Newsgroup: it.discussioni.misteri
Titolo: Y2K - Un altro disastro imminente

Salve a tutti,
ho trovato questo articolo e vorrei sapere se
ne siete al corrente e cosa ne pensate.
Vi prego, non mi fucilate, è in inglese...
Ecco qua:
Fire in the sky
°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
If the Sun spits, the Earth fries. Humankind is ill-prepared
for the furious climax of the next solar cycle.
David Appell reports
BATTEN down the hatches, there's a storm coming.Some time in the next
18 months, the Sun will turn from a relatively placid ball of hot
ionised gases into a raging tempest of plasma, spitting fireballs out
into the Solar System like an angry god. Woe betide any planet that
gets in its way.
Should one of those plasma storms hit Earth, the impact could be
devastating. Each fireball--known as a coronal mass ejection--is a
giant maelstrom of ionised gases at temperatures of well over a
million degrees. But the temperature is the least of Earth's worries.
The plasma will tear through the Earth's magnetic field like wind
through grass. These wildly fluctuating fields can knock out power
supplies, and charged particles from the plasma can fry the electronic
components inside telecommunications satellites, bringing down
communications networks over vast areas. A few scientists and
engineers are preparing for the worst while others, strangely, have
chosen to ignore the problem. The wary few are racing to put in place
measures to protect power grids and telecommunications networks, and
have launched sentinels that sit in space between the Earth and the
Sun watching for storm signs. In addition, they are developing complex
computer models to predict which parts of the Earth might be affected.
Others, fearing the worst, are waiting to see what happens to the
giant communications networks that have grown up since the last big
solar storm 10 years ago.
Scientists have been watching the changing nature of the Sun for over
200 years and have witnessed these solar rages every eleven years or
so. This will be the 23rd cycle on record and researchers believe it
will be every bit as bad as the last. Six million people in the
Canadian province of Quebec can testify to its effects.
The storm struck in the early hours of 13 March 1989. It was not a
good night to lose power. The temperature had dropped to -15 °C and
furnaces went quiet as six million Canadians lost heat and light.
After the winter sunrise, subways sat still for lack of power, traffic
lights hung dark and petrol pumps refused to deliver.
Later in the day, when public officials called for an explanation,
engineers at Hydro-Quebec, the region's power generating company, had
begun to suspect an unusual culprit. Four days earlier, a giant bubble
of plasma had burst from the surface of Sun. That morning it had hit
the Earth, wreaking havoc.
Rapidly changing magnetic fields generate currents in any conductors
within reach. This is how a dynamo works--except that the magnetic
field remains still in these devices while the conducting wires move
through it. When a magnetic storm hits the Earth, any networks of
conductors that stretch over the same scale as the magnetic
fluctuations act like giant dynamos. Hydro-Quebec's transmission lines
stretch for over 1000 kilometres. Power lines, telephone lines and
even railway lines are all potential conduits for "geomagnetically
induced currents" (GICs) of hundreds of amperes.
Power companies are vulnerable because their power lines guide the
GICs towards sensitive components such as transformers at power
stations and substations. A transformer changes a high voltage supply
of alternating current into a low voltage supply or vice versa. It
consists of a giant doughnut of iron with two sets of windings on each
side of the structure. The voltage in one set of windings induces a
magnetic field in the iron core, which in turn induces a voltage in
the second set of windings. The ratio of the number of windings in the
two coils determines the change in voltage.
High-performance transformers are delicate machines. They are designed
to cope with voltages within a specific range of amplitudes and
frequencies. Outside these bounds, the transformer behaves
unpredictably.
The trouble with GICs is that the voltages associated with them change
this delicate balance. In particular, they set up voltages at harmonic
frequencies to the ordinary load. These frequencies are transformed
but in a way that can rapidly spiral out of control. The result is
wildly fluctuating voltages called voltage asymmetries. If the power
is not shut down, these can create enough heat to damage the iron core
beyond repair. Worse, these fluctuations pass rapidly through the
network so that neighbouring transformers also become affected. Within
seconds an entire network can collapse as one transformer after
another fails.
Exactly this happened to Hydro-Quebec's power system that fateful
morning. "Voltage regulations need to be within 5 to 10 per cent of a
nominal value. If you fall outside that, you generally see a system
collapse and the start of a domino effect," says John Kappenman, an
expert in the effects of geomagnetic storms at the Metatech
Corporation, based in Goleta, California.
Many other electricity utilities around the world also suffered the
effects of GICs that morning. Further south, the iron core of a
transformer at a New Jersey power station burnt out and had to be
replaced at a cost of several million dollars. Later, researchers at
the Oak Ridge National Laboratory in Tennessee predicted the potential
effects of a geomagnetic storm only slightly more severe than the one
in 1989. They concluded that the ensuing blackouts and chaos could
cost the US economy up to $6 billion dollars in lost business.
Astronomers are forecasting storms just as big as those in 1989 for
the next solar maximum, if not bigger. As the Sun passes through its
11-year cycle, solar astronomers measure the activity on its surface
by counting the number of sunspots and the number of groups of
sunspots they can see during a predetermined period, usually a month
or a year. Together, these numbers allow them to calculate an index of
solar activity known as the International Sunspot Number. During the
solar minimum, the sunspot number can be as low as 10. In July 1989,
during the last solar maximum, it peaked at 159. And in March 1958, it
reached 201, the highest level ever recorded (see Figure).
Cycle 23 "will be one of the largest on record, and comparable to the
last two solar cycles", says a panel of international experts chaired
by Jo Ann Joselyn of the US National Oceanic and Atmospheric
Administration's Space Environment Center in Boulder, Colorado. They
warn that the sunspot number could reach 190, peaking sometime between
June this year and January 2001.
Can anything be done to avert disaster? Leonard Bolduc, a researcher
at Hydro-Quebec's Institute of Research in Electricity of Quebec, who
was working on the night of the failure, has studied the network's
breakdown. There is little that Hydro-Quebec can do to prevent GICs.
Instead, Bolduc says the company's strategy is to design grids that
can cope. "Hydro-Quebec has spent a lot of money trying to understand
the phenomena and to evaluate all its equipment during a GIC storm,"
he says.
Its solution has been to fit its power lines with capacitors, known as
transmission line series capacitors, that prevent the flow of direct
current without affecting alternating current. The company has spent
more than C$1.2 billion fitting the new capacitors. It has also set up
monitoring equipment that spots voltage asymmetries and warns
operators to redistribute the load to other parts of the network, by
bringing online other generators in different areas. "We are confident
that our network could now support such a big storm," says Bolduc.
Currents and electrojets
Another approach is to predict the severity of geomagnetic storms
before they hit the Earth so that preventive action can be taken. But
this isn't easy. The interaction between the Earth's magnetic field
and the particles in the hot plasma is extremely complex. Ari Viljanen
and Risto Pirjola of the Finnish Meteorological Institute have been
studying this process. They began by modelling the interaction between
plasma from the Sun and the Earth's magnetic field, and the way this
generates currents in ionised regions of the Earth's upper atmosphere.
These currents--called the auroral electrojet--have an electric field
associated with them. The horizontal component of this field at the
Earth's surface together with the conductance of the surface are the
crucial factors that determine the strength of GICs. So Viljanen and
Pirjola have had to model the conductivity too.
By combining their models of the auroral electrojet and the
conductivity of the Earth's surface, they have created a formidable
tool. Their overall model produces data that come within 20 per cent
of the values of GICs measured in the Finnish power system.
The Finnish researchers now want to turn the model on its head. They
say that by using data from GICs in Finland, their model can throw
light on the processes at work in the upper atmosphere. In effect,
they hope to turn the entire Finnish power grid system into a giant
instrument for studying the interaction between the magnetosphere and
the solar wind.
Kappenman also has ambitious plans. He is division manager for
Metatech's Applied Power Solutions Division, and the architect of a
new computer model called PowerCast designed to predict the effects of
GICs before they occur. His first customer is National Grid--the
company that operates Britain's power transmission network--which is
installing his system this month.
PowerCast uses a model of the interaction between solar plasma, the
magnetosphere and the geology of the Earth's surface. But it links
this to a model of the power grid itself. The National Grid uses about
900 transformers and PowerCast takes into account all of them when
deciding which might be damaged by impending magnetic storms.
The data that PowerCast uses to make its predictions come from a small
observatory called the Advanced Composition Explorer (ACE), a
spacecraft that sits in the solar wind approximately 1.5 million
kilometres upstream of Earth at the point where the gravitational
forces from the Earth and the Sun balance one another. ACE measures
the composition of the solar wind and gives roughly one hour's warning
of an impending solar storm.
Using these data, PowerCast will give the National Grid a
minute-by-minute update of the threat that GICs pose to the network.
Operators can then take appropriate steps to mitigate the effects of
any impending storm while maintaining the supply. It's a difficult
job, says Kappenman. "Power companies are not like phone companies
where, if it gets too busy, they can give you a busy signal." Metatech
claims that the system works with "reasonable accuracy". Just how it
it will perform during the forthcoming solar maximum remains to be
seen.
Satellites are also at risk during solar storms. The US Department of
Defense has estimated that disruptions to government satellites from
space weather cost about $100 million a year, and that even when the
Sun is relatively placid, as it was in 1994 and 1995, about 150
malfunctions occur annually.
When the communications satellite Galaxy IV failed last May, it
brought down communications networks and put 45 million pagers out of
action. The satellite's manufacturer, Hughes Electronics Corporation,
says an on-board processor failed as a result of a random event.
Others believe a more likely culprit is the Sun.
Killer electrons
Dan Baker, director of the Laboratory for Atmospheric and Space
Physics at the University of Colorado in Boulder, and his colleagues
have studied the solar weather conditions that existed at the time of
the failure. They found that a large number of high-energy electrons
had become trapped in the Earth's magnetosphere in the two-week period
before the satellite failed, as a result of exceptionally stormy solar
weather. According to Baker, it was "one of the most intense periods
that we've seen for the last two or three years".
Electrons with kinetic energies greater than a million electronvolts
have been dubbed "killer electrons". They smash through the skin of
spacecraft and lodge inside dielectric materials such as thermal
blankets, electronic boards, coaxial cables and electrical insulation.
If more electrons arrive than can leak away, the buildup of charge can
create strong electric fields inside the spacecraft, a process called
deep dielectric charging. Eventally, arcing occurs as electrons jump
between areas at different potentials. It is these tiny bolts of
lightning that destroy spacecrafts' electronics. "We don't know for
sure if this caused the Galaxy IV failure," says Baker, but he says
several other spacecraft also had problems during the same period.
And nobody knows whether networks that have been designed in the 10
years since the last solar maximum will cope. "As technologies change,
new vulnerabilities to solar events crop up," says Lou Lanzerotti, a
geophysicist at Bell Labs, the R&D arm of Lucent Technologies. He
points to the huge proliferation of wireless networks. "We find that
there are a few solar radio bursts every solar maximum that are larger
in amplitude at Earth than the noise level in a cellular system."
Could these bursts drown wireless networks in a sea of noise, putting
millions of cellphones and other wireless devices around the world out
of action? "It's something that we haven't thought about before
because we didn't have the technology and didn't need to think about
it," says Lanzerotti. With the solar maximum approaching, time is fast
running out.
David Appell is a science journalist based in Gilford, New Hampshire


Non ti fucilo, ma non pretendere che gli abbia dato una scorsa più che
sommaria, a parte la lingua è anche lunghissimo.
Mi pare che tratti del fatto già noto che l'attuale fase di calma delle
macchie solari faccia prevedere tempeste magnetiche di tutto rispetto a
cavallo del 2000 con possibilità di danneggiamento dei computer sui
satelliti artificiali, e forse anche di quelli a terra, e che poi ponga il
problema di come difendersi.
La notizia è già conosciuta e si prevede l'accavallarsi di questo problema a
quello del bug del 2000.
Il mio parere : allarmismo esagerato, probabilmente qualche difficoltà si
avrà, ma niente di irreparabile.
Ciao, Mauro.

In effetti i problemi ci sono e come.
Da studi scientifici, secondo cui un'attività delle tempeste solari piu
forte del normale oltre a favorire terremoti, è anche connesso con lo
spostamento dell'asse geomagnetico.
Questo vuol dire che, secondo teorie scientifiche, secondo le quali,
gli assi della terra si ribaltano piu o meno ogni 500.000 anni, e l'ultimo
sarebbe avvenuto circa 750.000 anni fa, un'attività solare esagerata non
sarebbe un evento da considerare con poca preoccupazione.
Fabrizio (Osiride)