Study may explain the extended solar minimum

March 15, 2010 by Lin Edwards, report
The Sun's "Great Conveyor Belt." The Great Conveyor Belt is a massive circulating current of fire (hot plasma) within the Sun. It has two branches, north and south, each taking about 40 years to perform one complete circuit. Researchers believe the turning of the belt controls the sunspot cycle. Image credit: NASA

( -- The recent solar minimum extended fifteen months longer than predicted, and a new study may explain why, and improve the predictions for future solar cycles.

The at the end of each 11-year solar cycle is characterized by a reduction in the number of sunspots, flares, and other solar activity. The most recent, from 2008 to the beginning of 2009, lasted fifteen months longer than expected.

The study used 13 years’ worth of results from SOHO, the Solar and Heliospheric Observatory, which was launched jointly by the European Space Angency and NASA. Among the data gathered by SOHO are measurements of the ionized gases moving from the ’s equator to the poles in what is known as the meridional flow. The scientists then tried to correlate the flow with variations in the cycle.

The researchers, Lisa Rightmire of the University of Memphis, Tennessee, and David Hathaway of the Marshall Space Flight Center in Huntsville, Alabama, found the normally slow meridional flows started to speed up a few years before 2008, when the number of sunspots declined. In the previous solar minimum the speed was around 30 kph, but in 2008-9 was about 47 kph. The scientists suggest the solar minimum was longer than usual because the magnetic fields produced by the gas flows at the poles were weaker, but it is not known why the speed of the meridional flow increased.

Hathaway said the meridional flow carries with it magnetic fields that oppose the flows of strongly magnetized material on the solar surface. When the meriodional flow is faster the opposition to the other flows is greater and the polar cannot become as strong as it otherwise would, and this may have delayed the start of the current solar cycle that began in 2009. Hathaway said the strength of the magnetic flow at the poles is critical since the magnetic fields fall below the surface and set up the conditions for sunspots, and when the fields are weaker they take longer to reach the required strength to produce sunspots. Hathaway and Rightmire also predict the current is likely to have less solar activity than the previous cycle.

The results of the study, published in Science, may improve the forecasting of the duration and intensity of solar cycles in the future, and this could be valuable since some can create magnetized clouds of charged particles that can damage orbiting satellites and disrupt power grids on Earth. Improved predictions of solar cycles could also help climate scientists with their long-term predictions. The results also suggest that models predicting that a fast meridional flow would lead to a stronger magnetic field at the poles, may have to be revised.

Explore further: Ulysses Flyby of the Sun's North Pole

More information: Variations in the Sun’s Meridional Flow over a Solar Cycle, David H. Hathaway and Lisa Rightmire, Science 12 March 2010: Vol. 327. no. 5971, pp. 1350 - 1352, DOI:10.1126/science.1181990

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2.1 / 5 (7) Mar 15, 2010
More discoveries and predictions from our space agency but no explanation why the "conveyor belt" speeds up and slows down. If one searches Landscheidt one will find that the solar cycle appears (high probability) to be driven, at least in part, by the total angular momentum of the solar system. Based on this, the next cycle will certainly be a weak one.
In spite of the agency's consistently wrong predictions of "the next cycle is starting now" over the past 3 - 4 yrs they refuse to look at the systems total angular momentum because it is NIH. Based on past performance though they may "discover" it in the future.

2 / 5 (7) Mar 15, 2010
The extended solar minimum; which is going to freeze our butts off when it is all said and done. .

2025, the year without a summer . . .
2 / 5 (4) Mar 15, 2010
Fortunately NASA recently launched another satelite that is equipped with more sensitive instrumentation that will be able to see deeper into the sun.
2.3 / 5 (3) Mar 15, 2010
Possibly related to fluid dynamics and relative densities differences over the solar surface -in terms of the increase in meridional current flow during weak magnetic polar field?
3.3 / 5 (4) Mar 15, 2010

This has really screwed many AGW deniers who were hoping we would go into a cold spell. Despite 18 months of low, no sunspots the earth didn't cool at all, in fact kept warming.
1 / 5 (2) Mar 15, 2010
The results of the study, published in Science, may improve the forecasting of the duration and intensity of solar cycles in the future

Another poorly written article about climate. There is absolutely no reason to include the "may improve the forecasting" if this study concluded the model is conclusive or has a high confidence/low error rating amongst peers.

Jerryd, the last 15 years have been in the midst of a solar reduction and have seen a stable global temperature, it hasn't warmed since 1998. Whether the sun spots and events are indicative of a re-start in warming remains to be seen, and many climate scientists don't think it has very much to do with warming rates:

1 / 5 (3) Mar 16, 2010
jerryd, next time you are in town, please drop by and tell my daffodils, they are not listening to the warmist propaganda and refuse to bloom.

There was a shortage of daffodils in the UK this past Mothersday, snow fell on the Spring parade in Beijing this Sunday, and like a boring ginger Celt in a Scottish pub, you keep on singing last year's hits!
3 / 5 (2) Mar 16, 2010
Yes, it is snowing somewhere, which means global warming is false! All praise Loodt for making that so very scientifically clear.
not rated yet Apr 21, 2010
Correct me if I'm wrong, but the only evidence of "warming" in the last few years has come from satellite observations that measure the temperature of the atmosphere above the clouds. Wouldn't it be expected that cloud cover would lead to colder temps on the surface and warmer temps above the clouds since the sunlight could not reach the surface and would be reflected back into space?

Leads to the obvious question: How relevant is the warming of the upper atmosphere to us down here on the surface? Seems the definition of "Global Warming" lacks scientific specificity.

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