[ETS/PARC List] Cycle 24 starting

[Drew Moore]

==> CYCLE 24 HERE, EXPERTS SAY

With the appearance of Sunspot 981 -- a high-latitude, reversed polarity
sunspot -- on Friday, January 4, experts at NASA and the National
Oceanic and Atmospheric Administration (NOAA) said that Cycle 24 is now
here. "This sunspot is like the first robin of spring," said solar
physicist Douglas Biesecker of the Space Weather Prediction Center
(SWPC), part of NOAA. "In this case, it's an early omen of solar storms
that will gradually increase over the next few years." 

Solar physicist David Hathaway of NASA's Marshall Space Flight Center in
Huntsville, Alabama concurred, saying that new solar cycles begin with a
"modest knot" of magnetism, like the one that appeared on December 11 on
the east limb of the Sun: "That patch of magnetism could be a sign of
the next solar cycle. New solar cycles always begin with a
high-latitude, reversed polarity sunspot." The region of magnetism that
appeared back in December achieved high latitude (24 degrees North) and
was magnetically reversed, but no supporting sunspot appeared until 25
days later. 

Reversed polarity describes a sunspot with opposite magnetic polarity
compared to sunspots from the previous solar cycle. High-latitude refers
to the Sun's grid of latitude and longitude. Old-cycle spots congregate
near the Sun's equator; new-cycle spots appear higher, around 25 or 30
degrees latitude. Sunspot 981's 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. 

While experts vary in their predictions on when the solar cycle will
peak and how strong it will be, NOAA, in April 2007, in coordination
with an international panel of solar experts, predicted that the next
11-year cycle of solar storms "would start in March 2008, plus or minus
six months, and peak in late 2011 or mid-2012." In the cycle forecast
issued in April 2007, half of the panel predicted a "moderately strong
cycle of 140 sunspots, plus or minus 20, expected to peak in October
2011. The other half predicted a moderately weak cycle of 90 sunspots,
plus or minus 10, peaking in August 2012. An average solar cycle ranges
from 75 to 155 sunspots. The late decline of Cycle 23 has helped shift
the panel away from its earlier leaning toward a strong Cycle 24. The
group is evenly split between a strong and a weak cycle." 

NASA's Hathaway, along with colleague Robert Wilson at a meeting of the
American Geophysical Union in San Francisco last month, said that Solar
Cycle 24 "looks like it's going to be one of the most intense cycles
since record-keeping began almost 400 years ago." They believe the next
solar maximum should peak around 2010 with a sunspot number of 160, plus
or minus 25. "This would make it one of the strongest solar cycles of
the past fifty years -- which is to say, one of the strongest in
recorded history." Four of the five biggest cycles on record have come
in the past 50 years. "Cycle 24 should fit right into that pattern,"
Hathaway said. 

According to Carl Luetzelschwab, K9LA, "As for improvement in
propagation on the higher bands, we still have a way to go before that
happens, and it depends on the magnitude of Cycle 24. The Solar Cycle 24
Prediction Panel has published predictions for Cycle 24, but
unfortunately the panel did not reach one consensus prediction. If the
larger of the two predictions comes true, we should expect consistent F2
propagation on 10 and 12 meters to start toward the end of 2009. If the
smaller prediction comes true, this will be delayed about one year." 

Luetzelschwab, who writes the column "Propagation" for the National
Contest Journal (NCJ), continued: "While we wait for improved high band
conditions, don't forget the low bands. Around solar minimum and for the
next year or so, the Earth's geomagnetic field is at its quietest. This
is good for low band propagation. Thus, right now is the time to start
(or add to) your 80 and 160 meter DXCC efforts." 

According to NASA's Tony Phillips, many forecasters believe Solar Cycle
24 will be big and intense. "Solar cycles usually take a few years to
build to a frenzy and Cycle 24 will be no exception. We still have some
quiet times ahead," says Hathaway.