The latest forecast by an international panel lead by NOAA's Space Weather
Prediction Center (SWPC) revises its 2007 prediction.
According to the new forecast, the sun should remain generally calm for at
least another year. The solar cycle is now in a deep valley -- the deepest of
the past century. In 2008 and 2009, the sun set Space Age records for low
sunspot counts, weak solar wind, and low solar irradiance. The sun has gone
more than two years without a significant solar flare.
The panel predicts that Solar Cycle 24 will peak in four years on May 2013 with
a sunspot number of 90, the lowest of any cycle since 1928 when Solar Cycle 16
peaked at 78.
Meanwhile, the sun pays little heed to human committees. There could be more
surprises, panelists acknowledge, and more revisions to the forecast. "Go
ahead and mark your calendar for May 2013," says Dean Pesnell of the Goddard
Space Flight Center, NASA's lead representative on the panel, "But use a
pencil..."
In recent months the sun has begun to show timid signs of life. Small sunspots
and "proto-sunspots" are popping up with increasing frequency. Enormous
currents of plasma on the sun’s surface ("zonal flows") are gaining strength
and slowly drifting toward the sun’s equator. Radio astronomers have detected a
tiny but significant uptick in solar radio emissions. All these things are
precursors of an awakening Solar Cycle 24 and form the basis for the panel's
new, almost unanimous forecast.
http://science.nasa.gov/headlines/y2009/images/noaaprediction/prediction_strip2.jpg
http://science.nasa.gov/headlines/y2009/29may_noaaprediction.htm?list69914
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|
