Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Powerful ’conveyor belts’ drive Sun’s 11-year cycle, new evidence suggests

20.06.2003


NASA and university astronomers have found evidence the 11-year sunspot cycle is driven in part by a giant conveyor belt-like, circulating current within the Sun.


Sunspots appear as dark spots on the Sun’s surface. (Big Bear Solar Observatory/New Jersey Institute of Technology)



The astronomers, Dr. David Hathaway, Robert Wilson and Ed Reichmann of NASA’s Marshall Space Flight Center in Huntsville, Ala., and Dr. Dibyendu Nandy of Montana State University in Bozeman, reported their findings the week of June 16 at the annual meeting of the Solar Physics Division of the American Astronomical Society in Laurel, Md. The results were also published in the May 20 issue of the Astrophysical Journal.

The astronomers made their discovery by reviewing the positions and sizes of all sunspots seen on the Sun since 1874. "The sunspots appear in two bands on either side of the Sun’s equator," said Hathaway. "Although the individual sunspots come and go from week-to-week, the central positions of the bands in which they appear drift slowly toward the solar equator over the course of each 11-year sunspot cycle."


Previously, scientists believed this equator-ward drift was a wave-like process involving magnetic forces. However, this new evidence suggests this drift is produced by a giant circulation system in which the compressed gases, 125,000 miles below the Sun’s surface, move from the Sun’s poles to its equator at about three mph — a leisurely walking pace. The gases then rise near the equator and turn back toward the poles, traveling in the surface layers where the gas is less compressed — moving at a faster rate of approximately 20 to 40 mph. Recent progress in theoretical modeling of the sunspot cycle has emphasized the important role of this circulation.

The speed of this circulation system, called a meridional circulation, changes slightly from one sunspot cycle to the next. The circulation is faster in cycles shorter than the average 11-year period and slower in cycles longer than the average period. This is a strong indication that this circulation acts like an internal clock that sets the period of the sunspot cycle.

The circulation also appears to influence the strength of future cycles, as seen in the number and sizes of the sunspots produced, not in the cycle immediately following, but rather in a two-cycle or 22-year time lag. When the flow is fast, it concentrates the magnetic field at the Sun’s poles. These stronger fields are then transported downward into the solar interior where they are further compressed and amplified to become the intense magnetic fields that form sunspots years later.

The Sun is now in the declining phase of the current sunspot cycle that peaked in 2000 and 2001. Because the circulation flow was fast during the previous cycle, the astronomers believe the next cycle will be a strong one, peaking in the years 2010 and 2011.

Contact: Steve Roy, steve.roy@msfc.nasa.gov

| NASA
Further information:
http://www.msfc.nasa.gov/news

More articles from Physics and Astronomy:

nachricht Magnetic field traces gas and dust swirling around supermassive black hole
22.02.2018 | Royal Astronomical Society

nachricht UMass Amherst physicists contribute to dark matter detector success
22.02.2018 | University of Massachusetts at Amherst

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>