Type of Project:Data analysis and numerical modeling

Skills/Interest Required: Interest in analysis of space-based observations and use of advanced modeling techniques. No advanced programming skills required.

Mentor:Aad van Ballegooijen and Yingna Su

Email:vanballe_at_cfa.harvard.edu

Background:

The solar corona is heated to temperatures in excess of 1 million degrees Kelvin. Extreme ultraviolet (EUV) and X-ray observations of the corona show bright loops that are aligned with the magnetic field. The precise mechanisms by which the corona is heated are not yet understood, but magnetic fields are known to play an important role. One possibility is that the heating is due to the dissipation of so-called Alfven waves, a type of magnetic waves that travel along magnetic field lines like waves on a string. The attached figure shows results from a simulation of the dynamics of Alfven waves in coronal loops. Specifically, the figure shows selected magnetic field lines (a) in the lower atmosphere at one end of the loop, and (b) in the loop itself. The actual loop length is much larger than its width; image (b) is vertically compressed by a factor 50.

Project:

The intern will analyze EUV observations of coronal loops obtained with the Atmospheric Imager Assembly (AIA) on the Solar Dynamics Observatory (SDO) satellite, and search for evidence of Alfven waves in the corona. He/she will learn about the physics of Alfven waves, and will use an existing software program ("braid") to simulate the dynamics of Alfven waves in coronal loops, as illustrated above. The goal of this project is to determine whether coronal loops may be heated by Alfven waves.

Figure: Braided Coronal Loops