Sunspot Record Reveals Sun's Past

[zavvy]

<b>Sunspot Record Reveals Sun's Past</b><br /><br />LINK<br /><br />The past 70 years has seen the longest and most intense period of sunspot activity for 8,000 years, according to scientists who have reconstructed a record of the Sun's last 11,000 years.<br /><br />Solar physicist Sami Solanki from the Max Planck Institute in Katlenburg-Lindau, Germany, and his colleagues found in November 2003 that the Sun is more active now than at any time in the past 1,000 years1. This, along with several record-breaking solar storms that occurred at around the same time, has triggered intense debate about why the Sun is now so active.<br /><br />However, Solanki's latest data reveals that before 8,000 years ago, the Sun went through several short periods where it was just as active as it is today. This suggests that the current high is part of the Sun's normal activity and that it will probably calm down again, returning to normal levels within the next few decades, he says.<br /><br />Sunspots are temporary dark patches on the Sun, caused when its magnetic field 'pinches' at the surface. The magnetic field is generated by hot, ionised gas that swirls around inside the star, acting like a dynamo.<br /><br />"But we don't really know how the Sun's dynamo works," Solanki says. The new record will help solar physicists to model how that dynamo changes over thousands of years.<br /><br />Scientists already have a good observational record of sunspots that dates back to the early seventeenth century. This shows that the Sun's activity varies on cycles that last roughly 11 and 88 years, although scientists are not yet sure why these cycles exist.<br /><br />David Hathaway, a solar physicist from NASA's Marshall Space Flight Centre in Huntsville, Alabama, recently predicted that the Sun's current spotty outbreak was on the wane and should reach a minimum by 2006, although this will still be significantly more acti