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A space mission worth its salt

Island researcher leads satellite-based study of salinity’s effect on climate.

It’s still T-minus four years until blast-off, and the cozy Parfitt Way offices of Earth and Space Research are far from launch control.

But a squall rattling the windows is a reminder that, while the Aquarius space mission may be years away, the realm of ESR’s research is close by.

“(The year) 2008 is a long way away, but the time seems to go by quickly. There’s a lot to do,” said ESR president and oceanographer Gary Lagerloef.

Early this year, the Bainbridge resident was named principal investigator for Aquarius/SAC-D, a near-earth satellite mission that will provide the first comprehensive measurements of a fundamental component of global climate: salt.

Aquarius’ three-year survey of seawater salinity will help link two critical mechanisms of climate change that have long been studied separately.

Ocean circulation – in which solar energy absorbed by seawater travels around the globe – is a major determinant of the world’s weather patterns. By measuring the temperature and salt content of seawater, both of which affect density, oceanographers can determine how that water moves.

That salt content, in turn, is affected by the “water cycle,” in which water moves through the environment. Most of that activity occurs over the world’s oceans; climatologists estimate that 86 percent of evaporation and 78 percent of precipitation occurs at sea – diluting or concentrating the salt at sea level, which helps drive ocean circulation.

A better understanding of the interaction between the water cycle and ocean circulation promises a significant payoff: vastly improved models of the Earth’s climate system, making it possible to forecast damaging events like El Niño six to 12 months sooner.

Sea sound

As it brings together two dynamos of climate change, the Aquarius mission will unite two of Lagerloef’s longtime interests: sea and space.

“I was glued to my TV every time there was a Mercury, Gemini or Apollo mission,” he admits.

After launching his career as a coastal oceanographer, Lagerloef became engaged in the possibilities of “remote sensing” – using satellites to study Earth’s systems, including the ocean – in the late 1980s during a stint at NASA.

Satellite remote sensing “just drew me like a magnet,” he said. “You have to push the boundaries of science and technology.”

While direct sampling produces accurate measurements of salt content, it’s never been possible to cover enough of the world’s oceans to get a complete picture.

“Almost all of the information has been collected by ships, and that’s been largely confined to shipping routes,” Lagerloef said. “Most of the southern hemisphere hasn’t been sampled at all.”

To measure salinity from orbit, Aquarius relies on “passive microwave radiometry,” which systematically scans the ocean surface for “noise” on a specific frequency, noise that’s determined by the amount of salt in the water.

While the technique doesn’t allow for pinpoint measurements, the comprehensiveness and frequency of the coverage represents a huge step forward for climate science. Aquarius will measure the entirety of the ocean surface every eight days for three years, and explore regions of the world’s oceans never before measured.

“It’s every scientist’s dream to be involved in discovery,” Lagerloef said. “I’m sure we’ll be surprised by what we find.”

New ground

The scientific institute that’s supporting the mission, Earth and Space Research, is itself an exploration of new territory.

Not affiliated with an academic or governmental institution, and not beholden to the private sector, ESR occupies a new niche for scientists searching to make money and fund research, Lagerloef says.

While working at a California-based research and engineering firm in the mid-’90s, he and fellow oceanographer Robin Muench began looking for alternatives to the product-oriented projects that drive private-sector science.

“We found our interests were in basic research,” Lagerloef said. “The purpose of forming ESR was to provide us with a base to do that research.

“We are pioneering this a little bit.”

Founded in Seattle in 1995, Earth and Space Research has since grown to eight scientists and two administrative staff, with satellite offices – home base to their affiliate researchers – in Seattle, New York, Oregon and Bainbridge.

Under the guidance of islander Karen Haig, business manager, the group is committed to staying “small and non-bureaucratic.” Operations are supported by government grants that fund research in the environmental sciences, with projects ranging from sea surface salinity to tidal activity in the polar oceans.

While the institute is a haven for basic science, the research couples intellectual curiosity with a concern for direct public benefit, Lagerloef says.

“We live on this planet,” he said. “All of us feel strongly that we want our work to have relevance to the public and not just let it collect dust somewhere in a scientific journal.”

That’s partly a practical concern; one of the mandates in accepting federal funding is to foster public awareness of the project, especially with children.

“We really want to communicate the wonder of science to kids,” said Camisa Carlson, ESR’s outreach coordinator.

That wonder is just as relevant for adults, says Lagerloef, who has seen interest in environmental science rise in recent years.

“There is a real thirst, hunger for information about climate change,” he said. “The question I most frequently get asked is, ‘So when’s the next El Niño?’”

Understanding the science behind environmental change is central to an increased awareness of human interaction with the planet, including global warming.

“Most of the time when I show the graphs about (long-term climate trends) people’s eyes pop,” he said. “The more well-informed people are, the more well-informed choices they make.”

Lagerloef says that, over the years, he has directed his own choices toward reducing his “footprint” on the environment. He regularly bikes to his Seattle office, and his family drives a gas/electric hybrid car.

“I started taking an inventory of what my own impact is on the planet.”

And while the oceanographer is convinced of Earth’s ultimate longevity – it has, after all, supported life for millions of years – the shorter-term fate of our own species is less certain.

“For the first time, the effect humans are having on the planet impacts our own civilization,” he said.

“What it means for that civilization is very much in our own hands.”

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