Exclusive: NASA captures image of massive solar flare

June 4, 2014 by  
Filed under Solar Energy Tips

The following is an interview with Joel Allred, PhD, IRIS Deputy Mission Scientist at NASA/GSFC. Below is an overview of NASA’s brand-new solar satellite, the Interface Region Imaging Spectograph (IRIS) — which finally caught its first solar flare last month — and coronal mass ejections (CMEs).

Are CMEs difficult to predict? Why?

The initiation of CMEs is quite difficult to predict. They are produced by rapid reconfigurations of the solar magnetic field in areas where the field is strong. There are observatories which monitor the sun’s magnetic field, and we can locate those areas that are most likely to produce CMEs. But there is considerable uncertainty in the prediction of the precise moment when that reconfiguration will happen. However, once a CME has erupted we can monitor it and make more accurate predictions if it will impact Earth.

What is the largest one on record?

As far as we know, the largest CME on record is known as the Carrington Event and occurred in August 1859. However, there is uncertainty in this because in that era there were no instruments which could accurately quantify its size. In the modern age, the fastest CME that has been recorded appears to be the 23 July 2012 event. However, that CME had a trajectory that did not bring it into contact with Earth. The CMEs that produced some of the largest geomagnetic storms on Earth occurred on 9 March 1989 and 28 – 29 October 2003.

What impacts do CMEs have on the Earth?

When CMEs collide with the earth environment, they affect both earth- and space-based technologies. For example, they can cause disruptions in satellite based telecommunications and GPS. They often cause Earth’s upper atmosphere to expand, increasing drag on spacecraft, and altering their orbits. On the ground, CMEs have been known to induce large electrical currents in power grids resulting in power disruptions. For example, the 9 March 1989 event caused a nine hour blackout in Quebec. But not all effects are disruptive, CMEs are also responsible for producing the spectacular light displays in the sky known as the aurora.

What discoveries have been made by the observation?

The 9 May 2014 event is the first CME observed by the Interface Region Imaging Spectrograph (IRIS). IRIS is NASA’s newest solar instrument, and there is much to be learned from it. It observes at sufficiently high resolution to see small-scale structures deep in the sun’s atmosphere. It is at these scale sizes that much of the energy that powers solar flares and coronal mass ejections is moved from the sun’s surface into its atmosphere. Additionally, using IRIS we can track the velocity of the ejected solar material as it is being accelerated which provides constraints on theories which describe CME initiation.

Were there any surprises?

The processes which initiate CMEs are not yet completely understood, but IRIS is providing essential data to determine these. This event is very recent and is still being analyzed. As it studied in further detail, there will surely be unanticipated discoveries.

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