UAH PHYSICS COLLOQUIUM
UAH Optics Building: OB-234
Cookies & Coffee at 2:15 PM
Lecture at 2:30 PM
Q & A at 3:20 PM

Big and Small Explosions on the Sun

by

Alphonse Sterling
16 October 2001

Activity in the Sun's atmosphere occurs on various size and energy scales. Spicules are among the smallest observed dynamic solar features. They appear as jets of relatively cool (chromospheric) material which extend into the hot outer atmosphere (the corona) of the Sun. They reach heights of about 10,000 km, and an individual spicule may carry 10²⁶ ergs of energy. Coronal Mass Ejections, or CMEs, are among the biggest and most energetic solar phenomena. A CME can grow to several times the size of the Sun, and carry 10³² ergs or more of energy. CMEs are of more than just theoretical interest, since they are capable of damaging satellites and other human systems. In this presentation, I will review properties of spicules and CMEs, and consider physical mechanisms for their occurrence. I will also discuss possible signatures of impending CMEs; such signatures may eventually be of practical use in predicting CME onset, and serve as warning signs for CMEs which could damage electronic and satellite systems.