Transcript prominance - WROCŁAWSKA STRONA HELAS-a

Our lazy Sun
Barbara Sylwester
Solar Physics Division
Space Research Center, Wrocław
SOHO activity cycle; 171 Å, ~1.3 MK plasma
SOHO UV  1997 & 1999 changing activity
Recurrent behavior of sunspots: 140 years
Butterfly
diagram
Sunspots are typically confined to an equatorial belt
(-35 degrees south and +35 degrees north latitude). At the beginning of a new cycle,
sunspots tend to form at high latitudes, but as the cycle reaches a maximum the spots
form at lower latitudes. This gives rise to the ``butterfly'' pattern first discovered by
Edward Maunder in 1904.
Solar activity - proxies
Rudolf Wolf, inventor of the
modern sunspot number
(1848, Zurich observatory).
Red: sunspot number, reconstructed
from historical observations
Blue: the beryllium-10 concentration
(104 atoms/(gram of ice)) as measured in
annually layered ice core (Greenland)
400 years of sunspot observations
1749Carrington cycles
Sporadic observations
Regular sunspot number observations (from 1749)
1610  Among a huge number of revolutionary discoveries of Galileo Galilei
was the first observations of sunspots using telescope.
( "And yet it does move").
1640-1710  the coldest period of Little Ice Age (LIA)  the taverns for frozen
ramblers have been built at the middle of Baltic Sea ; coincidence with
Maunder Minimum
Sunspot number prediction (March 2006)
6 latest cycles & solar cycles prediction
During the annual Space Weather Workshop held in April 2007 the
Solar Cycle 24 Prediction Panel released the prediction for the next
solar cycle. They expected that the new cycle will begin in late 2007 or
early 2008 – about a year later than earlier predictions.
Expected peak sunspot number  140 in October, 2011.
Next Cycle (25) peaking in 2022 could be one of the
weakest in centuries.
Predictive Fluxtransport Dynamo
Model Mausumi
Dikpati team
11 Dec. 2007 Solar Cycle 24 say: Hello !
SOHO UV-wavelength image of the Sun and a map showing positive
(white) and negative (black) magnetic polarities. This region fits
both criteria of new cycle: high latitude and magnetically reversed,
marking it as a harbinger of a new solar cycle. Good candidate…
But……the first swallow does not make a spring ….
and.…..Solar Cycle 24 official start was later 4 Jan. 2008
The large sunspot region just south of the equator is part of the waning Solar Cycle 23.
Few days later…. SOHO EIT instrument
This image was taken in extreme
ultraviolet: 195 Å; ~ 1.6 MK. It
shows the area of the solar surface
where the sunspot occured whose
appearing marked the start of the
new solar cycle (‘Cycle 24’) on 4
January 2008. SOHO also obsered
two associated „EIT waves”, blast
waves that spread out from the
active regions.
First southern hemisphere spots: 4.05.2008
Solar minimum is upon us !
New solar cycle had begun definitely!
EIT/SOHO; 284 Å; ~ 2MK
2008, September - Spotless Sun
Left: A photo of the Sun taken Sept. 27,
2008. The face of the sun is "blank”.
Right: The Sun on Sept. 27, 2001. The
Sun's face is peppered with sunspots.
The difference is the phase of the 11year solar cycle.
updated: Sept. 27, 2008
To find a year with more blank Sun, we
have to go back to 1954 (three years
before the launch of Sputnik). 
2008 the „blankest year” of the Space
Age
29 September 2008; 304 Å
NASA's STEREO (Ahead) spacecraft observed this prominence eruption. It rose up and cascaded
to the right over several hours, appearing something like a flag headed into space. The material
observed is actually ionized Helium at about 60,000 K. Prominences are relatively cool clouds of
gas controlled by magnetic forces.
New cycle flare activity; Oct. 2008
6 Oct. 2008 A6.4
Signs of life  …. Solar minimum behind us?
A new sunspot appeared on
11 Oct. 2008, the third spot
seen in many weeks.
New-cycle sunspot group 1007
emerges on Halloween and marches
across the face of the sun over a fourday period in early November 2008.
2 Nov. 2008; B7.2 flare
….boring Sun on 13th Jan. 2009 captured by amateur astronomer
A whole year after Solar Cycle 24 was
supposed to start (when the first
reversed polarity sunspot pair
appeared on the Sun’s surface) the Sun
is blank (featureless).
However we have had flares from „left
over” Cycle 23 and a bit of action from
Cycle 24 (A, B class flares). 2008 was a
year of overlap with both cycles weakly
active at the same time.
KORONAS Photon-TESIS: 20.02.2009
18:27 UT
Inner corona: Fe IX 171 Å; ~1 MK
18:34 UT; Outer corona: Fe IX 171 Å; ~1 MK
18:28 UT
He II 304; ~80 000 K
27 Feb. 2009; A3.2 flare
28 Feb. 2009 (8 hours period); TESIS
20 March 2009: Where have all activity gone?
SOHO MDI continuum
304 Å ; T ~ 80 000 K
http://sohowww.nascom.nasa.gov/data/realtime-images.html
284 Å ; T ~ 2 MK
Progression of the solar cycle
http://solarcycle24.com/
http://www.nwra-az.com/spawx/ssne-year.html
Data gathered by GOES
satellites which monitor solar
X-rays (tracking solar flares).
Solar flares can also trigger
geomagnetic storms which
produce aurora.
The daily effective sunspot numbers
over the past year. Two parameters
are plotted: solid line - based on
analysis of ionospheric data, and
dotted line based on the observed
10.7 cm solar radio flux.
HINODE XRT Present Sun; 305 Å; ~80 000 K
Why the Sun has gone quiet? Solar dynamo……
dipole field
the rotation
rate is 20 ℅
faster at the
equator
the magnetic field lines are wrapped
after many
rotations lines
are highly
twisted and
bundled
the resulting
buoyancy lifts the
bundle to the
surface
 something abruptly “switched off” in the inner workings of the solar
dynamo ?????
the Sun has slowed it’s internal dynamo to a similar level such as was seen
during the Dalton Minimum ????
The truth is, solar activity never stops, "not even during solar
minimum."
Conculding ….. the „new millenium solar minimum”?
The Sun is now in the quietest phase of its 11 - year activity cycle. In fact, it has
been unusually quiet during 2008 year. Scientists are unsure of the significance
of this unusual calm. The only way to know is to wait and see. Our closest star i
continually monitoring with an array of telescopes and satellites. Probably this
time next year we will be inundated with sunspots…fingers crossed.