Using sound waves, scientists develop findings that challenge standard theories of solar convection

A workforce of solar physicists at NYU Abu Dhabi’s Heart for Astrophysics and Area Science (CASS), led by Analysis Scientist Chris S. Hanson, Ph.D., has revealed the inside construction of the sun’s supergranules, a movement construction that transports warmth from the sun’s hidden inside to its floor. The researchers’ evaluation of the supergranules presents a problem to the present understanding of solar convection.

The sun generates vitality in its core via nuclear fusion; that vitality is then transported to the floor, the place it escapes as daylight. In a examine titled “Supergranular-scale solar convection not explained by mixing-length theory,” revealed within the journal Nature Astronomy, the researchers clarify how they utilized Doppler, depth and magnetic photographs from the helioseismic and magnetic imager (HMI) onboard NASA’s Photo voltaic Dynamics Observatory (SDO) satellite to establish and characterize roughly 23,000 supergranules.

For the reason that sun’s floor is opaque to gentle, the NYUAD scientists used sound waves to probe the inside construction of the supergranules. These sound waves, that are generated by the smaller granules and are in all places within the sun, have been efficiently used previously in a subject often called helioseismology.

By analyzing such a big dataset of supergranules, which had been estimated to increase 20,000 km (~3% into the inside) under the floor of the sun, the scientists had been capable of decide the up- and downflows related to supergranular warmth transport with unprecedented accuracy. Along with inferring how deep the supergranules prolong, the scientists additionally found that the downflows appeared roughly 40% weaker than the upflows, which means that some element was lacking from the downflows.

By way of in depth testing and theoretical arguments, the authors theorize that the “lacking” or unseen element may include small scale (roughly 100 km) plumes that transport cooler plasma down into the sun’s inside. The sound waves within the sun can be too huge to sense these plumes, making the downflows seem weaker. These findings can’t be defined by the extensively used mixing-length description of solar convection.

“Supergranules are a significant factor of the warmth transport mechanisms of the sun, however they current a severe problem for scientists to know,” mentioned Shravan Hanasoge, Ph.D., analysis professor, co-author of the paper and co-Principal Investigator of CASS. “Our findings counter assumptions which are central to the present understanding of solar convection, and may encourage additional investigation of the sun’s supergranules.”

The analysis was carried out inside CASS at NYUAD in collaboration with Tata Institute of Elementary Analysis, Princeton College, and New York College, utilizing NYUAD’s excessive efficiency computing sources.