# Presentation: 668959

## 3D Coronal Magnetic Field/Potential Field Source Surface

- Intern: Patrick Zhou
- Mentor: Peter MacNeice
- Group: Community Coordinated Modeling Center

## Overview of Presentation

**Background - The Sun’s Influence on the Earth**
**Sun’s Magnetic Field**
**Sun’s Relation to the Earth**
**Hazards of the Sun**
**3-D Diagrams of the Sun**
**Purpose of 3-D Diagrams**
**Brief Summary on Internship Tasks**
**Programming**
**Rendering**
**Animating**

## The Sun’s Magnetic Atmosphere

- Solar Atmosphere includes the photosphere, chromosphere, and corona.
- The Sun’s magnetism plays an important role in molding, shaping, and heating coronal gas.
- In the low solar corona, strong magnetic fields trap hot, dense, and electrified gas within loops.
- Away from the sun, the pressure of the hot gas breaks open the loops and escapes, forming solar winds and carrying magnetic fields.

## Sun-Earth Connection

- Earth’s Magnetic Dipole
- Interaction between solar and terrestrial magnetic fields.
- Interaction can result in the reinforcement or erosion of the Earth’s Magnetosphere.
- Erosion of Magnetic fields leaves Earth vulnerable to a Solar Wind or Coronal Mass Ejection.

## Hazards of the Sun

- High-Energy particles from solar winds can wipe out unprotected astronauts and destroy satellite electronics.
- Blasts from CME’s can threaten satellites and also overload transmission lines, causing black outs.
- Intense radiation can change electrical properties of atmosphere, disrupt communications.
- Space Travel unsafe, i.e. Mars expedition

## 3-D Diagrams of the Sun

- The “Potential Field Source Surface” enables us to construct a simple approximation of the magnetic field from the surface to 2.5 Solar Radii
- Based on assumptions that there are no electrical currents between the surface and the outer edge of the model edge at 2.5 solar Radii
- Diagrams are effective in inactive regions of the sun, ineffective in active regions.
- Missing data from back side of the sun.  Estimated that magnetic field lines do not change.

## Purpose of the Diagram

- First attempt to create a 3D model of the sun and its magnetic fields
- Simplest model of the coronal magnetic field to construct
- Difficult to visualize 3D structure of magnetic fields as it changes daily, hence the use of 3D tools.
- Interplanetary magnetic field can be predicted based on sun’s magnetic field.
- Conclusions on the interaction of solar and terrestial magnetic fields can be drawn.

## Progress of Internship Work

- Programming Using Java
- Rendering using Perl scripts borrowed from team- members
- Animation of Images using Perspecta 3-D Display.

## Purpose of Programming

- Read Data Files of the Sun’s Magnetic Field at a given time
- Interpolate Data using formula:
-     y(X) = y0 (x1-x)(x2-x)/(x1-x0)(x2-x0) + y1 (x2-x)(x0-x)/(x2-x1)(x0-x1)
-                 +  y2 (x0-x)(x1-x)/(x0-x2)(x1-x2)
- Output Data Files of the Sun’s Magnetic Field

## Rendering Images

- Rendered Images in .gif format to test accuracy of Interpolation and smoothness

- Later recorded in .wrl format to use in 3-D Display

- .gif File

- .vrml file

## Animation

- Animated PSFF using .Gif files

- Animated PSFF in 3D Display for Final Project

## Slide 12