Annals of the Astrophysical Observatory of the Smithsonian Institution (1900)
Washington : Government printing office · leaf 190
a slight gradual increase during in solar-constant change, and that except for the low values the year from January to December but, since the two at Table Mountain in February to May there is little annual stations are 6,000 miles apart and one in the northern and variation due to terrestrial… … Figure 12. — Sunspots versus solar constants, 12-month running means, 1940 through 1952. Continuous line, solar constants; broken line, sunspot numbers.
Infrared spectra · Solar radiation
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