ROSES ID: NNH10ZDA001N Selection Year: 2011
Program Element: Solar Dynamics Observatory
Principal Investigator: Yi-Ming Wang
Affiliation(s): Naval Research Laboratory
Sheeley, Neil R Co-I Naval Research Laboratory
Summary:OBJECTIVES/APPROACH: Employing simultaneous, coaligned SDO/AIA and SDO/HMI observations, we will carry out the following four projects: (1) We will study the formation and growth of the dark moats (also known as circumfacular areas) surrounding active regions, in the context of the evolving photospheric field. A particular goal will be to understand the role of supergranular convection, reconnection, and flux cancellation in the transition from fibril structures to PIL-aligned filaments. (2) We will track coronal cavities to determine if they have a tendency to evolve from arcade-like structures to flux ropes with circular cross sections. In addition, we will test our prediction that the preferred direction of the cavity spinning motions changes from equatorward to poleward as the polar fields weaken. (3) We will exploit the multiple EUV channels provided by AIA to study the temperature dependence of coronal dimmings, and to seek further support for our hypothesis that most of the coronal plasma cooler than 1 MK is not expelled in eruptive events. (4) We will study the formation of coronal holes during the emergence of active regions, and determine whether the formation process is accompanied by the expansion of coronal loops or the ejection of mass. In addition, we will investigate the causes of the observed short-term fluctuations in coronal hole boundaries and relate these fluctuations to in situ measurements of the slow solar wind.
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