Temporal Evolution of a Streamer Complex: Coronal and in Situ Plasma Parameters

TitleTemporal Evolution of a Streamer Complex: Coronal and in Situ Plasma Parameters
Publication TypeJournal Article
Year of Publication2003
AuthorsBemporad, A., Poletto G., Suess S. T., Ko Y. K., Parenti S., Riley P., Romoli M., and Zurbuchen T. Z.
JournalAstrophysical Journal
Date PublishedAug

We report on observations acquired by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and Heliospheric Observatory (SOHO), from 2000 June 10 to June 17 at the time of a SOHO-Sun-Ulysses quadrature. UVCS took data at 1.6 and 1.9 R$_{solar}$ with a slit normal to the solar radius and centered along the radial to Ulysses. A streamer complex was sampled by UVCS throughout the quadrature campaign, giving us the opportunity to derive plasma parameters in different streamers and to compare them with plasma properties measured in situ. Large Angle Spectroscopic Coronagraph images above 2 R$_{solar}$ helped us understand the temporal evolution of the streamer complex. We derive densities, temperatures, and elemental abundances in two streamers, which have different temperatures and element abundances. In spite of these differences, both structures have the same first ionization potential (FIP) bias. The Fe/O ratio, which may be considered a proxy for the FIP effect, was measured in situ by the Solar Wind Ion Composition Spectrometer aboard the Ulysses spacecraft. Values of Fe/O measured in the corona at the sites where in situ plasma originated agree with in situ Fe/O values.