Measurements of Solar Radiation Intensity And

MONTHLY WEATHER REVIEW Editor, ALFRED J. HENRY

VOL. 58,No. 2 CLOSEDAPRIL 3, 1930 W. B. No. 1008 FEBRUARY, 1930 ISSUEDMAY 2, 1930

MEASUREMENTS OF.SOLAR RADIATION INTENSITY AND DETERMINATIONS OF ITS DEPLETION BY THE ATMOSPHERE By HERBERTH. KIMBALL

[Weather Bureau, Washington, 1). C., 1;ebruary 26. 19301 This paper is intended as a supplement to one on the TABLE1.-Slations which obtain recorda of the total radiation received on a horizontal surface from the ~uiiand sky same subjects that was published in this REVIEW, ~. - 55: 155-169, April, 1927. It is based principally on Longi- Alti- replies to a circular letter dated December 1, 1027, tude tude Period Instruments addressed to 30 heads of observatories or meteorological - services, and requesting corrections and additions to the (I, t4eftr (1) Liucoln. W5uh Yti 41 w 351 July, 1YlbDecem Callendar. lists of pyrheliometric stations and the pyrheliometric Nebr. ber, 11129. (2) Madison, 43 05 N 8Y 23 w 309 April, 1911-Decem Do. data published in the earlier paper. Wis. ber, 1929. The replies received have resulted in the addition of 11 (3) Chicago, I11 - 41 47 N 8; 35 W 210 September, 1923- Weather Bureau December. 1928. thermoelectric. stations to the list of those measuring and publishing the (5) H ashington, 3Y 56 N 77 05 W 137 November 1914- Callendar. total radiation (direct diffuse) received on a horizontal D. C. October,'lQTZ. + 126 November. 1922- Weather Bureau surface, and of 4 stations that include in this measure- December, 1~29, thermoelectrlc. (6) New ?York. 40 46 N 73 5s w 43 April, 1924-Decem Do. ment direct solar radiation only. N.Z.(Cen- ber, 1929. tral Park Forty stations have been added to the list of those Obsema- measuring and publishing the intensity of direct solar tory.) (11) Davos Platz, 46 48 N 9 49 E L, GOO Jauuary,cember, 1922-De- 1W. Davov pyrhelio- radiation at normal incidence, but of these eight are Switzer- graph. stations in Union of Socialist Soviet Republics whose land. (14) Stockholm, 59 21 N 18 04 E 44 July, 192>June, Kngstram.1 publications are not available to me. Sweden. 1Y2i. (15) S 10 u t z k 59 41 N 30 29 E 40 Jauuary, lQZ@-De- Crova-Sloutzk; I A considerable number of stations previously listed (P3vlovsli, . cember, 19s. Savinoff. have published additional data or summaries. These Union of Socialist include all with station numbers less than 18 in Tables Soviet Re- publics. 1 and 2, apd less than 100 in Tables 6, 7, and 8. (19) La Jolla, 32 50N 17 15 W 26 July, 19% and Weather Bureau Calif. November, 19%- thermoelectric. December, 1929. (19 Pasadena, 3.4 15N 118 17 \V WG 1926-1923- - __ - -. Do. CORRECTIONS AND ADDITIONS TO PREVIOUSLY PUBLISHED Calif. DATA (20) Fresuo,Calif. 36 43 N 1Y 4Y w 26 October.cember, 1923-De- 19%. Moll-Engelhard.

14 25 w 9 300 January, 1927-De- Weather Bureau Idaho. cember. 1~29. thermoelectric. The following corrections should be made in the data (22) Qainesville, 29 39 N $2 21 w 71 October. 1YZWsu- hIoll-Richard. published the REVIEWabove cited: Fia. uary. 1Y30. in f2) Pittsliurgh, 40 26 N YO 02 w 34 1 Uec. 24, 192&J31l. Weather Bureau Pa. 28,1930. thermoelectric. Table 1 : Toronto, period, blank; should be August, 191 1-Septem- (24) hluottas- 46 32N 9 53 E !, 4% July 21-Aug. 2, dngstriim pyra- ber, 1916. Muraigl. uut. 2-14, 192.3, nometer. Jan. %3i, Mar. Table 6: 3-13, 1024. Batavia, altitude should be 15 meters. (25) Zugspitze, 4i 25 N 10 59 E !, 962 August, 1926-July Do. Innsbruck, longitude should be 11' 24' E. Qermany. 1YZi. 20' (26) Theodosia, 45 02 N 35 24 E 15 March,cember. 192GDe- 1828. Crova-Sloutekf La Quiaca, latitude should be 06' S; longitude should be Union of Savinoff. 65" 36' W; altitude should be 3,462 meters. Socialist Mount Czarnohora, Worchta should be Worochta. Soviet Re- Pangerango, latitude should be 6' 45' S; longitude should be ' publics. (27) Kislovodsk, 43 54 N 42 42 E 850 July-Decemher, Do.1 106' 58' E. Union 01 19%. Paris, latitude should be 48" 48' N. 8 o ci a1i s t Sonnblick, longitude should be 12' 57' E. Soviet Re- publics. Ursanova should be Ursynov. (28) Mount El- 43 17N 40 12E 8. 200 Aug. 10-19. 1926 ... Do.1 Zakopane, Austria, should be Poland. brus, Un- ion of So- Table 8: cialist So- Jungfraujoch, Stein, M. Edward, should be Stenr, Edward. viet Re- Paris, Bureau Central Meteorologique de France, 1907-1914, publics. should be 1907-1924. 1 Radiation records BS recorded have bean reduced to the Smithsonian pyrheliometric MBmoires, 1907-1914, should be 1907-1924. scale of 1913 by multiplying by 1.035. 105732-3G-1 43

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TABLE1.-Stations which obtain record8:of the total radiation received TABLE2.-Sources of data given in Tables 3, 4, and 64ontinued. on a horizontal surface from the sun and sky-Continued (23) PITTSBURGH. ~~ I KIMBALL,H. H. 1930. Solar Observations. Mo. Wea. Longi- Alti- Period Instruments Rev. 58: 26. tude tude (24) MUOTTAS-MURAIQL. ___~- -__ DORNO,C. 1927. Grundzuge des Klimas von Muottas- 0, ’ Meters Muraigl. (Oberengadin.) (29) Paris, France 48 48 N 229E 50 1926 _._.-.- - ..._ - Moll thermopile; (25) ZUGSPITZE. (Paw St. Richard register. Maw). (For cloudless LIPP, HERMANN.1928. Beitrage zum Strahlungsklima skies.) der Zugspitze. Deutschen Meteorologischen Jahrbuch (30) Tiflis, Union 41 43 N 44 48 E 421 June-August, 192i A. &1i..l Crova- fur Bayern. of Socialist Sloutzk. Soviet Re- (26) THEODOSIA. KALITIN,N. N. 1927-1929. Bulletin de la Cornmission 68 18 E 476 19261928. - - - -... A. Crova.1 Actinombtriaue permanente de la Observatoir6 G6ophv--- sique Centril, 1‘926-1928. (27) KISLOVODSK. publics. KALITIN, N. N. 1929. Bulletin de la Commission (33) Irkutsk. 52 16N 1W 19E 467 A. 1 Crova-Sloutzk- Union of Linke. Actinombtrique permanente de la Observatoir6 GBophy- Socialist sique Central, 1928, 2-3. Soviet Re- (28) MOUNTELBRUS. publics. KALITIN,N. N. 1928. Solar, Diffused and Terrestrial Radiation According to Observations Effected on 1 Radiation records as recorded have been reduced to the Smithsonian pyrheliometric Mount Elbrus. Jr. Geophysics and Meteorology. scale of 1913 by multiplying by 1.035. 3. No. 3. 195-209. (Reprint.) (29) PARIS. T.4BLE 2.-Sources of data given in Tables S, 4, and 6 BRAZIER,C. E. 1926. Observations et Travaus Acti- (1) LINCOLN. nom6triques effectuis A 1’Observatoire du Parc Saint- KIMBALL,HERBERT, H. 1916-1929. Solar and Sky Maur pendant l’anne 1926. Annales, Iiistitut de Radiation Measurements. Mo. Wea. Rev., 44: 178. Physique du Globe de 1’UniversitB de Paris, VI., 121. Monthly thereafter. (30) TIFLIS. (2) MADISON. Mossidse, Schalva. Aktinometrische Beohachungen am KIMBALL,HERBERT H., and MILLER, ERIC R. 1916. Geophysikalischen Observatorium Georgiens zu Tiflis. The Total Radiation Received on a Horizontal Surface Aktinometrischer Monatsbericht, 1928, No. 1. (Geor- from the Sun and Sky at Madison, Wis. Mo. Wen. gien and Russian text with German abstract.) Rev., 44: 180. (31) TASHKENT. KIMBALL,HERBERT H. 1916-1929. Solar and Sky Radi- KALITIN,N. N. 1926-1928. Bulletin de la Commission ation Measurements. Mo. Wea. Rev., 44: 179. Actinombtrique permanente de l’observatoire GBo- Monthly thereafter. physique Central. (3) CHICAQO. (32) IRKUT~K. KIMBALL, HERBERT H. 1923-1929. Solar and Sky KALITIN, N. N. 1928. Bulletin de la Commission Radiation Measurements. Mo. Wea. Rev., 51: 533. Actinom6triaue permanente de l’Observatoir6 GBo- Monthly thereafter. physique Cehrac (5) WASHINGTON. KIMBALL,HERBERT, H. 1915-1929. The Total Radia- NEW DATA tion Received on a Horizontal Surface at Washington, D. C. Mo. Wea. Rev. 43: 100-111. Monthly there- Vertical component of solar radiation.-Table 3 gives after. (6) NEW YORK. monthly averages of daily totals of solar radiation received KIMBALL,HERBERT H. 1924-1929. Solar and Sky Radi- on a horizontal surface, (1) including both that received ation Measurements. Mo. Wea. Rev., 52: 225. directly from the sun and that received diffusely from the Monthly thereafter. sky; (2) the component received directly from the sun; (11) DAVOS. DORNO,C. 1928. Tagliche und Sakulare Schwenk- and (3) the component received diffusely from the sky. ungen du Sonnenstrahlung im Davos. These daily totals are obtained by means of instruments (14) STOCKHOLM. that make a continuous record of the intensity of the AN~STROM,ANDERS. 1928. Recording Solar Radia- solar radiation that falls upon their receiving surfaces. tion. Meddelanden frhStatens Meteorologisk-Hydro- In most cases the instrument records (l),the intensity grafiska Anstalt. Band 4, No. 3. (15) SLOUTZK. of the total radiation (direct + diffuse). An increasing KALITIN,N. N. Bulletin de la Commission Actinom6- number of stations are now recording continuously the - trique permanente de l’Observatoir6 Gdophysique Cen- intensity of direct solar radiation at normal incidence. tral, 1925-1928. The vertical component of this intensity gives (2), above, Rates of solar energy according to observations effected at the Magnetic-Meteorological Observatory Sloutzk and the difference between (1) and (2) gives (3), the (Pavlovsk). Recu6il de Gbophysik. Tome VT, Fas- intensity of the diffuse solar radiation received on a cule 1. horizontal surface. (18) LA JOLLA. This latter measurement ma.y be made by an instru- RICHARDSON,BURT. 1929. See Solar Observations. Mo. Wea. Rev., 57: 300. Monthly thereafter. ment that will give the total (direct + diffuse) radiation, (15) PASADENA. by interposing a screen between its receiving surface and RICHARDSON,BURT. 1929. See Solar Observations. the sun. It includes radiation received from both clear Mo. Wea. Rev.. 57: 300. and cloudy skies. (20) FRESNO. KIMBALL,H. H. Solar Observations. Mo. Wea. Rev. Table 4 gives smoothed weekly averages of the total 57: 26. Monthly thereafter. solar radiation (direct + diffuse) received on a horizontal (21) TWINFALLS. surface. The averages have been smoothed by the well- KIMBALL,H. H. 1927. Solar Observations. Mo. Wea. known smoothing formula, Rev. 55: 29. Monthly thereafter. (22) GAINESVILLE. KIMBALL,H. H. 1930. Solar Observations. Mo. Wea. a+2b+c Rev. 58: 26. 4

Unauthenticated | Downloaded 10/01/21 04:47 AM UTC FEBRUARY,1930 MONTHLY WEATHER REVIEW 45 TABLE3.-Monthly averages ojdaily totals oj solar radiation received Table 5 gives the annual totals of solar radiation on a horizontal surface (gram-calories per square centimeter) (direct + diffuse) received on a horizontal surface. They L - - are expressed in both gram-calories per square centimeter and in kilowatt-hours per square dekameter. The latter values are included for the reason that the general public WAB : d 22 2 is more familiar with electrical t,han with heat units. - -I- - -_ - -I--- They are obtained from the former by multiplying by Pasadena I ______1 302 383 427 532 568 512 582 565 490 1 400 I 365 the factor 1.161. ___..__. .__------.__. 2% 35s 3S1 470 454 487 524 500 ____ ._,- ____ ‘80: ..-. TABLE5.-Annual totals of solar radiation received on a horizontal ‘34 325 424 473 562 433 509 sitrface (direct +diguse) 73 181 295 344 416 422 310 209 110 47 i5 1% 295 432 450 414 319 218 107 49 T--..- 39 105 219 318 347 32s 332 147 50 12 Direct soh 11 Kilowatt- Statious Or. CJIJ Kilowatt- Diffusesolar E-.... 18 36 81 76 104 103 86 87 71 5i 3i hours I rm.2 1 hours Sloutzk 1 ...__...... _._25 70 194 269 34 1 39 445 256 176 69 19 ~ Direct 7 .__._..__..Y “6 113 130 194 20 311 1% 104 30 4 Disuse 3 _.._._._._16 45 81 129 14i 163 134 112 2 39 1.5 Passndena, Calif___... 16,5410 1YZO.IB Theodosic, Union of Theodosia I ___._____._76 108 195 282 433 534 519 442 338 215 113 Fresuo, Calif. _....._169691 197011 Socialist Soviet ..-. .... 117 ..-. 312 451 408 ._.. 143 34 Direct 7 _____._.___-, 84 Tsvin E’ulls, IddltJ... 15IGlB lis345 llM30 Diffuse 8____._._._ .... .-.. ,b .... 121 b3 141 ... 54 ?2 79 Lincnln, Nebr ___.___13634li 15s298 Kislovodsk 1____._._.. ..--..._ 810 357 37i 393 4h3 ... 26.4 240 193 htadison, Wis. -.---.118i44 13iSD2 Direct solar rktion only Direct 7_____._ _-.----- .... 169 1s1 236 255 372 ..._____ I ____-132 Chirago, Ill ....______90280 1M792 Ditruse 8______. ~ ...... 141 li6 141 13s 111 .__-_._ _.__- GI W’nsliington. D. C... 121641 141225 1, I Mount Elbrus: 1 New Tork, N. I-.-.. Y-lSOl 11m.I 11 Paris. France: i Clear sky..------___.------...... - .- -. ti97 ______.._.._.Stockholm. Sweden. I774YG lS9S3S 53227 61797 .-. .. -. .. -. Cloudy sky ....-----.. ..-. .------__-. - - - 3M - - - - - . 2 78851 125893 145930 Pxis: 7 L):~vor PIatd, Swit- Clear sky___._ ____ 110 1so 305 475 660 5x0 570 500 390 ”75 135 wrhntl.-. ______13N57 151693 Average sky---..- 24 5G 104 190 269 273 279 L60 172 i -77 1 32 Zugspitze, Uermany. 123125 1417Y6 102105 llY544 Tiflis 7 ._..._._._._-_-_---- .-.. .- - - -...... -. 430 Si? 379 Yleutzk. Union of Tashkent 1_._..___-___ 65 119 186 293 332 541 5‘22 511 Swialist Soviet Irkutsk 7 .______._.___28 Si 204 260 285 334 345 272 Republics. - __ .- __ - 6M97 blm 74545 - - -

1 Total radiat,iou (direct 4- diffuse) 8 For Oct. 2-14, 1 Instrumental record, 192527. 8 Computed. a For Jan. 2Ck2i. 1 c’oruyutrd from relation between recorded YIUOUU~sud degree of cloudiness 2 For Mar. F13. 7 Vertical component of direct. 4 For July 23-Aug. 2. 8 Vertical component of diguse. Solur rtrtlitrtiotb intensity ut tiorid incidence.-In Table TABLE4.-Weekly means of dailv total solar radiation (direct 4- G, under “Instruments, ” the following abbreviations diffuse) received on a horizontal surface (gram-calories per square have been eniployed : centimeter) ~ ~ ~ ~ ik =Angstrom electrical compensation pyrheliometer. Madi- Lin- Chi- New Twin Fresnc >a Jolls Ma. =Marvin electrical resistance pyrheliometer. Week I son coln cago York Falls S. I. = Smit,hsonian silver-disk pyrheliometer. I- I- =Moll pyrheliometer as modified by Gorczyfislii. 138 185 79 107 17E 123 272 M. G. 148 192 80 108 183 134 2&1 Mi. = Michelson bimetallic pyrheliometer. 164 m2 88 115 191 190 243 182 215 100 140 18C 235 257 Table 7 sunmarizes the measurements of solar radia- 196 233 108 141 186 257 260 tion intensity at normal incidence. In the column 210 267 110 139 238 308 268 230 284 127 138 267 363 310 headed “Data” t’he symbols have the following signifi- 255 310 160 174 257 398 361 280 338 189 234 249 397 376 cance : 288 356 196 287 258 386 344 A,=intensity after the solar rays have passed through 316 377 208 262 286 391 322 335 397 m 256 2ea 470 3i8 air mass in, where unit air mass is the atmosphere 358 407 238 270 258 510 417 380 413 276 309 349 512 446 passed through with the sun in the zenith; and 39i 421 304 332 422 551 456 in general 410 442 308 334 455 595 424 428 469 319 346 529 639 473 450 480 355 355 eQ4 691 608 465 487 377 362 639 677 488 a tniospheric refraction in seconds 474 515 384 375 710 656 ------m= 482 528 402 396 734 686 ------58.36” X sin Z(Z = sun’s zenith distance) 493 522 420 411 693 706 ------505 528 421 412 657 667 ------509 536 412 408 664 6% 4% A,,, = mean of daily maximum intensities. 520 560 414 399 712 731 508 533 586 4% 402 710 734 517 a = atmospheric transmission. 534 583 4411 410 700 727 530 Numerical subscripts designate tlie vnlues of m for 526 572 432 405 73 723 548 512 562 415 402 i15 710 515 which values of d or a are given. Thus, 480 543 396 397 681 690 429 469 521 366 370 618 678 42i A2= radiation intensity when in = 3. 454 504 356 346 e38 647 442 443 495 362 331 617 609 454 430 485 388 314 591 602 453 404 462 357 317 669 601 400 a+1 or the transmission when the sun is in the zenith. 370 428 315 289 544 575 289 A0 347 405 2% 308 530 516 232 335 373 267 274 496 467 288 a 298 349 2.34 u4 464 459 388 = atniospheric transmission indicated by -3 270 323 2x3 247 429 444 .-_--- 364 247 307 190 247 407 414 423 2M A2 224 294 171 198 390 379 448 252 a09 2n9 1.54 188 351 335 423 248 Table 8 gives tlie sources of the data summarized in 184 241 136 171 292 305 354 237 162 221 114 144 232 290 344 240 Table 7. 143 #xi 99 124 184 289 338 255 131 198 92 116 152 241 274 272 It will be noted that tlie values of A? in Table 7 are 128 187 80 108 143 208 272 291 higher in wintor than in summer. This is partly due to 121 172 71 101 136 174 307 290 118 165 68 86 122 159 275 287 the fact that the earth’s radius ve,ctor reac,hes its maxi- 122 170 72 99 130 1M) 2R3 280 159 mum value in e,arly July and its minimum in early 129 179 79 104 137 317 262 January, and partly to the fact that the atmosphere contains niuch less water vapor in winter than in summer.

Unauthenticated | Downloaded 10/01/21 04:47 AM UTC 46 MONTHLY WEATHER REVIEW FEBRUARY,1930 TABLE6.-List 01 pyrheliometric stations - __ Altl- Statlon Latitud Longitudi tude Perlod Instrument __ I 0, 0, Wetera (100) Antibes, France ______43 34h 7 7E 35 (101) Antra, Finland ______61 00h e 14 E 15 (102) Ariana Tunis______36 49 h I 57E 10 (103) Baku, bnion of Socialist Soviet Republics 40 22 h 49 50 E 14 (1M) Borovoy, Samara, Union Socialist Soviet 5300h 52 03 E 82 Republics. (15) Davos, Switzerland-...... 46 48 h 9 49 E 1,600 (17) Eskdalernuir, Scotland ______55 19 h 3 12 w 244 (24) Fresno. Calif. - ______~ ______36 43 h 119 49 w 110 (105) Qiewont, Poland .._.__._._._._._____.-~.- 49 15 h 20WE 1.900 (loti) Go1odnay.a Steppe, Union Socialist Soviet 40 25 N 68 45 E 320 Republics. (10:) Helsinglors, Finland ______60 10 N 24 67 E 40 (108) Irkutsk, Union Socialist Soviet Republics- 52 16 N 104 19E 470 (108) Jokkmokk, Sweden ...... __ 66 36 N 19 51 E 256 (110) Jungfruskar, Finland ...... 60 9N 21 5E 20 (34) Ratharinenhurg (Sverdlovsk), Unionof So. 56 SON 60 38 E 290 cialist Republics. (35) Kew Obs'y. Eng ______51 28N 0 18 w 6 1922-19% (continuatiou).______.______d.1 (111) Khangn, -4lgeria ______.____.__.._____._._.34 49 N 6 13 E 253 June 17, 1877 ______Violle. (36) Kef, Union of Socialist Soviet Republirs- 50ZN 30 30 E 183 1W3-1893, 19!20-1928 ___.______.______Vlolle, Crow actinograph, Chowolwrl. hl I (112) Kislovodsk, Union of Socialist Soviet Re- 43 54 14 42 42 E 850 MapDecember, 1928.______.______b.,1 Crova. publics. (113) Koursk, Uniou of Socialist Soviet Repub- 51 45 N 36 12E 250 May, 1925-December, 1928...... Mi. lics. (114) Lsghouat Algeria--...... 33 48 N 2 55 E 750 July 12-13 1877. - ____..______Violle. (42).. Leninmad, Union of Socialist Soviet Re- 59 56 N 30 16 E 5 1915-16, d18, 1933-24, 1928-1928 ______I MI., Mi.-Marten, Chwolson. pubflcs. (43) Lincoln, Nebr ______40 60 N 96 41 W 373 (115) Ltitschenlihke~~ .. ~ (Berne).. ,. Switzerland-. ____ 46 2s N 7 57E 3,240 (iiii, Lysina, Poland ______49 46 N 20 4E 912 (45) Madison, Wis 43 05 N 86 23 w 297 (49) Mont Blanc, France 45 49 N 6 52E 4,810 3,050 1,200 (117) Montana (Wallis), Switzerland 46 19N 7283 1.515 (52) MontpeUier, France 43 37 N 3 53 E 44 (53) Moscow, Union of Socialist Soviet Repub- 55 50 N 37 33 E 185 lics. (118) Mount Elbrus (Erugozor), Unionofsocial- 43 17N 40 12 E 3,200 Aug. azo, 1926______d.,i Savinoe. ist Sovlet Republics. (119) Mount Evans, Greenland 64 51 N 50 50 W 394 September, 1927-Apri1, 1928...... Moll. (9. I. scale). '5550 August 1927______(120) Muottas-Muraigl______.46 32 N 958E a, 456 July-Abgust, 1923; October-January, 1923-24; MI., 8. I. March-June, 1924. (121) Oura-Tiube. Union of Socialist Soviet Re- 3965N 88 WE 1.040 January, 1907- ______d. publics. (63) Pars, Parc St. Maw 48 48 N 229E 50 (67) Potadem, Germany 52 Z3N 12 4E 106 (122) Repetek, Union of Socialist Soviet Repub- 38 35 N 63 10E 185 lica. (123) Rovaniemi, Finland 66 29N 25 44 E 200 (124) Schbreiberhau (Reisengeberge) Germany.. 50 50 N 15 32 E 700 (125) Sebastopol, Union of Socialist 'Soviet Re- 44 36N 33 32 E 12 publiar. (64) Sloptzk (Pavlovsk), Union of Socialist So- 59 41 N 30 29 E 30 January, 1925December, 1928 Mi., i.1 viet Republics. 1%) Smokovek, Czechoslovakia- - ____ ------49 8N 20 13E 1,015 (127) Stolzalpe, Austrla 47 08N 14 12 E 1, 180 (128) Swinica, Poland 49 15 N 2000E (75) Tashkent, Union of Socialist Soviet Repub- 41 20N 80 l8E a, :E lics.

(129) Tacubaya, Mexico 19 24 N Ml 12w 2,308 1911-1915 __.__._____~ ______A., 8. I. (130) Tagrait, Algeria 34 49N 643E 993 June 17, 1877______.______Violle. (131) Tchimigan, Union of Socialist Soviet Re- 70 km. E Tash- 1,400 June-July, 1923______Mi. publics. I It 1,980 July-August, 1925.__. -. ------3, 200 ______(81) Theodosia, Union of Socialist Soviet Repub 45 02 N 35 24 E 15 February, 1925December. 1928______- - - __ hfi., d.1 lics. June-August, 1921_____ .____ - ______- - - - - Crova-Savinov actinograph. (132) Tiflis, Union of Socialist Soviet Republics-. 41 43 N 44 48 E 420 September, 1913-December, 1915; June-August, 1.,1 MI. 1921' January-December 1928. (133) Tomak, Union of Socialist Soviet Republica. 60 30N 84583 124 Mar& to May, October tdNovember, 1901--.-- Viol Saveliev. (134) Touggourt, Algeria 33 08 N 6 02 E March-April, 1924_____.______Mi., 6. I. (135) Vienna, Austria 48 15N 16 22 E 203 March, 1904-September, 1906 A.1 (136) Vladivostok, Union of Socialist Soviet Re- 43 07N L33 55 E 50 January-December, 1929. - ______- ______- ___ __ A.1 Crova, Viole-Saveliev. 52 13 N 21 01 E 138 1919-1922 .______...______Mi., A, 8. I. 52 13N 21 03 E 86 igztiwm______M. G. (89) Washington, D. C 38 56 N 72 05 W 127 1914-1928 ___...... __._._____--~-----~.~-~-.~~---Ma. (137) Yalta, Union of Socialist Soviet Republics.. 44 30N 34 11E 100 June-September, 19%; May-September, 1927---. Mi. (YO) Zakopme, Poland. 49 17N 19 58 E 833 Aug. 25-Sept. 15, 10%--. _.._....______..-..M. 0. (138) Zaleszczyki, Poland. ___- ____.._.._____ 48 39 N 25 44 E 190 Jan. 1C-Sept. 21, I924 __....._...______--.-.-..M. A. (9. I. scale). (139) Zugspitze, Germany 47 25 N 10 59 E 2,962 Aug., 1926-July, 1927______...... _._____--.....- 8. I., i..Mi. (91) Atlantlc Ocean North I is--...... Apr. 5-May 2; July 1bAug. 15, 1923...___.__ .-.. Universal actinometer of Hartman a Hraun. Frankfurt a Main. Hamburg to Buenos Aires and return. oft SF ,ish coas NP. trade. off Cap1 rude Islam calm zo SE. trade:

1 Radiation records as recorded have bean reduced to the Smithsonlan pyrheliometric scale of 1913 by multiplying by 1.035.

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TABLE6.-List of pyrheliometric stations-Continued

Station Latitudi dongltudel 1 Period Instrument

TABLE7.-Monthly means of solar radiation and atmospheric TABLE7.--lllontltly means of solar radiation and atmospheric transmission t ransmission-Continued

TacubaYa (129): Ariana (102)- A,(m=) ______._.___1.66 1.62 1.541.54 1.52 1.541.51 1.53 1.57 1.60 1.57 1.63 AI______._.___..____.______1.29 1.29 1.18 1.19 1.13 1.10 1.11 0.990.91 1.14 1.29 1.33 A,,, ___.______._____1.41 1.46 1.40 1.39 1.42 1.45 1.39 1.44 1.45 1.45 1.43 1.44 IL~J ______..______.______.83 .83 .80 .SI .y .84 .83 .79 .79 .84 .86 .86 m- .______1.31 1.18 1.07 1.02 1.00 1.01 1.00 1.01 1.05 1.13 1.27 1.36 &.I ___._....______.78 .79 .78 .79 . ti5 .75 .75 .70 .66 .74 .78 .78 ~p-~-______.___.75 .77 .74 .76 .______...... ___ Vienna (135): Fresno (24): An ___.__.___....______.Bo ____ ._-..EM .______.81 _____ .___.87 ______A,----.------.------.------.------I 1.14^^ ______82.3. __..._.____.__..______.86 ______..7S .__. ._...82 ___._..__.85 .___ .___ BO-I .__....__._..__...._-..--.60 ..____-_ .59 __...--. .5i _.___..______.__. ___. Stolzalpe (127):

AP______.___..__..___~------.------.--.----...-- 1.24 .___~ _....__..__ a~.3.-----..---..--..----.----.------. _...__.___.._.._ B0.I ...... -___.___._...79.-..-.----..--.. Davns (15): A! ____...._...__..._..__....1.421.381.31 1.331.251.21 1.23 1.29'1.31 1.33 1.35 1.43 82.3 ..__..___..__..._.._-.-...85 .86 . S2 .88 .92 .93 .83 .# . S9 .89' .871 .82 @.I-. __.___.__.__..__..__...84 .83 .SI .S1 .79 .7S .75 .78 .79 .81 .82;____ Muottas-hiuraigl (1%): A?___..___.___..___.__..---- 1.57 _.__1.47 ______1.27 1.34 ______1.47 ______a2.3.. -..._._.___..__.____.__ .Ci2 ..._. 90 _.______. Bo .Bo ______.92 ___.____ Bo.,-. __..__..__.______.84 ______._1 . 78 .S2 ___..____ .86 __..____ Lotschenliicke (115): A2 _____...____.____.__-.----______..______I ._____._1.35 __.. _.__ __.. ____ a*a-.- _..__..____..__..____.__.______.....-- .91__.______.__...__....._..______.______~ ._._...- .83 ..__ _.______1:::: hlontana (117):

AI ______.____.______.______~ ______.1.28 ______. a?a. ____..____..______..____ .______' ______..88 ______-... Bp.1_..______._____...______~--~- I---1 ____ .&l-.__~ ______.._ Zugspitze (139): A2 ___.____.___...______1.56 1.59 1.55 1.49 1.42 1.41 1.42 1.44 1.47 1.53 1.63 1.51 89.8 ______._.______. .EM .94 .92 .91 911 .92 .90 .sa .Q2 .92 .Bo .95 B~.I______..______-...- ____ .85 .86 .85 :84!.83 .85 .85 .85 .82 ______Eskdalemuir (17): A, ___._____._____._..______.89 1.02 1.15 1.17 1.2811.10 1.25 1.20 1.19 1.14 .89 .85 m __.____.____.______4.142.701.83 1.43 1.24 1.18 1.20 1.33 1.63 2.293.554.98 Kew (35) : A, ______..____.______.70 .94 .97 1.01 1.05 1.06 1.03 1.06 1.00 .95 .74 .Bo rn ______.___....______3.28 2.31 1.69 1.33 1.18 1.13 1.15 1.26 1.50 2.02 2. Bo 3.77 Potsdam (67): AI.____...____..______-..-- ____ 1.18 1.a 1.13 1.07 1.06 .QQ .98 1.13 1.19 ______-- &______.______LOB 1.05 .EM .93 .90 .89 .BO .77 .93 1 01 .96 1. IO 814- - __ __.______.89 .87 .82 .84 .84 .81 .79 .82' 85 ______[10.1-. ______.____...______.63 .70 .70 .70 .65 .64 .71 ______-_ Rchreiberhau (124): Ai ______1.37 1.31 1.21 1.121.19 1.12 1.23 1.261.39 1.38 ---- A3 ______._____..______1.37 1.25 1.13 .98 .85 .%3 .92 1.13 1.181.24 1.281.30 a24 .______....______.91 .8i .81 .76 .83 .82 .92 .93 .89 .92 ___- 80-1 ._____.____..______.So .78 . 78 .76 .76 .74 .79 .80 .76 __-- Smokovek (126): AI _.____._._.___....______1.48 1.4? 1.40 1.30 1.18 1.21 1.18 1.18 1.321.38 1.31 ---- Ad ______._____..______1.21 1.17 1.03 .92 .83 .93 .92 .881.061.06 1.201.19 82.3 ______._...______.90 .91 .86 .S6 .82 .S .sS .84 .91 .89 .97 ---- a.,o. -. __._...______..._..______.83 .7i .75 .75 .74 .73 .73 .74 ____ _--- Lysins (116): A0 .-.-...... ------.------..------aP.Q.------.-.------. 80.~______.______._._____ --..____ .___.i3 ______----- Giewont (105): AI ___.______.______..___..___ __._ ___. ___. __.. L.50- _--____------a?.-. -. - - _.__- - __ -. __ - _.- ______-.__. . .97 -______------BO.~_.______..______.______..86 ______------

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TABLE7.-Moiiihly niea.ns of solar radiation and atmospheric TABLE7.-Monlhly means of solar radiation wid utmospheric traiismission-Continued trnt~smi~siori-Continued

I Within 30 miles east from Mount Evans. 2 Not found in 1'. S. Weather Bureau lihrary. 2 Not founll in U. 8. Weather Bureau libraryt I.8ee date8 in Tnhle 6.

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TABLE7.-Monfhly mentis of solar radiation atid atmospheric TABLE8.-Source of pyrheliometric data-Continued Ira nm?issko?i--C:ontin ued KATHARINENBURG(SVERDLOVSK) UNION OF SOCIALISTSOVIET REPUBLICS. Iiatharinenburg Magnetic Meteorological Observatory. Ob- servations, No. 1, 1915-16. KEW OBSERVATORY,RICHMOND, ENGLAND. GREAT BRITAIN, METEOROLOQICALOFFICE. 1922-1926. Richmond (Kew Observatory) Solar Radiation. Meauure- Bay of Biscay- ments of Radiation by Angstrom Pyrheliometer, 1922-1027. The Observatories’ Year Book. OB Spain- KHANQA,ALGERIA. Ai.,?---_._...__ ~ ______.___ __._..__ 1.35 ______._._._I---] .___ Off AZOP~S- VIOLLE, J. 1878. Mesures actinomBtriques relevees en Alg6rie pendant l’Bt6 de 1877. Comptes Rendus (Paris) 86 :820. KIEF UNIONOF SOCIALISTSOVIET REPUBLICS. Al.08______1.32 ____ ._____...______...- LVELIEFF, R. N. S. Temperate- Works of the Net of Meteorological Stations of South- AI.~______.___..______._ __._.___.-.- 1.28 ______.-.-______.-.____- S. Temuerate- //iiI/lIIll/ west Russia. 112: 481. 1891. Results of Actinometric Observations in 1890 in Kef. Meteorological Review. 1926. Ukraine Meteorological- Service. The Decade A1 09 ..______[ ..__I ____I __._ 1.___ 11.191 ____ [ ____ 1_____ 1 .___ [ ____1 ____ I____ Bulletin. _____ KISLOVODSK,UNION OF SOCIALISTSOVIET REPUBLICS. KALITIN,N. N. 1929. Bulletin de la Commission Actino- TABLES.--Source of pyrheliometric data mBtrique permanente de l’observatoire GBophysique Cen- tral, 1928, Nos. 2-3. ANTIBES, FRANCE. KOURSK,UNION OF SOCIALISTSOVIET REPUBLICS. RAYMOND,G. 1918. Observations actinomBtriques journal- KALITIN,N. N. 1929. Bulletin de la Commission actino- %res pendant les annes 1914-1916. B~il.de la SOC. Lan- mbtrique permanente de I’Observatoire GBophysique Cen- guedoc de G6ogr. de Montpellier, 1918. tral, 1928, Nos. 1-3. ANTRE& FINLAND.- LAGHOUATALGERIA. LUNELUND,HAROLD. 1924. uber die Warme- und Licht- VIOLLE, J. 1878. Mesures actinom6triques relevdes en strahluna in Finland. Societas Scientiaruni Fennica. Alg6rie. pendant 1’6td de 1877. Comptes Rendus (Paris) Cornme$at,iones Physico-Mathematicae, 11, 11 -8Rt - . 818- - -. ARIANA,TUNIS. LENINGRAD,UNION OF SOCIALISTSOVIET REPUBLICS. GORCZY~SKI,L. 1928. Quelques traits caracthristiques du Annals, Central Physical Observatory, 1915-16, 1918, 1923- climat solar reel du littoral Tunisien. Aniiales du Service 24, 1926-28. Botanique de Tunisie, Tome V, fascicule 2. LINCOLN,NEBR. BAKU,UNION OF SOCIALISTSOVIET REPUBLICS. KIMBALL,HERBERT H. 1926-1928. Solar Observations. MALINOVSKY,N. 1926. Solar Radiation and the Trans- Mo. Wea. Rev., vols. 54-56, Nos. 1-12. parency of the Air in Baku. Meteorological Messenger, LOTSCHENLUCKE(BERNE) SWITZERLAND. Marine Observatory of Baku. LOEWE,F. 1927. Strahlungs- und Temperaturmessungen an BOROVOY(SAMARA) UNION OF SOCIALIST SOVIET REPUBLICS. der Lotschenlucke im .August, 1926. Beit,r;ige zur Physik TOLSEY,A. 1921. Daily Amount of Solar Radiation on der freien dtmosphare. 13: 183. Clear Days. Borovoy Experimental Forestry. Meteoro- LPSINA,POLAND. logical Messenger, 1921. STENZ, EDWARD.1924. The Optical Properties of the DAVOS,SWITZERLAND. Atmosphere Above the Top of Lysina (Polish Beskids) DORNO,C. 1928. Tiigliche und Sakulsre Schwenkungen du [Polish text with English abstract]. Odbitka z Rocanika Sonnenstrahlung im Davos. Paris. Ohserwatorjum Astronomicznego IZrakowskiego Na Rok ERKDALEMUIR,SCOTLAND. 1924, Tom 111. GREATBRITAIN, METEOROLOGICAL OFFICE. 1922-1926. Esk- ILI ADISON, WIS. dalemuir Observatory, Solar Radiation. Measurements of KIMBALL,HERBERT H. 1926-1928. Solor observations. Radiation by Rngstrtim Pyrheliometer, 1922-1927. The Mo. Wea. Rev. vols. 54-56, Nos. 1-12. Observatories’ Yenr Book. MONTBLANC, FRANCE. FREHNO,CALIF. VIOLLE,J. 1876. Mesures actinomdtriques au sommet du KIMBALL, HERBERTH. 1929. Solar Observations. Mo. Mont Blanc. Comptes Rendus (Paris) 82: 898. Wea. Rev., 57: 27, Table 3. MONTANA(WALLIS), SWITZERLAND. GIEWONT,POLAND. GOTZ,F. W. PAUL. 1927. Strahlungsmessungen in Montana STENZ,EDWARD. 1928. Mesures au sommet de Giewont. (Wallis) Gerlands Beitrage zur Physik, 18, 262. Estrait du “~mos,”Journal de la SociBt6 Polonaise des MONTPELLIER,FRANCE. Naturalistes Iiopernik,” vol. 53, Fase 11-111, sei. A., CROVA,A. 1876 and 1879. Mesure de l’intensit6 calorifique mem. . 444, Table 10. des radiations solaires. Bulletin Meteorologique du De- CfOLODNAYA gTEPPE, UNION OF SOCIALIST SOVIET REPUBLICS. partment d l’Herault, 1876 and 1879. AGRICULTURALEXPERIMENT STATION. Golodnaya Steppe, BOUTARIC,A. 1918. L’6tude du pouvoir absorbant de Samarkand region, 1914. (Bulletin (Izvestia), No. 1, 1915, l’tltmosphhre terrestre, Paris. Nr. 2.) MOSCOW,UNION OF SOCIALISTSOVIET REPUBLICS. HELSINGFORS,FINLAND. (a) Moscow Agricultural Institute, 1909 to date. Observa- See Antrea, Finland. tions of the Meteorological Observatory. IRKUTSH,UNION OF SOCIALISTSOVIET REPUBLICS. (b) See under Warsaw, Zborowski, Pierre, 1929. (a) SHASTAKOVITCH,V. B. Solar Radiation and the Climate MOUNTELBRUS, UNION OF SOCIALIST SOVIET REPUBLICS. of Irkutsk. See also Works of the Magnetic Meteorological KALITIN, N. N. 1928. Solar, Diffused, and Terrestrial Observatory of Irkutsk. Radiation According to Observations Effected on Mount (b) KALITIN, N. W., 1929. Bulletin de la Commission Elbrus. Jr. Geophysics and Meteorology, 3, No. 3: 195-209.

Actinom6trioue Dermanente de I’Observatoire GBophysicrue-- ~ (Reprint.) Central, 1926, Nos. 1-3. MOUNTEVANS, GREENLAND. JOKKMOKS,SWEDEN. KALLQUIRT,C. R. 1929. Manuscript tables. STENZ,EDWARD. 1929. Radiat.ion solaire et l’opacit6 at- MUOTTAS-MURAIGL,SWITZERLAND. iiiosph6rique pendant l’eclipse du solei1 du 29, VI, 1927. DORNO,C. 1927. Grundzuge des Klimas von Muottas- Gerlands Beitrage zur Geophysik. Bd. 21, heft 2-3. Muraigl (Oberengadin) . Braunschweig. JUNGFRUGKAR, FINLAND. OURA,TIUBE, TJNION OF SOCIALISTSOVIET REPUBLICS. See Antrea, Finland. Acad. Sci. 1910. Memoires.

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TABLE8.--Source of pyrheliometric data-Continued TABLE8.-Source of pyrheliometric data-Continued

PARIS (P.4RC SAINT MAUR). TOUGGOURT,ALGERIA. BRAZIER,C.-E. 1924-1926. Observations actinomBtriqries. GORCZY~~SKI,L. 1025. RCsicmC des RIesures actinonidtriques faites 1’Observatoire du Parc Saint-Maur, 1924-1976. effectuees B Touggourt (Mars-Avril, 1924). Annals du Annales, Inst. Physique du Globe de 1’UniversitB de Paris, Service Bot,aniqrie de Tunis, fasciculo 1, p. 4s. Tome IV, V, VI. VIENNA, AUSTRIA. POTSDAM,GERMANY. SCHNEIDER,RUDOLF. 1908. Messungen der Soiineiistrahlung MARTEN, W. 1927. Das Strahlungsklima von Potsdnm. an der I<. IC. Zent,ralanstalt, fur Met,eorologieund Geodynarn- Veroffentlichungen des Prussischen Meteorologischen Inht i- ik in Wien. Jahrgang 1906. Neue Folge Band 43. tuts Abh. Bd. 8, No. 4. VLADIVOSTOCK,UNION OF SOCIALISTSOVIET REPUBLICS. REPETEH,UNION OF SOCIALISTSOVIET REPUBLICS. I~ALITIN,N. N. 1929. Bulletin de la Commission ActinomB- ORLOV,B. P. 1925. Data Regarding Diurnal Intensity of trique permai1ent.e de I’Ohservat,oire GCophysique Central, Solor Radiation at Repetek. Meteorological Messenger, 1928, NOS.3-3. 35, NO. 12, pp. 257-261. WARSAW,POLAND. ROVANIEMI, FINLAND ZBOROWSKI, PIERRE.1929. Mesures sctinometriques 8, See btrea, Finland. pendant la pBriode 1919-1928. Extrait des SCHREIBERHAU(REISENGEBERGE), GERMANY. $tudes gkophysiques” (prkcBdemment tude des mCt6oro- TICHY,HANS. 1926. Untersuchungen uber die Eignung des logiques et hpdragraphiques ’’j publiCes par A. B. Dobrowol- mittelgebirges fiir de Behandlung chirurgischen Iilinischen ski, fasc. I1 (VIII), 1929. und Gelenkleiden. Bruns’ Beitrage zur klinischen chirurgie, WASHINGTON,D. C. 137: 217. KIMBALL,H. H. 1926-1928. Solar Observations. Mo. Wea. SEBASTOPOL,UNION OF SOCIALISTSOVIET REPUBLICS. Rev. vols. 54-58, Nos. 1-12. RUDOVITZ,L. 1925. Actinometric Observations at Sebas- YALTA,UNION OF SOCIALISTSOVIET REPUBLICS. topol. Hydrographical management, Union of Socialist Institute for Studies on Tuberciilosis, 192627. Journal Soviet Republics. Kurortnoye Djelo, 1926-27. SLOUTZK(PAVLOVSK) , UNION OF SOCIALISTSOVIET REPUBLICS. ZA4HOPANE, POLAND. KALITIN,N. N. STENZ,EDWARD. 1928. Mesures de 1s radiation solaire il (a) 1925-1929. Bulletin de la CodssionActinomBtrique Znleszczyki et 8, Zakopane. Extrait du “IIosmos” Joynal permanente de l’observatoire GBophysique Central, de la societe Polanaise des Naturalistes “Kopernik, 53, 19251928. Fasces 11-111, serie A. MBmoires. (b) 1927. Rates of Solar Radiant Energy According to Observations Effected at the Magnetic-Meteorological ZALESZCZYKI,POLAND. Observatory Sloutzk (Pavlovsk). Recueil de GBo- See Zakopane. physique, Tome VI, fascule 1. ZUQSPITZE,GERMANY. SMOKOVEK,CZECHOSLOVAKIA. LIPP, HERMANN.1928. Beitrage zum Strahling der Zug- VOLOCHINE,F. E. 1928. Climat solaire de la Haut Tatra. spitze. Deutschen Meteorologischen Jahrbuch fiie Bayern. (Czechoslovakian text with French RBsumC.) Z ‘‘ VBstniku ATLANTICOCEAN. min. vir. zdrav. a t61. vychovy” cis. 4. roEnik X. LINKE,F. 1924. Results of Measurements of Solar Radia- STOLBALPE,AUSTRIA. t.ion and Atmospheric Turbidity Over the Atlantic Ocean WEGENER,ALFRED. 1926. Messungen der Sonnenstrahlung and in Argentina. Mo. Wea. Rev. 52: 157-160. am Sanatorium Stolzalpe. Met. Zeit., 43: 104. STENTZ,EDWARD. 1927. Sonnenstrahlung und Atmosphar- SWINICA,POLAND. ische Triibung Ciber dem Atlsntischeii Ozean. Beitrlge zur STENZ, EDWARD.1928. Mesures au sommet de Swinicn. Geophysik, 16: 436-452. Also manuscript tables. Extrait du “ Hosmos,” Jprnal de la SociBtB Polonaise des GORCZY~SHI,LADISLAUS. 1928. Manilscript tables. Naturalistes “ Kopernik. Vol. 53, Fasc. 11-111, 1928, NoTE.-Aft,er this paper had been subniitted for publication the Memoirs, p. 444, Table 11. following was received : “ Tnbellen der 1nt.ensit.Stder Sonnenstrah- TASHKENT,UNION OF SOCIALISTSOVIET REPUBLICS. 1Ilng in RIittel-Europa,” Heft. 1, Jnnunr, 1930. Zusarninengest.ellt KALITIN, N. N. 1926-1929. Bulletin de la Commission voni Met,eorologisch-hlngnet.ischen Observat~oriiiinPobsdam. It ActinomBtrique permanente de 1’Observatoire GQophysique siinininrizes pyrheliometric ohservations for January, 1930, for the Central, 1926-1928. following st.ations: Breslau-Krietern; Davos; I

Unauthenticated | Downloaded 10/01/21 04:47 AM UTC FEBRUARY,1930 MONTHLY WEATHER REVIEW 51 In connection with the construction of Figure 1 it was necessary to determine the intensity of solar radiation in different parts of the spectrum both for dry air and for air containing different amounts of water vapor. The deterniinations were made for sea-level conditions, B=760 mm., and also for the height of Calama, Chile, 582 B = 582 mm., in'= - =0.766. Having determined these 760 intensities, it is a simple matter to compute the relative energy in the solar spectrum between different wave- length limits. For dust-free air at an altitude of 2,250 meters the results are given in Table 10, and for dust- free air at sea level, in Table 11 (A). In both tables the second column also, gives the distribution of energy outside the atmosphere. Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Der. ______--- TABLE 10.--Percenfoge of iota1 ejiergy in dzferetit parts of solnr p (mm.) ______754 753 iS/ 751 750 750 750 751 753 753 7453 754 spectriim oittside the atmosphere (m=O) criid iilith a dmt-free 6.0 6.1 8.2 11.1 17.6 'I24.~133.1 31.7 24.5 16.4j10.0 6.9 w(mm.) ______ninaosphere at the ultitude of Calnma, Chale (?n'=#ij=0.766); I ao-1 i ulvo dppletion by nilnospheric dust (depletion ~n total spectrum= p(Pyr.) ~ _------_- - __------.71 .i1 .W .65 .63 Dust-free air ______.__.__.81 .M) .77 .74 .72 10 per cent of solar constant) Dust depletion-- ____..____.10 .09 .09 .09 .09 -I: ~ ~ (Pyr.)_____-_-___ .61 .59 .58 .57 .52 .48 .50 .51 .W .61 Dust-free air _____ .74 .74 . 71 .70 .6i .61 .6u .60 .63 Energy distrlbution Depletion by dust Dust depletion-- .13 . 15 . 13 .I3 . 15 .13 . 10 .09 .09 - Air mass (m') ______0 0.766 0.766 0.766 0.766 0.766 0.766 MADISON, WIS. Water-vapor content of atmosphere(cm.) ______/ 0 1 0 1 .421 1.281 0 1 .42I 1.28 P (mm.) ______73ii 7361 73.51 7351 7361 7361 737 737 733 737 737 W(mm.) ______73613.8 4.0 6.3 9.3 13.6 25.6 26.51 26.0 19.9 13.0 6.1 3.9 Place in aptdrum 1 Per cent Per cent Per ce,"' Per eeiit Per cent Per cent Per cent .BY .il .72 ..__._____ Below0.346p ___.______.____3.1 1.8 I., 1.5 29.1 30.4 31.9 .75 .77 .io ______0.3460.405~______5.0 3.8 4.0 4.1 23.6 W.6 26.0 0.405-0.7lMg 40.1 39.5 42.3 43.6 14.9 15.6 16.4 ~~ .OB .06 .o; .____._-.______80-2: Above0.701~______51.8 54.9 52.0 50.8 7.0 7.1 7.1 Dust-frei(Pyr.) ar__._ .XI.68 .69.761 ..66 i41 .63,721 ,691.S8 .6Sl.56 : .sa .60 .61 .66 .65 1 .I33 .66 .70 .73 .76 Dust depletion-- .08 .07 .OS .09 . 11 . 10 .07 .05 .06 [email protected] .I1 IIIIIIIIIIII

TABLE11

(41 PERC'ENTAGE OF TOTAL ENERGY IN DIFFERENT PARTS OF SOLAR BPECTRIT31 AFTER DEPLETION BY DUST-FREE AIR

-4ir mass______..__. ~.. '4

Water-vapor content of atmosphere(cm.).______._____ O.Oll.O 2.0 3.0 0.0 1.0 20 3.0 00 10'20'30 lli------L-"l-I-L IIIIII"" Place in spectrum 80-1: Below0.346p ___..______.___ 0.346-0.405p.. ______.______~.. 0.405-0.7fMp.. __._____..__._.. .- 80-2: Above 0.704~______(Pyr.) ~ .71: ,691 ,671 ,691 ,661 ,641 . 6Si . MI ~ Dust-free air__.._ . iil .76 .76 .74 .72 .70 .ti9 .69 .75.6Y .76.i0 Dust depletion.. .05 .05 . . OE @I .01 03 .05 .07 1 . 06 .ai .07 oli . .

Depletion by atmospheric dust.-The difference between (B) DEPLETION OF ENERQY BY AThIOSPHERIC' DUST (TOTAL the values of a,,+ or aO-? as given by pyrheliometricread- DEPLETION=lO PER CENT OF SOL.4R CONSTANT) ings and the corresponding values as computed for dust- free air by means of Figure 1 represents the depletion of 0.34rrO.105pBelow 0.346~ ______..______..______..._..3(h.3 6126.727.9129.32. 7'34. 4 35. 7'32.4 511.833.71 40.9141.8 43.3 91 41.521 48. ip :p solar radiation by atmospheric dust. It will be noted in 0.405-0.7CM,i---~....____._..._.___ 15.5 16.8'17.5 18.3 18.119.7 20.921.6'20.425.027.530.5 Table 9 that the depletion by dust diminishes with an AboveO.7Oip _____.______._._____6.4 7.3 7.8 6.2 6.9 9.0 9.511.2 8.711.213.215.2 increase of altitude. Measurements made at the Astro- ph sical Observatory of the Smithsonian Institution at (C) TOTAL DEPLETION=IO PER CENT OF INTENSITY OF DUST-FREE Ca ama, Chile, altitude 2,250 meters, indicates that with AIR the3 sun in the zenith in the driest part of the year the depletion of solar radiation by atmospheric dust amounts to only about 3 per cent of the solar constant, and that during the remainder of the year it is inappreciable.

Unauthenticated | Downloaded 10/01/21 04:47 AM UTC 52 MONTHLY WEATHER REVIEW FEBRUARY,1930 Angstrom' has recently shown that the depletion of atmospheric dust of 9 per cent, the percentage depletions solar radiation by atmospheric dust may be expressed obtained from table 11 (B) for the different spectral 6 regions are, respectively, 38.2, 31.0, 18.1, and 9.3. by the equation y =- He has also found that under X" - The corresponding intensities in these spectral bands normal conditions the value of CY departs but little from may be obtained from Tables 11 (A) and 11 (B) as 1.28, although following the eruption of Katma.i Volcano follows : in 1912 its value was reduced about one-half. I have Intensity below 0.346~=0.002 (1.94)<0.637)(1-0.382) =0.0015. applied this equation to the intensities of solar radiation Intensity between 0.346~ and 0.406~ =0.24(1.94><0.637) (1 -0.310) =0.0205. at different wave lengths after depletion by dust-free Intensity between 0.405~ and 0.704~=0.438(1.94)<0.637) air, including the absorption by ozone, water vapor and (1-0.181) =0.4433. other gases of the atmosphere. Table 10 and Table Intensity above 0.704~=0.536(1.94><0.637) (1-0.093) =0.6008. 11 (B) give the resulting percentages of depletion by Intensity in total solar spectrum with earth at mean solar atmospheric dust, computed for a depletion in the total distance= 1.0663. Intensity reduced to mean solar distance for September= -__1.0663 spectrum amounting to 10 per cent of the solar constant. R= For any other percentage of depletion, as x, the percent- =1.055 gram calories per minute per square centimeter, or prac- age given in the tables must be multiplied by 5. At tically the same as in Table 7. 10 It must be understood that the above computation of

Davos, in April, August and September, In'= 616~ = 0.811, intensities in different parts of the spectrum are for aver- 760 age conditions only, and take no account of the effect of

Air Mass. m. (Pressure - 760 cm)

urn FIGURE1.-Atmospheric transmission by dust-free air the depletion by atmospheric dust amounts to only 1 variations in the ozone content of the atmosphere with per cent, and interpolation between Table 10 and both time and place, or of possible variations in the dis- Table 11 (B) indicates that the depletion in the different tribution of energy in the spectriun of solar radiation spectral regions, beginning with the shortest wave before it enters the earth's atmosphere. Therefore they length, would be about 3.1, 3.5, 1.6, and 0.7 per cent, can not take the place of careful measurements, and respectively. only serve to indicate approximately how much energy On the other hand, at Washington in September, with is to be expected in different spe.ctra1 regions under the sun 60' from the zenith (m=2), an atmospheric different atmospheric conditions. The variations in the water-vapor content of 2.45 cm., and a depletion by ozone content of the atmosphere must exert a marked effect upon the amount of solar energy of wave lengths 1 Angstmm, Anders. On the atmospheric transmission of solar radiation and on dust in the air. GeograEska Annaler, 1928, H. 2. below 0.346~that reaches the surface of the earth.

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