens, which made favorable progress; at the close of the month
gardens were in excellent condition, ant1 a good crop of grain was be-
ginning to ripeu in the earlier sections. A good crop of native hay was being secured, liut showers interfered with its harvest. Ranges con- tiiiued excelleiit and cure(1 very slowly, in some sections rvmaining
green to the close of the month. All stock was in excellent condi-
tion.--T1: S. Pdnwr.
SPECIAL ARTICLES.
STUDIES ON THE DIURNAL PERIODS IN THE LOWER STRATA OF THE ATMOSPHERE.
By Prof. FRANK H. BICcEI.4bW.
V.-THE VARIABLE ACTION OF THE SUN AND ITS EFFECT UPON
TERRESTRIAL WEATHER CON1)ITIONS.
APPLICATIONS TO THE PItOBLEBlh OF THE WEITHER.
The foregoing correlation of the connections between the
phenomena of temperature, pressure, vapor tension, atmos-
pheric electricity, ionization, and magnetic vectors seems to
give a natural unity to these data which have been detached
from one another in the previous scientific researches. The
entire train of causes and effects is arranged by i t in n satis-
factory sequeuce, so that we are for the first time in a position
to summarize the masses of evidence lying before us. It will
be now possible, having a clear working hypothesis before us,
to indicate the proper iuanner of continuing the investign-
tions with every prospect of reaching a successful practical
result. I propose in the remaining papers of this series to
lay down a working program for American meteorologists to
use, including in that term those astrophysicists mho are
interested in the sources of our radiant energy, RS well as the
climatologist and the forecaster mho are concernecl with the
effects of radiation upon climatic and weather variations.
The first paper will contain a popular statement of the general
conditions; the seconcl, a more technical account of the theo-
retical aspects of tlie problem of cosmical meteorology; and the
third, a description of the organization of the Mount Weather
Research Observatory which is designed to inediate between
the theoretical and the practical sides of the subject.
THE SUN A VARIABLE STAR.
In order to bring out the underlying reason for believing
that variable solar action is responsible, a t least indirectly, for
changes in the terrestrial weather from year to year, i t is nec-
essary to shorn in what wag the sun is itself unequal in its in-
ternal movements. The stin is an immense solid-liquid mass,
8G6,000 miles in diameter, mrrounclecl by a gaseous envelope
which gradually changes to rarefied matter similar to that
seen in vacuum tubes. Recent computations indicate that at
the center of the sun there is a nucleus which instead of be-
ing gaseous is nearly as solid as the interior of the earth, with
a temperature of about 1O,O0Oo centigrade; the average
density of the whole sun is 1.13 times that of water, and this
is located a t half the distance froin the center to the surface;
the surface density is not far from 0.87 that of water, and its
temperature, according to my calculation, ranges between
7000 and 6000 centigrade; a t the surface there is a sudden
transition from liquids to gases, which occurs as an explosion,
caused by the uprush of liquids from the interior. The solar
mass in such a physical state while rotating on its axis sets up
a peculiar circulation, in consequeiice of which a t the surface
a huge wave is formed like a tide that advances most rapidly
in the equatorial belt.
The body of the sun is divided up into layers of different
temperatures, like a set of dice boxes inside one another, the
longest axis extends through the sun from pole to pole, and
these slide by one another st different velocities. This pro-
duces a stronger discharge of warm material in the polar re-
gions than near t,he equator, SO that on the sun the heat is
greatest a t the poles, reversing the conclitions with which we
are familiar in the enrt,hs atmosphere.
The ericlence for these facts is found in a study of the (1 )
sun spots, which occur in belts within 35 of the ecluator; (2 )
the faculw or fleecy cloud-like forms found on all parts of
the suns surface, but most abunclrtntly wound the spots; (3 ) the prominences or gaseous flames projected in all latitudes
above the disk; and (4) the coronas, which extend to great
clistances from the surface and somewhat resemble auroras
in their nature.
3
FIG. 61.
The visible surface is divided for conrenieiice illto succes-
sive zones beginning a t the equator as shown on fig. 64, where
the advancing equatorial wave is indicated, the time of rota-
tion being marked in different latitucles with 26.68 days at
the equator, increasing to 29.50 clays a t the poles. The time
of the rotation of the internal solid nucleus is not known.
There are some arguments for supposing i t to be 26.00 days,
and others for making it 36.68 clays, but the subject has not
yet yielded to study. The above periods of rotation are those
seen from the earth as i t passes around the sun in its orbit of
365 clays.
This
is mottled with cloud-like forms resembling the heads of
ciiinulus clouds, and probably they represent the tops of
coluinns of liquid or gaseous matter rising froin the interior;
there are three minute sun spots to be seen on it, and esten-
sive regions of white crtlcium flocculi in the sun-spot belts.
The spectroheliograph has developed the power to make
pictures like this a t different levels in the suns atmosphere,
representing sections through it,, so that the action of the
vapors ancl gases surrounding a spot can be studied a t several
elevations, just as we make out the cloud forms at different
Fig. 6.5 gives an excellent idea of the risible surface.
JULY, 1905;. MONTHLY WEATHER REVIEW.
levels in the earths atmosphere by their types. I n this
picture the details are quite perfectly brought out.
Fig. 66 is an illustration of a great sun spot and the cloucls
or the flocculi in its neighborhood. Three or four such sec-
tion pictures are macle one over the other, wherein the fornis
change gradually from the lowest level to the highest. It is
very probable that the true circulation in the region of the
spots can be determined by examining the details of such
pictures. The sun spots of the winter 1904-5 closely resemble
the one in this illustration in size and appearance.
Fig. 67 gives some examples of quiescent ancl eruptive promi-
nences or hydrogen flames, as observed a t Iialocsa Observa-
tory. The forms resemble flash illuminations in clouds clur-
ing storms where no lightning discharge occurs, and are
probably due to the light from the photosphere passing
through rarefied layers of gas, in about the same way that the
aurora illumination is formed. Electrical glow discharges ancl
magnetic forces are probably in operation :It the same time.
The eruptive prominences are clue to uprushes of gas esplocl-
ing from the surface. The liquids in the interior are a t very
great pressure and temperature, but on reaching the surface
this pressure diminishes suddenly and the liquid explodes
into gaseous formations such as are shown. Enormous ve-
locities up to 1000 miles per hour are indicated. and great al-
titudes up to 300,000 miles abo.ve the surface have been noted.
Beyond the limits of the gaseous constituents of the sun
extends the corona which reaches altitudes of from 1,000,000
to 5,000,000 miles above the suns surface. The lower section of
fig. 68 gives four typical shapes, one a t the minimum of solar
activity, one a t the maximum. one a t the rising, and one a t
the falling phase. At t,he minimum the polar region is capped
with a ray-like structure in which the streamers bend away to
either side, as if they were the lines of force in a magnetic field
surrounding a spheroidal magnet. At the maximum of the
period the coronal forms are confused ancl no definite structure
is preserved, indicating that some cause is operating to obscure
the beautiful magnetic structure seen a t the minimum when
the sun is not very active. The corona of the sun can not
be observed except during total eclipses, but it is founcl by
coniparing the forms secured during the past 40 years that
i t passes through a well defined cycle. repeated in about 11
years, as is indicated in the diagram. The next total eclipse
will occur on August 29-30, 1006, and will be visible in Spain
ancl northern Africa. Parties are already being foriuecl in the
United States to make observations on that occasion.
The passage from a quiet to a strongly agitated condition
of the sun is marked also by other remarkable variations in
phenomena which are visible from the earth. The upper
section of fig. GH gives the relative frequency of the sun-spot
area as colup11ted a t the Greenwich Observatory. A minimum
occurred in 1889, a maximum in 1894, and a second minimum
in 1900, about 11 years later. The height of the shaded area
is proportional to the number of sun spots seen on the sun,
and i t indicates that the rate of increase following the mini-
nium is more rapid than the rate of decrease following the
masiiuum. Siinilar curves of sun-spot frequency have been
constructed for the last century, and in them i t is found that
there is considerable irregularity in the curve from one period
to another, S O that the 11-year period is merely an average of
the range between 8 years and 14 years. On coniparing the
sun-spot curve with the changes in the magnetic and electric
fields as obbervetl on the earth, that is to say with the posi-
tions assumed by the magnetic needle ancl with the auroral
clisplays in the polar regions, i t is shown that these three
systems are in very close accordance, and i t is conceded that
some relation of cause and eflect prevails. The inference
that the difference in the number of spots is the cause of the
corresponding change in the earths electricity or magnetism
is not sustained by more minute examination of the details,
except in a general way. The better theory is that the inter-
nal solar action produces all of these phenomena simultane-
ously, as the effects of an underlying cause which is not yet
fully nnderhtood.
We can, perhaps, convey some idea of the present state of
the investigation in the following way. The dif-liculty of the
research has been due to the fact that the sun spots are only
a sluggish register of the true solar action which causes the
variable weather conditions, and i t has been a great task to
discover a better pulse. I n 1894 the author published some
results of a stucly of the meteorological conditions in the
United States for the interval 1SS8-1893, in which it wis
found that the barometric pressure and tho temperature vary
slightly, not only in an 11-year period, but, also, in a 3-year
period which is inore clearly defined. In the same work i t
appeared that the average position of the storm tracks in the
United States sways up and down in latitude, and also that
the speed with which the storms drift eastward varies in the
same short period. The annual magnetic field gives both
periods in combination, the 3-year period superposed upon
the 11-year period, thus making the inference probable that
Frc. C8.
a94 MONTHLY WEATHER REVIEW. JULY, 1905
both periods in the meteorological and magnetic elements
depend upon solar operations. Unfortunately the siin spots
show us the 11-year period strongly and the 3-gear period
very feebly. This point has recently been cleared up by a
study of the solar prominences, which have been continuously
observed by the Italian spectroscopists since 1871.
Fig. 69 shows that great variationsoccur in the number of the
prominences and the faculw, the former being represented by
the red marks on the diagram, and the latter by the blue
marks. I n the year of minimum activity, 1889, both proini-
nences and facuh are very few in nuniber, but in the year of
maximum activity, 1894, they are very abundant in the central
zones, the prominences estencling into the higher latitucles.
r- Northern R e m imhere. I
FIG. 70.
These eruptions on the surface of the sun move up and clown
the solar disk by a law of their own, and this must depend
upon the internal energy of the sun, which, like a variable
star, is passing through a series of periodic convulsions in its
process of evolution. Lockyer, in 1902, published the result
of his discussion of the prominences, as they occur in each 10-
degree zone between the two poles of the sun. Thus, i t is
seen by fig. 70, for the Northeru Hemisphere, how different
the distribution of the prominences is in latitude. I n the equa-
torial regions,' where the spots prevail, the 1.1-gear period is
very pronounced, though there are signs of the :%year period
in connection with it. On the other hand, in the higher lati-
tudes,' the 11-year period diminishes in importance and the
%year period supersedes it.
THE STNCHRUNOITS iMETEOROLOl+IC'AL CONDITIONS ON THE EARTH.
Now, i t happens that the freqiiency variation of the solar
prominences in the higher latitudes gives the key that was
wanted to enable us to study the meteorological conditions in
the earth's atmosphere with some prospect of success. This
variation shows that the meteorological pulse is registered
most fnvorslily not in the sun-spot belts, but in the zones of
the sun corresponeling with the temperate zones of the earth,
from Iatitucle 30' to G O O . I n the polar zones in certain years
the I'roluinence frequency is very well markecl, ancl these years
corresponcl with the years of special activit,y in the earth's
electric and magnetic fields.
FIG. 71.
In order to extend the comparison of the solar-terrestrial
conditions further, I computed the annual mean pressure and
annual mean temperature for the series of years, 1872-1900,
over inany portions of the earth, comprising records for several
hunclrecl stations. They were grouped together by countries
nncl a few of the ciirves are brought together in fig. 71. I n
the upper section of this figure the prominence frequency on
t,he sun is areragecl for all zones, and the resulting curve con-
tains a 3-year period superposed upon the 11-year period. The
iuidclle section, inarked "temperatures," contains temperature
curves from the tropical and temperate zones, and i t is easily
seen, by coinparing the crests with the solar curre a t the top,
that in spite of some irregularities there is a tendency to form
the same number of crests and to make them fall on the same
years as the crests in the promiuences. The third section,
marked 'Lpressures," gives a few curves of the variations in the
annual pressures ancl these conform quite closely to the same
&em. Each curve ought to be comparecl with the solar curve
by itself, to judge of the general fact of agreement. It should,
however, be observed that this agreement is not everywhere
direct, but that in cert,ain regions an inversion takes place.
Thus, the pressures clo not increase simultaneously all over the
earth in one year and clecrease in another year, rather there
is a general surging by which the atmosphere is piled up in
JULY, 1905. MONTHLY WEATHER REMEW. 295
one region and lowered in another during the same year. This
is necessary in order to avoid the clifficulty of making the
total weight of the earths atmosphere vary from year to year.
When the pressure is generally high in North or South Bmer-
ica, it is low in Asia, the Indian Ocean, and Australia. This
condition is brought about by some profound modification in
the circulation of the earths atmosphere, by which high areas
tend to form in one hemisphere at the same time that low areas
prevail in the opposite hemisphere. I n a similar way the
changes of temperature from year to year are such that in the
tropical zones, where the sun shines fully on the earths sur-
face, temperatures rise and fall directly with the solar promi-
nence frequency; but in the middle latitudes of the earth the
opposite or reverse conditions of temperature prei ail. Hence,
when solar activity increases and more spots or prominences
can be seen, there is an increase of heat in the earths Tropics,
ancl this produces an increase in the circulation of the entire
atmosphere. The warm air of the Tropics rises more rapidly
than usual, the cold air of the upper strata over the temperate
zones pours down vigorously upon the United States, Europe,
and Asia, and these countries are covered with a rapid succes-
sion of pronounced cold waves, such as have marked the years
1904 and 1905.
The increase in solar activity shows itself in yet another way.
By putting together the tables of prominences so as to stucly
their behavior in longitude, that is around the sun in the
same zones, it has been found that the retardation of the solar
rotation in the higher latitudes relatii e to the primary equa-
torial period of 26.68 days, sways backward and forward in
harmony with the same proniinence frequency curve. This
indicates that the internal solar energy, in trying to free
itself after accumulation and congestion, sends fortli great
waves, which rotate the circulation in the polar zones fartlier
backward. The visible symptoms of this operation a t the
surface are changes in the number and location of the promi-
nences, the facule, the sun hpots, the granulation of the
photosphere, and in the form and extent of tlie great coronal
streamers. Besides this visible effect of tlie internal action,
there is the more important ancl invisible radiation which
streams from the sun and falls upon the earth.
Besides the general synchronism in the solar action just
outlined, we have a corresponding inorement in the earths
atmobphere embracing the magnetic ancl electrical forces, the
pressure, temperature, vapor tension, ancl precipitation. Con-
flicting evidence will no doubt be reconciled by a more
thorough study of the underlying facts of inversion, ancl gen-
erally the entire subject needs most careful inve-tigation.
THE METEOROLOGICAL WORK OF THE U. S. NAVAL ECLIPSE EXPEDITION TO SPAIN AND ALGERIA, AUGUST 30,1905.
At the request of Rear-Admiral C. &I. Chester, U. S. N.,
Commander in Chief of the Special Ssriice Squadron JIinw-
opolis, Dixie, and Cirsar, sent to obserre the total eclipse of
the sun, August 30, 1905, in Spain ancl north Africa, the
Chief of the Weather Bureau detailed myself and Dr.
Stanislav Hanzlik to carry out the ineteorological observations
required in this connection. Advantage was taken of the
voyage on the C ~s n r , which sailed from Norfolk on June 22,
to make some kite ascensions with self-recording meteoro-
graphs for data over the ocean, and, also, to observe the elec-
trical conditions near the water areas. We Becured seven as-
censions on the trip to Spain, aud have made suitable prepa-
rations to continue the work on the return voyage in Septein-
ber. The southwest current prevailing on the mestern side
of the Atlantic reached its maximum force about 1000 miles
east of Norfolk, and the northeast current on the eastern side
was a t a maximum less than 500 miles froin Spain. The former
is much broader than the latter, and the wind did not reach a
By Prof. FRINR H B I ~.~I W Data d 1)aroc.l. s p u n , irlgii4 27. 1705
40-2
velocity as great on the western side as on the eastern side of
the Atlantic. We found that there was no tendency to re-
versal of the temperature gradients such as Hergesell ob-
served farther to the south in the trades, and me did not
note any important diurnal variation of the temperature even
a t short distances above the surface of the ocean, though the
kites were in the air as much as eight hours during several
clays. The electrical observations on the Ctesnr include a
fen- records of the potential graclieut over the side of the ship,
an escellent series of observations on the coefficient of dissi-
pation with the Elster ancl Geitel apparatus, and a complete
set for the numl)er of ions per cubic centimeter with the
Ebert apparatus, the velocity observations being omitted.
All these electrical records were made in the calm region
surrounding the Azores, lying between tmhe two great currents
just mentioned.
After landing at GilJraltar the especlition separated into
two branches, Doctor Hanzlik in charge of the part in Al-
geria, ancl Professor Bigelow in charge of that in Spain. The
African party sailed for Bona on July 19, a i d the astronomi-
cal and meteorological station w~ils established at Guelma. It
was plaiined to organize two secondary stat.ions to supplement
the work at GLielma, but these seein to hale Leen abandoned
for sonie reason. The Spauih parties landed at Valencia
July 21, ancl the work of equipping the several stations pro-
ceeded regularly to a conclusion. On Jclg 25 a meteorologi-
cal station was arranged in the Iuqtitute of Castellon, Seiior
Josi Sariz Bremon, Director; on ,July 27 another station was
plannrcl at, Tortosa, or rather the Director of the Cosmical
Observatory of the Ebro, Rev. P. R. Cirern, S. J., agreed to
furnish copies of the regular recorclb as desired. The plan of
tliis observatory is similar to that of the Mount Weather Re-
search Observatory and contains a very excellent equipment of
modern instruments mid a corps of coiupetent observers. As it
is located mithin the belt of the eclipse shadow, it ought to give
a fine account of itself, having such remarkable advantages
for tliis occasion. On July 30-August 1 the work was organ-
ized at Porta Coeli, where the astronomical station No. 2, near
tlie southern border of the track, was located. Besides the
regular meteorological instruments, an Elxter and Geitel appa-
ratus ant1 a potential electrometer were put in operation. and
AIessrs. Scrivener ancl Straupe being left in charge. This
station has been in operation for fully four weeks, a portion
of the time clay ancl night, and a ~e r y extensive series of ob-
servations is in hand.
On August 3-6 another station was installed at Daroca in
connection with tlie astronomical station No. 1, near the center
of the belt. I n aclclition to the instruments mentioned at
Porta Coeli, an Ebert apparatnr for the number and velocity
of the ions, a Brashear polarimeter, and a solar image tele-
scope were set up. It was intended to execute a series of
radiation observations with a mercury actinometer, but the
copper box as originally made failed and it was not possible
to secure a new one till too late to make that work profitable.
The magnetic observations were inadequately organized at this
station and will not be important in this connection. All the
instruments a t Daroca have been in constant use by myself
aided by Nessrs. Rickerd. Trainor, and Olivier, and we
have obtained several thousand observations, some of the
electrical series continuing uninterruptedly day and night for
more than a week. From Daroca I proceeded to Zaragoza
and arranged for suitable observations at, the Colegio del Sal-
vador in charge of Rev. .Tosir Albiiiana, 8. J., August 8; then
to Guadalajara, where similar observations will be furnished by
Lieut. Col. Pedro Vives y Vich, chief of the Spanish aerostatic
serxice, who, also, has charge of all the balloon ascensions
a t Burgos undertaken by the International Committee dudng
this eclipse. The homing pigeon service and the balloon equip-
ment at Cfuadalajara were very interesting and instructive.
.
Plate 11.
N
Fret. 65.- Spectroheliograph of the sun, August 12, 1903, taken a
the bright sur appearance of
I
;pot of October, 1903, showir Le calcium floccu mounding ii
i
*. 67.-Typical forms of the solar prominences or red hydrogen flamer
Plate IV.