Scientists Gain New Insight Into Solar Structures Creating High-Speed Solar Wind

NASA scientists have combined data and cutting-edge image processing to gain new insights into solar structures responsible for creating the sun's flow of high-speed solar wind. The study involves a first look at relatively small structures on the sun known as plumelets. The small structures could help scientists understand how and why disturbances form in the solar wind.

The solar wind is a driving force for the sun's magnetic influence, which stretches for billions of miles, far past Pluto's orbit. Changes in the solar wind create space weather that impacts planets and human and robotic explorers in the solar system. Researchers found that the latest study that previously-unexplored features close to the sun's surface play a crucial role in the characteristics of the solar wind.

The study highlights the importance of small-scale structures and processes on the sun for understanding large-scale solar winds and space weather. The solar wind is controlled by very complex magnetic forces inside the sun's atmosphere. The sun's surface is threaded with a constantly-changing combination of closed loops of magnetic field and open magnetic field lines stretching out into the solar system.

Some areas of open magnetic field on the sun can create coronal holes or patches of relatively low density that appear as dark splotches in some ultraviolet views of the Sun. Often inside of those coronal holes are geysers of solar material that stream outward for the sun, sometimes for days at a time, called plumes. The solar plumes appear bright in extreme ultraviolet views making them easily visible using the NASA Solar Dynamics Observatory and other spacecraft instruments.

Researchers say these plumes play a large role in creating high-speed solar wind because they are regions of particularly dense solar material in an open magnetic field. Researchers used high-resolution observations from the NASA Solar Dynamics Observatory to observe plumes along with new image processing technique developed specifically for the work. The team found the plumes are made up of much smaller strands of a material called plumelets.

While the entirety of the plume stretches about 70,000 miles in the images, each plumelet strand's width is only a few thousand miles across. This study marks the first time scientists have observed plumelets in sharp focus.