Terrifying twister clusters a sign of the future, say scientistsBy Andrew Fazekas | Geekquinox – 7 hours agoTwo tornadoes touch down near Pilger, Nebraska June 16, 2014. (Reuters) On Tuesday, 5 tornadoes touched down in the Atlanta, Georgia region, all part of the same storm system. If scientists are correct, terrifying clusters of twisters like this are becoming the norm.In a new study published this week in the journal Science, researchers looked at 60 years worth of weather data across the United States, counting up all tornadoes and found that while in the 1970s there were about 150 days a year with at least one twister, that number has now dropped to about 100 days.While on the surface this may appear to be great news for folks in tornado country, the study discovered that on the days when there is tornado activity, they appear to occur in clusters, making them potentially much more devastating.“We started from looking at the monthly records and then went back to looking at daily distributions, and what we found was there was a variability of tornado occurrence that appears to be increasing without changing the average occurrence,” explained study lead author Harold Brooks, research meteorologist with the National Oceanic and Atmospheric Administration’s (NOAA) National Severe Storms Laboratory in Norman, Oklahoma in an interview with Yahoo Canada News.According to NOAA, there have been 966 tornadoes across the U.S. in 2014 so far, ranking second lowest in number since 2005. In terms of absolute tornado counts, the U.S. has had the most by far with an average of over 1,000 twisters recorded annually, while Canada has only about one-tenth of that per year.The study also found that F0 tornadoes, the weakest on the scale used to measure their intensity, appears to have increased from about 100 per year in the 1950s to about 800 a year in the 2000s. Brooks attributes this rise to a number of factors, including better awareness and better efforts to collect reports. The data on tornadoes ranking at least F1 and above shoes that they, too, are appearing on fewer days per year, but on days when they do appear, there are more likely to be multiple tornadoes.‘Takeaway is that we’re seeing an increase in variability of tornado occurrence without a change in the average,” said Brooks.“More periods with lots, more periods with very few or none.”People pick though debris from a house destroyed by the tornado near Vilonia, Arkansas. (Reuters)However Brooks and his team are not sure yet what environmental conditions are exactly driving this clustering effect. “How such a change would relate to the increase in global temperature, if it relates at all, is unknown at this time,” Brooks and his team wrote in their paper. „Nevertheless, if the variability continues to increase, it could lead to an even greater concentration of tornadoes on fewer days.”At this point, the jury is still out on a definite link between tornado clustering with climate change. But if we want to explore that possible link, Brook says we will have to improve our statistical models and understanding of the relationships between the large scale weather conditions, and the much smaller-scaled tornado occurrences so that we can draw more informed conclusions.In terms of direct, practical implications of these findings, it may end up affecting tornado preparedness, including response and recovery. “If there are more “big” [tornado acitivty] days, then emergency management on the state and federal level and insurance/reinsurance industries may need to adjust their approach to resource management,” warned Brooks. “They’ll need resources to respond to big events more often, but those resources will set around unused for long periods of time.”Geek out with the latest in science and weather.Follow @YGeekquinox on Twitter!
Rare comet fly-by of Mars on Sunday By Kerry SheridanOctober 15, 2014 10:07 PM Washington (AFP) – A fast-moving comet is about to fly by Mars for a one-in-a-million-year encounter with the Red Planet, photographed and documented by a flurry of spacecraft, NASA said.The comet, known as Siding Spring (C/2013 A1), has a core about a mile (1.6 kilometers) wide in diameter, but is only as solid as a pile of talcum powder.Siding Spring is set to hurtle past Mars at a close distance of about 88,000 miles (139,500 kilometers).If the comet were passing by our planet, that would be about a third of the way between the Earth and the Moon.Siding Spring will come closest to Mars at 2:27 pm (1827 GMT) on Sunday, October 19, NASA said.Flying through space at a breakneck speed of 122,400 miles per hour (202,000 km per hour), the small comet faces little risk of colliding with the Red Planet.A file photo shows the NASA logo at Kennedy Space Center in Florida. A fast-moving comet is about to …But scientists are keen to study its trajectory and trail.”Are we going to see meteors in the Mars atmosphere? Comets are very unpredictable,” said Jim Green, director of the Planetary Science Division at NASA headquarters in Washington.”I think it is unlikely that it will be destroyed,” Green told reporters. „But whether it retains its structure or not is of interest.”NASA has maneuvered its Mars orbiters to the far side of the planet so they won’t be damaged by the comet’s high-speed debris.Even as the Mars Reconnaissance Orbiter, Mars Odyssey and MAVEN have been repositioned to avoid hazardous dust, scientists hope they will be able to capture a trove of data about the flyby for Earthlings to study.View galleryAn image of the planet Mars taken by the India’s ISRO Mars Orbiter Mission spacecraft. A comet w …NASA’s two rovers — Curiosity and Opportunity — will turn their cameras skyward and send back pictures of the comet’s pass in the coming days, weeks and months, the US space agency said.- Billions of years old -The comet was discovered by Robert McNaught at Australia’s Siding Spring Observatory in January 2013.It is believed to have originated billions of years ago in the Oort Cloud, a distant region of space that is a source of comets that are „largely unchanged since the early days of the solar system,” NASA said.Carey Lisse, senior astrophysicist at Johns Hopkins University Applied Physics Laboratory, said scientists are intrigued by comets for many reasons.”It is amazing that they are still around after four and a half billion years, but most of the reason for that is they have been living very, very far from the Sun and are in a deep freeze,” he said.This particular comet is about the size of a small mountain, but is probably the consistency of powder, or a meringue that would melt in your mouth, he explained.”It should have more of the really volatile ices — methane, carbon monoxide — things that boil off very easily. It has never been heat treated very strongly before.”Scientists say they are curious to learn if the comet may have already broken up some on its approach to Mars.”There is a possibility that Mars may drive some more activity, that is why we are looking,” Lisse said.The comet has traveled more than one million years to make its first pass by Mars, and will not return for another million years, after it completes its next long loop around the Sun.