Global Spectral Irradiance
11. January 1996, Australia
solar altitude 50°
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 17: 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
9/Oct/2011
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 292 - 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 ) | ( 0.4 ; 0.37 ) | ( 0.25 ; 0.3 ; 0.28 ) |
| CCT | 6700 Kelvin | 4900 Kelvin | 5600 Kelvin |
| distance | 0.03 | 0.04 | |
| 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) 37500 µW/cm² = 375 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) 37500 µW/cm² = 375 W/m² UVB (EU) ( 280 nm - 315 nm) 160 µW/cm² = 1.6 W/m² UVB (US) ( 280 nm - 320 nm) 263 µW/cm² = 2.63 W/m² UVA+B ( 280 nm - 380 nm) 3600 µW/cm² = 36 W/m² Solar UVB ( 290 nm - 315 nm) 160 µW/cm² = 1.6 W/m² UVA D3 regulating ( 315 nm - 335 nm) 792 µW/cm² = 7.92 W/m² UVA (EU) ( 315 nm - 380 nm) 3440 µW/cm² = 34.4 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 883 µW/cm² = 8.83 W/m² UVA (US) ( 320 nm - 380 nm) 3340 µW/cm² = 33.4 W/m² UVA1 (variant) ( 335 nm - 380 nm) 2650 µW/cm² = 26.5 W/m² UVA1 (medical) ( 340 nm - 400 nm) 3880 µW/cm² = 38.8 W/m² vis. UVA ( 350 nm - 380 nm) 1920 µW/cm² = 19.2 W/m² VIS Rep3 ( 350 nm - 600 nm) 30000 µW/cm² = 300 W/m² VIS Rep4 ( 350 nm - 700 nm) 35800 µW/cm² = 358 W/m² purple ( 380 nm - 420 nm) 3690 µW/cm² = 36.9 W/m² VIS ( 380 nm - 780 nm) 33900 µW/cm² = 339 W/m² PAR ( 400 nm - 700 nm) 32500 µW/cm² = 325 W/m² blue ( 420 nm - 490 nm) 9600 µW/cm² = 96 W/m² green ( 490 nm - 575 nm) 12300 µW/cm² = 123 W/m² yellow ( 575 nm - 585 nm) 1270 µW/cm² = 12.7 W/m² orange ( 585 nm - 650 nm) 7060 µW/cm² = 70.6 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 7.55 UV-Index Pyrimidine dimerization of DNA 100 µW/cm² Photoceratitis 9.81 µW/cm² Photoconjunctivitis 0.115 µW/cm² DNA Damage 0.387 Vitamin D3 31.8 µW/cm² Photosynthesis 21300 µW/cm² Luminosity 98800 lx Human L-Cone 14600 µW/cm² Human M-Cone 12700 µW/cm² Human S-Cone 7850 µW/cm² CIE X 12500 µW/cm² CIE Y 13700 µW/cm² CIE Z 14500 µW/cm² PAR 136000000 mol photons Extinction preD3 280 e-3*m²/mol Extinction Tachysterol 1030 e-3*m²/mol Exctincition PreD3 145000 m²/mol Extinction Lumisterol 19.8 m²/mol Exctincition Tachysterol 1700000 m²/mol Extinction 7DHC 11 m²/mol L-Cone 11900 µW/cm² M-Cone 14100 µW/cm² S-Cone 12900 µW/cm² U-Cone 7900 µW/cm² UVR - ICNIRP 2004 4.65 Rel Biol Eff Melatonin Supression 12000 µW/cm² Blue Light Hazard 8880 µW/cm² (89.8 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 34.6 µW/cm² Lumen Reptil 107000 "pseudo-lx" Vitamin D3 Degradation 54.8 µW/cm² Actinic UV 4.66 µW/cm² (0.471 mW/klm) Exctincition Lumisterol 36900 m²/mol Exctincition 7DHC 16900 m²/mol Exctincition Toxisterols 32600 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 374 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 9.83 Leybold UVB 249 µW/cm² Leybold UVA 2480 µW/cm² Leybold UVC 0.00134 µW/cm² DeltaOhm UVB 861 µW/cm² DeltaOhm UVC 77.4 µW/cm² Vernier UVB 77.2 µW/cm² Vernier UVA 2200 µW/cm² Gröbel UVA 2840 µW/cm² Gröbel UVB 113 µW/cm² Gröbel UVC -0.0654 µW/cm² Solarmeter 6.4 (D3) 30.7 IU/min UVX-31 998 µW/cm² IL UVB 0.177 µW/cm² IL UVA 2910 µW/cm² Solarmeter 6.5 (UVI, post 2010) 8.62 UV-Index Solarmeter 6.2 (UVB, post 2010) 272 µW/cm² (Solarmeter Ratio = 31.6) Solarmeter AlGaN 6.5 UVI sensor 128 UV Index GenUV 7.1 UV-Index 8.11 UV-Index Solarmeter 10.0 (Global Power) 329 W/m² Solarmeter 4.0 (UVA) 47.8 mW/cm² LS122 0 W/m² ISM400 194 W/m²