‰ Now 18 WPM transition file follows ‰

We just saw more 0 sunspot days, followed by the brief emergence of
small spots, then more days with no sunspots. The average daily
sunspot number for the past week was down nearly 70 percent from the
previous week, to 5R9.  A solar wind hit earth on Tuesday, March 13,
and a rise in geomagnetic indices was the result, with the planetary
A index rising to 26.  The A index measured at Fairbanks, Alaska,
the college A index, rose to 50. The next period of higher
geomagnetic activity is predicted for March 27, then April 9 and
April 23.  Last weeks note about 11 being the smallest sunspot
number greater than 0 brought several puzzled responses, including
one from Darrell Bellerive, VA7TO of Grand Forks, British Columbia,
who wondered if there were other gaps in the range of possible
sunspot numbers.  Barry Pfeil, K6RM of Mountain View, California
wrote, I thought the sunspot number was LITERALLY the number of
sunspots and could be anything from 1 on up.  One might think so,
but the number is actually somewhat subjective, and factors in the
number of groups of sunspots. The National Geophysical Data Center
has a link at ngdc.noaa.gov/ which explains the method. The number
of groups of spots is counted, and that number is multiplied by 10,
then added to the number of individual sunspots. So if you saw 7
sunspots in 4 groups, the sunspot number would be 47. One spot would
be 11, two spots in one group would be 12, etc. By subjective, I
mean that someone must look at the spots, decide what constitutes a
group, and count them.  Note that the Vernal Equinox is coming up in
a few days. At 0007z on March 21, which is Tuesday, March 20 in
North America, the sunlight hitting the northern and southern
hemispheres will be equal. All over the world, the sun will rise in
the morning, and then set 12 hours later. Sunrise in Seattle at
47R67 degrees north latitude will be 1416z, sunset at 0216z. In
Matto Grosso Brazil at 15 degrees south latitude, sunrise at 0943z,
sunset at 2143z. In England at 52R2 degrees north latitude, 1 degree
west longitude, sunrise at 0611z, sunset at 1811z. With an equal
measure of sunlight striking both hemispheres, the equinox is a good
time for HF propagation, with the possible exception that we have
very low sunspot activity.  Sunspot numbers were 0, 0, 16, 14, 11, 0
and 0 with a mean of 5R9. 10R7 cm flux was 72R5, 71R6, 71R2, 71,
71R2, 71R4, and 70, with a mean of 71R3. Estimated planetary A
indices were 4, 2, 4, 8, 9, 26 and 8 with a mean of 8R7. Estimated
mid latitude A indices were 3, 1, 2, 6, 7, 18 and 9, with a mean of
6R6‚


‰ End of 18 WPM transition file ‚