Extraterrestrial Solar Spectrum, 3000-6100 A at1-A Intervals

Matthew P. Thekaekara

Standard values of the solar constant and extraterrestrial solar spectrum are reviewed. In the visibleand near uv, this listing of average irradiance over 100-A bandwidths at 50-A intervals was found to beinadequate for many applications. A more detailed spectrum obtained from solar scans with a Perkin-Elmer, Model 112 monochromator was found to give sufficient detail. A normalization program was de-

veloped to make the Perkin-Elmer curve agree with the standard curve. Values of extraterrestrial solarspectral irradiance at 1-A intervals in the range 3000-6100 A have been derived. The results are present-ed in tabular form and as spectral charts.

Introduction

One of the principal workers in solar constantstudies during the past ten years was A. J. Drum-mond, as was observed by Howard and Garing in arecent review paper.' His measurements during theEppley-JPL program2 -4 and his work in the ad hoccommittee on solar electromagnetic radiation werelargely instrumental in developing the values of thesolar constant and extraterrestrial solar spectral irra-diance that are now currently accepted. Thesevalues have become the standard adopted by theAmerican Society for Testing and Materials5 and thedesign values for NASA space vehicles design crite-ria.6 The value of the solar constant is 1353 W m-2 ;it is the average of many series of measurementsmade at high altitude from CV 990 and B-57B air-craft, X-15 rocket aircraft, and balloons and theMars Mariner spacecraft. The table of values of theextraterrestrial solar spectral irradiance is basedmainly on the data from the CV 990 flights made byNASA/GSFC7 and from the aircraft flights of theEppley-JPL program.2 '3 Details about the deriva-tion of the standard solar spectrum are given in Ref.8, where an abridged version of the table was pub-lished. The complete version is given here in TableI. A project was undertaken recently to develop amore detailed spectral irradiance table for the wave-length range 0.3-0.61 m. This paper discussesbriefly how this table was developed and presentsthe results.

The author is with Goddard Space Flight Center, Greenbelt,Maryland 20771.

Received 18 June 1973.

Standard Table

Table I follows closely the format of an earliertable published by the GSFC experimenters as TableIII of Ref. 7, which is also available in the currentedition of the American Institute of Physics Hand-book.9 Over a great part of the wavelength rangethe earlier spectral irradiance values have been re-.tained. A comparison of the GSFC data with thoseobtained by Drummond showed that in the wave-length range of X > 0.7 gm Drummond's integralvalue obtained from cutoff filters was exactly thesame as the GSFC value. In the wavelength range0.3 gm < X < 0.7 Aum, the results from Drummond'sbandpass interference filters were in fairly closeagreement with the integrals over the respectiveranges from the GSFC curve, but there were a fewdifferences. Hence a weighted average of the GSFCdata and the Drummond data was taken to derivethe standard curve of Table I. The maximumchanges from the GSFC curve are +2.3% at 0.34 Am,-0.7% at 0.45 gm, and +1.6% at 0.63 Am, and per-centages varying between zero and these maxima atintermediate wavelengths of 0.3 Am < X < 0.7 ,im.With these changes the integral under the spectralcurve was raised from the GSFC value, 1351 W m- 2,to the revised solar constant, 1353 W m- 2. For thewavelength range 0.3 Am > X > 15 Aim; which wasnot adequately covered by the measurements ofGSFC or Drummond the data of Hinteregger,10Heath,'1 and Shimabukoro and Stacey12 were used.

For Table I the spectral irradiance values Ex areaveraged over finite bandwidths centered at X, thebandwidths being (all units in Am) 0.01 for 0.3 < X< 0.75; 0.05 for 0.75 < X < 1.0; 0.1 for 1.0 < X < 5.The entries are at intervals of 0.005 for 0.22 < X <0.605 and at wider intervals for the rest of the range.This mode of presentation was chosen in order tolimit the table to one page and to present the spec-

518 APPLIED OPTICS / Vol. 13, No. 3 / March 1974

tral irradiance independently of the Fraunhoferstructure, which different instruments show differ-ently according to their wavelength resolution.

But for many practical applications this mode ofpresentation at wide intervals is inadequate, espe-cially in the visible and near uv where line absorp-tion in the solar atmosphere is most pronounced andthe extraterrestrial solar spectrum is most widely ap-plied. Thus, for example, in filter radiometry of theEppley-JPL program or the Earth Radiation Budgetexperiment of Nimbus F, an important parameter isthe filter factor F defined by3

F = f Ed/ f(1)

where E is spectral irradiance, -rx is spectral trans-mittance, and X1, 2 are the limits of nonzero trans-mittance. For an interference filter having -r nearlyconstant over a range of a few hundred angstromsbut dropping rapidly to zero, the evaluation of F re-quires E to be known to a few angstroms. Otherapplications, as shown by feedback from the users ofthe spectral irradiance table, are atmospheric mod-eling, transmittance and scattering in the atmo-sphere, source and sink mechanisms of pollutants,radiation budget, chemical processes in the upper at-mosphere, oceanographic surveys, night sky ra-diance, solar energy at ground level, etc.

The spectral irradiance values of Table I in thenear uv and visible ranges are based on the data offour instruments: a Perkin-Elmer monochromator,Model 112; a Leiss quartz double-prism monochro-mator; an Eppley Mark V filter radiometer (modi-fied by GSFC, with twenty-two narrow bandpass fil-ters in the range 0.3-0.6 gim); and multichannel filterradiometers. The first three were flown in theGSFC CV 990 program and the fourth in the Ep-pley-JPL program. Of these the Perkin-Elmer wasthe most complex and versatile instrument, had thebest wavelength resolution, and yielded the mostabundant data.' 3 The data were recorded on stripcharts and on magnetic tapes, the latter for comput-er analysis. Spectral curves based on these chartsand tapes were published as Figs. 13 and 14 of Ref. 7but no detailed spectral irradiance tables were pre-pared or published. The curves are based on thedata from about seventy scans. The wavelength res-olution, while not sufficient to show the line shapesof the Fraunhofer lines, is adequate for many com-puter programs; the value of X/AS varied from 1100at 3000 A to 455 at 5000 A. A complete mapping ofthe Fraunhofer lines would require a resolution of60,000 or better. Such data are available in theMinnaert atlas14 and other sources. The spectralcurve obtained from the Perkin-Elmer does not agreeat all wavelengths with the standard curve of TableI, since the latter is a weighted average of the datafrom four instruments.

Normalization Program

A normalization program was undertaken to shiftthe Perkin-Elmer curve up or down parallel to the y

axis, so that the curve remains everywhere continu-ous, wavelengths of flexion points are not shifted,and the integrals over 50-A intervals are the same asin the standard table.

The normalization procedure is briefly reviewed.An enlarged version of the Perkin-Elmer curve wasproduced. It was traced manually with a crosshairlocator and the y coordinate (irradiance) waspunched on IBM cards. Let these values be desig-nated e. Let Ap be the average of fifty consecutivevalues of e from - 24 to X + 25 ( in angstroms)and let b be the difference E - Ap, where Ex is thestandard spectral irradiance at X in Table I. Let aand c be the corresponding values of the difference intwo 50-A ranges just below and above , that is, inranges centered at - 50 and A + 50. A correctionfactor D is added to each e from - 24 to + 25such that (1) for the first e, D is (a + b)/2, (2) forthe fiftieth e, D is (b + c)/2, and (3) the average ofD's for all fifty ex's is b.

These conditions can be satisfied if D is of theform

D = a + ,Bn + yn2 .

Thus, for

n=1, a + + y = (a + b)/2,n 50, a + 50, + 502y = (b +c)/2,

n = 1, 2, ... 50,

;[50a + (n) + (n2)-y] = b.

Equation (5) can be simplified as

a + 25.5,B + 858.5 = b

(2)

(3)

(4)

(5)

(6)

From equations (3), (4) and (6),

-y = (c + a-2b)/1568; = (c-a-4998y)/98;ac = [(a + b) /2]- 1-y. (7)

Using Eqs. (2) and (7), we compute the correctionfactor D for each wavelength at I-A intervals andadd it to ex to give the normalized value of the spec-tral irradiance.

This procedure proved satisfactory over the wholerange 3000-6100 A, except between 3926 A and 4025A, where the E values of Table I, which are aver-ages over the 100-A band, fail to show the sharpdiscontinuity of the Perkin-Elmer curve. Here thefirst computer output showed a spurious inflectionaround 3970 A. Values of Ex at 3950 A and 4000 Awere adjusted by subtracting a small amount fromthe first and adding the same to the second, and newvalues of the difference Ex - AP were computed.

Results

The results are presented in Table II and Figs. 1and 2. Table II is in the format of trigonometric ta-bles. Wavelengths are in angstroms and irradiancein W m- 2 gm- or mW m-2 nm-. The accuracy isestimated to be 5%, the same as in the standard

March 1974 / Vol. 13, No. 3 / APPLIED OPTICS 519

Table I. Solar Spectral Irradiance-standard Curve

Z X [ o- |1| 11 EX | DX X EX E X f D

.0001

.0005.130 007 .0071 .0005.140 .030 .0073 .0005.150 .070 .0078 .0005.160 .230 .0093 .0006.170 .630 .0136 .0010.180 1.250 .0230 .0016.190 2.710 .0428 .0031

.200 £0.7 .1098 .0081

.210 22.9 .2778 .0205

.220 57.5 .6798 .0502.0728.0971.1204.1430.1680.1944.2266

.269

.328

.405

.485

.564

.663

.8101.0071.2101.417

1.6551.9242.2182.5522.9283.3233.7214.1174.5174.919

5.3165.7236.1506.5827.0037.4137.8198.2418.7259.293

9.92010.57111.22211.85812.47313.08313.72514.41515.14015.891

i6.65317.41318.16718.92119.68120.43021.15521.87822.59923.312

.510

.515

.520

.525.5'0.535.54a. 545.55a.555

.56a.565.571.575.58C.5 85.59C.59.601.60E

.61

.62

.63

.64

.65

.66.67.6t.69.70

.71

.72

.7!

.74

.75

.76

.77

.78

.75

.80

.81

.82

.83.84.85.8e.87.88.89.90

.91

.92

.93

.94

.95

.96

.97

.98

.991.00

1.051.101.151.201.251.301.351.401.451.50

1882183318331852184218181783175417251720

16q5170517121719171517121700168216661647

1635160215701544151114861456142714021369

1344131412901260123512111185115911341109

10851060103610 13990968947926908891

880869858847837820803785767748

668593535485438397358337312288

324.926334.214343.379352. 591361.826370. 976379 9793 88. 821397.519406. 131

414.669423.169431.711440. 289448. 874457.441465.971474. 426482. 796491.079

499. 284515.469531.329546.899562.174577.1595q1.86960 6.284620.429634.284

647. 849661.139674. 15968 6. 909

;699.384L711. 6147 723. 594735. 314

*746. 779757. 994

;768.966l779.694i790.174

80 0.419810.434820.224829. 7998 839.164848. 334

L85 7.329

86i6. 184sr4.s29883.5648 92.089900.50990 8. 7949 916. 909

i924. 84993 2.609

2.3 594

975.584L007. 109L035.3091060.809L083.884L104.7591123.6341141.0091157.234172.234

24. 01524.70125. 37926. 0 5926.74227. 41528. 08428. 73729. 3803 0. 017

30. 64831. 27631.90732. 54133. 17633.80934.43935. 0 6435. 68336. 295

36.90238. 09839. 27040.42141. 55042. 65743.74444. 8 1045. 85546.879

47. 88248 .86449.82650.76951.69152. 59553.48054.34655.19456. 0 23

56. 83457.62758.40159.15859.89960.62261. 33062. 0 2262.70063.3 65

64. 01964.6656s.394650.334&K. So'67. 16867.76868.35568. 92869.488

72.10574.43576.51978;. 40480.10981.65283. 04784. 33185.53086.639

1.551.601.651.701.7s1.801. 851.901.952.00

2.t2.?2.32.4?.5?.62.72. A2.93.0

3.13.23.33.43.53.63.73.83.94.0

4.14.24.34.44.54.64.74.84.95.0

6789

101112131415

1617181920253035n

5 0

r.n

267245223202180159142126114t03

90796962554843393531

26.022.619.216.614.613.512.311.110.39.5

8.707.807.10e6.505.925.354.864.474.113.79

1.8200.9900.5850.3670.2410.1650.1170.0851.0634.0481

.03710 0

.02910 0

.0210 0

.01860015200

.006170

.002979

.00160 0.n.,. ,

.00 0391

I186.109198. 909

1210. 6091 221.2341230.7841239.2591 246. 7841253.48412 59.48412 64.909

1274.5591283.0091290. 4091296. 9591302. 8091307. 9591312.5091316.6091320. 309132 3. 609

1326.4591328. 8891330.9791332.7691334.3291335.7341 337. 0241338. 1941339.2641340.254

1341.16411341.98911342.73411343.41411344. 03511344.59861345. 109.11345.57571346.00491346.3999

1349.20491350.60991351.39741351.87341352.17741352.38041352.52141352.62241352.69671352.7524

1352.79501352.82811352.85421352.87511352.89201352.94541352.96831352.97971 xq an-n1352.9927

.nnn.annnI 15,9.9Qao

87.68588.61189.47590.26190. 96791.59392.14992. 64493. 0 8893.489

94. 2 02494.826995.373995.858096. 290396.671097. 00 7397.310397.583897.8277

98. 0 38398. 2179.98. 72498.504798.6 20098.723898.819298.905698. 984799.0579

99.1252199.1861899.2412499. 2915099.3374099.3790599.4167899.4512799.4829999.51219

99.7195099.8233599.8815599.9167399.9392099.9542099.9646299.9720999.9775899.98170

99.9848599.9873099.9892399.9907799.9920299. 9959699.9976599.998509QQQQRQ799.99946

99. qqq6780 *00006160 1352.9981 99.99986100 .00002570 1352-9990 99.99992120 .nnnn fn 1352@9&1 99.99995150200250300400

100

.00000523

.00000165.00000070.00000034.00000011.00000000

1352.99971352.99981352.99991352.99991352.99991353.0000

99.9999799.999999q.9999999.9999999.99999100.00000

I ... A I _________ J J _______________ ___________

. X x - Wavelength in micrometers

E - Solar spectral irradiance averaged over small bandwidth centered at , in W m AimE% ~~~~~~~~~~~~~~~~~~~~-2

0-k - Integrated solar irradiance in the wavelength range o to X, in W m

Do X - Percentage of solar constant associated with wavelengths shorter than X

Solar consitant - 1353 W -2

Note: lines indicate change in wavelength interval of integration

520 APPLIED OPTICS / Vol. 13, No. 3 / March 1974

115

.125

.007

.900

.807

.0 025.0048.0070

.225

.230.235.240.245.2 50.255

.260

.265

.?70

.275.280.285.250.295.300.305

.310.315.320.325.3 30.335.340.345.350.355

.360.365.370.375.380.385.390.395.400.405

.410

.415

.420.425.430.435.440.445.450.455

.460.465.470.475.480.485.490.495.500.505

64.966.759.363.072.370.4

104.0

130185232204222315482584514603

6897648 30975

105910811074106910931083

10681132118111571120i10981098118914291644

1751i177417471693163916631810192220062057

2066204820332044207419761950i1960I19421920

.98581.31481. 62981. 93562. 27382. 63063.0666

3. 65164.43915. 48166.57167.63668.9791

10.971613. 636616.381619.1741

22.404126. 036630.021634. 534139.619144.969150. 356655.7t4161.119166.5591

?1.936677. 436E83.219189.064194.7566

100.3016105. 7916111.5091118.0541125. 736E

134.224143. 036151.839160.439168. 769177. 024185. 706195.036204. 856215. 014

225. 321235. 606245. 809256. 001266. 296276.42128 6. 236296.011305.766315. 421

l

- - - -- - - - -. - - - - - - -

I Wx |_t I t U I 2 we S sx X f

-f S_ w _ _ _ _ _

_:L

Table II. The Extraterrestrial Solar Spectrum, 3000-6100 A, at 1-A Intervals'

SOLAR SPECT.AL IRRAOIANCE, 3000 TO 6100A I A INTERVALS

wAVELENGTH IN A, IRRAOIANCE IN W PER M SO AREA NhM ANO

I---0 --- 1 --- 2 --- 3 --- 4---5 --- 6 --- 7---8 ---

54J4535414605525476b0772690553

743 765775 748744 751751 714713 711749 730730 739879 db9803 SU830 843

918 915805 8. 777 771042 0b4911 900

1022 10471139 1122104310 lb

964 901147 1 10

1086 1061 1034 10161030 1041 1054 10651078 1080 1091 10901040 1090 1068 1OO1161 I175 112 11051033 1037 1045 10501084 1089 1090 1071031 1020 1031 1Ob210b9 lObb 1005 10941089 1074 107Z 1070

535 527 5e 519 Sib461 462 467 401 490541 540 b3b b23 50465 40 477 494 5eJ594 611 036 652 653544 559 59b 14 1 61704 720 735 748 771778 787 791 791 79u609 575 564 561 560549 545 543 542 544

799 810 010 0U5 790722 709 106 707 71J757 762 753 762 6o761 771 7dO 708 79'713 719 730 742 7be725 705 094 609 607794 016 a2e 839 057744 739 730 741 756795 783 17 772 17.854 d63 004 895 911

903 892 S80 868 861850 051 b5O 847 8Sb771 770 782 796 80866 873 884 693 d99900 098 9u2 915 9et

100 1102 1111 1112 I11Illb 110 1111 1110 1100994 987 9d2 979 975

1003 1071 10.5 1109 11121151 1149 1142 1135 IIIa

1011 1013 1020 1022 10211073 1077 1075 1002 10o1103 1070 1049 1037 10J1105 1137 1145 1145 11401105 1103 1155 1120 107'1030 10 1 17 10eo 1042079 1070 1050 10.9 I0s11096 1103 1100 1094 1081125 1135 1137 1136 11I1067 1049 1033 1013 90'

I _ - r

40004010402040 304040405040 6040 7040 804090

4100411041204130414041504160417041804190

4200421042204230424042504260427042804290

4300431043204330434043504360437043804390

4400441044204430444044504460447044804490

1739 1739 1740 1740 17291699 1699 1701 1703 170u170t 1706 1704 1700 16911657 1657 165b 16S 10541617 1609 1599 15I 1S071582 1506 10sd 1589 15911612 1623 1644 16b2 166051740 1743 1746 1748 11501704 1692 16084 107 16751686 1600 1691 1o96 1701

1739 174 175U 1754 1 791814 1821 1825 1627 180I1018 1815 1810 1805 17991780 1779 1778 1778 17771773 1772 1771 1770 17691769 1769 1770 1771 17711775 1775 1776 1776 1 7701772 1772 1770 1709 1b71742 1735 1730 1727 17271732 1732 1732 1731 1730

1731 1733 1736 1740 17441764 1768 1771 1772 17121766 1764 1763 1760 17571711 1702 1696 1090 10041065 1663 1602 1661 1o00060 1671 1673 1675 1.77109 1692 1695 1698 17ue1725 1727 1728 1730 173U1753 1757 1761 1765 1771732 1730 1723 1717 1712

1666 1657 1640 1638 1611568 1553 1544 1529 1S1b1472 1471 1477 1479 148u1526 1532 1544 1583 15d31042 1653 1659 1603 16601699 1700 1700 1099 16981692 1692 1692 1695 17u1760 1758 178u 1706 17831809 1812 Id15 1818 I8191021 1821 1020 1019 I18

1810 1007-1804 1801 17971790 1790 1791 1792 17941023 1827 131 1d34 10J71.46 1640 1bO 1053 18571090 1896 1903 190b 1911927 1931 1937 1941 19471967 1969 1970 1971 19731977 1977 1976 1976 19741965 1963 1962 1961 19001963 1965 196 1969 1971

1715 1707 1703 1701 17001707 1709 1709 1709 17001681 1668 1002 1659 10501002 1650 1648 1605 163J1582 1570 I57 1576 15791592 1595 1597 1599 0021677 1705 1729 1733 17301752 1749 1742 1722 17001676 1677 1679 108l 100j1707 171.3 1720 172 1732

1766 1771 1782 1801 10071828 1827 1025 Ide3 18211793 1791 17e7 1784 17821777 1776 1/75 1774 1771769 1768 118 1700 17081772 1773 177. 1774 17751770 1775 177S 1774 17731705 1762 17b 17S4 17491727 1728 1129 1131 17321730 1729 1729 1729 1730

1748 1751 1755 1759 17611771 1770 1t9 1708 17.,1754 1751 1744 1736 17251679 1675 1672 1009 1601660 1661 1601 1603 1665179 1681 1083 100S 16811706 1710 1114 1718 17221731 1729 1735 1741 17401766 175o 1754 1742 I7331706 1699 1090 IdO 172

1621 1,09 1597 1508 158u1508 1499 1490 1482 147014d2 148 1504 1505 1Id1586 1596 15o 1626 16281682 1685 1688 1692 10951097 1696 109S 1693 16921719 1725 1731 1743 17b41798 1002 IO3 1805 100821 1822 1de3 1823 10221817 1017 1816 1814 1012

1794 1791 1790 1789 17891796 1799 1dO3 1810 I8181840 1840 140 1842 14'1862 1869 1075 1881 1851917 1919 1921 1922 19241951 1954 1958 1951 19691974 1975 1975 1976 19701972 1909 1908 1967 19001960 1900 1961 1902 19521974 1976 1979 1901 190b

510051105120513051405150516051705 I80

5190

5200521052205230524052505260527052805290

5300531053205330534053505360537053805390

5400541054205430544054505460547054805490

5500551055205530554055505560557055905590

1870 1869 1869 1d69 18691871 1872 1873 1875 18761879 1879 1879 1878 187d1874 1874 1874 1873 1d721059 1857 1855 1854 180e1834 1831 1829 1825 1d221806 1803 180 1799 17971788 1786 1785 1784 17841787 178d 1790 1791 11921802 1sO3 1805 107t I8lu

1837 1840 1843 1846 18491862 1865 1867 1809 1871179 1879 1800 I1d 18021087 1887 1s 1dd9 18091089 1080 1885 1879 18701841 1836 1832 1829 1S281021 1820 1820 1820 Idel1.26 1826 1826 1827 1deId36 1838 1839 1040 104eIdS5 185 1855 0S4 1853

184 18461839 18381835 1831836 18361b30 1291021 18201809 18071793 17921789 17901787 1787

1780 17851780 1 7801773 17711766 17661763 17621755 17541747 17471741 17411732 17311723 1722

1719 17191723 17231728 17291731 173.11728 17271722 17221714 17131704 17031696 16961692 1092

1845 1844 184.1830 1837 18j7I037 103d Ib81035 134 1d34129 1029 102dId9 11d Il71805 10i 101I790 1789 17901790 1790 17091787 17d7 17d7

1705 1785 17041779 1778 17701770 175Z9 1781700 1765 17651761 1761 17001753 175Z 17511746 1 7.6 1 7451740 1739 17391730 1729 172d1721 1721 1720

1719 1719 17201723 1724 17'.173U 1731 17311731 1731 17301727 1727 17261721 1720 17191712 1711 171u1702 1701 17001695 1695 16941692 1692 1692

1869 1d69 1d9 1870 18781877 1878 1070 1879 1I791879 1075 1.75 1875 18741871 1d6d 1866 1804 10611850 1847 1844 1040 18311820 1017 1.14 lb2 10091795 1794 1792 1790 170917 83 1782 1783 1704 17851794 1795 197 1799 180V1813 1818 I22 120 I03

1852 1854 lds6 1858 106u1874 1875 1.77 170 17w1881 1882 1d83 Id IdoI089 1889 1890 1890 10891868 d62 Id0 1850 10451826 1d25 Id23 1822 10211822 1824 1d25 126 18201830 1832 1d33 1833 1831844 1046 150 1bb Ibb1852 1851 105o 1849. 1840

1843 1842 1041 1840 1b401837 1036 1036 1836 10301839 1840 1039 1id I31833 1832 1031 1031 103u1827 1025 beb 1b23 18221816 18*5 1014 1813 18111799 1798 1797 1796 17951790 1789 1709 17a9 17891789 1788 1788d 1708 17dd1787 1707 1707 1786 17806

1783 17d2 1782 17011775 177 1774 17741767 1/67 107 17001764 1764 1764 17631758 1757 1757 17501750 1749 1748 17401744 1743 1742 174d173d 1136 1735 17341726 1725 1724 172J1720 1119 1719 I7Z9

1720 1721 1721 1722 17221725 1725 1720 1727 17201732 1732 1732 1732 17311730 1730 1729 1729 17201725 1725 1725 1724 172.1719 1710 1717 1716 171b1709 1708 1707 1706 1701700 1699 1698 1697 16971694 1693 1093 1693 10921692 1692 1092 1692 109

-l t i i i i975 901

I095 11041091 1019933 941

1118 11201094 11001095 10181008 10021004 10121204 120

1138 1301023 10271155 11591231 I2311230 12301017 1013967 90dd27 828

1122 11501182 1104

1047 1035 1021 10151017 1007 1001 9971 131 1131 1110 11031095 1090 100 1067982 1008 1016 10191127 1138 11o 11721245 1247 124d 12481234 1237 1230 123411 8 1124 1121 112012 101221 1227 12e

101599b

10 751030

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113310 64

02b92e

12141 1911171I 7 11711057

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1039 1038 1036 1032950 9-4 923 911758 03 833 093

1161 1231 1245 13241557 1502 159 16e91710 1717 1724 1730

990 lOlb 1Od 1069 10731114 1122 1020 112d 11211056 1030 IU2j 996 950969 1054 1073 1003 1095I11 0119 1117 1Z11 IIU1108 111 1122 129 11311009 1007 100 1069 1072lOS 1047 180 1020 10101027 1031 1000 1096 11201207 1201 11d 1120 1127

1126 1100 1U70 1044 10321039 1009 lOd 1090 11021163 1171 1184 12Oo 12001241 1244 1246 0247 12401215 1191 11d3 1181 II01012 1019 1024 1026 1020891 072 056 843 d3829 d41 855 694 920

1178 1191 1195 1197 11401139 1114 1100 1086 1OU

1022 1031 1039 1039 1035999 1031 1U79 1107 1127

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1232 1237 1240I17 1107 11091161 1109 l17u1034 1042 1040107 1006 1000l2ed 1220 02241193 1190 11 91349 1351 135J125 5 1103 1139lu0 1059 1071

1144 1148 1150 1151 11401006 984 952 924 903

830 82. 832 842 0b2

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1202 1199 119. 1189 11701012 978 901 944 920754 7J1 706 o93 607921 991 1032 1036 10301020 1022 lolo 1004 98871 757 734 730 731971 107 1043 1083 1122

1347 1376 14e9 1456 151.1649 1666 150 16089 16901734 1730 1742 1744 1740

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500050105020503050 40005050 6050 7050 805090

1990 1994 1998 2003 20102040 2040 2040 2041 20412076 2082 2080 2092 20972103 2103 2103 2102 21022095 2093 2091 208 20802061 20056 2050 2041 20352011 2011 2012 2012 20132014 2015 2017 2021 20262059 2062 2065 Z067 20692077 2077 2077 2077 0077

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2044 2044 2044 2094 20432039 2038 2037 2035 20342028 2020 2027 2028 20272031 2032 2034 2035 20362040 2041 2042 2043 20442048 2048 20.8 2048 20472047 2048 2048 2U49 20O02054 2055 2055 2055 eUb52051 2050 2051 2051 0532062 2003 2065 067 2059

2078 2079 208u 2082 20032089 2090 2091 2091 20922090 2088 2087 2006 20052079 2078 2o76 20 73 20712046 2041 2037 2032 2020190 1973 1966 1958 19511908 0902 1896 1887 1811864 1863 1t02 10O Id591875 1881 1805 192 1891940 1947 1951 19b 1960

1978 1981 1982 1984 19b51987 1987 1986 1980 19041974 1972 1971 1969 19671955 1953 1951 1949 19471943 1943 1944 1995 19451958 1960 1902 1963 19041968 1969 1969 1969 19701975 1977 1978 1979 1901977 1975 1972 1969 19651962 1962 1961 1951 1900

1947 1944 1941 1939 19371924 1922 1920 1918 19151901 1900 1899 1098 1091902 1903 1904 1904 19091912 1913 1914 1915 19161928 1929 1930 1931 I93e1935 1934 1935 1935 19341929 1927 1925 I924 I9z21907 1904 1901 18ds 18951881 1879 1870 1076 1875

2015 2022 2030 2037 20J2041 2044 2054 2063 207u2099 2101 2103 2103 21032101 2101 2100 2099 20972082 2078 2074 2069 Ob2028 202 2 2016 e13 20l2013 2013 2013 2013 201J2033 2039 2044 2050 20552071 2073 2A1'. 2076 20702077 2076 2076 2075 o74

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2083 2084 2085 20d6 eo02092 2092 2u92 2092 e0912084 2001 2080 2080 20792068 2065 2060 eb 20542019 2010 2006 1999 19d1943 1937 1932 0923 1911877 1d73 1010 108 100Id59 1860 Id1O 1864 1091901 1905 191a 1926 193J1964 1960 1970 1972 1974

1986 1987 19d 1987 19871983 190l 1980 1978 19701965 1964 1952 1960 19571946 1945 1945 1944 19431948 1950 1952 1954 195019b5 1966 1966 1907 19001970 1971 1972 1973 19711981 1980 I980 1979 19s1964 1903 1963 1902 19e1959 1956 1954 1951 1949

1935 1934 1931 1929 19271912 1909 1906 1904 19021897 1897 1d9 1899 19011904 1900 1907 1900 19101918 1919 1I 1923 19261933 1934 1934 1935 193'1934 1933 1933 1931 19301920 1920 1917 1914 191UId93 1891 1ds8 1886 1d41874 1873 1072 1871 1870

5600561056205630564056505660567056805690

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6000601060 20603060 40605060 6060 7060806090

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6100 1630

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1714 1713 1713 1713 1713*714 1714 1714 1714 171.1714 1713 1713 1713 17131714 1714 1114 1714 17141714 1714 1714 1714 17141712 1712 1712 1711 17111710 1709 1709 1709 17001706 1706 1705 1705 170b1704 1704 1/04 1704 17031702 170e ,100 1702 1701

1700 1699 1099 *090 16901695 1695 1694 1694 169.169* 1691 1090 1690 109U1680 1687 1007 1687 16d1683 [683 lde 1602 16d1680 l6dO 1079 1679 16791677 1670 1076 1670 16751574 1673 107J 1673 10721671 1671 1670 1070 167U1667 1671 1606 lo10 I00o

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1637 103 10b3. 1030 103b1634 1633 1033 1b34 10331631 1630 1531 l0I 1530

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March 1974 / Vol. 13, No. 3 / APPLIED OPTICS 521

576 5b6 557 549511 502 490 477513 527 536 540490 480 471 470539 544 545 549647 626 591 w.,7523 628 640 658777 775 772 770787 770 732 691560 559 558 bb

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178317771767176517b917501744173817271720

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921 923 9271103 1110 11051096 1091 10911129 1124 11111073 1073 10711010 1006 10041169 1182 1201

1127 1131 11361024 1022 I0211116 1126 11401213 12 20 12201248 1246 12411167 1057 10241024 1007 981

830 828 827966 10 58107'.

1196 1192 . 180

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1694 16941696 1697169d 16981699 1IO

1702 17031705 17061710 1710171d 17131712 17111711 1711

1711 17111712 17121716 17161719 17191720 17e01719 17191719 17191718 17181717 17171715 1715

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10771140808862

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3900 11863910 1 1563920 0493930 0863940 10 393950 9763960 7343970 11 353990 15393990 1703

aWavelength in A; spectral irradiance in mW m- 2 nm-'. Spectral irradiance values are given in the format of trigonometric tables.

.

I - - . - -l

1600E

E

E 1200

800

4003000 3200 3400. 3600

WAVELENGTH (A)

Fig. 1. Solar spectral irradiance, 3000-4000 A;standard values of Table I.

-table. In Figs. 1 and 2 the dashed curve gives the" standard values of Table I.

The spectral irradiance data of Tables I and II areavailable in the form of punched cards to any organi-zation that has need of this type of data. The cardsgive X and Ex, three pairs per card for Table I andeight pairs per card for Table II. They can be ob-

4i , ,' tained from National Space Science Data Center,Code 601, NASA/GSFC, Greenbelt, Maryland

Ii' ~20771.The author acknowledges his indebtedness to R.

v \ q _ Stair, who helped in the early analysis of the Perkin-Elmer data; to A. J. Drummond, discussions withwhom showed the need for more detailed spectraldata; to J. DeLuisi of the National Center for Atmo-spheric Research, Boulder, Colorado, for tracing the

3800 4000 Perkin-Elmer curves and punching the values; to L.Bieberman of the Institute for Defense Analyses, Ar-

dashed line shows lington, Virginia for the main part of the computer-aided normalization, and to W. Mocarsky and R.Mitchell of Goddard Space Flight Center for helpwith the GSFC computers.

1900

E

E

E

0

700E

36004 l

4100 4600WAVELENGT

Fig. 2. Solar spectral irradiance, 360Cstandard values of

References1. J. N. Howard and J. S. Garing, EOS, Trans. Am. Geophys. U.

52, IUGG 371 (1971).2. A. J. Drummond et al., J. Spacecr. Rockets 4, 1200 (1967).

3. A. J. Drummond and J. R. Hickey, Sol. Energy 10, 1 (1966).

"ZN 4. A. J. Drummond et al., Nature 218, 259 (1968).

5. Anon., paper no. 82, in Space Simulation, NASA SP 298

(NASA, Washington, D.C., 1972), p. 955.6. Anon., Solar Electromagnetic Radiation, NASA SP 8005

_ (NASA, Washington, D.C., May 1971).7. M. P. Thekaekara, R. Kruger, and C. H. Duncan, Appl. Opt.

8, 1713 (1969).8. M. P. Thekaekara and A. J. Drummond, Nat. Phys. Sci. 229,

6 (1971).9. J. Kasper, in American Institute of Physics Handbook, D. E.

Gray, Ed. (McGraw-Hill, New York, 1972), pp. 6-216, 6-217.10. H. E. Hinteregger, Ann. Geophys. 26, 547 (1970).

_______ 11. D. F. Heath, J. Atmos. Sci. 26, 1157 (1969)._______ 12. F. J. Shimabukoro and J. M. Stacey, Astrophys. J. 152, 777

5100 5600 6100 (1968).

H (A) 13. M. P. Thekaekara and R. Stair, J. Opt. Soc. Am. 58, 1553A(1968).

0-6100 A; dashed line shows 14. M. Minnaert et al., Photometric Atlas of the Solar Spectrum

Table I. (Amsterdam, D. Schnabel, 1940).

Michael R. SmithLibrascope DivisionSinger Company

522 APPLIED OPTICS / Vol. 13, No. 3 / March 1974