MAY, 1925 MONTHLY' WEATHER REVIEW 221 Low. In relation to these types the following typical This latter fact, however, may he due in part at least to surfaces of discontinuity were distinguishable: 1. Xeur the prosimity of t,he lake. While it is true the European the s.wrfme.-These appear frequently on the front side observations were not made under the same conditions of secondary de ressions and are related to the shadow so far as the pressure distribution is concerned, yet the cold strata whict are separated from the upper warmer American observations were ma.de during conditions current by an abrupt change in teni erature. 3. Inver- favorable for cloudless weather and the downward move- sions ~6thFr. Nb.-The mean alt,itucf e of these cloutls is ment of air. It is evident from this table that under about 600 m. below the main cloud mass a.nd they are similar c.ircumstances in this c.ouiit:y t,he same condition often accorn anied by sniall inversions. Witah more Irevails, viz, a gradual decrense in the mean relative observationa Pdata it would be interesting to investigate Iiuniidity with increase in elevation.-L. T. S. the relationship which this condition beais to t.he Bjerk- ness theory of surface discontinuities. An inversion SUNSPOTS AND THE WEATHER AT GALVESTON, TEXJ was found directly below the main Nb. la er in only 3 By I. R. TANNEHILL cases. 3. Inversions in the main Nb. L.yer.Slight frequent here especially at the beginning [Weather Bureau office, Ctalvcrt.on.Trs., May 25, IE5l of precipitation. 4. hi.t~er.sioii.sat the iipper The chief difficulty in coordinating solar sncl terrestrial clouds.-These occur only witrh relat'ively conditions lies in the. absence of coinplet,eseries of obser- which there is only moderate recipitation, vat,ions on solar activity. Present observat,ions of that most frequently above 3,000 m. in the %. Cu. level. nature cover too short a period to yield permanent An adequate explanation of any of t.he above results. classes is hardly possible from the records of on y?;:: 3 The variation in the number of sun s ots as related to aerological st,ation. the weather on the earth has been the suf: ject of numerous The author gives in tabular forni the percentsge fre- studies most of which probably are faiiiiliar to tlie reader. quency of wind direct,ion up to 4,000 ni. (luring the In some of these investigations it is assumed that the occurrence of preci itation. The predoniinat,ing direc- effect of changes in solar radiation will be felt throughout tion is west for all R eights. The striking charact,eristk the atmosphere, as a general rise or fall in the temperature is shown that especially in sout.hern Germany winds with of the atmosphere as a whole, the effect being greatest a N-coniponent. greatly predominate over winds wit?h in the Tropics. Others have assumed that the changes in a S-corn onent durin the occurrence of recipitat,ion. the earth's ntinospliere will be felt chiefly in the higher In the AP pine forelan 8s all winds from SE- k7 have more leveb of the troposphere, that these changes will entail or less of the foehn character, while those blowing taoward other changes in the surface pressure of the earth, etc. the mountains necessarily roduce phenomena associat,ed Still others claim, and with resuon! that the correlation with the forced ascent oP air currents. It was found coefficients will be negative in one region and positive impossible to classify these records according to definite in another. ressure t pes since in 80 per cent of the cases there was The writer presents in outline the results of studies found to rl e an irregular pressure distribution in which of the records of a single station in an effort to associate secondary depressions played an important rde. This changes in the spottedness of the sun with terrestrial latter fact reveals the difficulties in the prediction of weather changes. precipitation for this region. The zcr.ind.-Dat.a of frequency of south and southwest Disciission.--The reference by the author to tlie de- win& in suinnier months, 1571-1024, smoothed b taking crease in t.he mean relative humidity up to over 4,000 m. t.he niean of bhree consecutive values allocateB to the and his inference therefrom relatiye to the supposition middle year were compiled and plotted in a curve. A that the descent of air froni higher altitudes is the cause curve was also prepared showing the chan es from year of its dryness, etc., might, lead the reader to sus ect to year in 6he frequency of southeast winds !?or the month some undue influence of local character, since tR ese of July. This curve is practically the inverse. of the c.urve observations were made near a lake. It therefore would for south and southwest winds. seem of interest here to show the results found for the There is a rough para.llelisni between the frequency of southeast quadrant of anticyclones in this country as sout.11 and southwest winds and the curve of sun spots, determined froni kite observations made at the Drerel alt,liough the curves for t,he two eleinenbs are at times Aerological Station near Omaha, Nebr., froin 1915 to lacking in synchronism. 1924. These are given in the following table and are Wind Telocit,y data for April and May, tlie two months based on 50 and 61 flights made during the sumnier and best suited t.0 the ur ose of the investigation, were winter seasons, revpectwely : prepared and stuclie(t: KO correct.ion was attenipted for the results of a change in the anemometer esposure made in 1901. An increase in wind ve1ocit.y with increase in sun spots is noted in four periods bet,ween lSS0 and 1920, although here again t.he two curves are not. closely congruent. The wind speed for July-a month in wliich accidental changes in wind speed are at a minimum, by reason of the sniall number of cyclones which app~OaChwithin 500 These data represent the ascent only, the average time miles of the station-is shown by two curves, the first of which occurred about 7 a. in. and 8 a. in. for suininer representing t.lie chmges froni year to year in t,he wind and winter, respectively. This fact, of course, esplains speed at the hour of least wind movement, near sunrise, the rapid decrease in the lower levels from the relatively t.ncI the second representing the changes for t.1~hour of high values found at the surface. It is probable that the greatest wind speed, or tlie converse of the first,. sanie method was used for the European data since this I Author's ahstmct. Origind text snd illus1ratioi:s arc file4 in \!'cather Bureau rapid decrease is even more pronounced than for Dresel. Library. Unauthenticated | Downloaded 09/28/21 04:14 PM UTC 222 MONTHLY WEATHER REVIEW &Y, 1925 The relation of these two curves to the sun-spot curve A 1330 and at 7 a. m. and 11 a. m., May 1. Numerous is not clear. iP ot balloon runs wero made May 1 at the local aviation The temperatu.re-relat.ion.-A variety of material was Eeld by the United States Army meteorological service. collated to illustrate this relation and the conclusion was Other information furnished by the Weather Bureau reached that the reaction of terrestrial tern erature to included daily weather maps, daily weather bulletins, solar changes due to variations in the spottea ness of the forecasts for Missouri, Kansas, Nebraska and Iowa, a sun is quite com les and that there are apparently other s ecial weather summary and indications issued by the influences not fuP ly understood. $strict forecaster at Chica 0, based on special noon The rainfall relation is likewise not obvious. I con- observations May 1, and sc%. edules of radio broadcasts dude as a final sumniation of the results of the study: for the benefit of the contestants, three of which carried (1) There are some striking resemblances between the radio receiving set.s. Porecasts and summaries of upper curves of weather elements and that of sun spots, but air conditions were broadcast for the benefit of the pilots with numerous irregulnritles of short period not removed at intervals during the time the balloons were in the air. by the smoothing processes. Theso radio bulletins were prepared by the Weather (3) The change in weather conditions frequently Bureau at Washinoton and Chicago and sent by telegraph precedes the change in sun spott,edness which leads to the to a number of Kroadcasting stations that were most inference that they are npt related as cause and effect. favorably located wit.11 respect to the probable path of (3) There is some evidence that the effect of solar the balloons. variations differs with tile season and the locality. On startiii the balloons were carried to the south- (4.j The problem is quite complex and the meteornlogi- southeast. fiiose rising to higher levels within a few cnl records are of inadequate length for the purpose. houis after starting moved more in a southeasterly direction and at a greater speed than those keeping nearer MILD WINTER OF 1924-25 IN BERLIN the ground. The courses of all the balloons were .the results of winds flowin from a ridge of high ressure Dr. G. Hellniann in the April, 1925, number of the which estended from Eanada to the Gulf of bexico.