Quite a few websites, blogs, and discussions are using the NOAA 'preliminary' data of days during which no sunspots can be seen on the Earth-facing solar surface. The last period of blank-Sun days ended on September 1, 2009. According to NOAA's preliminary record, the Sun was blank for 50 days.

However, NOAA's record is preliminary, and may be adjusted. A more accurate record is kept by the 'official' record-keepers of sunspot counts, the SIDC - Solar Influences Data Analysis Center.  Based on their official report for July 2009 (see the full report), a sunspot occurred on July 23, and again on July 30, 2009.  The number of days between July 30 and September 1, 2009 is 32 days.

So, by official count (and remember, the SIDC daily record that includes these two sunspots is included in the official Provisional Monthly Sunspot Number), the last run of zero sunspots was not 50 days, but only 32 days.  This goes against the sensational reports that this last quiet spell was nearly a record-long quiet.

For the record, the longest known quiet run was April 8, 1913 through July 8, 1913 (91 days).  This last quiet period ranks at about 15th longest since 1849, the year that accurate daily sunspot counts have been kept.  During this current cycle transition between Sunspot Cycle 23 and Cycle 24, however, this last run of spotless days is the longest, by one day.  That run was from July 21 through August 20, 2008.  But, don't let the sensationalists convince you that this last run is historical.  Other cycles have had longer runs.

What does all of this mean?  Clearly, there is another cycle (or perhaps more than one other cycle) at work (at least, we think there are other cycles) besides the 22-year magnetic cycle to which the 11-year average cycle belongs.  Some suggest that there is a 200 to 250 year cycle where we see very low sunspot activity (Maunder Minimum was one of those).  Others see possible longer-term cycles. (See The Spotless Page)

There is a lot of speculation going around that we're about to enter a phase of the solar cycle in which the solar energy will be very low.  Will this result in a cooling of the Earth?  We'll report on research and current discussion points, in up-coming podcast episodes.  Be sure to subscribe to our podcast.

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George Kominiak  - None that I know of!   |71.210.202.xxx |2009-09-02 21:10:14 Hey Guys! I'm glad you're paying attention to this topic!! The importamt thimg is that the overall level of solar activity is down (big time!) I'll be back with more for you in a day or so. G. P.S. I;m glad that I wasn't the only one who noticed the baby sunspot near 1025! Reply 0 1

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