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Changes in photochemically significant solar uv spectral irradiance as estimated by the composite mg ii index and scale factors
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Cebula, Richard P. Deland, Matthew T. |
| Copyright Year | 1994 |
| Description | Quantitative assessment of the impact of solar ultraviolet irradiance variations on stratospheric ozone abundances currently requires the use of proxy indicators. The Mg II core-to-wing index has been developed as an indicator of solar UV activity between 175-400 nm that is independent of most instrument artifacts, and measures solar variability on both rotational and solar cycle time scales. Linear regression fits have been used to merge the individual Mg II index data sets from the Nimbus-7, NOAA-9, and NOAA-11 instruments onto a single reference scale. The change in 27-dayrunning average of the composite Mg II index from solar maximum to solar minimum is approximately 8 percent for solar cycle 21, and approximately 9 percent for solar cycle 22 through January 1992. Scaling factors based on the short-term variations in the Mg II index and solar irradiance data sets have been developed to estimate solar variability at mid-UV and near-UV wavelengths. Near 205 nm, where solar irradiance variations are important for stratospheric photo-chemistry and dynamics, the estimated change in irradiance during solar cycle 22 is approximately 10 percent using the composite Mg II index and scale factors. |
| File Size | 284135 |
| Page Count | 4 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19950004711 |
| Archival Resource Key | ark:/13960/t0kt1mk6p |
| Language | English |
| Publisher Date | 1994-04-01 |
| Access Restriction | Open |
| Subject Keyword | Geophysics Solar Spectra Atmospheric Composition Photochemical Reactions Light Visible Radiation Solar Activity Effects Ultraviolet Spectra Nimbus 7 Satellite Stratosphere Ozone Irradiance Solar Radiation Solar Cycles Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
