2000 ASTM Standard Extraterrestrial Spectrum Reference E-490-00
In 2000, the American Society for Testing and Materials (ASTM) developed an air mass zero reference spectrum (ASTM E-490) for use by the aerospace community. The ASTM E-490 solar spectral irradiance is based on data from satellites, space shuttle missions, high-altitude aircraft, rocket soundings, ground-based solar telescopes, and modeled spectral irradiance.
The integrated spectral irradiance has been made to conform to the value of the solar constant accepted by the space community, which is 1366.1 W/m2.
| Solar constant | = 1366.1 W*m-2 [SI unit] = 0.13661 W*cm-2 = 136.61 mW*cm-2 = 1.3661 x 106 erg*cm-2*s-1 = 126.9 W*ft-2 = 1.959 cal*cm-2*min-1 (± 0.03 cal*cm-2*min-1) = 0.0326 cal*cm-2*s-1 = 433.4 Btu*ft-2*h-1 = 0.1202 Btu*ft-2*s-1 = 1.956 Langleys*min-1 |
|---|
- The calorie is the thermochemical calorie-gram and is defined as 4.1840 absolute joules.
- The Btu is the thermochemical British thermal unit and is defined by the relationship: 1 Btu (thermochemical)/(°F*lb) = 1 cal*g (thermochemical)/(°C*g).
- The Langley, however, is defined in terms of the older thermal unit, the calorie*g (mean); that is, 1 Langley = 1 cal*g (mean)*cm-2; 1 cal*g (mean) = 4.19002 J.
In the 0.1195 to 0.41 µm range, the values are averages of two different instruments on the Upper Atmosphere Research Satellite, the Solar Ultraviolet Spectral Irradiance Monitor, and the SOLar STellar Irradiance Comparison Experiment (SOLSTICE), reported by Woods et al. These data were obtained in April 1993 during a period of moderate solar activity and were scaled by a factor of 0.96843 to match the Neckel and Labs data over the 0.33 to 0.41 µm range. In the 0.41 to 0.825 µm range, the values are from the McMath Solar Telescope at Kitt Peak, Arizona, as reported by Neckel and Labs. In the 0.825 to 4.0 µm range, the values are from the high-resolution solar atlas computed by Kurucz. These data were smoothed to 2-and 20-nm wavelength resolution and scaled by a factor of 1.00085 to match the Neckel and Labs data at 0.825 µm. In the 4.0 to 1000 µm range, the values are from the logarithmic irradiance versus wavelength fits reported by Smith and Gottlieb. These data were scaled by a factor of 0.99437 to match the Kurucz data at 4.0 µm. The composite spectral irradiance data were then scaled by a factor of 0.99745 to force the integrated total irradiance equal to the solar constant.
| Planet | Solar Irradiance, W*m-2 | ||
|---|---|---|---|
| Mean | Perihelion | Aphelion | |
| Mercury | 9116.4 | 14447.5 | 6271.1 |
| Venus | 2611.0 | 2646.4 | 2575.7 |
| Earth | 1366.1 | 1412.5 | 1321.7 |
| Mars | 588.6 | 715.9 | 491.7 |
| Jupiter | 50.5 | 55.7 | 45.9 |
| Saturn | 15.04 | 16.76 | 13.53 |
| Uranus | 3.72 | 4.11 | 3.37 |
| Neptune | 1.510 | 1.515 | 1.507 |
| Pluto | 0.878 | 1.571 | 0.560 |
Data Files
Download 2000 ASTM Standard Extraterrestrial Spectrum Reference E-490-00 (119.5–1,000,000.0 nm). By accessing this file, you agree to abide by the NREL data disclaimer.
References
Fröhlich, C., and Lean, J., "Total Solar Irradiance Variations: The Construction of a Composite and its Comparison with Models," International Astronomical Union Symposium 185: New Eyes to See Inside the Sun and Stars, Kluwer Academic Publ., Dortrecht, The Netherlands, pp. 89–102.
Kurucz, R. L., "ATLAS9 Stellar Atmosphere Programs and 2 km/s Grid," Harvard-Smithsonian Center for Astrophysics CD-ROM No. 13, 1993.
Neckel, H., and Labs, D., "The Solar Spectrum Between 3300 and 12500 Å," Solar Physics, Vol. 90, 1984, pp. 205–258.
Smith, E. V. P., and Gottlieb, D. M., "Solar Flux and its Variations," Space Science Reviews, Vol. 16, Nos. 5/6, November/December 1974, pp. 771–802.
Woods, T. N., et al, "Validation of the UARS Solar Ultraviolet Irradiances: Comparison with the ATLAS 1 and 2 Measurements," Journal of the Geophysical Research, Vol. 101, No. D6, April 30, 1996, pp. 9541–9569.
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