Thursday, July 23, 2009

Is the Sun Missing Its Spots?

July 21, 2009
NASA SUN GAZING These photos show sunspots near solar maximum on July 19, 2000, and near solar minimum on March 18, 2009. Some global warming skeptics speculate that the Sun may be on the verge of an extended slumber.

The Sun is still blank (mostly).

Ever since Samuel Heinrich Schwabe, a German astronomer, first noted in 1843 that sunspots burgeon and wane over a roughly 11-year cycle, scientists have carefully watched the Sun's activity. In the latest lull, the Sun should have reached its calmest, least pockmarked state last fall.

Indeed, last year marked the blankest year of the Sun in the last half-century — 266 days with not a single sunspot visible from Earth. Then, in the first four months of 2009, the Sun became even more blank, the pace of sunspots slowing more.

"It's been as dead as a doornail," David Hathaway, a solar physicist at NASA's Marshall Space Flight Center in Huntsville, Ala., said a couple of months ago.

The Sun perked up in June and July, with a sizeable clump of 20 sunspots earlier this month.

Now it is blank again, consistent with expectations that this solar cycle will be smaller and calmer, and the maximum of activity, expected to arrive in May 2013 will not be all that maximum.

For operators of satellites and power grids, that is good news. The same roiling magnetic fields that generate sunspot blotches also accelerate a devastating rain of particles that can overload and wreck electronic equipment in orbit or on Earth.

A panel of 12 scientists assembled by the National Oceanic and Atmospheric Administration now predicts that the May 2013 peak will average 90 sunspots during that month. That would make it the weakest solar maximum since 1928, which peaked at 78 sunspots. During an average solar maximum, the Sun is covered with an average of 120 sunspots.

But the panel's consensus "was not a unanimous decision," said Douglas A. Biesecker, chairman of the panel. One member still believed the cycle would roar to life while others thought the maximum would peter out at only 70.

Among some global warming skeptics, there is speculation that the Sun may be on the verge of falling into an extended slumber similar to the so-called Maunder Minimum, several sunspot-scarce decades during the 17th and 18th centuries that coincided with an extended chilly period.

Most solar physicists do not think anything that odd is going on with the Sun. With the recent burst of sunspots, "I don't see we're going into that," Dr. Hathaway said last week.

Still, something like the Dalton Minimum — two solar cycles in the early 1800s that peaked at about an average of 50 sunspots — lies in the realm of the possible, Dr. Hathaway said. (The minimums are named after scientists who helped identify them: Edward W. Maunder and John Dalton.)

With better telescopes on the ground and a fleet of Sun-watching spacecraft, solar scientists know a lot more about the Sun than ever before. But they do not understand everything. Solar dynamo models, which seek to capture the dynamics of the magnetic field, cannot yet explain many basic questions, not even why the solar cycles average 11 years in length.

Predicting the solar cycle is, in many ways, much like predicting the stock market. A full understanding of the forces driving solar dynamics is far out of reach, so scientists look to key indicators that correlate with future events and create models based on those.

For example, in 2006, Dr. Hathaway looked at disturbances in the Earth's magnetic field that are caused by the Sun, and they were strong. During past cycles, strong disturbances at minimum indicated strong fields all over the Sun at maximum and a bounty of sunspots. Because the previous cycles had been shorter than average, Dr. Hathaway thought the next one would be shorter and thus solar minimum was imminent. He predicted the new solar cycle would be a ferocious one, consistent with a short cycle.

Instead, the new cycle did not arrive as quickly as Dr. Hathaway anticipated, and the disturbances weakened. His revised prediction is for a smaller-than-average maximum. Last November, it looked like the new cycle was finally getting started, with the new cycle sunspots in the middle latitudes outnumbering the old sunspots of the dying cycle that are closer to the equator.

After a minimum, solar activity usually takes off quickly, but instead the Sun returned to slumber. "There was a long lull of several months of virtually no activity, which had me worried," Dr. Hathaway said.

The idea that solar cycles are related to climate is hard to fit with the actual change in energy output from the sun. From solar maximum to solar minimum, the Sun's energy output drops a minuscule 0.1 percent.

But the overlap of the Maunder Minimum with the Little Ice Age, when Europe experienced unusually cold weather, suggests that the solar cycle could have more subtle influences on climate.

One possibility proposed a decade ago by Henrik Svensmark and other scientists at the Danish National Space Center in Copenhagen looks to high-energy interstellar particles known as cosmic rays. When cosmic rays slam into the atmosphere, they break apart air molecules into ions and electrons, which causes water and sulfuric acid in the air to stick together in tiny droplets. These droplets are seeds that can grow into clouds, and clouds reflect sunlight, potentially lowering temperatures.

The Sun, the Danish scientists say, influences how many cosmic rays impinge on the atmosphere and thus the number of clouds. When the Sun is frenetic, the solar wind of charged particles it spews out increases. That expands the cocoon of magnetic fields around the solar system, deflecting some of the cosmic rays.

But, according to the hypothesis, when the sunspots and solar winds die down, the magnetic cocoon contracts, more cosmic rays reach Earth, more clouds form, less sunlight reaches the ground, and temperatures cool.

"I think it's an important effect," Dr. Svensmark said, although he agrees that carbon dioxide is a greenhouse gas that has certainly contributed to recent warming.

Dr. Svensmark and his colleagues found a correlation between the rate of incoming cosmic rays and the coverage of low-level clouds between 1984 and 2002. They have also found that cosmic ray levels, reflected in concentrations of various isotopes, correlate well with climate extending back thousands of years.

But other scientists found no such pattern with higher clouds, and some other observations seem inconsistent with the hypothesis.

Terry Sloan, a cosmic ray expert at the University of Lancaster in England, said if the idea were true, one would expect the cloud-generation effect to be greatest in the polar regions where the Earth's magnetic field tends to funnel cosmic rays.

"You'd expect clouds to be modulated in the same way," Dr. Sloan said. "We can't find any such behavior."

Still, "I would think there could well be some effect," he said, but he thought the effect was probably small. Dr. Sloan's findings indicate that the cosmic rays could at most account for 20 percent of the warming of recent years.

Even without cosmic rays, however, a 0.1 percent change in the Sun's energy output is enough to set off El Niño- and La Niña-like events that can influence weather around the world, according to new research led by the National Center for Atmospheric Research in Boulder, Colo.

Climate modeling showed that over the largely cloud-free areas of the Pacific Ocean, the extra heating over several years warms the water, increasing evaporation. That intensifies the tropical storms and trade winds in the eastern Pacific, and the result is cooler-than-normal waters, as in a La Niña event, the scientists reported this month in the Journal of Climate.

In a year or two, the cool water pattern evolves into a pool of El Niño-like warm water, the scientists said.

New instruments should provide more information for scientists to work with. A 1.7-meter telescope at the Big Bear Solar Observatory in Southern California is up and running, and one of its first photographs shows "a string of pearls," each about 50 miles across.

"At that scale, they can only be the fundamental fibril structure of the Sun's magnetic field," said Philip R. Goode, director of the solar observatory. Other telescopes may have caught hints of these tiny structures, he said, but "never so many in a row and not so clearly resolved."

Sun-watching spacecraft cannot match the acuity of ground-based telescopes, but they can see wavelengths that are blocked by the atmosphere — and there are never any clouds in the way. The National Aeronautics and Space Administration's newest sun-watching spacecraft, the Solar Dynamics Observatory, which is scheduled for launching this fall, will carry an instrument that will essentially be able to take sonograms that deduce the convection flows generating the magnetic fields.

That could help explain why strong magnetic fields sometimes coalesce into sunspots and why sometimes the strong fields remain disorganized without forming spots. The mechanics of how solar storms erupt out of a sunspot are also not fully understood.

A quiet cycle is no guarantee no cataclysmic solar storms will occur. The largest storm ever observed occurred in 1859, during a solar cycle similar to what is predicted.

Back then, it scrambled telegraph wires. Today, it could knock out an expanse of the power grid from Maine south to Georgia and west to Illinois. Ten percent of the orbiting satellites would be disabled. A study by the National Academy of Sciences calculated the damage would exceed a trillion dollars.

But no one can quite explain the current behavior or reliably predict the future.

"We still don't quite understand this beast," Dr. Hathaway said. "The theories we had for how the sunspot cycle works have major problems."

This article has been revised to reflect the following correction:

Correction: July 22, 2009
An article on Tuesday about the recent decline in the frequency of sunspots incorrectly described the research of David Hathaway, a scientist at NASA's Marshall Space Flight Center. His forecasts for the strength of the solar cycle are based on the magnitude of sunspot-caused disturbances in the Earth's magnetic field, not in the Sun's polar magnetic fields.

Friday, May 1, 2009

Green Power :: Cheap political points and misleading scare tactics

Dear Partha Sarathi,

Cheap political points and misleading scare tactics. You'd be surprised what
defenders of the status quo would do to derail progress toward a clean
energy jobs plan.

One member of Congress went so low as to say that closing the carbon
pollution loophole "is the greatest assault on democracy and freedom that
I've ever seen in Congress." He said he feared it more than wars. More than
terrorist attacks.

We can't let these desperate scare tactics stop the creation of millions of
clean energy jobs and close the window of opportunity to solve the climate
crisis that we have right now.

We have organizers across the country working hard to support clean energy
jobs and solutions to the climate crisis. Your support will help them reach
thousands of people.

Will you support their efforts with a $25 donation today?

Vice President Al Gore testified with Senator John Warner (R-VA), co-author
of the Lieberman-Warner bill considered by the Senate in 2008, on the
Bipartisan Leaders' Panel for the American Clean Energy and Security Act.

Gore spoke of the economic and environmental damage that would be caused by
delaying action, saying "Each day that we continue with the status quo sees
more of our fellow Americans struggling to provide for their families. Each
day we continue on our current path, America loses more of its competitive
edge. And each day we wait, we increase the risk that we will leave our
children and grandchildren an irreparably damaged planet."

There is no doubt that the economic, environmental and security challenges
we face demand sweeping, comprehensive legislation. But overcoming the
opposition's scare tactics to pass a historic clean energy jobs plan will
require your help.

Please stand with me, Vice President Al Gore and millions of other Americans
in saying that we won't be defeated by the same old divisive tactics. Please
donate $25 to support our grassroots effort at this crucial time.

Thanks for all you do,

Steve Bouchard
Campaign Manager

P.S. Click here to watch Vice President Gore's testimony.
(Please consider the environment before printing this email and its

Monday, April 6, 2009

Five Elements Mountain or Kunlun Mountains :: Reffered in The Forbidden Kingdom

Firstly it is one of the Places where I would like to go...

The Kunlun Mountains (simplified Chinese: 昆仑山; traditional Chinese: 崑崙山; pinyin: Kūnlún Shān; Mongolian: Хөндлөн Уулс) is one of the longest mountain chains in Asia, extending more than 3,000 km.

The Kunlun runs westwards along the northern part of the Tibetan plateau to form the border range of northern Tibet. It stretches along the southern edge of what is now called the Tarim Basin, the infamous Takla Makan or "sand-buried houses" desert, and the Gobi desert. A number of important rivers flow from it including theKarakash River ('Black Jade River') and the Yurungkash River ('White Jade River'), which flow through the Khotan Oasis into the Taklamakan Desert.

The highest mountain of the Kunlun Shan is the Kunlun Goddess (7,167 m) in the Keriya area. The Arka Tagh is in the center of the Kunlun Shan; its highest point is Ulugh Muztagh. Some authorities claim that the Kunlun extends north westwards as far as Kongur Tagh (7,649 m) and the famous Muztagh Ata (7,546 m). But these mountains are physically much more closely linked to the Pamir group (ancient Mount Imeon).

Bayan Har Mountains, a southern branch of the Kunlun Mountains, forms the watershed between the catchment basins of China's two longest rivers, the Yangtze River and the Huang He.

The mountain range formed at the northern edges of the Cimmerian Plate during its collision, in the Late Triassic, with Siberia, which resulted in the closing of thePaleo-Tethys Ocean.


The Kunlun mountains are believed to be Taoist paradise. The first to visit this paradise was, according to the legends, King Mu (976-922 BCE) of the Zhou Dynasty. He supposedly discovered there the Jade Palace of Huang-Di, the mythical Yellow Emperor and originator of Chinese culture, and met Hsi Wang Mu (Xi Wang Mu) , the 'Spirit Mother of the West' usually called the 'Queen Mother of the West', who was the object of an ancient religious cult which reached its peak in the Han Dynasty, also had her mythical abode in these mountains. Jesuit missionaries, the noted American Sinologist Charles Hucker, and London University’s Dr Bernard Leeman (2005) have suggested that Xiwangmu and the Queen of Sheba were one and the same person. The Transcendency of Sheba, a religious group, believes that the Queen of Sheba's pre-Deuteronomic Torah recorded in the Kebra Nagast was influential in the development of Daoism. They insist that after vacating the throne for her son Solomon the queen journeyed to the Kunlun Mountains where, known as the Queen from the West, she attained spiritual enlightenment.

The Kunlun Pass


Coordinates36°00′N 84°00′E / 36°N 84°E / 36; 84

The Forbidden Kingdom (2008)

One of the best films I ever saw...
Jackie Chan and Jet Li together - Crouching Tiger & Sprinting Monkey

Leopard style, dragon style. Fight to the air, fight on water, Prying Mantis,  Bouncing Sparrow 
IMDB : 5556/  


Pass: kosovadc

It is the first film to star together two of the best-known names in the martial arts film genre, Jackie Chan and Jet Li. The action sequences were choreographed by Yuen Woo-ping.
the inebriated traveling scholar Lu Yan (Jackie Chan), a supposed 'immortal', who is surprisingly alert and agile even when drunk. Later that night, seated in a teahouse, Lu Yan tells Jason of a legend of the Monkey King, who caused havoc at the banquet held by the Immortals on Five Elements Mountain celebrating the Jade Emperor's forthcoming 500-year period of meditation. The Jade Emperor took a liking to the Monkey King and awarded him a heavenly title, much to the chagrin of the Jade Warlord (Collin Chou), who was the Emperor's general. The Emperor then left the Jade Warlord to rule Heaven before retreating to his period of seclusion. The Warlord then challenged the Monkey King to a duel to display their fighting and magical abilities. After tricking the Monkey King into setting aside his magic staff Ruyi Jingu Bang, the Warlord changed him into a statue of himself, whereupon the Monkey King threw the staff beyond the Warlord's grasp. Lu Yan ends the tale by stating a prophecy in which a person known as the "Seeker" will find the staff and free the Monkey King. Lu Yan and Jason are then attacked by the Jade Warlord's soldiers, from whom they are rescued by Golden Sparrow (Liu Yifei), a young girl who refers to herself in the third person, who reveals that her family was murdered by the Jade Warlord, against whom she has therefore sworn revenge.

Friday, March 13, 2009

Goddess Durga, Scroll of the Dragon Warrior and CSS 2.1

While I am writing the story its 6:37 am in the morning and I just woke up after a unique dream of mine, all dreams are unique & priceless to me, as usual.
The summery of the dream was – I found after a long journey to a village like place, I found Goddess Durga was giving me the Scroll of the Dragon Warriors, after seeing it I just find all the knowledge on CSS, ever gathered by human being, everything just became aligned properly, now I can interact with the environment, colorize them and align them, even control there shadows, wow.
Soon after while I woke up, it was the bird chirpings that I heard, cuckoo, crow, pigeon, florican, finch and many others, it’s the set of sounds I always like to hear in the morning, from my childhood. Now it is only available in some places like my home, not in my urban residence. Often Barsha, my wife starts talking in the morning but soon discovers I am not giving any reply – why she asks, it is the sounds I reply, in the morning I don’t like to talk until I became saturated with natural sounds, inner peace…
Then soon after I have decided to write this story, hence opened the window, Right then the sounds of police parade from nearest headquarters entered my ears, LEFT-RIGHT-LEFT, LEFT-RIGHT-LEFT – the entire experience was turning bitter as some one is poisoning my ears, soon I turned my mind, started writing, and turned on my love – my shortwave radio.
For the logical weird: Last night my mother was watching some TV Serials regarding Goddesses, I have recapped yesterday Kungfu Panda, and obviously I was working on my web development projects.
But yesterday’s best experience was having a dozens of hot white rice pie (sada pitha) with red sweet syrup made from dates (khejuri goorer rash) in the evening.

ভয়াবহ ভবিষ্যৎ পৃথিবীর সামনে

আমাদের বিশ্বের সামনে রয়েছে খুব কম সময় – সমুদ্রপৃষ্ঠের উচ্চতা বৃদ্ধি প্রসঙ্গে কথাগুলো বললেন আইপিসিসি বা জাতিসংঘের জলবায়ু পরিবর্তন সংক্রান্ত প্যানেলের প্রধান রাজেন্দ্র পাচাউরি৷

এর আগে বিভিন্ন সময়ে করা সমীক্ষা বা গবেষণার পর বলা হয়েছিল ২১০০ সাল নাগাদ পৃথিবীর সমুদ্রপুষ্ঠের উচ্চতা ১৮ থেকে ৫৯ সেন্টিমিটার বা সাত থেকে ২৩ ইঞ্চি বৃদ্ধি পাবে৷ ফলে পৃথিবীর সমুদ্র উপকূলবর্তী বেশীরভাগ এলাকা পানির তলে তলিয়ে যাবে৷ কিন্তু কোপেনহেগেনে অনুষ্ঠিত বিশেষজ্ঞ সম্মেলনে সর্বশেষ গবেষণার ফলাফলে জানানো হলো আরও ভয়ঙ্কর তথ্য৷
এই সম্মেলনে বলা হয়েছে, আগের যে গবেষণা তাঁরা করেছিলেন, তার থেকেও ভয়াবহ ভবিষ্যৎ পৃথিবীর সামনে৷ নতুন গবেষণায় দেখা যাচ্ছে,একই সময়ের মধ্যে বিশ্বের সমুদ্রপৃষ্ঠের উচ্চতা ৭৫ থেকে ১৯০ সেন্টিমিটার বৃদ্ধি পাবে৷ এমনকী যদি সবকিছু ঠিকঠাকও থাকে এবং গ্রীনহাউস গ্যাস নির্গমন বেশ ভালোমাত্রায় কমানোও হয়, তাহলেও ২১০০ সাল নাগাদ সমুদ্রের উচ্চতা বাড়বে এক মিটার৷
এক্ষেত্রে বাংলাদেশ ও ভারত মহাসাগরের উপকূলবর্তী দেশগুলো কিংবা আফ্রিকার দেশগুলোই বেশী ক্ষতিগ্রস্ত হবে বলেই মনে করা হচ্ছে৷ কিন্তু প্রশ্ন হচ্ছে, হঠাৎ করে দুই বছর আগের হিসাবটি পাল্টে গেলো কেন? উত্তরে জানানো হলো, মূলত মেরু অঞ্চলের বরফ অতিমাত্রায় গলতে থাকার কারণেই এই ভিন্ন চিত্র৷
বিশ্বের প্রায় ৬০ কোটি মানুষ বসবাস করছে সমুদ্র উপকূলীয় নিবিড় অঞ্চলে৷ নতুন এই গবেষণায় দেখা গিয়েছে, দেশগুলোর মধ্যে সবচেয়ে বেশী ক্ষতিগ্রস্ত হবে বাংলাদেশ৷ প্রায় দেড় কোটি মানুষ বাস্তুচ্যুত হবে৷ মোট আয়তনের শতকরা ১৭ ভাগ জমি পানির তলে ডুবে যাবে৷

ধর্মশালায় অন্যরকম দিন - from DWorld

ধর্মশালায় অন্যরকম দিন

ধর্মশালায় তিব্বতীদের সমাবেশে দালাই লামা৷
Großansicht des Bildes mit der Bildunterschrift: ধর্মশালায় তিব্বতীদের সমাবেশে দালাই লামা৷

ধর্মশালার মঙ্গলবারের দিনটা ছিল অন্যরকম৷ উত্তর ভারতের পাহাড় ঘেরা এই শহরে সমাবেশে যোগ দিয়েছেন হাজারো তিব্বতী৷ লক্ষ্য – তাঁদের ধর্মগুরু এবং তিব্বতীদের আন্দোলনের নেতা দালাই লামার বক্তব্য শোনা৷

বিশ্বের বিভিন্ন প্রান্ত থেকে তাঁরা জড়ো হয়েছেন চীনের নিয়ন্ত্রণ থেকে মুক্তি আন্দোলনের সুবর্ণ জয়ন্তী  ও পাশাপাশি গত বছর তিব্বতীদের প্রচণ্ড বিক্ষোভের একবছর পূর্তি উপলক্ষ্যে৷ ১৯৫৯ সালের ১০ই মার্চ তিব্বতে সূত্রপাত ঘটেছিলো এই আন্দোলনের৷ যদিও সেই আন্দোলনের বিরুদ্ধে চীনা কর্তৃপক্ষের কঠোর হস্তক্ষেপের ফলে পরবর্তীতে সেটা ব্যর্থ হয়ে গিয়েছিলো৷ আজ সেই দিন উপলক্ষে দেয়া ভাষণে দালাই লামা কঠোর ভাষায় বললেন,  তিব্বতীরা বাস করছে পৃথিবীর এক জাহান্নামে৷লাসায় কড়া নিরাপত্তাBildunterschrift: Großansicht des Bildes mit der Bildunterschrift:  লাসায় কড়া নিরাপত্তা
তিব্বতীদের আন্দোলনে নানা নির্যাতনের কারণে দালাই লামা বহু বছর আগেই ধর্মশালায় নির্বাসনে রয়েছেন৷ পূর্ণ স্বাধীনতার বদলে তিনি অবশ্য চীনের শাসনের মধ্যেই তিব্বতীদের জন্য স্বায়ত্ত্বশাসনের দাবি করে আসছেন৷ সেখানকার প্রধান বৌদ্ধ মন্দিরের সামনে দাঁড়িয়ে দেয়া ভাষণে নির্বাসিত এই নেতা বলেন,  পাঁচ দশক ধরে চীনা শাসনে তিব্বতীরা এক অবর্ণনীয় দুর্দশায় ভুগছেন৷
এই দিবস উপলক্ষে চীনা সরকার তিব্বতে কঠোর নিরাপত্তা ব্যবস্থা গ্রহণ করেছে বলে বার্তা সংস্থাগুলোর খবর৷ বিশেষ করে তিব্বতের সাউথ ওয়েস্ট ন্যাশনালিটিইজ বিশ্ববিদ্যালয় এলাকায় নেয়া হয়েছে কঠোর নিরাপত্তা ব্যবস্থা৷ সেখানে মোতায়েন করা হয়েছে আধা সামরিক বাহিনী৷ সেখানে বিদেশীদের যাতায়াতের উপর নিষেধাজ্ঞা আরোপ করা হয়েছে৷
ধর্মশালায় দেয়া বক্তব্যে দালাই লামা আরও বলেন, স্মরণকাল থেকে তিব্বতী ও চীনা জনগণ প্রতিবেশী হিসেবে অবস্থান করে আসছে৷ আমরা তিব্বতে একটি বৈধ স্বায়ত্তশাসন প্রত্যাশা করছি৷
দালাই লামা চীনের কমিউনিস্ট নীতির সমালোচনা করে বলেন,  তিব্বতীরা এমন এক তীব্র দুর্দশা ও কষ্টের মধ্যে আছে যা আক্ষরিক অর্থে পৃথিবীতে দোজখে থাকার নামান্তর৷  দালাই লামা বলেন, আজও তিব্বতীরা তিব্বতে ভীতিকর পরিবেশে বাস করছেন৷ আজ তিব্বতীদের ভাষা, সংস্কৃতি, ধর্ম, পরিচয় সব কিছু মৃতপ্রায়৷ তিব্বতীদের সঙ্গে অপরাধীর মত আচরণ করা হচ্ছে৷ বার্তা সংস্থাগুলো জানাচ্ছে, দালাই লামার ভাষণের আগে তিব্বতের জাতীয় সঙ্গীত বাজানো হয়৷ সেই সঙ্গে ২০০৮ সালে চীনের বিক্ষোভ দমন অভিযানে নিহতদের স্মরণে এক মিনিট নীরবতা পালন করা হয়৷
মূল অনুষ্ঠানের পর বেশ কয়েক হাজার তিব্বতী  'তিব্বত মুক্ত কর' লেখা পোস্টার নিয়ে ধর্মশালার বিভিন্ন পথ প্রদক্ষিণ করে৷ তারা তিব্বতে বর্তমানে চীনের কঠোর নিরাপত্তা ও কড়াকড়িরও প্রতিবাদ জানায়৷
তবে দালাই লামার বক্তব্যের বিষয়ে সরাসরি কোন মন্তব্য না দিয়ে চীনা পররাষ্ট্র মন্ত্রনালয়ের এক মুখপাত্র কেবল বলেছেন, আমি দালাই লামার মিথ্যা বক্তব্যের বিষয়ে কোন মন্তব্য করতে চাই না৷
সাগর সরওয়ার

Thursday, February 19, 2009

Jamming: a primer By Chris Cork

Tuesday, February 17, 2009

Much has been talked but little actually done in the matter of jamming the
so-called "Mullah Radio" that has done much to inflame the situation in
Swat. The government appears to take the position that this is an immensely
complex and expensive task, requires vast resources and the import of
foreign equipment - most of which is not necessarily the case.

Few will have little idea of what "jamming" actually entails - or even what
it is. Radio jamming is the generally deliberate transmission of radio
signals that disrupt communications or the radio channel by increasing the
signal-to-noise ratio; which is defined as the ratio of a signal power to
the noise power corrupting the signal. Signals can be unintentionally jammed
or interfered with by another broadcaster transmitting on the same frequency
without first checking that the channel is in use; alternatively, the signal
can be disrupted by the switching on of something like a cable TV plant. The
plant radiates a signal which, for instance, could interfere with the
emergency frequency used by aircraft. None of this is "new knowledge" and
has been around almost as long as radio itself. (Marconi is generally
credited with the invention of radio in the last years of the 19th century
and the early years of the 20th.)

Intentional communications jamming is usually aimed at an adversary's radio
signals to disrupt control of their equipment and communication/information
systems during a battle. A transmitter, tuned to the same frequency as the
opponent's receiving equipment, and with the same type of modulation, can,
with enough power, override any signal at the receiver. There is a range of
ways in which this can be done. The most common types of this form of signal
jamming are random noise (sometimes called "white" noise), random pulse,
stepped tones, warbler, tone, rotary, pulse, spark, recorded sounds, gulls
(as in the sound of the common seagull, which is a disconcerting "squawk")
and sweep-through. These are all forms of noise designed to overlay
broadcast and render it unintelligible, and they can be divided into two
groups - obvious and subtle.

Obvious jamming is easy to detect because it can be heard on the receiving
equipment. It usually is some type of noise such as stepped tones (bagpipes,
for instance, an instrument played in Scotland with a penetrating "drone"),
random-keyed code, pulses, music (often distorted), erratically warbling
tones, highly distorted speech, random noise (hiss or "white noise") and
recorded sounds. Various combinations of these methods may be used, often
accompanied by a regular Morse-code identification signal to enable
individual transmitters to be identified in order to assess their
effectiveness. For example, China, which has used jamming extensively, and
still does, plays a loop of traditional Chinese music while it is jamming
channels. The purpose of this type of jamming is to block the reception of
transmitted signals and to cause a nuisance to the receiving operator.

Subtle jamming is jamming during which no sound is heard on the receiving
equipment. The radio does not receive incoming signals, yet everything seems
superficially normal to the operator. These are often technical attacks on
modern equipment, such as "squelch capture." Thanks to the FM capture
effect, Frequency Modulated broadcasts may be jammed, unnoticed, by a simple
unmodulated carrier - something that would present little or no difficulty
to the communications wing of our armed forces were they to be directed to
locate and interdict transmissions from "Mullah Radio." (Location will not
be a problem either - simple signal triangulation will suffice.)

Screwing up the oppositions comms (radio-geek-speak for "communications")
has been something in the military manifest for many years. During World War
II ground radio operators would attempt to mislead pilots by false
instructions in their own language, in what was more precisely a "spoofing
attack" than jamming. Jamming of foreign radio broadcast stations has also
often been used in wartime (and during periods of tense international
relations) to prevent or deter citizens from listening to broadcasts from
enemy countries. However, such jamming is usually of limited effectiveness
because the affected stations usually change frequencies, put on additional
frequencies and/or increase transmission power.

A more sophisticated form of jamming is used to limit access to the Internet
by totalitarian regimes - China and Saudi Arabia, for example, both of which
severely limit Net access. Pakistan has the capacity to do this also, but it
has been used infrequently. Netizens are usually able to find a way around
Net jamming by using proxy servers. Jihadi groups make extensive use of the
Internet to propagate their message. The increased use of Net-based comms
systems like Messenger and Skype present other challenges to the jammer;
with Skype giving particular difficulties as it uses an encryption system
whose key it refuses to release.

In occupied Europe during WW2 the Nazis attempted to jam broadcasts to the
continent from the BBC and other allied stations. Post-war and into the Cold
War Soviet jamming of some Western broadcasters led to a "power race" in
which broadcasters and jammers alike repeatedly increased their transmission
power, utilised highly directional antennas and added extra frequencies to
the already heavily overcrowded shortwave bands, to such an extent that many
broadcasters not directly targeted by the jammers (including pro-Soviet
stations) suffered from the rising levels of noise and interference. Radio
Free Europe and its sister service Radio Liberty were the main target of
Soviet jammers, followed by Voice of America and the BBC World Service. The
BBC World Service is still jammed in China from time-to-time.

Against this background of nigh-on a century of interruptive activity of
radio signals, both shortwave and FM, we may be able to see that our own
inability to shut down or disrupt Mullah Radio is not a failure of
technology on our part, nor is it something beyond our technological reach.
Indeed, were we to be really serious about shutting down Mullah Radio it
would be a simple matter at field-level to locate the signal source and then
vector an appropriately armed aircraft and blow the thing - and its
operators - to kingdom-come. It is doubtful that the operators are yet so
sophisticated that they can auto-shift frequencies to confuse any jammer,
their on-air timings are not difficult to determine and the equipment they
use is not so portable as to be something they can backpack from location to
location. Simply put, they are the proverbial sitting ducks.

The failure is not military or technological - it is political. It is a
failure that stretches far back into the Musharraf years and is probably
linked to the fallacious notion of "strategic depth" that still in part
informs military and political thinking. Today we are seeing a shift in the
political winds as the new American crew breezes through our part of the
world. President Zardari has spoken clearly and forcefully in the last few
days of the threat presented to us by the Taliban. Their power and reach are
both extended and consolidated by the use of radio and other media, and the
State has been either absent, slow or simply negligent in terms of
understanding the threat presented by Mullah-radio. We can and should switch
off their mouthpiece. Jamming would be the humane way of accomplishing
that - starting tomorrow.

The writer is a British social worker settled in Pakistan. Email:

Tuesday, February 17, 2009