Featured Research

from universities, journals, and other organizations

Sunspot Cycle Closely Following Prediction -- Maximum Expected In The Year 2000

Date:
October 20, 1998
Source:
NASA/Marshall Space Flight Center--Space Sciences Laboratory
Summary:
Scientists at NASA's Marshall Space Flight Center appear to have done a good job of predicting Cycle 23 of the sunspot cycle. "Except for the last few days, it's followed our curve very closely," said Dr. David Hathaway, head of the solar physics branch at NASA/Marshall.

Oct. 19, 1998: Scientists at NASA's Marshall Space Flight Center appear to have done a good job of predicting Cycle 23 of the sunspot cycle.

"Except for the last few days, it's followed our curve very closely," said Dr. David Hathaway, head of the solar physics branch at NASA/Marshall. "Last week there was one day when the sunspot number dropped to 20 as compared to an average of 90 for the past few weeks. But the sun normally does that sort of thing during any cycle."

Indeed, a plot of actual vs. predicted sunspot numbers for Cycle 23 shows a few peaks and valleys, but the sun is staying close to what was predicted by Hathaway, Robert M. Wilson, and Edwin J. Reichmann, also at NASA/Marshall, in September 1996.

"We can say with a little more confidence, now, that this prediction is right," Hathaway said. "When we made the prediction in September 1996, we were stepping out in front of things." The explanation of the prediction was published in the May 1998 issue of the Journal of Geophysical Research (Space Physics).

"That it seems to be following our line as if it knows it was there is heartening," Hathaway said. But, he cautioned that the sun often defies predictions.

In their May article, Hathaway and his colleagues said that Cycle 23 will be above average but no record setter. The sun now is on the upswing of its 23rd activity cycle, a numbering scheme that dates from the mid-19th century, although the sunspot cycle may have lasted as long as the sun has burned. The "relative sunspot number" was introduced by Rudolf Wolf of the Zurich Observatory in 1848.

What is now called the International sunspot number or the Zurich number is a blend of actual numbers of individual spots and numbers of groups of spots on the sun. On average, the sunspot number varies from a minimum through a maximum to the next minimum in about 11 years. Because the solar magnetic fields reverse at the peak of each 11-year cycle, solar activity cycle actually spans a 22-year "Hale cycle." Cycle 23 is the last half of the current Hale cycle (composed of Cycles 22 and 23) that began in 1986. Predicting the solar cycle is more than a matter of scientific curiosity. An active sun can cause geomagnetic storms that endanger satellites and disrupt communications and power systems on Earth. It also heats the Earth's outer atmosphere so that spacecraft are exposed to more atmospheric drag and to greater erosion by atomic oxygen.

The NASA/Marshall team's predictions are based variations in geomagnetic indices, the occurrences of high-latitude spots, the inferred strengths of the sun's polar fields, and the number of geomagnetically disturbed days over the course of the preceding cycle. Based on various precursor techniques, Hathaway, Wilson, and Reichmann predicted that Cycle 23 will rise faster than normal to its peak, attaining maximum amplitude sometime during the latter half of 1999 to the first half of 2000, and that it will measure about 170 plus or minus 20 units (yearly sunspot number). They expect Cycle 23 to continue until sometime in 2006 when the next cycle, Cycle 24, should begin.


Story Source:

The above story is based on materials provided by NASA/Marshall Space Flight Center--Space Sciences Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Marshall Space Flight Center--Space Sciences Laboratory. "Sunspot Cycle Closely Following Prediction -- Maximum Expected In The Year 2000." ScienceDaily. ScienceDaily, 20 October 1998. <www.sciencedaily.com/releases/1998/10/981020074447.htm>.
NASA/Marshall Space Flight Center--Space Sciences Laboratory. (1998, October 20). Sunspot Cycle Closely Following Prediction -- Maximum Expected In The Year 2000. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/1998/10/981020074447.htm
NASA/Marshall Space Flight Center--Space Sciences Laboratory. "Sunspot Cycle Closely Following Prediction -- Maximum Expected In The Year 2000." ScienceDaily. www.sciencedaily.com/releases/1998/10/981020074447.htm (accessed July 25, 2014).

Share This




More Space & Time News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
Powered by NewsLook.com
Raw: Cargo Craft Undocks from Space Station

Raw: Cargo Craft Undocks from Space Station

AP (July 22, 2014) A Russian Soyuz cargo-carrying spacecraft undocked from the International Space Station on Monday. The craft is due to undergo about ten days of engineering tests before it burns up in the Earth's atmosphere. (July 22) Video provided by AP
Powered by NewsLook.com
NASA Ceremony Honors Moon Walker Neil Armstrong

NASA Ceremony Honors Moon Walker Neil Armstrong

AP (July 21, 2014) NASA honored one of its most famous astronauts Monday by renaming a historic building at the Kennedy Space Center in Florida. It now bears the name of Neil Armstrong, the first man to walk on the moon. (July 21) Video provided by AP
Powered by NewsLook.com
Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

    Health News

      Environment News

        Technology News



          Save/Print:
          Share:

          Free Subscriptions


          Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

          Get Social & Mobile


          Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

          Have Feedback?


          Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
          Mobile: iPhone Android Web
          Follow: Facebook Twitter Google+
          Subscribe: RSS Feeds Email Newsletters
          Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins