Extended Data Fig. 2: Daytime spectral irradiance and ratios with and without twilight (10 m depth).

(a) Daylight average per day across the year between sunrise to sunset without twilight times for each wavelength. For 3D-rotational graph: Supplementary Data 2. (b) 2-D pcolor plot of (a). (c) Daylight spectrum across the year for each wavelength between astronomical dawn to astronomical dusk (raw data). For 3D-rotational graph: Supplementary Data 3. (d) 2-D pcolor plot of (c). (e) Daytime monthly irradiance averages comparing periods of equal photoperiods. Long day photoperiod example: 14 April – 15 May 2011 (yellow) and 27 July – 27 August 2010 (blue), short day photoperiod example: 9 January – 9 February 2011 (black) and 1 November – 2 December 2010 (red). (f, g) Equinox day spectra without twilight (f) and between astronomical twilight (g). For 3D-plot: Supplementary Data 6 and 9. (h,i) Screenshot of weather data for spring and autumnal equinox days: https://www.timeanddate.com/weather. (j, k) 3D-surface plot of equinox day ratio - September 23, 2010/March 21, 2011 (j) and September 23, 2010/March 24, 2011 (k). For 3D-rotational graph: Supplementary Data 7 and 8. (l) Ratios of wavelengths averaged across the day for fall and spring equinox days including twilight times. Black dotted lines: range of strong c-opsin1 activation. Data were corrected for daylight saving time.