[IGPP Everyone] Space Physics Seminar, Friday April 25th: Formation and evolution of solar filaments and coronal pseudostreamers (O. Panasenco, Advanced Heliophysics)

[Emmanuel V. Masongsong]

SPACE PHYSICS SEMINAR 

DEPARTMENT OF EARTH, PLANETARY, AND SPACE SCIENCES 

DEPARTMENT OF ATMOSPHERIC AND OCEANIC SCIENCES 

UNIVERSITY OF CALIFORNIA, LOS ANGELES 

(EPSS M288A, AOS M275A ) 







Olga Panasenco 


Advanced Heliophysics 





Formation and evolution of solar filaments and coronal pseudostreamers 






The solar dynamo and plasma convection produce three main observed structures extending from the solar surface into the corona – active regions, solar filaments (prominences when observed at the limb) and coronal holes. Each of these three key features is interlinked with the other two in its evolution and dynamics. Active regions can form clusters of magnetic activity and sunspots. When active regions decay, solar filaments form at their boundaries separating opposite magnetic polarities (neutral lines). Alternatively, decaying active regions in the presence of flux imbalance can give birth to lower latitude coronal holes. Accumulation of magnetic flux at coronal hole boundaries also creates the conditions for filament formation. Polar crown filaments are permanently present at the boundaries of the polar coronal holes. Middle-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers if other coronal holes of the same polarity are present. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. There is debate as to the speed and nature of the wind from pseudostreamers: it could be fast, slow, or in between. I will demonstrate how the resulting wind type depends on the presence or absence of filaments at the pseudostreamer base. I will discuss mechanisms of formation and evolution for solar filaments and pseudostreamers, and the role active regions play in these processes. 



Friday, April 25, 2015 

Room 6704 Geology 

3:30 - 5:00 PM 



Refreshments served after the seminar in Room 6850. 



In-Charge 
M. Velli 


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