Global Spectral Irradiance
11. January 1996, Australia
solar altitude 70°
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 19: 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 290 - 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 | 0.029 | 0.038 | |
| 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) 48100 µW/cm² = 481 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) 48100 µW/cm² = 481 W/m² UVB (EU) ( 280 nm - 315 nm) 252 µW/cm² = 2.52 W/m² UVB (US) ( 280 nm - 320 nm) 397 µW/cm² = 3.97 W/m² UVA+B ( 280 nm - 380 nm) 4800 µW/cm² = 48 W/m² Solar UVB ( 290 nm - 315 nm) 252 µW/cm² = 2.52 W/m² UVA D3 regulating ( 315 nm - 335 nm) 1070 µW/cm² = 10.7 W/m² UVA (EU) ( 315 nm - 380 nm) 4550 µW/cm² = 45.5 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 1190 µW/cm² = 11.9 W/m² UVA (US) ( 320 nm - 380 nm) 4400 µW/cm² = 44 W/m² UVA1 (variant) ( 335 nm - 380 nm) 3470 µW/cm² = 34.7 W/m² UVA1 (medical) ( 340 nm - 400 nm) 5060 µW/cm² = 50.6 W/m² vis. UVA ( 350 nm - 380 nm) 2510 µW/cm² = 25.1 W/m² VIS Rep3 ( 350 nm - 600 nm) 38300 µW/cm² = 383 W/m² VIS Rep4 ( 350 nm - 700 nm) 45800 µW/cm² = 458 W/m² purple ( 380 nm - 420 nm) 4770 µW/cm² = 47.7 W/m² VIS ( 380 nm - 780 nm) 43300 µW/cm² = 433 W/m² PAR ( 400 nm - 700 nm) 41500 µW/cm² = 415 W/m² blue ( 420 nm - 490 nm) 12200 µW/cm² = 122 W/m² green ( 490 nm - 575 nm) 15600 µW/cm² = 156 W/m² yellow ( 575 nm - 585 nm) 1630 µW/cm² = 16.3 W/m² orange ( 585 nm - 650 nm) 9110 µW/cm² = 91.1 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 12.9 UV-Index Pyrimidine dimerization of DNA 158 µW/cm² Photoceratitis 17.3 µW/cm² Photoconjunctivitis 0.234 µW/cm² DNA Damage 0.794 Vitamin D3 55.8 µW/cm² Photosynthesis 27200 µW/cm² Luminosity 126000 lx Human L-Cone 18600 µW/cm² Human M-Cone 16200 µW/cm² Human S-Cone 10000 µW/cm² CIE X 16000 µW/cm² CIE Y 17500 µW/cm² CIE Z 18500 µW/cm² PAR 174000000 mol photons Extinction preD3 434 e-3*m²/mol Extinction Tachysterol 1570 e-3*m²/mol Exctincition PreD3 220000 m²/mol Extinction Lumisterol 39.3 m²/mol Exctincition Tachysterol 2520000 m²/mol Extinction 7DHC 24.9 m²/mol L-Cone 15200 µW/cm² M-Cone 17800 µW/cm² S-Cone 16500 µW/cm² U-Cone 10200 µW/cm² UVR - ICNIRP 2004 8.53 Rel Biol Eff Melatonin Supression 15200 µW/cm² Blue Light Hazard 11300 µW/cm² (90 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 61.3 µW/cm² Lumen Reptil 136000 "pseudo-lx" Vitamin D3 Degradation 82.8 µW/cm² Actinic UV 8.52 µW/cm² (0.677 mW/klm) Exctincition Lumisterol 66600 m²/mol Exctincition 7DHC 35900 m²/mol Exctincition Toxisterols 46600 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 549 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 16.8 Leybold UVB 372 µW/cm² Leybold UVA 3260 µW/cm² Leybold UVC 0.00463 µW/cm² DeltaOhm UVB 1200 µW/cm² DeltaOhm UVC 111 µW/cm² Vernier UVB 128 µW/cm² Vernier UVA 2930 µW/cm² Gröbel UVA 3760 µW/cm² Gröbel UVB 176 µW/cm² Gröbel UVC -0.0917 µW/cm² Solarmeter 6.4 (D3) 52.7 IU/min UVX-31 1380 µW/cm² IL UVB 0.256 µW/cm² IL UVA 3830 µW/cm² Solarmeter 6.5 (UVI, post 2010) 14.5 UV-Index Solarmeter 6.2 (UVB, post 2010) 391 µW/cm² (Solarmeter Ratio = 27) Solarmeter AlGaN 6.5 UVI sensor 203 UV Index GenUV 7.1 UV-Index 12.4 UV-Index Solarmeter 10.0 (Global Power) 421 W/m² Solarmeter 4.0 (UVA) 62.7 mW/cm² LS122 0 W/m² ISM400 248 W/m²