2015 04 Astronomers Space Particles Electrical Field
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Astronomers use space particles to measure electrical field in thunderstorms 30 April 2015, by Bob Yirka In this composite image, a cosmic ray produces a shower of secondary particles (pink and purple) that emit radio waves as they interact with the Earth’s magnetic field. LOFAR radio antennas (small and large squares) record the waves, which may contain signatures of strong electric fields from thunderstorms. Credit: Radboud University Nijmegen/ Physics (Phys.org)—A very large team of European astronomers has found that they were able to measure the degree of electrical activity in thunderstorms using information derived by collisions of space particles with Earth's atmosphere. In their paper published in Physical Review Letters, the researchers describe how they used data obtained over a several year period from an observatory to calculate thunderstorm voltage activity. Despite living with thunderstorms for our entire existence, we humans still do not really know much about the lightening they spawn, and worse when and where such strikes will occur. One bit of information scientists would like to have is the amount of electricity produced during storms, which could help reveal more about the formation of lighting. Getting that information has been difficult because storms are unpredictable and the tools available for research efforts are not optimal. In this new effort, the research team found a completely different way to measure the electrical field in a thunderstorm—by tracking secondary particles that are produced when cosmic rays collide with atmospheric atoms, or when gamma rays decay into pairs of electrons. In both cases, the result is a shower of particles falling to Earth in a predictable way. It was that predictability that allowed researchers to use them to measure electrical patterns in thunderstorms. If a thunderstorm passes over an observatory, the researchers inside are able to detect changes in the trajectory of such secondary particles that result due to interaction with electricity in the clouds. By plotting the trajectories of a lot of the particles that fell in the past (over the years 2011–2014 using the Low Frequency Array (LOFAR) radio telescope in the Netherlands) the researchers were able to note changes wrought by thunderstorms (changes in trajectories versus times when there were no storms) and to make out where the electricity was in those storms (by creating a computer simulation) and how much was there. In looking at the data, the researchers were able to confirm a theory that suggested that thunderstorms have two layers of electrical activity—the gradient ran from 50 kV/m in the upper layer, to 27 kV/m in the lower layer. The team believes their findings could lead to further studies being conducted with the aim of helping to better understand the nature of lightening in storms in general, and perhaps leading to ways to better predict when lightning 1 / 2
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Transcript of 2015 04 Astronomers Space Particles Electrical Field
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Astronomers use space particles to measureelectrical field in thunderstorms30 April 2015, by Bob Yirka
In this composite image, a cosmic ray produces ashower of secondary particles (pink and purple) that emitradio waves as they interact with the Earths magneticfield. LOFAR radio antennas (small and large squares)record the waves, which may contain signatures ofstrong electric fields from thunderstorms. Credit:Radboud University Nijmegen/ Physics
(Phys.org)A very large team of Europeanastronomers has found that they were able tomeasure the degree of electrical activity inthunderstorms using information derived bycollisions of space particles with Earth'satmosphere. In their paper published in PhysicalReview Letters, the researchers describe how theyused data obtained over a several year period froman observatory to calculate thunderstorm voltageactivity.
Despite living with thunderstorms for our entireexistence, we humans still do not really know muchabout the lightening they spawn, and worse whenand where such strikes will occur. One bit of
information scientists would like to have is theamount of electricity produced during storms, whichcould help reveal more about the formation oflighting. Getting that information has been difficultbecause storms are unpredictable and the toolsavailable for research efforts are not optimal.
In this new effort, the research team found acompletely different way to measure the electricalfield in a thunderstormby tracking secondaryparticles that are produced when cosmic rayscollide with atmospheric atoms, or when gammarays decay into pairs of electrons. In both cases,the result is a shower of particles falling to Earth ina predictable way. It was that predictability thatallowed researchers to use them to measureelectrical patterns in thunderstorms. If athunderstorm passes over an observatory, theresearchers inside are able to detect changes inthe trajectory of such secondary particles that resultdue to interaction with electricity in the clouds.
By plotting the trajectories of a lot of the particlesthat fell in the past (over the years 20112014using the Low Frequency Array (LOFAR) radiotelescope in the Netherlands) the researchers wereable to note changes wrought by thunderstorms(changes in trajectories versus times when therewere no storms) and to make out where theelectricity was in those storms (by creating acomputer simulation) and how much was there.
In looking at the data, the researchers were able toconfirm a theory that suggested that thunderstormshave two layers of electrical activitythe gradientran from 50 kV/m in the upper layer, to 27 kV/m inthe lower layer. The team believes their findingscould lead to further studies being conducted withthe aim of helping to better understand the natureof lightening in storms in general, and perhapsleading to ways to better predict when lightning
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strikes will occur and where.
More information: Probing Atmospheric ElectricFields in Thunderstorms through Radio Emissionfrom Cosmic-Ray-Induced Air Showers, Phys. Rev.Lett. 114, 165001 Published 24 April 2015. dx.doi.org/10.1103/PhysRevLett.114.165001 . On Arxiv: arxiv.org/abs/1504.05742
ABSTRACTWe present measurements of radio emission fromcosmic ray air showers that took place duringthunderstorms. The intensity and polarizationpatterns of these air showers are radically differentfrom those measured during fair-weatherconditions. With the use of a simple two-layermodel for the atmospheric electric field, thesepatterns can be well reproduced by state-of-the-artsimulation codes. This in turn provides a novel wayto study atmospheric electric fields.
2015 Phys.org
APA citation: Astronomers use space particles to measure electrical field in thunderstorms (2015, April 30)retrieved 30 April 2015 from http://phys.org/news/2015-04-astronomers-space-particles-electrical-field.html
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