Posted on 06/21/2009 1:56:57 PM PDT by neverdem
Wake-up call. The sun's jet streams (in red, right) have reached their critical position, and soon the first sunspots of the new solar cycle may mar the star's currently placid-looking surface (inset).
Credit: National Solar Observatory/GONG (main image); SOHO/MDI (inset)
Maybe old Sol didn't hear the alarm clock. After a mysterious 2-year delay, the next 11-year solar cycle seems ready to begin, scientists say. That means the reemergence of sunspots, and with them periodic electromagnetic assaults on global navigation, communications, and power supplies--as well as brilliant auroras in the polar regions.
For unknown reasons, the sun goes through cycles of activity that last about 11 years. During this time, the number of sunspots on its surface increases to a point called a solar maximum, in which the star's magnetic field grows strongest, and then gradually drops, with a corresponding weakening of its magnetism. These dark, Earth-sized zones of cooler temperatures and powerful magnetic forces sometimes disappear altogether. However, sunspots haven't stayed away this long--2 years--in nearly a century.
Scientists had been at a loss to explain the lull, as ScienceNOW reported last month (ScienceNOW, 8 May), but now a group from the National Solar Observatory (NSO) in Tucson, Arizona, thinks it has found the reason. It has to do with a magnetic phenomenon called solar jet streams. Every 11 years, the sun simultaneously generates twin streams of plasma at each of its poles. Unlike the jet streams on Earth, the solar versions are magnetized and travel only toward the equator. This migration takes place very slowly--at about 10 kilometers per hour. For reasons still not understood, when the streams reach 22 degrees of latitude, north and south, they touch off a new solar cycle, and the sunspots reappear.
That is what has just happened on the sun, but with a twist, says NSO scientist Frank Hill. He and colleague Rachel Howe have been tracking the solar jet streams since the mid-1990s using a technique called helioseismology. The method is similar to that used by seismologists to detect and evaluate earthquakes, and it's necessary because the solar streams occur several thousand kilometers beneath the sun's surface. Hill and Howe discovered that the jet streams generated in 1996 have migrated more slowly than normal, taking 13 years to reach the critical 22-degree latitude instead of the usual 11 years.
But now the new solar cycle has begun, and Hill reports that scientists have detected the first sunspot of that cycle. "It's now under way," he told reporters at a news conference in Boulder, Colorado, yesterday. "We are going to rise to the solar maximum in the next few years."
The research amounts to a "reasonable and clever" way to determine why the beginning of the next solar cycle has been tardy, says space scientist Nancy Crooker of Boston University in Massachusetts. And she's excited about the new approach, too. "It is the first time the technology has been available to make detailed, space-based measurements of both the sun and the solar wind under [the] extreme conditions" of an extended solar minimum, she says.
Global cooling alert!
“But now the new solar cycle has begun, and Hill reports that scientists have detected the first sunspot of that cycle. “It’s now under way,” he told reporters at a news conference in Boulder, Colorado, yesterday.”
Huh. I thought back in January or whenever they had announced the first sunspot of the new cycle. Seems to me they are really stretching just to make it the start of the next cycle.
When Sol finally wakes up...he’s gonna be PO’d when he finds out what Al Gores been doing on Earth...
I really hope the sunspots appear. I really didn’t want to start budgeting to run the furnace 24/7/365.
I guess the scientists are more confident this time than in December 2007— when they predicted the new cycle would start in February 2008...
hh
Yea. Sunspots and Auroras! I’ve seen them this far South (Mountains of North Georgia) but only in red, no other colors. I hope I see some in August when I’m in Northern Minnesota.
Interesting theory. But what happens if it *doesn’t* bring about new sunspots? There is always the strong possibility that correlation does not equal causation.
Guess someone needs to inform the Sun of that:
From the Space Weather Prediction Center
Updated 2009 Jun 20 2201 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 171 Issued at 2200Z on 20 Jun 2009
Analysis of Solar Active Regions and Activity from 19/2100Z to 20/2100Z: Solar activity was very low. No flares were observed. The visible disk remained spotless.
Solar Activity Forecast: Solar activity is expected to remain very low for the next three days (21 - 23 June).
Geophysical Activity Summary 19/2100Z to 20/2100Z: The geomagnetic field was quiet.
Geophysical Activity Forecast: The geomagnetic field is expected to remain quiet for the next three days (21 - 23 June).
The idea is that otherwise invisible jet streams in the Sun's atmosphere carry nascent Sunspots to the surface.
This phenomenon has never been observed ~
There are others who believe there's a pot of gold at the end of a rainbow.
12 year old boys imagine there are beautiful actresses just waiting for their attention.
Did you see that shot of the amount of snow and ice still in the Arctic at Midsommer comparing this year to 1999? Try:
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=06&fd=18&fy=1999&sm=06&sd=18&sy=2009
Even if they started appearing tomorrow, its too late to help for this coming winter. Better get started on that woodpile.
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