[CQ-Contest] LONG!!...of interest from NASA - JET STREAMS FLOWING INSIDE THE SUN

[Ronald D Rossi]

I thought some of you might be interested in this NASA press release..

-- 
73 de KK1L ex N1PBT...ron (rrossi at btv.ibm.com) <><
Ron Rossi H/P SRAM Engineering -- IBM Microelectronics

---------------------------copy-----------------------------
Donald Savage
Headquarters, Washington, DC                       August 28, 1997
(Phone:  202/358-1547)                    EMBARGOED UNTIL 1 PM EDT

Bill Steigerwald
Goddard Space Flight Center, Greenbelt, MD
(Phone:  301/286-8955)

RELEASE:  97-184

SCIENTISTS DISCOVER MASSIVE JET STREAMS FLOWING INSIDE THE SUN

       Scientists using the joint European Space Agency (ESA)/NASA 
Solar and Heliospheric Observatory (SOHO) spacecraft have 
discovered "jet streams" or "rivers" of hot, electrically charged 
gas called plasma flowing beneath the surface of the Sun.  They 
also found features similar to trade winds that transport gas 
beneath the Sun's fiery surface.  

       These new findings will help them understand the famous 
sunspot cycle and associated increases in solar activity that can 
affect the Earth with power and communications disruptions.  The 
observations are the latest made by the Solar Oscillations 
Investigation (SOI) group at Stanford University, Palo Alto, CA, 
and they build on discoveries by the SOHO science team over the 
past year.

       "We have detected motion similar to the weather patterns in 
the Earth's atmosphere," said Dr. Jesper Schou of Stanford.  
"Moreover, in what is a completely new discovery, we have found a 
jet-like flow near the poles.  This flow is totally inside the 
Sun.  It is completely unexpected, and cannot be seen at the surface."

       "These polar streams are on a small scale, compared to the 
whole Sun, but they are still immense compared to atmospheric jet 
streams on the Earth," added Dr. Philip Scherrer, the SOI 
principal investigator at Stanford.  "Ringing the Sun at about 75 
degrees latitude, they consist of flattened oval regions about 
17,000 miles across where material moves about 10 percent (about 
80 mph) faster than its surroundings.  Although these are the 
smallest structures yet observed inside the Sun, each is still 
large enough to engulf two Earths."

        Additionally, there are features similar to the Earth's 
trade winds on the surface of the Sun.  The Sun rotates much 
faster at the equator than at the poles.  However, Stanford 
researchers Schou and Dr. Alexander G. Kosovichev have found that 
there are belts in the northern and southern hemispheres where 
currents flow at different speeds relative to each other.  Six of 
these gaseous bands move slightly faster than the material 
surrounding them.  The solar belts are more than 40 thousand miles 
across and they contain "winds" that move about ten miles per hour 
relative to their surroundings.

       The first evidence of these belts was found more than a decade
ago by Dr. Robert Howard of the Mount Wilson Observatory.  The Stanford 
researchers have now shown that, rather than being superficial 
surface motion, the belts extend down to a depth of at least 
12,000 miles below the Sun's surface.

       "In one way, the Sun's zonal belts behave more like the 
colorful banding found on Jupiter than the region of tradewinds on 
the Earth," said Stanford's Dr. Craig DeForest.  "Somewhat like 
stripes on a barber pole, they start in the mid-latitudes and 
gradually move toward the equator during the eleven-year solar 
cycle.  They also appear to have a relationship to sunspot 
formation as sunspots tend to form at the edges of these zones.

       "We speculate that the differences in speed of the plasma 
at the edge of these bands may be connected with the generation of 
the solar magnetic cycle which, in turn, generates periodic 
increases in solar activity, but we'll need more observations to 
see if this is correct," said DeForest.

       Finally, the solar physicists have determined that the 
entire outer layer of the Sun, to a depth of at least 15,000 
miles, is slowly but steadily flowing from the equator to the 
poles.  The polar flow rate is relatively slow, about 50 miles per 
hour, compared to its rotation speed, about 4,000 miles per hour; 
however, this is fast enough to transport an object from the 
equator to the pole in a bit more than a year.

       "Oddly enough, the polar flow moves in the opposite 
direction from that of the sunspots and the zonal belts, which are 
moving from higher to lower latitudes," said DeForest.

       Evidence for polar flow previously had been observed at the 
Sun's surface, but scientists did not know how deep the motion 
extended.  With a volume equal to about 4 percent of the total 
Sun, this feature probably has an important impact on the Sun's 
activity, argue Stanford researchers Scherrer, with Dr. Thomas L. 
Duvall Jr., Dr. Richard S. Bogart, and graduate student Peter M. Giles.

        For the last year, the SOHO spacecraft has been aiming its 
battery of 12 scientific instruments at the Sun from a position 
930,000 miles sunward from the Earth.  The Stanford research team 
has been viewing the Sun's surface with one of these instruments 
called a Michelson Doppler Imager that can measure the vertical 
motion of the Sun's surface at one million different points once 
per minute.  The measurements show the effects of sound waves that 
permeate the interior.  The researchers then apply techniques 
similar to Earth-based seismology and computer-aided tomography to 
infer and map the flow patterns and temperature beneath the Sun's 
roiling surface.

       "These techniques allow us to peer inside the Sun using 
sound waves, much like a doctor can look inside a pregnant woman 
with a sonogram," said Dr. Schou.

       Currently, the Stanford scientists have both identified new 
structures in the interior of the Sun and clarified the form of 
previously discovered ones.  Understanding their relationship to 
solar activity will require more observations and time for analysis.

       "At this point, we do not know whether the plasma streams 
snake around like the jet stream on Earth, or whether it is a less 
dynamic feature," said Dr. Douglas Gough, of Cambridge University, 
UK.  "It is intriguing to speculate that these streams may affect 
solar weather like the terrestrial jetstream impacts weather 
patterns on Earth, but this is completely unclear right now.  The 
same speculation may apply to the other flows we've observed, or 
they may act in concert.  It will be especially helpful to make 
observations as the Sun enters its next active cycle, expected to 
peak around the year 2001." 

                          - end -

Images to support this story can be found at the following 
Internet address:

http://pao.gsfc.nasa.gov/gsfc/newsroom/flash/flash.htm




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