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A5 DAILY 04-20-09 MD RE A5 CMYK

The Washington Post R Monday, April 20, 2009 A5

» Green Science Keep up with the latest environmental news at Green, a special online section at washingtonpost.com/green. Tornado-Chasing Project Aims to Improve Forecasts By Kari Lydersen The technology move rapidly, tracking over 100 Washington Post Staff Writer available this time miles. thunderstorms is far superior. The may also create “mesocyclones,” Sampling Storms When a tornado is about to cut a inaugural Vortex swirling winds embedded within In May and June, a nomadic team of scientists, using a wide devastating swath through an used Doppler radar the larger thunderhead that can be American town, those in its path on planes, which as much as six miles in diameter. variety of instruments, will chase tornado-forming storms get a warning lead time of 13 min- would pass over a About five to 10 percent of these across the Central Plains. utes on average to try to reach shel- tornado at about storms actually spin off tornadoes, ter. five-minute inter- which are typically about 500 feet “If you live in a trailer communi- vals. Now radar in diameter. Scientists know what ty, is 13 minutes enough to wake mounted on trucks, forms a mesocyclone, but they are your family and get them bundled which can get with- largely lost when it comes to un- are severe up and outside?” asks tornado re- in two miles of a derstanding which ones will spawn Mesocyclone searcher , head of PHOTO COURTESY OF THE CENTER FOR RESEARCH tornado, will pro- tornadoes and how violent they thunderstorms with a Mobile Doppler radar scans a tornado in 2004. the nonprofit Center for Severe vide uninterrupted will be. rotating updraft, or Weather Research. And “if you are data. “A number of things have to hap- mesocyclone. elderly or handicapped, you’re go- the public will take warnings.” “We will be able to distinguish pen sequentially and at the same ing to have a hard time getting to a Now comes Vortex2, a five-week between rain, hail, dust, debris, fly- time and in the right order,” said shelter in 13 minutes,” he said. tornado-chasing project beginning ing cows,” said Howard Bluestein, John Monteverdi, a meteorologist And that’s the average; many next month that scientists hope a professor at the Uni- at San Francisco State University times people are warned about six will finally provide the knowledge versity of Oklahoma and member who has been chasing tornadoes or seven minutes earlier. That is to accurately predict when and of the Vortex2 steering committee. for 24 years. “You have to start Tornado because although scientists know where a tornado will develop. Two ingredients are necessary knocking the dominos down to that certain kinds of “supercell” “Ultimately we’d like to get to to form the supercell thunder- find out what happens in that last Targeting the Mesocyclone thunderclouds can spin off torna- the point where we can put suffi- storms that spawn tornadoes: a stage. I think we’re getting close, Scientists will mobilize to focus does, they know very little about cient data into our models so we source of buoyant energy, namely and this project should help.” closely on a supercell’s the exact conditions that indicate a know when a tornado will happen,” warm and moist air near the Risky though it appears, mem- mesocyclone, the diameter tornado will occur and whether it said Stephan P. Nelson, a program ground, and a rotational force gen- bers of the project note that their of which may be as much Top view Storm will be a mild twister or a violent director in the atmospheric sci- erated by winds at the surface crews have never logged a death or as six miles. through a supercell movement Mesocyclones killer. ences division of the National Sci- blowing at a different speed or di- severe injury. But they say amateur An idealized strategy for In the mid-1990s, a two-year ence Foundation, which, along rection than winds high in the at- tornado-chasers who follow scien- sometimes studying tornado formation study called Vortex had a phalanx with the National Oceanic and At- mosphere. tists around with video cameras spawn of scientists chasing tornadoes mospheric Administration, provid- A typical thundercloud develops are endangering themselves and tornadoes. Light around the Great Plains, inspiring ed the $12 million funding for Vor- as warm air rises into colder air others. Not only do these adrenalin rain much public fascination, daredevil tex2. “Then you can get first re- masses above, then usually dis- junkies put themselves in harm’s Heavy amateur tornado-chasers and the sponders to be better prepared — sipates quickly once rain falls. Su- way, the scientists say, they often rain 1996 movie “Twister.” police, fire, medical personnel, percell thunderstorms, by con- speed and park their cars in the Hail Vortex (which stands for Ver- even power companies. Now, that’s trast, can last for hours and can middle of the road, endangering ification of the Origins of Rotation not even remotely possible.” other motorists and distracting in Tornadoes Experiment) result- As part of Vortex2, about 80 vet- VORTEX2 area of study highway patrol officers. ed in significant advances, includ- eran scientists and graduate stu- Scientists warn that it is only a ing the revelation that tornadoes dents will chase storms across a ND MN matter of time before a major tor- can occur on smaller time and wide swath from South Dakota to MT WI nado sweeps through a densely SD space scales than previously Texas and from eastern Colorado St. Paul populated urban area and causes Pierre Mesocyclone thought and that sometimes they to Iowa and Minnesota, with their WY horrific damage and loss of life. do not show up on radar. Knowl- nerve center in Norman, Okla. Chicago, Atlanta, Dallas and Instruments are not to scale with either storm or with one another. edge gained from the study led to They will be armed with a host IA Houston, in particular, are in re- an increase in average warning of tools, including lasers that meas- gions prone to violent tornadoes. An arsenal of sensors times, but it did not unlock the se- ure raindrops, Doppler radar NE Wurman said in a 2007 study that a Sticknet: Measures temperature, Photography Denver crets of exactly when and why tor- mounted on trucks, high-tech bal- Kansas tornado cutting through Chicago humidity, barometric pressure, wind nadoes form. loons, unmanned aircraft and in- City could kill 13,000 to 45,000 people speed and direction, rainfall and hail. CO KS Rawinsonde: Balloon-borne As a result, predictions about struments on tripods anchored in MO and cause tens of billions of dollars Mobile mesonet: A sticknet on radio that measures the wind aloft. tornado occurrence are successful the tornadoes’ path. in damage. wheels; GPS device allows accurate only about a quarter of the time. “We’re throwing everything but NM OK “Tornadoes have a great beauty wind measurements while driving. Unmanned aerial vehicle: “Sometimes people will choose the kitchen sink at it,” said Wur- Norman AR to them sometimes,” Wurman said. A 12-pound plane that measures not to take shelter even if they’re man, who has chased 141 torna- “There’s a great elegance to the Mobile radar: Several types of temperature, pressure, humidity told to,” said Yvette P. Richardson, does over 14 years. “We’ll have a vortex itself. But when you see it radar, including rapid-scanning and wind velocity; can remain aloft TX a meteorology professor at Penn- whole potpourri of instruments going toward a town or city, there’s Doppler, mounted on different trucks. for as long as an hour. LA sylvania State University. “In gen- surrounding the storm, all measur- Dallas a quick change in your impression, SOURCES: National Oceanic and Atmospheric Administration, Center for Severe Weather Research eral, the more we can reduce the ing different things in different and it’s like a tiger: Something BY PATTERSON CLARK — THE WASHINGTON POST false-alarm rate, the more seriously ways.” beautiful becomes deadly.”

Spirit Is Ailing But Still Running Scientists Unsure How Rover’s Stint On Mars Will End NASA VIA ASSOCIATED PRESS By Joel Achenbach This 2007 image shows the deck of Spirit encased in dust. The Mars rover, Washington Post Staff Writer more than five years old, is operating at about 30 percent of normal power.

The old rover was supposed to how these rovers will eventually end terstellar space far beyond Nep- work for only 90 days, enough time on Mars,” Callas said. “Will they tune’s orbit. to crawl two-thirds of a mile across gradually degrade until their me- There’s not much to see out there, the Martian desert. More than five chanical functionality goes or will and, in any event, no operational years later, Spirit has put five miles they have a catastrophic end, where camera to see it with, as the space- on its odometer and is still rolling something inside the rover breaks?” craft’s batteries, powered by radio- along — but getting mighty cranky. When the rovers were designed, isotope decay, slowly become en- The rover, one of two NASA vehi- the presumption was that dust feebled. But a few instruments still cles operating on Mars, has a broken would blanket the solar panels with- function, and scientists have re- right wheel. It has dust on its solar in a few months of being on Mars buffed efforts to shut down the Voy- panels. It’s operating at about 30 and that the rovers would grind to a ager program. percent of normal power. Various halt. Martian winds blew to the res- Spacecraft can also be sent to sensors and software programs have cue, cleaning the panels periodically their deaths. Casani was the project gone screwy. and letting the rovers extend their manager on Galileo, a probe to the Then, on April 9, Spirit refused to missions. Jupiter system. When Galileo ran wake up. The rover is designed to Spirit is now driving around a pla- low on propellant, engineers knew sleep at night, when there is no sun- teau called Home Plate in a valley that eventually it would lose attitude light hitting the solar panels. But known as the Inner Basin. Opportu- control and start tumbling. That Spirit snoozed right through its nity, on the other side of Mars, has raised the fear that Galileo would wake-up call. It happened three left Victoria Crater and is rambling crash into one of Jupiter’s moons, times in succession. Finally a backup toward a large crater named Endea- which potentially harbor life and timer got Spirit up and moving again vour. might be contaminated by stowaway after a 27-hour slumber. Day-to-day life on Mars can be Earth microbes. So Casani and his John Callas, project manager for rocky. The temperature can swing colleagues used the last bit of propel- the Mars rovers at the Jet Pro- 150 degrees Fahrenheit between lant to send Galileo into Jupiter, pulsion Laboratory in Pasadena, night and day because of the thin at- where it burned up in the thick at- Calif., said he doesn’t have an expla- mosphere. That heating and cooling mosphere. nation for what ailed Spirit. Nor can cycle puts stress on metal. When things go wrong, scientists he explain why the rover repeatedly “Metal parts and glass parts ex- and engineers often have a worka- rebooted itself when engineers at pand and contract as the tempera- round. Sometimes they just get the JPL tried to send it commands. ture changes,” said John Casani, lucky, which is what happened when The engineers found a fix — they re- who has worked on robotic space Spirit’s right front wheel broke three layed commands via a spacecraft missions for decades at the JPL. “If years ago. that orbits Mars — but the incidents you take a piece of metal and keep The other five wheels on the rover suggest that Spirit is getting erratic. bending it back and forth, pretty were functional and were capable of Or maybe just old. soon it’s going to break.” dragging the broken wheel across By any measure, Spirit and its sis- Casani said spacecraft — the ones the surface. The inoperative wheel, ter rover, Opportunity, which is a that stick to space and don’t try to locked, gouged a trench as it went good bit healthier, have been tri- land on a planet or some such feat — along. By examining that trench, umphs of the civilian space program. exist in a much more stable environ- Spirit was able to detect a certain Spirit may yet operate for several ment. Thus the JPL is still getting kind of silica that offered evidence of more years, or it may be on its last data from the two Voyager craft ancient hot springs on Mars. legs. In any event, it is providing a launched in 1977. According to the “When life hands you lemons, you tutorial on how even the most ex- JPL, the oldest functioning space- make lemonade,” Callas said. quisitely designed machines even- craft is Voyager 2 (launched slightly So that’s not really a broken wheel tually die. earlier, strangely enough, than Voy- on Spirit — it’s a scientific instru-

“I don’t think anyone can tell you ager 1), which is zipping toward in- ment.

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