Map, 1921. IkONTfdrY WEATHER hEViEw. rn
THE CRITICAL PERIOD OF WHEAT AT COLLEQE PARK, MD.'
By W. J. SANDO.
(Author's abstract.]
In the fall of 1920 a careful study was initiated for the pur ose of ascertaining the relation of climate to the yiel of wheat grown on the Maryland ricultural Ex- periment Station farm at College Park. our varieties of wheat were used in making the study. The yield records cover a period of '12 years.
tion for each month of the o m period an for each variety were determined. fsignikxmt negative corre- lation waa found between recipitation and yield for March and May. No signi cant correlation could be found between temperature and yield. Other factors were also investigated, but further study
w i l l be necessary before their actual relation to yield are determined.
% s
Ppita-
Correlation coefficients for temperature and
DISCUSSION.
In the discussion of Mr. Sando's
C. F. Brooks that a tabulation of
inches of annual rain 9 all, and that the yields where the
rainfall was over 50 inches were about as poor as in the
s onding rainfall in different &owed that the best ields
__ - - -- - - -. . __ I Presented bolore American Meteorologicnl Society, Apr. 20.1991.
INDICATOR PRECIPITATION-STATIONS FOR PREDICTING STREAM DISCHARQE.
By H. L. STONER.
[Abstracted by J . Cecil Alter h.om an omce report, bted Jenuarp, 1921.1
SYNOPSLg.
Three precipitation stations, widely separated-and manned by coop- erative weather obwrvem, are ubhzed to redict the flood-time dis- charge of Bear River, a Utah-Wyoming-Ida%o stream who? watershed coven 2,900 quare. miles. From precipitation data avrulable at the end of January a prediction can be made,.accordjn to the author, aa to whether the flood period of March-July WIU be h q %y low aa cqmpared with the average; at the end of February a ven6cauon or mowcabon of the January predwtion can be made. at the end of March an a proxi- mation of the uantity of t h ~ run-off 'in day second-feet may !e v p - tured; and at %e end of d p d a uantity eetmnate can be given whlch will no doubt closely a proach %e actual flood-period run-off. From
a developed relation of flood and nonflood penod run-off, It ia also claimed to he possible to predict in advance the run-off durin the non- flood period. On1 quantity forecasts are attempted, no effort being made to state the Zrm of rim-off curve.-J. C. A.
From the im ortance which Bear Lake, Utah-Idaho
s tem of the Ut& Power and Light Company, comes
robable run-off susceptible to storage.'
s uare miles, and the inaccessibility of the greater part o! it, which includes mountain regions from 8,000 to 10,000 feet in elevation, the ordinary methods of deter- mining probable run-off by intensive snow surveys can not be attempted. Several years ago studies were begun by the author to determine whether the data obtained by the existing cooperative stations of the United States Weather Bureau could be us+ in forecasting probable run-off. The belief waa entertamed that while these stations were situated in the vallegs, they still might serve as "indi- cators" of the precipitation which occurs over the whole area. This has been found to be approximately the case; and is due apparently to the fact that the more important winter storms extend over large areas and precipitation occurs over similar elevations and slopes with considerable uniformity.
storage has in t K e successful operating of the generating
t f e desire to successfully predict as far in advance as
gn account o P the size of the drainage area, about 2,900 ossible the
The precipitation records from three cooperative stations have been used, namel Border and Evanston,
Wyomin Idaho border about 12 miles northeast of the north ed-of Betw Lake; Evanston is near the W om' Utah border about 60 miles south-southeast of t IY-Y e sout end of Bear Lake; and Laketown is about 2 miles south of the south end of the Lake. These are the only weather stations in this general re on havin continuous records
about 18 years. Forttnately these stations are locate rather far apart, are n desirable locations, and have dependable observers T rho have served almost continu- ously at each of the stations. As the normal precipitation at the three stations b not the same, in order to give e ual weight to the three
for each station has been converted into percentages of the average for the 18-year period, and the mean of the three percentages has been used as required in the
corn arisons. T%e run-off records available are from the Dingle gaging station from 1903 to 1915 and from the Harm g station since 1913. T h e annual values appear in Tab e 1
Both stations are situated above the point of diversion. into Bear Lake from Bear River. The quantity of water diverted from the main stream above Harer is partly a matter of river stage, and more water is diverted when the bulk of the run-off occurs in June rather than when it occurs earlier in the season. This statement, it is believed, explains the somewhat erratic plot- ting of a part of the Dingle points on the comparison di rams.
8 n figure 2 four comparisons of precipitation and m- off are made. These consist of four calendar arrange- ments of the precipitation, namel , November-JanuaPy; November-Febru April, each of w h x is compared with the March-July or flood run-off measured a t Dingle rind Harer.
Wyo., and Laketown, Utah. 5 order is located on the
%
for many years, the lengt f of the s% ortest record bein
records, the amount in inches 7 or the various periods
Yg
, November- J arch, and November-
sod UONTaY WEATHER REVIEW. MAY, mi
The purpose of the four arrangements is to furnish ag
w l y as possible each season as much of a prediction rqarding probable run-& as might be ventured. From
In figure 3 the AugustFebruary or nodood run-off of Bear River for the ears 1903-1919 has been plotted a ainst the previous drch-July or flood period run-off. the relations shown in the comparisons it is possible, as B rom the relation found to exist between the run-off
FIG. l.--Cokpsrisons of precipltstlon and run-OR.
the recipitation records are received from nionth to mont \ , to venture the following predictions with the ositire assurance that the actual run-off performance will [ear them out: At the end of Januar a prediction as to whether the
or hgh as compared with other years; a t the end of F%i ruary a verification or modification of the end of January prediction; a t the end of March an approximation of the quantity of run-off in day second-feet may be ventured; and a t the end of A ril a quantitative estimate can be
actual run-off. This last estimate can be ‘ven when the storage period is less than half elapsed. fft should be noted that the comparisons provide quantity forecasts only. The rate and time of occurrence are not attempted, as an inspec- tion of the existing run-off records reveals the fact that
the form of the flood run-off curves for different years bear little relation to one another. The straight line raphs on each of the four parts of
age run-off, MarchJuly, were comparable wit the aver-
e precipitation, expressed in percentages, for each of g e periods shown. This assumption was used for the November-January and the NovembeiLFehruttry periods simp1 to show that the tendency of the points was to €dl t d ~ some such line. The points plotted so scatter- for t ese dates, as a matter of fact, that it was impos- a 3 e to develop the apparent relation between run-off
+d precipitation at these times. This assumed relation was continued through the other two periods to show the difference between such assumption and the apparent relation developed by the curves drawn. These curves am a parently the curves of best fit. d k o n hetween 3ood and nonflood period run-of.-It being apparent that there is little relation between the precipitation during the suimer and the run-off during
the correaponding months, the curves shown on Diagram No. 2 have been prepared coin aring the run-off for the MerchJuly and the August- Ep ebruary periods. This is essential for the purpose of also determining in advance of its occurrence the available energy of the generating
syateru during the nonflood period.
run-off for the coming ir ood period will be low, aver
given which will no B oubt be closely approached by the
f
@re 2 have been f ram as if the percenta e of aver-
periods as expressed by the curves, it would seem appar- ent that the variation of the run-off of one year with another is practically dependent upon the amount of
precipitation during the previous winter period, con-
Fxa3.-NonBood r u n 4 of Bear River, 1W-1919 compared with p d h g flood periodrun4.
~a y , imr. UONTHLY WEATHER REVIEW. 303
sidered as November-April; and that the precipitation which occurs outside that winter period, unless abnormal, has relatively little effect in varying the run-off. In other words, i t would seem that the winter snows afford the main su plv from which the entire gear’s run-off
shown on Diagram No. 2.
The purpose a8 stated above for attempting to show the relation expressed by the curves oil the diagrams is to permit estimating probable water supply as far in
occurs. Tab P e No. 2 (not reproduced) gives the data
advance as possible. During the period August-Febru-
my the flow of Bear River is relatively steady and not subject to great range in stage. Hydrographs show much less variation in form during this nonflood period than occur during the flood period. Such being the case, it should be possible to airly accurately estunate in advance the monthly run-of? durin period by using the form shown by the previous years, being relation shoyn in the 5 iagranis. uided as to total
NOTES, ABSTRACTS, AND REVIEWS.
RESIGNATION OF DR. C. F. BROOKS.
Charles F. Brooks, Meteorologist, Unit,ed States Weather Bureau and Editor of the Mommy WEATHER REVIEW, resigned on June 30, 1921, to nccept a newly created associate rofessorship in meteorolog and cli- matology at Clar! University, Worcester, &ass. He writes as follows concerning his new work:
Dr. WalIace W. Atwood. the new president of Clark University. is a graduate school of geography. He fittingly recognizes
Et%$% the first requisites in any well-rounded system of instruc- tion in geography is a study of climates. for the atmospheric condition8 control to a large extent both the agricultural products and the living habits of man. President Atwood also appreciates that climatology can not be taught adequately without the hysical aspects of mete-
. Thus, beginni3i.n the Summer &hool of 1921. elementary s %w .w e d courses an op rtunities for research in both mete- orology and climatology are aged. The titles of those to be givenin the mnter semester are: Meteorology, The Paasing Weather, Clima- tology, Climates of the World. Climatic Environmenta of the White Race. A fair1 complete weather-observing station is being estab- lished, primarir for urpoees of inatruction. The plan of dark tniversity includes research aa well aa teaching. For example, each member of the staff of the School of Geograph is
expected to spend several months every two years in travel. $he results of each expedition are to be published within a year after the return. The United Statea Weather Bureau haa been most helpful in various ways, especially in providing publications for the univereity library.
This addition to the all-too-few institutions offering graduate instruction in Meteorology and Climatology is welcomed by the Weather Bureau as providing anot,her source from which ih scientific personnel can be re- cruited.-A. J. H.
THE AURORA OF MAY 14-15, 1921.
A brief summary of this brilliant and noteworthy aurora will be’ presented in the next issue (June) of the REVIEW. Sufficient data were not available in time to include the account in this REVIEW.-A. J. H.
FATHER FROC, S. J., HONORED BY FRANCE.
From Nature London (May 5, 1921, p. 3081, we learn that the French Government has awarded the Cross of the Legion of Honor to Father Roc, S. J., who for more than a uarter of centu haa been connected with the
at the Jesuit observatory in Manila that Father Faura in 1879 for the h t time predicted the existence, dure
meteor0 4. ogical work at 2-ka-wei Observatory. It was
tion, and course of a typhoon in the Far East, and the work at both Manila md Zi-ka-wei has been of the
reatest importance to those who sail the China seas.
!kka-wei, which stands about 4 miles from the inter- national settlement of Shanghai, derives its name from a
distin uished Chinese who was converted to the Christian
lies close to the observatory. Besides the observatory the Jesuit mission has here a fine cathedral, a college, an
e, a convent, and a natural history museum.
Chevalier and Gauthier, has the support of the com- munity at Shanghai, and the observatory at Zi-ka-wei and those at Zose and Liu-ka-pong connected with it are an object lesson to the Chinese Government.
faith % y Matthew Ricci 300 years ago, and whose grave
The OrphanY wor- of Father Froc and of his colleagues, Fathers
5---.5s (54)
ORIGIN OF THE SOUTHWEST MONSOON.’
By G. C. SIMPSON.
[Reprinted from Nulure, London, Mar. 31,1921, p. 154.1
It has generally been held that the southwest monsoon owes its origin to the great difference of temperature which exists during the summer months between the heated land surface of India and the surrounding oceans, the general idea being that the warm air over the land rises, and damp air from the sea flows into India to take itas place, thus resulting in the stron southwest winds, the rainfall itself being due to the coo 7 ing of the air as it rises over India. This theory has to face the difficulties that the tem- perature over India is much higher in May, before the monsoon sets in, than it is during the monsoon itself; that the temperature is higher in years of bad monsoon than in years of good monsoon; and that the part of India which has the highest temperature and the lowest pressure, and where ascendin currents should be the greatest, is a region of practic 3 ly no rainfall throughout the monsoon. The true explanation of the southwest monsoon can be obtained on1 by taking a wide view of the weather
the summer nionths in the Northern Hemisphere. It is then seen that the southwest winds are not due to the temperature in India, but are a relatively small part of a
general circulation of the atmosphere caused by a region of high pressure over the South Indian Ocean and a region
conditions over T arge parts of the earth’s surface during
1 Abstract of 8 paper entitled “The Southwest Mnmoon;’ read to the Royal M e b
orological 6Oeiety on Wednesday, March 16