Abstract

We present the first measurements of radiance spectra of rainbows. The bows on two sunny days (3 and 6 June 2008) were produced by the fountain in the Parque de las Ciencias, Granada, Spain, that consists of a rectangular perimeter of 40 spray nozzles. Optical thickness of the spray from each nozzle was approximately 0.5. Spectral purity of the primary bow was highest for orange and blue, reaching values of 23% and 7%, respectively, while skylight $90°$ from the Sun had a color purity of 34% (on 6 June). The secondary bow had much lower color purity with red absent because the regions around the bows and in Alexander’s dark band were pale blue. The narrow sickle shape of the chromaticity curves for the primary bows and the absence of supernumerary bows indicated that the drop radius was between 0.2 and $0.4\mathrm{mm}$.

© 2008 Optical Society of America

Simulating rainbows in their atmospheric environment

Stanley David Gedzelman
Appl. Opt. 47(34) H176-H181 (2008)

Spectral measurement and modeling of natural rainbows

Raymond L. Lee
Appl. Opt. 56(19) G42-G50 (2017)

Imaging polarimetry of the rainbow

András Barta, Gábor Horváth, Balázs Bernáth, and Viktor Benno Meyer-Rochow
Appl. Opt. 42(3) 399-405 (2003)

Rainbows and fogbows

David K. Lynch and Ptolemy Schwartz
Appl. Opt. 30(24) 3415-3420 (1991)

Mie theory, Airy theory, and the natural rainbow

Raymond L. Lee
Appl. Opt. 37(9) 1506-1519 (1998)