Global Spectral Irradiance
11. January 1996, Australia
solar altitude 40°
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 16: 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 293.5 - 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 ) | ( 0.41 ; 0.37 ) | ( 0.26 ; 0.3 ; 0.28 ) |
| CCT | 6700 Kelvin | 4800 Kelvin | 5500 Kelvin |
| distance | 0.03 | 0.041 | |
| 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) 30200 µW/cm² = 302 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) 30200 µW/cm² = 302 W/m² UVB (EU) ( 280 nm - 315 nm) 107 µW/cm² = 1.07 W/m² UVB (US) ( 280 nm - 320 nm) 183 µW/cm² = 1.83 W/m² UVA+B ( 280 nm - 380 nm) 2810 µW/cm² = 28.1 W/m² Solar UVB ( 290 nm - 315 nm) 107 µW/cm² = 1.07 W/m² UVA D3 regulating ( 315 nm - 335 nm) 609 µW/cm² = 6.09 W/m² UVA (EU) ( 315 nm - 380 nm) 2700 µW/cm² = 27 W/m² UVA2 (medical definition) ( 320 nm - 340 nm) 684 µW/cm² = 6.84 W/m² UVA (US) ( 320 nm - 380 nm) 2620 µW/cm² = 26.2 W/m² UVA1 (variant) ( 335 nm - 380 nm) 2090 µW/cm² = 20.9 W/m² UVA1 (medical) ( 340 nm - 400 nm) 3070 µW/cm² = 30.7 W/m² vis. UVA ( 350 nm - 380 nm) 1520 µW/cm² = 15.2 W/m² VIS Rep3 ( 350 nm - 600 nm) 24200 µW/cm² = 242 W/m² VIS Rep4 ( 350 nm - 700 nm) 28900 µW/cm² = 289 W/m² purple ( 380 nm - 420 nm) 2950 µW/cm² = 29.5 W/m² VIS ( 380 nm - 780 nm) 27400 µW/cm² = 274 W/m² PAR ( 400 nm - 700 nm) 26300 µW/cm² = 263 W/m² blue ( 420 nm - 490 nm) 7760 µW/cm² = 77.6 W/m² green ( 490 nm - 575 nm) 9970 µW/cm² = 99.7 W/m² yellow ( 575 nm - 585 nm) 1020 µW/cm² = 10.2 W/m² orange ( 585 nm - 650 nm) 5700 µW/cm² = 57 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 4.81 UV-Index Pyrimidine dimerization of DNA 67 µW/cm² Photoceratitis 5.98 µW/cm² Photoconjunctivitis 0.0618 µW/cm² DNA Damage 0.209 Vitamin D3 19.4 µW/cm² Photosynthesis 17300 µW/cm² Luminosity 80100 lx Human L-Cone 11800 µW/cm² Human M-Cone 10300 µW/cm² Human S-Cone 6340 µW/cm² CIE X 10100 µW/cm² CIE Y 11100 µW/cm² CIE Z 11700 µW/cm² PAR 110000000 mol photons Extinction preD3 191 e-3*m²/mol Extinction Tachysterol 714 e-3*m²/mol Exctincition PreD3 102000 m²/mol Extinction Lumisterol 10.9 m²/mol Exctincition Tachysterol 1210000 m²/mol Extinction 7DHC 5.41 m²/mol L-Cone 9640 µW/cm² M-Cone 11400 µW/cm² S-Cone 10400 µW/cm² U-Cone 6290 µW/cm² UVR - ICNIRP 2004 2.79 Rel Biol Eff Melatonin Supression 9670 µW/cm² Blue Light Hazard 7170 µW/cm² (89.5 µW/cm² per 1000 lx) CIE 174:2006 PreVit D3 20.8 µW/cm² Lumen Reptil 86200 "pseudo-lx" Vitamin D3 Degradation 38.4 µW/cm² Actinic UV 2.81 µW/cm² (0.351 mW/klm) Exctincition Lumisterol 22300 m²/mol Exctincition 7DHC 8920 m²/mol Exctincition Toxisterols 24100 m²/mol
Broadbandmeters
Solarmeter 6.2 (UVB, pre 2010) 269 µW/cm² Solarmeter 6.5 (UV-Index, pre 2010) 6.16 Leybold UVB 175 µW/cm² Leybold UVA 1950 µW/cm² Leybold UVC 0.000415 µW/cm² DeltaOhm UVB 648 µW/cm² DeltaOhm UVC 56.5 µW/cm² Vernier UVB 49.1 µW/cm² Vernier UVA 1710 µW/cm² Gröbel UVA 2230 µW/cm² Gröbel UVB 77.4 µW/cm² Gröbel UVC -0.0492 µW/cm² Solarmeter 6.4 (D3) 19.2 IU/min UVX-31 755 µW/cm² IL UVB 0.129 µW/cm² IL UVA 2290 µW/cm² Solarmeter 6.5 (UVI, post 2010) 5.47 UV-Index Solarmeter 6.2 (UVB, post 2010) 199 µW/cm² (Solarmeter Ratio = 36.3) Solarmeter AlGaN 6.5 UVI sensor 84.7 UV Index GenUV 7.1 UV-Index 5.6 UV-Index Solarmeter 10.0 (Global Power) 266 W/m² Solarmeter 4.0 (UVA) 37.7 mW/cm² LS122 0 W/m² ISM400 157 W/m²