NASA's next El Niño-watcher to launch Friday
June 15, 1999
By CNN Interactive
VANDENBERG AIR FORCE BASE, California (CNN) -- Weather is a safe conversation topic for most people, but when scientists discuss the climate, they sometimes come up short-winded -- that is, short of crucial data on the Earth's winds.
NASA is preparing to launch a satellite that could help fill in the gap by exploring the relationship between sea winds and the weather. The QuikScat mission is designed to measure the speed and direction of vast ocean winds as they sweep the globe and influence weather patterns and marine currents.
QuikScat, managed by NASA's Jet Propulsion Laboratory and designed and built by Ball Aerospace and Technologies Corp. of Colorado, is scheduled for liftoff Friday aboard a Titan II rocket from California's Vandenberg Air Force Base at 7:15 p.m.
"A major reason that we can't predict the weather tomorrow is that we don't know the weather today," says Michael Freilich, an Oregon State University oceanographer who is the principal investigator for the wind-measuring instrument aboard QuikScat.
"Even if you had a perfect computer model of the atmosphere to predict weather, if you don't know how to initialize the model, obviously, it's garbage in, garbage out."
QuikScat is designed to change that. The two-year $93 million mission is expected to provide meteorologists and oceanographers with daily, detailed snapshots of ocean winds. It will cover 90 percent of the Earth's ice-free oceans each day, rain or shine, cutting a 1,100-mile swath during polar orbits as the Earth turns under it.
The gathering of wind speed and direction data should greatly improve weather forecasting and increase knowledge of such abnormalities as El Niño and the dry La Niña pattern that has drained some of the nation of its typical rainfall this spring. It also could help scientists determine the location, structure and strength of Atlantic hurricanes, Asian typhoons and cyclones worldwide.
The data will be collected by a device called a scatterometer, which can bounce microwaves off ocean surfaces and measure ripples in the returned signals caused by winds at the ocean's surface.
The instrument can make hundreds of times more observations per day than the current ships and buoys doing the job, and it will make measurements from parts of the globe where readings currently are unavailable.
The QuikScat satellite was built in record time -- a year -- because scientists wanted to replace an earlier satellite, the NASA Scatterometer, that had failed. It suffered a solar power failure in June 1997.
Wind measurements also are crucial for oceanographers' work, Freilich says, because winds drive the oceans and are its single largest source of momentum.
"They generate the waves that people surf on as well as those that ship captains have to navigate, that silt harbors and erode beaches," he says. Winds also are responsible for ocean currents and coastal ocean circulation, which have economic repercussions as they cause the upwelling of nutrient-rich waters that support fisheries and coastal ecosystems, Freilich says.
Although oceans cover 70 percent of Earth's surface, there are very few measurements the meteorological variables linked with it. "Nobody lives there," Freilich says. "We're talking about an expanse that is more than twice as large as all the land masses on Earth."
If it succeeds, QuikScat could become the satellite that launched a thousand weather conversations, or more.
Busy hurricane season predicted, due to La Niña
NASA Jet Propulsion Laboratory
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