The student nitric oxide explorer (SNOE) satellite made daily solar observations of the solar soft X-ray irradiance over most of the period from March 10 , 1998through March 16 , 2002
For that purpose, we develop a compact, fully coherent, THz-driven attosecond X-ray source based on coherent inverse Compton scattering off a free-electron crystal, to outrun radiation damage effects due to the necessary high X-ray irradiance required to acquire diffraction signals.
The new measurements indicate higher solar soft X-ray irradiance but lower flux in the H Lyman-β line than earlier estimates by Hinteregger et al. [Hinteregger, H.E., Fukui, K., Gilson, B.R., Observational, reference, and model data on soalr EUV, from measurements on AE E. Geophys. Res. Lett. 8 (1981 1147]] based on measurements from Atmosphere Explorer and from rocket flights.
There have been significant, recent advances in understanding the solar ultraviolet (UV) and X-ray spectral irradiance from several different satellite missions and from new efforts in modeling the variations of the solar spectral irradiance.
The solar soft X-ray spectral irradiance between 0.6 and 2.5 nm varies by orders of magnitude between the "quiet Sun" and X-class solar flares, with the spectral distribution of emission changing markedly with increasing level of activity.
There are a number of scientific questions underlying the goal of understanding solar EUV/UV variability such as what are the primary mechanisms by which solar ultraviolet (UV), extreme ultraviolet (EUV), and soft X-ray (XUV) irradiance variations affect terrestrial global climate change and/or weather and what is their significance?
The DIRINDEX model was designed to estimate hourly solar beam irradiances from hourly global horizontal irradiances.
Available open solar flux, modulation strength, cosmic ray flux, total solar irradiance data, reconstructed back to 1700, solar wind parameters (speed and density) and the magnitude of the heliospheric magnetic field at 1 AU, reconstructed back to 1870, as well as the time series of geomagnetic activity indices (aa, IDV, IHV), going back to 1870, have been considered.
Fig. 2 Schematic of energy transfer processes linking the upper and lower atmosphere: GCR galactic cosmic rays, TSI total solar irradiance, SEP solar energetic particles (Gray et al. 2010).
During that period, great progress was made in measuring, understanding, and modeling the highly variable UV-Soft X-ray (XUV) solar spectral irradiance (SSI), and its effects on the upper atmosphere.
Moreover, the correlation between clouds of different type and two solar proxies, UV irradiance and cosmic ray induced ionisation, is partly improved.
