GEOPHYSICISTS CHASE STORMS' `SPRITES, ELVES' : COLORFUL EMISSIONS' CAUSE UNKNOWN.

Byline: John D. Cox Scripps-McClatchy Western Service

The flashes of lightning that punctuate powerful thunderstorms are only part of the show.

Since they uncovered these strange goings-on above the clouds only a few years ago, scientists have been developing increasingly far-reaching explanations for flashes of red ``sprites,'' blue jets and flickering red halos called ``elves'' high in the atmosphere.

Among the 7,000 scientists at the annual meeting of the American Geophysical Union earlier this month was a cadre of specialists who are contemplating ideas that suggest thunderstorms affect not only weather but climate not only on Earth but in space.

While a thunderstorm is sending bolts of lightning toward the ground, an even more powerful exchange of energy is taking place between 25 and 60 miles overhead, above the clouds.

Accompanying many big thunderstorm complexes - which commonly girdle the globe, especially in the tropics - are violent red flashes that scientists say are formed by a ``runaway atmospheric breakdown'' that blows apart air molecules and sends electrons out into space faster than the speed of light.

A prominent theory holds that this breakdown is sparked by a cosmic ray, part of the constant rain from space, striking an air molecule and kicking out a high- speed electron left in the atmosphere after a normal lightning bolt.

A fountain of high-energy electrons is produced, emitting blue light in the lower atmosphere and red light in the rarefied upper air when it collides with air molecules.

Davis Sentman, a University of Alaska researcher, who chaired a recent session on the subject, said scientists suspect that these phenomena produce copious amounts of nitric oxide, a common greenhouse gas, and so may affect global climate.

Sentman is trying to interest atmospheric chemists in the phenomena. One scientist presented calculations that showed that a single blue jet, which lasts one-tenth of a second produces more nitric oxide than any other source does in a year.

Above the atmosphere, meanwhile, the sprites send into space a shower of electrons, which at least one theorist suggests is the source of one of Earth's radiation belts, which extend far out in a doughnut shape formed by the planet's magnetic field.

``This is a fundamentally different idea than what has been supposed for the past 30 years of how the radiation belts are formed,'' said Sentman.

Scientists have thought the belts were formed by cosmic rays, the sun and high-altitude nuclear explosions.

``We don't know if it's right or not . . . but it's an exciting idea, because it means what happens in space would be intimately tied to weather patterns, what happens on the ground,'' Sentman said.

Stanford University researchers presented a study that confirms the presence of so-called elves, above the jets and sprites. These elves are flashes that last only one-thousandth of a second, but spread in a ringlike shape that can expand horizontally more than 160 miles in diameter.

Elves (short for Emissions of Light and Very Low Frequency Perturbations From Electromagnetic Pulse Sources) flash as electromagnetic pulses from the clouds below strike electrically charged atoms in the ionosphere, the region above the stratosphere, the scientists said.

``The ring expands faster than the speed of light for the same reason that waves, when striking the beach at an angle, travel along the shore at a faster speed than the waves move through the water,'' said Umran Inan, a Stanford professor of electrical engineering.

Researchers from Los Alamos National Laboratory in New Mexico have developed a computer model that shows that elves are a byproduct of the sprites and jets.

``This work has the potential to change prevailing views on how electromagnetic pulses accompanying lightning are produced and what consequences they have,'' said Yuri Taranenko of Los Alamos. ``It makes the picture of interactions in the upper atmosphere much more rich and complex than we previous thought.''

The exotic interconnections between these weather events and their potential impact on climate and space pose a special problem for researchers seeking financial support, scientists said, because research funding administrators are not accustomed to thinking in such terms.

``It produces a bit of a quandary,'' said Sentman.