HR: 1400h
AN: SH23C-02    [Abstracts]
TI: Understanding the relationship between photospheric magnetic field observations and in situ observations of the interplanetary magnetic field
AU: * Riley, P
EM: Pete.Riley@saic.com
AF: SAIC, 10260 Campus Point Dr., San Diego, CA 92121, United States
AU: Mikic, Z
EM: Zoran.Mikic@saic.com
AF: SAIC, 10260 Campus Point Dr., San Diego, CA 92121, United States
AU: Linker, J A
EM: Jon.A.Linker@saic.com
AF: SAIC, 10260 Campus Point Dr., San Diego, CA 92121, United States
AB: Understanding the Sun's open flux and its variability during the course of the solar cycle is important for a number of reasons. For example, recent claims that it has increased significantly over the last century may have had significant space- and even terrestrial-weather consequences. A key relationship in understanding this evolution lies between the observed photospheric magnetic field and the open flux measured in situ by spacecraft. Global potential field source surface (PFSS) and MHD models can be used to address this relationship; however, several issues make this a difficult task. First, there is controversy about how to convert un-calibrated magnetogram measurements at some solar observatories into radial magnetic fields (which are the primary input into most numerical models). Second, it is not clear what contribution coronal mass ejections (CMEs) and other transient phenomena make to the observed open flux in interplanetary space. Third, it is difficult to assess what errors the different models introduce. In this study we investigate the relationship between solar observations of the photospheric magnetic field and in situ measurements by addressing each issue systematically. Here, we focus on deriving the best estimate of the photospheric magnetic field by inter-calibrating data from a number of solar observatories and assessing the sensitivity of the models to these inputs.
DE: 2101 Coronal mass ejections (7513)
DE: 2134 Interplanetary magnetic fields
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7529 Photosphere
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly