Global Spectral Irradiance
11. January 1996, Australia
solar altitude 77.5°
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 20: 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 | 6600 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) 50700 µW/cm² = 507 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) 50700 µW/cm² = 507 W/m² UVB (EU) ( 280 nm - 315 nm) 275 µW/cm² = 2.75 W/m² UVB (US) ( 280 nm - 320 nm) 430 µW/cm² = 4.3 W/m² UVA+B ( 280 nm - 380 nm) 5100 µW/cm² = 51 W/m² Solar UVB ( 290 nm - 315 nm) 275 µW/cm² = 2.75 W/m² UVA D3 regulating ( 315 nm - 335 nm) 1150 µW/cm² = 11.5 W/m² UVA (EU) ( 315 nm - 380 nm) 4820 µW/cm² = 48.2 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 1260 µW/cm² = 12.6 W/m² UVA (US) ( 320 nm - 380 nm) 4660 µW/cm² = 46.6 W/m² UVA1 (variant) ( 335 nm - 380 nm) 3680 µW/cm² = 36.8 W/m² UVA1 (medical) ( 340 nm - 400 nm) 5350 µW/cm² = 53.5 W/m² vis. UVA ( 350 nm - 380 nm) 2650 µW/cm² = 26.5 W/m² VIS Rep3 ( 350 nm - 600 nm) 40300 µW/cm² = 403 W/m² VIS Rep4 ( 350 nm - 700 nm) 48300 µW/cm² = 483 W/m² purple ( 380 nm - 420 nm) 5020 µW/cm² = 50.2 W/m² VIS ( 380 nm - 780 nm) 45600 µW/cm² = 456 W/m² PAR ( 400 nm - 700 nm) 43700 µW/cm² = 437 W/m² blue ( 420 nm - 490 nm) 12900 µW/cm² = 129 W/m² green ( 490 nm - 575 nm) 16400 µW/cm² = 164 W/m² yellow ( 575 nm - 585 nm) 1720 µW/cm² = 17.2 W/m² orange ( 585 nm - 650 nm) 9650 µW/cm² = 96.5 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 14.2 UV-Index Pyrimidine dimerization of DNA 173 µW/cm² Photoceratitis 19.2 µW/cm² Photoconjunctivitis 0.266 µW/cm² DNA Damage 0.906 Vitamin D3 61.8 µW/cm² Photosynthesis 28700 µW/cm² Luminosity 133000 lx Human L-Cone 19500 µW/cm² Human M-Cone 17000 µW/cm² Human S-Cone 10500 µW/cm² CIE X 16900 µW/cm² CIE Y 18400 µW/cm² CIE Z 19400 µW/cm² PAR 183000000 mol photons Extinction preD3 472 e-3*m²/mol Extinction Tachysterol 1710 e-3*m²/mol Exctincition PreD3 239000 m²/mol Extinction Lumisterol 44.4 m²/mol Exctincition Tachysterol 2720000 m²/mol Extinction 7DHC 28.9 m²/mol L-Cone 16000 µW/cm² M-Cone 18700 µW/cm² S-Cone 17300 µW/cm² U-Cone 10800 µW/cm² UVR - ICNIRP 2004 9.57 Rel Biol Eff Melatonin Supression 16000 µW/cm² Blue Light Hazard 11900 µW/cm² (89.9 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 67.9 µW/cm² Lumen Reptil 143000 "pseudo-lx" Vitamin D3 Degradation 89.7 µW/cm² Actinic UV 9.54 µW/cm² (0.72 mW/klm) Exctincition Lumisterol 74400 m²/mol Exctincition 7DHC 41300 m²/mol Exctincition Toxisterols 50200 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 593 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 18.6 Leybold UVB 403 µW/cm² Leybold UVA 3450 µW/cm² Leybold UVC 0.00579 µW/cm² DeltaOhm UVB 1280 µW/cm² DeltaOhm UVC 120 µW/cm² Vernier UVB 141 µW/cm² Vernier UVA 3110 µW/cm² Gröbel UVA 3980 µW/cm² Gröbel UVB 192 µW/cm² Gröbel UVC -0.0988 µW/cm² Solarmeter 6.4 (D3) 58.1 IU/min UVX-31 1480 µW/cm² IL UVB 0.276 µW/cm² IL UVA 4060 µW/cm² Solarmeter 6.5 (UVI, post 2010) 16 UV-Index Solarmeter 6.2 (UVB, post 2010) 421 µW/cm² (Solarmeter Ratio = 26.4) Solarmeter AlGaN 6.5 UVI sensor 221 UV Index GenUV 7.1 UV-Index 13.5 UV-Index Solarmeter 10.0 (Global Power) 444 W/m² Solarmeter 4.0 (UVA) 66.4 mW/cm² LS122 0 W/m² ISM400 261 W/m²