sabato 2 luglio 2016

The K7RA Solar Update

Eight days with no sunspots, at least so far. Average daily sunspot number for our reporting week was down 33.6 points to zero. Earlier in this month we saw four days with a blank sun (sunspot number of zero) from June 3-6.

There were no sunspots during all of Field Day weekend.

The last time we saw a blank sun (before June 2016) was 2014. Just one day, on July 17, 2014. Sunspot number was zero, and only for one day. Prior to that, there were just two days in 2011, on January 27, and on August 14.

Prior to that there were 51 days with a blank sun in 2010, with 12 periods ranging from 1 to 13 days. The longest periods were 11 days beginning on May 9, 2010 and 13 days beginning on April 1, 2010.

These recent periods of no sunspot activity are a surprise to me, even though we are in a declining half of the solar cycle. I didn’t expect the extended periods with no sunspot activity would begin so early following the peak of Cycle 24. But perhaps we will see some extended periods of more sunspot activity, since we’ve seen in the past that nothing moves in a straight line up or down. There is plenty of variation.

Or perhaps that reference to memory suggests the classic gambler’s fallacy. This refers to the illogical feeling that because a particular ball in the lottery hasn’t been drawn for a long time that somehow it is overdue, making it more likely that the numbered ball will be drawn soon. This, of course, concerns only a random draw with all independent variables.

Mentioned earlier was the observation that the average daily sunspot number was zero over our reporting week (June 23-29) compared to 33.6 on the previous seven days. Average daily solar flux during the same two weeks dropped from 83.8 to 75.6.

Average daily planetary A index increased from 7 to 9, while the mid-latitude A index went from 6.9 to 9.1.

The latest prediction (June 30) sees solar flux at 75 on July 1-7, 80 on July 8, 80 on July 11, 82 on July 12-13, 80 on July 14-17, 78 on July 18-23, 77 on July 24 and 80 on July 25-31. Following this, the prediction shows solar flux rising two points for the first week in August...