Sun's dippers raise riddle storms

By M H Ahssan

"Now there's a look in your eyes, like black holes in the sky.
Shine on you crazy diamond."

A quieter sun is sporting fewer black eyes, and we could have reasons to be concerned. The fewer sunspots, the hole-like dark blotches seen on the solar face, means the sun has been its least active in the past 100 years, scientists say.

Sunspots are considered the best available indicator of solar activity. A prolonged phase of a more internally peaceful sun could cause significant climate changes on Earth. Cooler weather will affect crop patterns, or even cause a "Little Ice Age", scientists theorize.

In an increasingly inter-connected world, Asia, as the world's largest populated continent, is unlikely to escape geographic or economic side effects.

Not surprisingly, prominent Asian solar scientists such as Arnab Rai Choudhury of the premier Indian Institute of Science have invested over a quarter of a century of time studying sunspots.

Sunspots are riddles giving new twists in a 4.6 billion-year-old story (the estimated age of the sun). Question marks over sunspots reflect the continuing mystery of this ordinary little yellow dwarf star, one of millions of similar nondescript stars in the Milky Way galaxy. Yet the sun contains 98% of the total mass of the solar system, and its interior is so vast it can hold over 1.3 million Earths.

Sunspots offer clues to internal solar mood swings. The number of sunspots indicates the intensity of nuclear reactions deep within the solar core, at mind-boggling temperatures of between 15 million to 20 million degrees Celsius.

These inner solar upheavals eject energy, heat and light that keep us alive. But like many things in life that come as double-edge swords, the sun's inner turmoil could also cause catastrophe on earth. More sunspots would mean more violent solar storms that can destroy satellite-dependent communication systems and electricity supplies for millions of people.

The laws of nature of course apply equally to all animate and inanimate matter. Just as very disturbed people will inevitably disturb others, a very internally disturbed sun suffering excessive inner turmoil will disturb the Earth.

While more tangibly felt disasters, like the swine flu, can hog obvious headlines, any abnormal solar mood swings could be no less significant given earth’s dependency on the sun. This is why sunspot-watching could gain more importance than ever before.

Scientists have used sunspots to track the approximately 11-year cycles of intense solar activity. In the ongoing sun cycle, year 2008 should have been relatively inactive and 2009 was scheduled to have a cyclic upsurge in solar activity, according to some scientific estimates.

But fewer sunspots have been seen this year than expected. In 2008 the Ulysses space probe detected fewer sunspots, say scientists at the National Aeronautics and Space Administration (NASA).

Seventy-eight of the first 90 days of 2009 have been without sunspots, pointing to the dimmest solar activity in a hundred years. "Even the sun appears headed for a recession," wryly observed the National Geographic journal on May 4.

The riddle is whether the current lesser number of sunspots is good or bad news, or a mixture of both. "Fewer sunspots means lesser solar activity and solar storms," said Professor Arnab Rai Choudhuri, a leading physicist in the Bangalore-based Indian Institute of Science. "Solar storms can damage human-made satellites and also trip power grids on earth, particularly in geopolar countries like Canada."

Solar storms are bursts of charged particles churned out from the sun's inner nuclear upheavals, hurtling earthwards carrying billions of watts of power at speeds of millions of kilometers per second.

Excessive nuclear turmoil within the sun, as indicated by higher numbers of sunspots, can unleash potentially destructive solar storms. The last major solar storm 20 years ago blew out the power grid of Hydro-Quebec, one of North America's largest electricity suppliers. At 2:44am on March 13, 1989, a magnetic storm hit a single transformer grid and caused a catastrophic collapse that brought down the entire grid in just 90 seconds. Nearly seven million people suffered without electricity and the Canadian government was left with a US$10 million repair bill.

But the downside of a quieter sun could be a colder climate. Scientists are debating the possibility of a "Little Ice Age”, like the one between 1645 and 1715 in Europe that caused glaciers to swallow entire villages and water to remain frozen for a year in Iceland in 1695. The National Geographic article of May 4 discussed the chances of this.

"Overwhelming evidence is building up that the sunspot cycle and related activity are correlated with global climate and temperature," said a research paper [1] available at the Indian Institute of Astrophysics.

The authors said sunspots can affect the sea surface temperatures of the Earth's three main oceans - the Atlantic, Pacific and Indian - as well as cloud cover and Indian monsoon rainfall.

But not all scientists are convinced sunspots can influence climatic patterns, and therefore dependent essentials such as food crops. "How much sunspots affect climate is still a subject of debate," Professor Choudhari told Asia Times Online.

Choudhari, a leading Indian astrophysicist, developed his academically well-known “solar dynamo theory” to explain the inner workings of the sun. "I and my students have developed a code named Surya [a Sanskrit word meaning the sun] for solving the basic equations of solar dynamo theory," he said.

Interestingly, Choudhary's celebrated research paper "Sunspots and their cycles" had already predicted that the current sunspot cycle would be the weakest ever. This 2007 research paper, with his two PhD students Piyali Chatterjee and Jie Jiang from China [2], received the rare honor as "Editors' suggestion" in the Physical Review Letters (PRL) of the American Physical Society. The PRL, considered the world's foremost physics journal, ranks among leading scientific journals in any discipline.

More crucially, Choudhuri predicted that the next sunspot cycle will reach its peak in the years 2011-2012. If accurate, earthlings can expect increased solar storms.

"Not all sunspot cycles are of equal strength. Some are weak and some are strong," said Choudhari, "A stronger cycle is more likely to cause these disturbances. Hence it is important to understand why different cycles are of unequal strength, [in order to] predict the strength of a sunspot cycle in advance." An early warning can limit damage, such as reducing power loads on electric grids in solar storm prone regions.

Choudhari has been studying the sun for the past 25 years. "I was inspired after doing my PhD in physics from the University of Chicago under the supervision of Eugene Parker," he said. Legendary physicist Eugene Parker is credited with path-breaking theories such as the existence of a solar wind - the stream of charged electronic particles, or plasma, ejected from the upper atmosphere of the Sun.

"More than 99% of the material in the universe exists in the plasma state - often called the fourth state of matter,” said Choudhari. "The sun, our nearest star, is an enormous plasma laboratory in which we observe many puzzling phenomena."

In 1844, German astronomer Samuel Heinrich Schwabe discovered one such puzzle. He noticed that sunspots appear on the sun's surface in a cyclic phase - in a period of 11 years in which they wax and wane by appearing in a higher number and a lower number.

The sunspot cycle nearing its peak unleashes violent solar phenomena such as gigantic explosions, called solar flares, or Coronal Mass Ejections, in which billions of tons of charged particles are hurled out of the solar surface at speeds of millions of kilometers per hour.

Sunspots are considered the oldest pointers to such spectacular solar activity. Scientists like Galileo have been monitoring sunspots since the 17th century. The earliest recorded sunspot dates back to 28 BC, in the 100-volume encyclopedic work, Book of Han, in China.

Leading sunspot trackers of today include the Solar Influences Data Analysis Center (SIDC) - the solar physics research department of the Royal Observatory of Belgium. The SIDC releases the International Sunspot Index, with daily sunspot data stretching back from today to 1812.

Sunspots are evolving chapters in the enigmatic story of the sun, a revered object of worship in ancient India, Egypt and Inca civilizations. Surya Namaskar, or a ritualistic salute to the sun, continues to be part of a daily morning routine for millions of Indians.

A relationship becomes less disturbing with acceptance of the unavoidable reality that everything changes and evolves. This includes the billion-year Earth-sun relationship. Having lived 4.6 billion years, the sun has enough inner fuel to burn for approximately another five billion years. On its deathbed, the sun will start fusing heavier elements such as helium and begin to bloat in size across the solar system. Ultimately, the expanding, dying sun will swallow the Earth and other planets in the solar system.

Then, after another billion years of life as a dull red giant, the sun is expected to suddenly collapse into a white dwarf, the final corpse for a star its humble size. Scientists estimate it would take a trillion years to fully cool off from its internal inferno. The sunspots reflect the trillion-year death throes in the making, with humankind as a little footnote.

Real-time live updates of sunspot images, now available online through observatories such as the Solar Influences Data Analysis Center, tell this daily story of how the sun, the giver of life, will one day take away life on Earth. Nothing lasts forever, including the sun.

A nearer hour of reckoning possibly beckons. The year 2011-2012 for maximum solar activity would mark the first time ever that detailed predictions were made in advance for a sunspot cycle, according to Choudhari. "We now have to wait for a few years for the sun-god himself to give a verdict on our debate," he said. Hopefully the verdict will not be another catastrophic solar storm from this enigmatic diamond shining in the sky.