Global Spectral Irradiance
11. January 1996, Australia
solar altitude 20°
from: Bernhard, G., B. Mayer, G. Seckmeyer, and A. Moise (1997), Measurements of spectral solar UV irradiance in tropical Australia, J. Geophys. Res., 102(D7), 8719–8730
Spectrum 14: SUN Edit
DeleteMeasurement
| Brand |
other other |
|---|---|
| Lamp Product |
Sun Direct sunlight |
| Lamp ID |
SUN (01/2000) |
| Spectrometer | - |
| Ballast | - no ballast or default/unknown ballast - |
| Reflector | |
| Distance | 0 cm |
| Age | 0 hours |
| Originator (measurement) | Publication |
Database entry created:
Sarina Wunderlich
12/Nov/2009 ; updated:
Sarina Wunderlich
25/Oct/2016
Colorimetry
Colorimetry is the science to describe physically the human color perception. The wavelength range 380 nm - 780 nm is visible to humans and detected by three different photoreceptors. Many Reptiles see the range 350 nm - 800 nm and have an additional UV photoreceptor in their retina.
WARNING: The measurement range (350 - 800 nm) is not sufficient for this evaluation! Data is only available in the range 297.5 - 650 nm. Results are shown anyway but should be ignored by anyone except experts.
Whereas a spectrometer measures the intensity in every tiny wavelength interval resulting in thousands of individual intensities, the human eye only measures three intensities detected by the three cones. The same is true for the reptile eye with usually three or four photoreceptors. Effectively the detailled spectrum displayed above reduces to a much compacter bar graph displayed below. The photoreceptor sensitivites from these L-Cone, M-Cone, S-Cone, and U-Cone are used, they are chosen as an average of measured reptile photoreceptor sensitivity curves. The bar graph also shows as reference the intensity seen by the three or four photoreceptors for average sunlight (id 1).
From these three numbers the colour coordinate and the correlated colour temperature for humans are calculated using the CIE standard method. I adapted this concept to a "3 cone reptile (M,S,U)" and a "4 cone reptile (L,M,S,U)". I am sure, that this adaption to other colour spaces makes sense mathematically and this is also done in scientific research regarding colour vision of animals, however I have not seen calculation of colour temperatures for other animals in the scientific literature. Even if it is hypothetical, at least this shows, how arbitrary the colour temperature is, and that the colour temperature calculated for humans does not apply to reptiles. The colour spaces also show the colour coordinates of different phases of daylight ((ids 1, 338 – 451, 511 – 513 ), indicated by crosses, coloured in the appriximate colour perceived by a human.
| Human (CIE) | 3 cone reptile | 4 cone reptile | |
|---|---|---|---|
| Cone Excitation | |||
| Colour Coordinate | ( 0.31 ; 0.34 ) | ( 0.42 ; 0.37 ) | ( 0.26 ; 0.31 ; 0.27 ) |
| CCT | 6600 Kelvin | 4700 Kelvin | 5400 Kelvin |
| distance | 0.031 | 0.045 | |
| colour space | 3-D-graph not implemented yet |
Vitamin D3 Analysis
Vitamin D3 is produced by UVB radiation around 300 nm. 7DHC/ProD3 present in the skin is converted to PreD3 when absorbing an UV photon. PreD3 can be converted back to ProD3, to Lumisterol, or to Tachysterol when absorbing another UV photon or can be converted to Vitamin D3 in a warm environment.
This process prevents any overdose of vitamin D3 from UV radiation with a spectrum similar to sunlight. As a comparison the solar spectra at 20°(id:14) and at 85°(id:21) solar angle are shown.
The ratio of the two solarmeters 6.2 (UVB) and 6.5 (UV index) readings has proven a useful and very simply number to acess the spectral shape in the vitamin-d3-active region.
Effective Irradiances
Effective irradiances are calculated for all ranges, actionspectra and radiometers currently present in this database.
The calculation method is a numerical implementation (Simpson's rule) of the formula
To learn more about calculating effective irradiances and radiometers I recommend this excellent report on UVB meters: Characterizing the Performance of Integral Measuring UV-Meters (pdf).
The numbers in the following tables can also be used to estimate certain (effective) irradiances from radiomer readings. Example: If the database lists
- range: UVB (US) = 13.8 µW/cm²
- radiometer: Solarmeter 6.2 = 19.6 µW/cm²
Ranges
total ( 0 nm - 0 nm) 13700 µW/cm² = 137 W/m² UVC ( 0 nm - 280 nm) 0 µW/cm² = 0 W/m² non-terrestrial ( 0 nm - 290 nm) 0 µW/cm² = 0 W/m² total2 ( 250 nm - 880 nm) 13700 µW/cm² = 137 W/m² UVB (EU) ( 280 nm - 315 nm) 22.8 µW/cm² = 0.228 W/m² UVB (US) ( 280 nm - 320 nm) 46.9 µW/cm² = 0.469 W/m² UVA+B ( 280 nm - 380 nm) 1110 µW/cm² = 11.1 W/m² Solar UVB ( 290 nm - 315 nm) 22.8 µW/cm² = 0.228 W/m² UVA D3 regulating ( 315 nm - 335 nm) 227 µW/cm² = 2.27 W/m² UVA (EU) ( 315 nm - 380 nm) 1090 µW/cm² = 10.9 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 264 µW/cm² = 2.64 W/m² UVA (US) ( 320 nm - 380 nm) 1070 µW/cm² = 10.7 W/m² UVA1 (variant) ( 335 nm - 380 nm) 863 µW/cm² = 8.63 W/m² UVA1 (medical) ( 340 nm - 400 nm) 1290 µW/cm² = 12.9 W/m² vis. UVA ( 350 nm - 380 nm) 631 µW/cm² = 6.31 W/m² VIS Rep3 ( 350 nm - 600 nm) 11000 µW/cm² = 110 W/m² VIS Rep4 ( 350 nm - 700 nm) 13200 µW/cm² = 132 W/m² purple ( 380 nm - 420 nm) 1280 µW/cm² = 12.8 W/m² VIS ( 380 nm - 780 nm) 12600 µW/cm² = 126 W/m² PAR ( 400 nm - 700 nm) 12100 µW/cm² = 121 W/m² blue ( 420 nm - 490 nm) 3520 µW/cm² = 35.2 W/m² green ( 490 nm - 575 nm) 4640 µW/cm² = 46.4 W/m² yellow ( 575 nm - 585 nm) 469 µW/cm² = 4.69 W/m² orange ( 585 nm - 650 nm) 2670 µW/cm² = 26.7 W/m² red ( 650 nm - 780 nm) 0 µW/cm² = 0 W/m² IRA ( 700 nm - 1400 nm) 0 µW/cm² = 0 W/m² IRB ( 1400 nm - 3000 nm) 0 µW/cm² = 0 W/m²
Actionspectra
Erythema 1.03 UV-Index Pyrimidine dimerization of DNA 15.4 µW/cm² Photoceratitis 0.942 µW/cm² Photoconjunctivitis 0.0059 µW/cm² DNA Damage 0.0245 Vitamin D3 3.03 µW/cm² Photosynthesis 7910 µW/cm² Luminosity 37200 lx Human L-Cone 5480 µW/cm² Human M-Cone 4790 µW/cm² Human S-Cone 2870 µW/cm² CIE X 4680 µW/cm² CIE Y 5160 µW/cm² CIE Z 5320 µW/cm² PAR 50700000 mol photons Extinction preD3 48.4 e-3*m²/mol Extinction Tachysterol 191 e-3*m²/mol Exctincition PreD3 28900 m²/mol Extinction Lumisterol 1.19 m²/mol Exctincition Tachysterol 365000 m²/mol Extinction 7DHC 0.411 m²/mol L-Cone 4480 µW/cm² M-Cone 5290 µW/cm² S-Cone 4670 µW/cm² U-Cone 2680 µW/cm² UVR - ICNIRP 2004 0.531 Rel Biol Eff Melatonin Supression 4400 µW/cm² Blue Light Hazard 3230 µW/cm² (86.9 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 2.95 µW/cm² Lumen Reptil 39400 "pseudo-lx" Vitamin D3 Degradation 10.5 µW/cm² Actinic UV 0.536 µW/cm² (0.144 mW/klm) Exctincition Lumisterol 3740 m²/mol Exctincition 7DHC 1060 m²/mol Exctincition Toxisterols 7990 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 79.2 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 1.14 Leybold UVB 48.2 µW/cm² Leybold UVA 798 µW/cm² Leybold UVC 3.06E-6 µW/cm² DeltaOhm UVB 228 µW/cm² DeltaOhm UVC 17.7 µW/cm² Vernier UVB 8.61 µW/cm² Vernier UVA 675 µW/cm² Gröbel UVA 899 µW/cm² Gröbel UVB 19.3 µW/cm² Gröbel UVC -0.0154 µW/cm² Solarmeter 6.4 (D3) 3.55 IU/min UVX-31 270 µW/cm² IL UVB 0.0409 µW/cm² IL UVA 936 µW/cm² Solarmeter 6.5 (UVI, post 2010) 1.03 UV-Index Solarmeter 6.2 (UVB, post 2010) 62.3 µW/cm² (Solarmeter Ratio = 60.2) Solarmeter AlGaN 6.5 UVI sensor 18.1 UV Index GenUV 7.1 UV-Index 1.43 UV-Index Solarmeter 10.0 (Global Power) 122 W/m² Solarmeter 4.0 (UVA) 15.6 mW/cm² LS122 0 W/m² ISM400 72.6 W/m²