Heating and Cooling of Plasma in a Solar Flare

Advisors: Dana Longcope and Jiong Qiu

A solar flare is a sudden conversion of energy from magnetic energy into other forms. As a result of the conversion, high-temperature coronal plasma is heated and evaporated, it then cools as it radiates X-rays. Observations of flares appear to corroborate this picture: there is always a sudden rise in X-ray intensity (evaporation) followed by a gradual decrease (cooling). Applying physical principles shows, however, that the cooling phase lasts far longer than the time it should take to radiate away the initial energy. Images made (from space) in extreme ultraviolet (EUV) show the result of this energy conversion as numerous distinct loops of plasma (confined by magnetic field). Each loop appears to cool through radiation as predicted by physical laws. It appears, however, that new loops are being heated for hours following the flare.

In this project the student will analyze sequences of EUV images form the new Solar Dynamic Observatory (SDO) spacecraft. From this data we will measure the rate at which new loops are being heated. We will then use models of radiation to estimate the temperature that each one is heated to and from that the power which is being released by the flare over time.

For background on this project from last summer's REU program, see Theresa Carranza-Fulmer's 2009 REU Research Log and Presentation.