Author Topic: ‘Terminators’ on the Sun trigger plasma tsunamis and the start of new solar cycles  (Read 1083 times)

0 Members and 1 Guest are viewing this topic.

Offline Elderberry

  • TBR Contributor
  • *****
  • Posts: 24,280
NCAR & UCAR News Jul 24, 2019 - by Laura Snider

The next solar cycle is predicted to take off within a year

In a pair of new papers, scientists paint a picture of how solar cycles suddenly die, potentially causing tsunamis of plasma to race through the Sun’s interior and trigger the birth of the next sunspot cycle only a few short weeks later.

The new findings provide insight into the mysterious timing of sunspot cycles, which are marked by the waxing and waning of sunspot activity on the solar surface. While scientists have long known that these cycles last approximately 11 years, predicting when one cycle ends and the next begins has been challenging to pin down with any accuracy. The new research could change that.

In one of the studies, which relies on nearly 140 years of solar observations from the ground and space, the scientists are able to identify “terminator” events that clearly mark the end of a sunspot cycle. With an understanding of what to look for in the run up to these terminators, the authors predict that the current solar cycle (Solar Cycle 24) will end in the first half of 2020, kicking off the growth of Solar Cycle 25 very shortly after.

In a second study, motivated by the first, scientists explore the mechanism for how a terminator event could trigger the start of a new sunspot cycle using a sophisticated computer model. The resulting simulations show that “solar tsunamis” could provide the connection and explain the Sun’s remarkably rapid transition from one cycle to the next.

Both studies were led by the National Center for Atmospheric Research (NCAR).

“The evidence for terminators has been hidden in the observational record for more than a century, but until now, we didn’t know what we were looking for,” said NCAR scientist Scott McIntosh, who directs the center’s High Altitude Observatory and worked on both studies. “By combining such a wide variety of observations over so many years, we were able to piece together these events and provide an entirely new look at how the Sun’s interior drives the solar cycle.”

The research was funded by the National Science Foundation, which is NCAR’s sponsor, NASA’s Living with a Star program, and the Indo-US Joint Networked R&D Center.

More: https://news.ucar.edu/132675/terminators-sun-trigger-plasma-tsunamis-and-start-new-solar-cycles