Heavy weather: from the cutting edge of computing, the Earth Simulator is taking scientists to new frontiers: the planet's most powerful computer seems straight out of Stanley Kubrick's eerie classic, 2001: A Space Odyssey. Yet the story the Earth Simulator is telling may be even more disturbing

Japan, Inc.,  Nov, 2003  by Tim Hornyak

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AKIRA KAGEYAMA IS STANDING at the center of the Earth. Around him, particles of light cascade, aquamarine vortices churn and arrows flow like schools of fish in a slow dance.

This is Kageyama's conception of the engine behind our planet's magnetic fields. He thumbs a button and another particle comes into being, tracing helical convection currents through the mantle as the perspective soars to a point several kilometers above the North Pole. Suddenly he flicks a laser wand and the mesh sphere disappears. The virtual reality chamber's walls go completely blank.

"The human eye is a nice tool to extract information from images," Kageyama notes as he removes his goggles. "We use this facility to visualize the 3D structure hidden in a sea of numerical data. By following the virtual particle's motion, we can visualize or understand fluid motion. It's very complicated, but we can extract some organization."

Kageyama is trying to understand the subterranean forces that make compasses point north, cause auroras to appear near the poles and ultimately shield our atmosphere from decimation by the solar wind.

Exactly how the magnetosphere is produced is a mystery being unraveled by scientists like Kageyama, a physicist at the Japan Marine Science and Technology Center (JAMSTEC). One of the reasons Kageyama and others like him are ahead of the game is because they work on the most advanced computer in the world.

Power tool

Tucked away amid moldering tatami shops and condominiums in a humdrum industrial and residential corner of Yokohama, the Earth Simulator is housed in a specially constructed building, taking up three floors and an area equivalent to four tennis courts. It became operational in March 2002 as the world's fastest supercomputer, so quick that its raw processing power equaled that of the 20 speediest US computers combined, far outpacing the previous title holder, the IBM-built ASCI white at Lawrence Livermore National Laboratory, which is used for nuclear weapons simulations.

Outside the fence surrounding the government-run Earth Simulator Center, you can hear the air conditioners humming around the massive hangar as the [yen] 40 billion NEC-built behemoth begins its work. Its primary mission is to render our world in digital form so that scientists can better understand environmental changes and processes, from the magnetosphere's origins to tectonic motion to sea temperature fluctuations.

"The primary objective is to make reliable prediction data for Earth's environmental changes, such as global warming and earthquake dynamics," says Tetsuya Sato, director general of the ESC, which is under JAMSTEC. "Already, global ocean circulation simulations have confirmed that mesoscale phenomena such as typhoons and rain fronts can be nicely reproduced."

It's been just over a year since actual research projects using the Earth Simulator were started in September 2002, with roughly 40 studies. While it's still too early for definitive conclusions from such complex analyses, the results so far are promising.

"We have already demonstrated that typhoons can be reproduced in global atmospheric circulation programs," notes Sato. Conventional simulators have a resolution of 100 km at most, but the Earth Simulator tightens the mesh to 10 km, providing an unprecedented level of detail. Meteorologists can now view the complex structures and origins of the whip like Kuroshio Current, a major warm water current flowing northeasterly along the Pacific coasts of Taiwan and Japan and moderating weather in the two countries by conveying heat and moisture from the south to higher latitudes. They can also pull back thousands of meters above the sea and study simulated births of cyclones off Madagascar that are both higher resolution and more realistic than satellite photos.

The big picture

"Many researchers have been interested in only parts of phenomena because their machines were not powerful enough to simulate the whole thing," says JAMSTEC climate investigator Keiko Takahashi. "The Earth Simulator allows us to simulate nearly the whole phenomenon."

Takahashi is doing unprecedented weather simulations with a "coupled" ocean-atmosphere model that incorporates the creation and depletion of sea ice to understand the mechanisms of climate change and what role the periodic El Nino effect plays in the process. The work is especially timely amid the high number of extreme weather incidents around the world this year, from tornadoes in the US in May that killed 41, to the summer heat wave in France that is believed to have caused a staggering 15,000 deaths.

Such events have led the UN World Meteorological Organization, which usually occupies itself with compiling statistics, to issue a warning that hazardous weather incidents could continue to increase in number and intensity, squarely blaming global warming and climate change. It added that land temperatures for May 2003 were the warmest on record.

"If we continue with similar lifestyles, we may see more severe conditions," Takahashi says, noting that the task of accurately unraveling the relationships between local weather conditions, climate and global warming is an extremely complex task and would require a next-generation Earth Simulator.