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J/ApJ/789/117          Solar spectral irradiance              (Marchenko+, 2014)

Solar spectral irradiance changes during cycle 24. Marchenko S.V., Deland M.T. <Astrophys. J., 789, 117 (2014)> =2014ApJ...789..117M (SIMBAD/NED BibCode)
ADC_Keywords: Sun ; Spectra, ultraviolet Keywords: Sun: activity - Sun: atmosphere - Sun: rotation - Sun: UV radiation Abstract: We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by ∼0.6%±0.2% around 265 nm. These changes gradually diminish to 0.15%±0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar "continuum." Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar "continuum," the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at λ ≳ 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region. Description: Combining the contemporaneous Ozone Monitoring Instrument (OMI) and GOME-2 observations with the records from previous solar cycles, we construct the normalized (to the Mg II doublet at 280 nm) solar variability spectrum in the 170-795 nm spectral range, which could be used in combination with a reference spectrum (e.g., Thuillier et al. 2004, Solar Variability and its Effects on Climate (Geophysical Monograph 141), ed. J. M. Pup et al. (Washington, DC: AGU Geophysical Monograph Series), 171) to reproduce a dynamical solar spectrum at any epoch.The remote-sensing OMI (part of the Aura instrumental suite; Levelt et al., 2006ITGRS..44.1093L) has collected information about trace gases in the Earth's atmosphere since 2004 July. OMI comprises three different spectral channels, UV1 (264-311 nm spectral domain, resolution δλ = 0.63 nm), UV2 (307-383 nm, δλ = 0.42 nm), and VIS (349-504 nm, δλ = 0.63 nm), each acquiring data through partially shared optical pathways (Dobber et al., 2006ITGRS..44.1209D). The UV1 and UV2 light falls on the same CCD detector while VIS spectra are recorded by a different CCD. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 18 3145 The normalized max-min difference spectra derived from the 27-day rotational modulation
See also: J/A+A/587/A65 : Visible and near-infrared solar spectra (Reiners+, 2016) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 5 F5.1 nm Wave Wavelength 7- 12 F6.3 % Diff Normalized max-min spectral difference (1) 14- 18 F5.3 % e_Diff The 1σ error in Diff
Note (1): Derived from the 27-day rotational modulation.
History: From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 09-Mar-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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