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Variations in total solar and spectral irradiance as measured by the VIRGO experiment on SOHO
Fröhlich, Claus; Wehrli, Christoph; Pap, Judit +3 more
The Variability IRradiance Gravity Oscillation (VIRGO) experiment on SOHO has been observing total solar and spectral irradiances at 402 nm (blue channel), 500 nm (green channel), and 862 nm (red channel) since January 1996. The VIRGO observations have shown that solar active regions influence both total and spectral irradiances in a similar fashi…
On the gradients of ACR oxygen at intermediate heliocentric distances: Ulysses/Soho results
Torsti, J.; Sanderson, T. R.; Marsden, R. G. +3 more
During 1997 and up to the present time, the heliocentric position of the Ulysses spacecraft has changed only slowly in distance and latitude, being close to the equator at a distance of ~5 AU. This period provides an excellent opportunity to observe the evolution of the Anomalous Cosmic Ray (ACR) spectrum at a location intermediate between 1 AU an…
Time-distance helioseismology
Kosovichev, A. G.; Scherrer, P. H.; Duvall, T. L.
The time-distance helioseismology (or helioseismic tomography) is a new promising method for probing 3-D structures and flows beneath the solar surface, which is potentially important for studying the birth of active regions in the sun's interior and for understanding the relation between the internal dynamics of active regions and chromospheric a…
Solar irradiances of UV and EUV lines during the minimum of the sunspot activity in 1996
Wilhelm, K.; Curdt, W.; Schühle, U. +6 more
Full Sun observations in UV and EUV emission lines were performed by SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on SOHO (Solar and Heliospheric Observatory) in 1996. The radiometric preflight calibration of SUMER is traceable to a primary radiometric source standard - the electron storage ring BESSY. Based on this calibration and …
Results from the GOLF instrument on SOHO
Baudin, F.; García, R. A.; Pallé, P. L. +9 more
An 800 day series of GOLF velocity data, with uniquely high continuity and stability, offers the best ever signal to noise ratio obtained in global Sun observations. Following meticulous efforts to provide reliable calibration, these data have been used for measurements of frequencies, line-widths and power in the p-modes, which are used for inver…