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A first cycle 24 sunspot #10,981


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The first sunspot marking a new solar cycle has been identified, physicists at the NOAA announced on January 4. This sunspot is a precursor for the normal increase in activity which takes place during the 11-year solar cycle.


This sunspot belongs clearly to solar cycle 24. An official definition of the start of a solar cycle does not exist. But, let's give it a try. The solar activity cycle can be quantified by the (daily, monthly, yearly) sunspot number. A next solar cycle manifest itself by the appearance of associated sunspots: high-latitude sunspots with a reversed magnetic configuration in comparison with sunspots of the previous cycle. The conditions about polarity is added only since magnetic field measurements were done. It is clear that cycles overlap: sunspots belonging to one cycle and sunspots belonging to a next cycle can simultanuous be present. In fact, the next cycle officially starts when a sunspot minimum is reached, this is at the crossing in time of the sunspot number curves of both cycles. The point is that we can only afterwards determine the starting time.


"This sunspot is like the first robin of spring. In this case, it’s an early omen of solar storms that will gradually increase over the next few years," said solar physicist Douglas Biesecker of National Oceanic and Atmospheric Administration’s (NOAA) Space Weather Prediction Center.


The new sunspot, identified as #10,981, is the latest visible spot to appear since NOAA began numbering them on January 5, 1972. Its high-latitude location at 27 degrees North, and its negative polarity leading to the right in the Northern Hemisphere are clear-cut signs of a new solar cycle, according to NOAA experts. The first active regions and sunspots of a new solar cycle can emerge at high latitudes while those from the previous cycle continue to form closer to the equator.


The sunspot has been reported by several observatories, confirming this is the first spot which developed into a visible sunspot group. SpaceWeather.com reported that it produced auroras on Jan. 5th. "It was a nice flowing display that persisted for an hour and a half," reports photographer Calvin Hall of Palmer, Alaska.


A sunspot is an area of highly organized magnetic activity on the surface of the sun. The new 11-year cycle is expected to build gradually, with the number of sunspots and solar storms reaching a maximum by 2011 or 2012, though devastating storms can occur at any time.


In December 2007, a high latitude area with the correct magnetic configuration but no sunspot was spotted (see the previous news item). Now, a sunspot with the correct magnetic configuration was seen.


The appearance of one sunspot isolated in time, even if it has the correct magnetic configuration, can be a false start if this sunspot is not followed by a sequence of sunspots with the correct magnetic configuration. But both the December and January event give a good indication that solar cycle 24 is about to arrive in it's full glory.

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