Why the Earth's magnetic poles could be about to swap places – and how it would affect usPhil Livermore, University of Leeds and Jon Mound, University of LeedsThe Earth’s magnetic field surrounds our planet like an invisible force field – protecting life from harmful solar radiation by deflecting charged particles away. Far from being constant, this field is continuously changing. Indeed, our planet’s history includes at least several hundred global magnetic reversals, where north and south magnetic poles swap places. So when’s the next one happening and how will it affect life on Earth? During a reversal the magnetic field won’t be zero, but will assume a weaker and more complex form. It may fall to 10% of the present-day strength and have magnetic poles at the equator or even the simultaneous existence of multiple “north” and “south” magnetic poles. Geomagnetic reversals occur a few times every million years on average. However, the interval between reversals is very irregular and can range up to tens of millions of years. There can also be temporary and incomplete reversals, known as events and excursions, in which the magnetic poles move away from the geographic poles – perhaps even crossing the equator – before returning back to their original locations. The last full reversal, the Brunhes-Matuyama, occurred around 780,000 years ago. A temporary reversal, the Laschamp event, occurred around 41,000 years ago. It lasted less than 1,000 years with the actual change of polarity lasting around 250 years. Power cut or mass extinction?The alteration in the magnetic field during a reversal will weaken its shielding effect, allowing heightened levels of radiation on and above the Earth’s surface. Were this to happen today, the increase in charged particles reaching the Earth would result in increased risks for satellites, aviation, and ground-based electrical infrastructure. Geomagnetic storms, driven by the interaction of anomalously large eruptions of solar energy with our magnetic field, give us a foretaste of what we can expect with a weakened magnetic shield. In 2003, the so-called Halloween storm caused local electricity-grid blackouts in Sweden, required the rerouting of flights to avoid communication blackout and radiation risk, and disrupted satellites and communication systems. But this storm was minor in comparison with other storms of the recent past, such as the 1859 Carrington event, which caused aurorae as far south as the Caribbean. The impact of a major storm on today’s electronic infrastructure is not fully known. Of course any time spent without electricity, heating, air conditioning, GPS or internet would have a major impact; widespread blackouts could result in economic disruptionmeasuring in tens of billions of dollars a day. In terms of life on Earth and the direct impact of a reversal on our species we cannot definitively predict what will happen as modern humans did not exist at the time of the last full reversal. Several studies have tried to link past reversals with mass extinctions – suggesting some reversals and episodes of extended volcanism could be driven by a common cause. However, there is no evidence of any impending cataclysmic volcanism and so we would only likely have to contend with the electromagnetic impact if the field does reverse relatively soon. We do know that many animal species have some form of magnetoreception that enables them to sense the Earth’s magnetic field. They may use this to assist in long-distance navigation during migration. But it is unclear what impact a reversal might have on such species. What is clear is that early humans did manage to live through the Laschamp event and life itself has survived the hundreds of full reversals evidenced in the geologic record. Can we predict geomagnetic reversals?The simple fact that we are “overdue” for a full reversal and the fact that the Earth’s field is currently decreasing at a rate of 5% per century, has led to suggestions that the field may reverse within the next 2,000 years. But pinning down an exact date – at least for now – will be difficult. The Earth’s magnetic field is generated within the liquid core of our planet, by the slow churning of molten iron. Like the atmosphere and oceans, the way in which it moves is governed by the laws of physics. We should therefore be able to predict the “weather of the core” by tracking this movement, just like we can predict real weather by looking at the atmosphere and ocean. A reversal can then be likened to a particular type of storm in the core, where the dynamics – and magnetic field – go haywire (at least for a short while), before settling down again. The difficulties of predicting the weather beyond a few days are widely known, despite us living within and directly observing the atmosphere. Yet predicting the Earth’s core is a far more difficult prospect, principally because it is buried beneath 3,000km of rock such that our observations are scant and indirect. However, we are not completely blind: we know the major composition of the material inside the core and that it is liquid. A global network of ground-based observatories and orbiting satellites also measure how the magnetic field is changing, which gives us insight into how the liquid core is moving. The recent discovery of a jet-stream within the core highlights our evolving ingenuity and increasing ability to measure and infer the dynamics of the core. Coupled with numerical simulations and laboratory experiments to study the fluid dynamics of the planet’s interior, our understanding is developing at a rapid rate. The prospect of being able to forecast the Earth’s core is perhaps not too far out of reach. Phil Livermore, Associate Professor of geophysics, University of Leeds and Jon Mound, Associate Professor of Geophysics, University of Leeds This article was originally published on The Conversation. Read the original article.
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Scientists at work: space balloons and charged particles above the Arctic CircleAlexa Halford, Dartmouth CollegeI research space weather. That’s how physicists describe how storms on the sun end up affecting us here on Earth. Most days I sit at a computer coding, attending telephone conference meetings with collaborators across the country and meeting with fellow space physicists. But sprinkled throughout the year I get to do exciting fieldwork in remote locations. We launch high-tech space balloons in an effort to help untangle what happens when charged particles from solar storms hit the Earth’s magnetic field, called its magnetosphere. I primarily work with the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL) mission, led by Robyn Millan here at Dartmouth College. We’re investigating the electrons and protons that travel all the way from the sun and then get trapped in the Earth’s magnetic field. Often they stick around, just bouncing and drifting along in our planet’s so-called radiation belts – these are donut-shaped regions rich in charged particles, held in place around Earth by its magnetic field. But during a geomagnetic storm, changes in the Earth’s magnetic field can accelerate and transport these electrons and protons. They can wind up getting “lost”: shot out of the radiation belts back into space or down into our atmosphere. If they start colliding with neutral, uncharged particles in the atmosphere, that can affect upper atmospheric chemistry – and be bad news for our technology down here on Earth. For example, geomagnetic storms can cause blackouts, increased corrosion in pipelines, destruction of satellites and a resulting loss of communication connections. My colleagues and I focus on the radiation belt electrons that get lost to the Earth’s atmosphere. If we can unravel more about what’s happening with them, the hope is we can figure out how to better predict space weather – and its effects on terrestrial weather. Ultimately, with better understanding of what’s going on, we can work on protecting our technology from these geomagnetic squalls. Magnets all around usYou can think of the Earth as a big bar magnet, like the kind you might have had in your elementary school classroom. You’re probably familiar with magnets’ attractive and repulsive properties. Around a bar magnet, iron shavings trace out what we can think of as lines of magnetic field. Protons and electrons trapped in Earth’s magnetosphere follow these same kinds of lines, converging at the poles. Typically the particles just gyrate and bounce along these lines, happily drifting around the Earth in those radiation belts. (To get a feel for how the magnetic field lines affect protons and electrons, check out the magnetospheric mini golf game.) Since space is so big, and the density of particles is so small, they can usually travel without bumping into each other. But during geomagnetic activity – like a storm in space – the particles can get pushed farther down the field line, closer to the Earth. In a process similar to what creates the auroras, they start colliding with the denser atmosphere. And this is when some of the charged particles wind up “lost” from the radiation belts. What happens to the “lost” particles that seem to disappear in the atmosphere, and why? To answer these questions, we travel to the polar regions to collect data. Polar hunt for solar particlesThis year we headed 90 miles above the Arctic Circle to the Swedish Space Corporation’s ESRANGE to launch our space balloons. Our goal is to send the balloons up as far as 22 miles (35 km) into the stratosphere to measure X-rays during a geomagnetic storm; since X-rays are created when electrons from the radiation belts interact with uncharged particles in the atmosphere, we can use them to infer when electrons are lost. Each balloon carries a payload of scientific equipment. A scintillator counts X-rays. A magnetometer measures the magnetic field of the Earth. Each payload and balloon has its own GPS tracker. During our last campaigns in Antarctica, we were flying during a period of circumpolar winds that blow long and hard in a circle around the poles. This allowed our 300,000-cubic-foot balloons to stay up, on average, for 12 days. This year in Sweden, though, we flew during a period called “turnaround,” when the stratospheric winds are changing direction, and our flights were lucky to last even four hours. When the balloon either starts falling below an altitude of 13.6 miles (22 km), or starts moving toward too densely populated regions, we have to terminate – that is, pop – the balloon. The balloon and the payload then separately fall back to Earth. When our BARREL balloons flew in Antarctica, we weren’t able to recover most of them because the terrain was so difficult to cross. This year in Sweden we were able to recover all the payloads. When they came down close to the launch base, we drove out and hiked through bogs and woods to retrieve payloads and balloons. When they flew a bit farther away (like into Norway or Finland), we had to rent a helicopter to travel out and pick them up. During the campaign, when we’re launching the balloons, we’re in constant contact with the instrument teams on NASA’s Van Allen Probes as well as other satellite missions. We work together, trying to predict when satellites will be lined up along the same magnetic field lines with the balloons. That way we can look at high-resolution data the satellites are collecting in space on the same magnetic field lines at the same time our balloons are flying. We want to make links between space conditions and our X-ray readings, which stand in for how many electrons are being lost to the atmosphere. Using our data to fill in what we knowThere’s still a lot to do once we wrap up the campaign and head home with our new data – the measurements taken in the magnetosphere during what are essentially space hurricanes. It takes plenty of ingenuity to translate the raw data into scientific understanding, and we have to do a lot of processing and analyzing. Our “lost” electrons interact with neutral particles in the atmosphere, producing the X-rays our balloons measure. The X-rays let us infer the energy of electrons we’re interested in. We combine our BARREL observations with those of satellites and other ground-based instruments to sort out how much energy the “lost” electrons had before they were lost. No single data set gives us the full picture, so we have to collaborate, fitting each piece of the puzzle together. Knowing how much energy the electron had before it got lost to the atmosphere, how large a region this phenomenon occurs over and how frequently this occurs gives us a better understanding of how the radiation belts work. This fall, we’re starting to write up papers and put together presentations about our research to share with colleagues. We were incredibly lucky with this campaign. Every balloon that we sent up got some amazing data! Here’s hoping we’re one step closer to understanding the dynamics of the Earth’s radiation belts. Alexa Halford, Postdoctoral Research Associate in Physics and Astronomy, Dartmouth College This article was originally published on The Conversation. Read the original article. SmallSat revolution: Tiny satellites poised to make big contributions to essential scienceJ. Vanderlei Martins, University of Maryland, Baltimore CountyTiny satellites, some smaller than a shoe box, are currently orbiting around 200 miles above Earth, collecting data about our planet and the universe. It’s not just their small stature but also their accompanying smaller cost that sets them apart from the bigger commercial satellites that beam phone calls and GPS signals around the world, for instance. These SmallSats are poised to change the way we do science from space. Their cheaper price tag means we can launch more of them, allowing for constellations of simultaneous measurements from different viewing locations multiple times a day – a bounty of data which would be cost-prohibitive with traditional, larger platforms. Called SmallSats, these devices can range from the size of large kitchen refrigerators down to the size of golf balls. Nanosatellites are on that smaller end of the spectrum, weighing between one and 10 kilograms and averaging the size of a loaf of bread. Starting in 1999, professors from Stanford and California Polytechnic universities established a standard for nanosatellites. They devised a modular system, with nominal units (1U cubes) of 10x10x10 centimeters and 1kg weight. CubeSats grow in size by the agglomeration of these units – 1.5U, 2U, 3U, 6U and so on. Since CubeSats can be built with commercial off-the-shelf parts, their development made space exploration accessible to many people and organizations, especially students, colleges and universities. Increased access also allowed various countries – including Colombia, Poland, Estonia, Hungary, Romania and Pakistan – to launch CubeSats as their first satellites and pioneer their space exploration programs. Initial CubeSats were designed as educational tools and technological proofs-of-concept, demonstrating their ability to fly and perform needed operations in the harsh space environment. Like all space explorers, they have to contend with vacuum conditions, cosmic radiation, wide temperature swings, high speed, atomic oxygen and more. With almost 500 launches to date, they’ve also raised concerns about the increasing amount of “space junk” orbiting Earth, especially as they come almost within reach for hobbyists. But as the capabilities of these nanosatellites increase and their possible contributions grow, they’ve earned their own place in space. From proof of concept to science applicationsWhen thinking about artificial satellites, we have to make a distinction between the spacecraft itself (often called the “satellite bus”) and the payload (usually a scientific instrument, cameras or active components with very specific functions). Typically, the size of a spacecraft determines how much it can carry and operate as a science payload. As technology improves, small spacecraft become more and more capable of supporting more and more sophisticated instruments. These advanced nanosatellite payloads mean SmallSats have grown up and can now help increase our knowledge about Earth and the universe. This revolution is well underway; many governmental organizations, private companies and foundations are investing in the design of CubeSat buses and payloads that aim to answer specific science questions, covering a broad range of sciences including weather and climate on Earth, space weather and cosmic rays, planetary exploration and much more. They can also act as pathfinders for bigger and more expensive satellite missions that will address these questions. I’m leading a team here at the University of Maryland, Baltimore County that’s collaborating on a science-focused CubeSat spacecraft. Our Hyper Angular Rainbow Polarimeter (HARP) payload is designed to observe interactions between clouds and aerosols – small particles such as pollution, dust, sea salt or pollen, suspended in Earth’s atmosphere. HARP is poised to be the first U.S. imaging polarimeter in space. It’s an example of the kind of advanced scientific instrument it wouldn’t have been possible to cram onto a tiny CubeSat in their early days. Funded by NASA’s Earth Science Technology Office, HARP will ride on the CubeSat spacecraft developed by Utah State University’s Space Dynamics Lab. Breaking the tradition of using consumer off-the-shelf parts for CubeSat payloads, the HARP team has taken a different approach. We’ve optimized our instrument with custom-designed and custom-fabricated parts specialized to perform the delicate multi-angle, multi-spectral polarization measurements required by HARP’s science objectives. HARP is currently scheduled for launch in June 2017 to the International Space Station. Shortly thereafter it will be released and become a fully autonomous, data-collecting satellite. SmallSats – big scienceHARP is designed to see how aerosols interact with the water droplets and ice particles that make up clouds. Aerosols and clouds are deeply connected in Earth’s atmosphere – it’s aerosol particles that seed cloud droplets and allow them to grow into clouds that eventually drop their precipitation. This interdependence implies that modifying the amount and type of particles in the atmosphere, via air pollution, will affect the type, size and lifetime of clouds, as well as when precipitation begins. These processes will affect Earth’s global water cycle, energy balance and climate. When sunlight interacts with aerosol particles or cloud droplets in the atmosphere, it scatters in different directions depending on the size, shape and composition of what it encountered. HARP will measure the scattered light that can be seen from space. We’ll be able to make inferences about amounts of aerosols and sizes of droplets in the atmosphere, and compare clean clouds to polluted clouds. In principle, the HARP instrument would have the ability to collect data daily, covering the whole globe; despite its mini size it would be gathering huge amounts of data for Earth observation. This type of capability is unprecedented in a tiny satellite and points to the future of cheaper, faster-to-deploy pathfinder precursors to bigger and more complex missions. HARP is one of several programs currently underway that harness the advantages of CubeSats for science data collection. NASA, universities and other institutions are exploring new earth sciences technology, Earth’s radiative cycle, Earth’s microwave emission, ice clouds and many other science and engineering challenges. Most recently MIT has been funded to launch a constellation of 12 CubeSats called TROPICS to study precipitation and storm intensity in Earth’s atmosphere. For now, size still mattersBut the nature of CubeSats still restricts the science they can do. Limitations in power, storage and, most importantly, ability to transmit the information back to Earth impede our ability to continuously run our HARP instrument within a CubeSat platform. So as another part of our effort, we’ll be observing how HARP does as it makes its scientific observations. Here at UMBC we’ve created the Center for Earth and Space Studies to study how well small satellites do at answering science questions regarding Earth systems and space. This is where HARP’s raw data will be converted and interpreted. Beyond answering questions about cloud/aerosol interactions, the next goal is to determine how to best use SmallSats and other technologies for Earth and space science applications. Seeing what works and what doesn’t will help inform larger space missions and future operations. The SmallSat revolution, boosted by popular access to space via CubeSats, is now rushing toward the next revolution. The next generation of nanosatellite payloads will advance the frontiers of science. They may never supersede the need for bigger and more powerful satellites, but NanoSats will continue to expand their own role in the ongoing race to explore Earth and the universe. J. Vanderlei Martins, Professor of Physics, University of Maryland, Baltimore County This article was originally published on The Conversation. Read the original article. Bad space weather may have caused fatal Afghan gun battleBrett Carter, RMIT University and John Retterer, Boston CollegeThree American soldiers* may have died in Afghanistan’s battle of Takur Ghar because of disruptions caused by plasma bubbles – a form of space weather – according to a new study. Space weather is normally associated with violent solar eruptions and geomagnetic storms. But the natural variability in the Earth’s ionosphere outside of these active events can still hinder a broad range of technologies. Equatorial Plasma Bubbles (EPBs) in the ionosphere are one such example, which cause daily disruptions on satellite communications and global satellite navigation systems, such as GPS, in the low-latitude regions across the globe. The new study, published in Space Weather, has found that plasma bubbles could have been the cause for radio communications disruptions during Operation ANACONDA in Afghanistan in 2002. The Battle of Takur GharDuring this battle, a Quick Reaction Force (QRF) on board a MH-47 Chinook helicopter was deployed to aid a team of Navy SEALs that were pinned down on a ridge dividing the Upper and Lower Shahikot valley. Repeated attempts to inform the QRF that the landing zone was “hot” were hindered by the failure of the satellite communications. Needless to say, the QRF never received this vital message, and this communication breakdown resulted in the Chinook crashing shortly after sunrise under heavy enemy fire, leading to three reported fatalities in the following firefight. Poor performance of the UHF radio on board the helicopter and to radio blockage by the terrain was later blamed for the communications failure during this battle. But re-analysis of this event by space scientists has provided strong evidence that ionospheric plasma bubbles observed over Afghanistan during the battle might have been to blame. The adverse impact of plasma bubbles on satellite communications and navigation is very well known to space scientists. As such, understanding ionospheric plasma bubbles – why they form, when they form, and their effects on radio waves – has been a top priority in the field. What are plasma bubbles?Plasma bubbles, as the name suggests, are essentially bubbles of low density plasma that rise into high density plasma in the Earth’s upper atmosphere. The bubbles are the result of a plasma instability that is triggered shortly after sunset, known as the generalised Rayleigh-Taylor instability. The situation is analogous to a heavy fluid sitting on top of a lighter fluid, which rises up into the heavy fluid, and the heavy fluid flows downwards under gravity. The only difference with the ionosphere bubbles is that electric and magnetic fields govern their drift. These bubbles strongly affect any radio waves that propagate through them, causing random fluctuations in amplitude and phase, called scintillations. From the perspective of a GPS receiver, the signals no longer resemble the normal GPS signals, and the receiver ultimately loses lock on the satellite. During severe events, a series of adjacent plasma bubbles can span from horizon to horizon, creating significant GPS positioning and timing errors. Similarly, radio receivers that use satellite communications need to be locked onto the satellite relaying the messages. Distortions in the signals can ultimately lead to communications blackouts, similar to that which occurred during Operation ANACONDA in 2002. Predicting plasma bubblesThe prediction of these plasma bubble events is still the topic of intense research interest. The seasonal climatology in the occurrence of plasma bubbles is relatively well documented and understood following decades of observations. We know that for most longitudes, the plasma bubbles occur almost every night during the equinox months, including during March when Operation ANACONDA took place and the current September equinox period. But we are still challenged by understanding and accurately describing the short-term variability – day-by-day and hour-by-hour – in the plasma bubble characteristics. Having said that, recent progress has been made in understanding why plasma bubbles occurred on one day, but not the next. But there still exists many open research questions such as, the potential impact of tropospheric weather – such as hurricanes and tropical storms – on the occurrence of ionospheric plasma bubbles. The 2013 Australian Defence White Paper states that:
Such a heavy reliance of Australia’s Defence on satellite communications is one of the primary reasons that we at RMIT’s SPACE Research Centre have teamed up with Australia’s Ionospheric Prediction Service and Boston College’s Institute for Scientific Research to join this international research effort. Our ultimate goal is to develop a global ionospheric scintillation forecasting system that will not only be potentially be useful for defence, but also anyone using satellite positioning and timing signals. * This article was edited on 25 September 2014 at the request of the author to replace the word “troops” with “soldiers” in the opening paragraph. Brett Carter, Postdoctoral Researcher in Space Weather and Ionospheric Physics, RMIT University and John Retterer, Senior Research Scientist at the Institute for Scientific Research, Boston College, Boston College This article was originally published on The Conversation. Read the original article. Damaging electric currents in space affect Earth's equatorial region, not just the polesBrett Carter, Boston College and Alexa Halford, Dartmouth CollegeThe Earth’s magnetic field – known as the “magnetosphere” – protects our atmosphere from the “solar wind.” That’s the constant stream of charged particles flowing outward from the sun. When the magnetosphere shields Earth from these solar particles, they get funneled toward the polar regions of our atmosphere. As the particles crash into the atmosphere’s ionospheric layer, light is given off, creating beautiful multicolored displays of aurora near both the North and South Poles. These are stunning visual representations of the complex interactions in the near-Earth space environment, which we collectively term “space weather.” The same space weather that generates these beautiful displays can cause havoc for a wide range of technologies. We’ve known for a while that space weather in high-latitude regions near the poles can cause power grid failures, sometimes causing heavy damage. The most famous instance was the March 1989 blackout in the Northeastern US and up through Quebec, Canada that left millions without power for 12 hours. But we haven’t thought of equatorial regions as being prime targets. Our new research shows that areas closer to the equator still experience bad space weather – and its disturbing effects on power grid infrastructure. Changing magnetic fields crank up electric currentsHigh above the ground in the upper atmosphere are fluctuating electric currents driven by interactions in the magnetosphere and ionosphere. These atmospheric currents cause strong changes in the strength of the local magnetic field on the ground. We can’t feel the magnetic field ourselves, but researchers measure and track it at various points on the Earth’s surface. That’s all well and good. The problem comes in when these atmospheric currents cause swift changes in the magnetic field. When the magnetic field abruptly changes, it can generate electric currents in conductors at the Earth’s surface – for instance, long pipes or wires such as oil and gas pipelines or power transmission lines. This process of electric current generation is called magnetic induction. These electric currents are not-so-creatively called geomagnetically induced currents, or GICs for short. The high-latitude regions are most susceptible to GICs because of the intense electric currents flowing through the auroras, thanks to the way the solar wind gets diverted when it hits the Earth’s magnetosphere. However, the entire planet can be affected to varying degrees. When they occur, GICs effectively generate extra electric current in power grid infrastructure through magnetic induction. Power grids, during large events, can end up taking on more electricity than they can handle. These induced currents have caused numerous equipment failures that have led to power outages for large populations. Trouble at the equator too, not just near the polesThose same geomagnetically induced currents that happen in the high-latitude regions can happen around the equator of our planet too. There, they are caused not by the auroral electric current system we find near the poles, but by a weaker low-latitude counterpart called the equatorial electrojet. Like the high-latitude ionospheric current system, the equatorial electrojet’s electric current can be detected on the ground using magnetic field observations. Recently researchers reported that GIC activity is enhanced at the equator during severe geomagnetic storms – that’s when solar eruptions called “coronal mass ejections” trigger shock waves that hit the Earth. They pointed the finger at the equatorial electrojet as a suspected cause. In our new research article in Geophysical Research Letters, we show that countries near the magnetic equator are more vulnerable to space weather than previously thought. Rather than focusing on severe geomagnetic storms, such as the 2003 Halloween event that caused power grid problems in Sweden (among many other things), we took a different tack. Our analysis focused on the arrival of interplanetary shocks. These are abrupt pressure increases in the solar wind - that stream of plasma constantly flowing out of the sun. When these shocks hit the Earth’s magnetosphere, the impact causes a sudden magnetic field change that can be measured all over the world. Interplanetary shocks regularly announce the beginning of a geomagnetic storm. But many pass by relatively benignly without developing into a full-blown geomagnetic storm. We noticed that the magnetic response to these shock arrivals was sometimes significantly stronger at the magnetic equator when compared to locations only a few degrees away. Why? An analysis of how these equatorial responses differed throughout the day revealed they were strongest around noon and weakest at night. This daily contrast corresponds to the well-known variations in the equatorial electrojet. It’s strong evidence that the equatorial electrojet is amplifying the geomagnetically induced current activity during interplanetary shock arrivals in a way that hasn’t really been recognized until now. Effects on equatorial power gridsThis result has significant implications for the many countries located beneath the equatorial electrojet that may be operating power infrastructure not initially designed to cope with space weather. These countries need to look into ways of protecting their infrastructure during geomagnetically quiet periods as well as during severe geomagnetic storms. One of our coauthors, Dr Endawoke Yizengaw from Boston College, grew up in Ethiopia, within the equatorial electrojet’s region of influence. He recalls regular unexplained power outages during his childhood and wonders whether interplanetary shocks may have played a role. We hope to be able to answer this question in the near future. Scientists around the world are conducting ongoing research to better understand the effects of these geomagnetically induced currents on power grids. It’s becoming increasingly clear that we need to investigate the effects of quiet periods, not just major events. What happens during these quiet times, and in regions often overlooked, can have a significant impact on our increasingly technology-dependent society. Brett Carter, Research Scientist in Space Weather and Ionospheric Physics, Boston College and Alexa Halford, Postdoctoral Research Associate in Physics and Astronomy, Dartmouth College This article was originally published on The Conversation. Read the original article. It's never been more important to keep an eye on space weatherBrett Carter, RMIT University and Delores Knipp, University of ColoradoAs technology becomes increasingly vital in our day-to-day lives, we are more susceptible to “space weather”. What begins with dark spots on the Sun’s surface, and magnetic field disruptions in the Sun’s atmosphere, can result in widespread technological disturbance. With our increasing reliance on telecommunications and other technologies, monitoring what happens in space has never been more important. During a solar flare, pulses of electromagnetic radiation are emitted into space, showering the solar system with intense radio waves, X-rays and ultraviolet radiation. At times, these flares are accompanied by solar material, in what is called a “coronal mass ejection”, or CME. These disturbances contribute to the variability in the near-Earth space environment. A lot of the technology on which we depend is susceptible to these disturbances. Satellites use radio waves to communicate, and thus are vulnerable to radio signal disruption, but so are more Earth-bound technologies – CMEs have been linked to the failure of some power grids and could impact high-speed railways. Disturbing historyThe first documented link between a CME and technology comes from 1841, when a telegraph system was affected by strong magnetic field fluctuations during a magnetic storm. “On the 18th of October, 1841, a very intense magnetic disturbance was recorded,” the journal Nature reported. The disturbance caused a train to be delayed by 16 minutes as “it was impossible to ascertain if the line was clear at Starcross”. The superintendent of Exeter station reported the next morning that “someone was playing tricks with the instruments, and would not let them work”, demonstrating how innocuous such events may appear. This event was less than 20 years before the largest known space weather event, the infamous Carrington geomagnetic storm in 1859, during which northern auroras were seen as far south as El Salvador in Central America. The 20th century also had its fair share of severe geomagnetic storms. Radio and telephone communications were widely disrupted during a May 1921 storm that saw the aurora borealis outshine Broadway in New York City. A telephone station in Sweden burned out, a New York telegraph operator claimed that “he was driven away from his instrument by a flare of flame which enveloped the switchboard and ignited the building”, and telegraph lines in France “seemed possessed by evil spirits”. The event even touched Australia, with the Argus reporting disruptions to telephone services between Melbourne, Sydney and Brisbane. CMEs and the Second World WarSeventy-five years ago, on September 18-19, 1941, there was another great geomagnetic storm, which also led to aurora sightings in the skies across the middle latitudes of the United States. At the time, Europe was at war and the Allies were heavily dependent on the flow of supplies across the North Atlantic Ocean. The geomagnetic storm appeared to have influenced the North Atlantic battle theatre by causing disruptions to short-wave radio transmissions, as reported by Kapitänleutnant Eitel-Friedrich Kentrat on board German U-boat U-74, which was actively hunting in the area. The storm had negative consequences for the Allied supply ships on route from North America to England, who found themselves travelling on a night that had been rendered as “bright as day”, according to Kentrat. Throughout the night, a Canadian convoy was attacked by U-74 and HMCS Lévis was torpedoed and sunk. Eighteen people lost their lives and 40 were rescued. A Solar Burst that could have taken us to warA great space weather storm in May 1967 began with a colossal solar radiation burst. Ultimately it produced a CME-driven, record-setting storm in Earth’s magnetic field (the magnetosphere) and upper atmosphere, including the ionosphere between 80km and 500km altitude. It currently stands as the eighth most intense storm since magnetic records began and one of the largest ever in the ionosphere. The intense solar radiation burst was accompanied by several additional flares and other space-based phenomena that negatively impacted radio surveillance and communications across North America. One of these systems was responsible for detecting incoming ballistic missiles over the polar region, providing a 15-minute warning to Canada, the United States and Britain. To the uninformed, the event easily have been misinterpreted as system radio jamming, potentially an act of war or an indication of an impending attack. This disturbance came during a tense time in the Cold War. The United States and Soviet Union were actively challenging each other for the top position as the dominant global superpower. The Vietnam War was ramping up and tensions were building in the Middle East, leading eventually to the Six-Day War in June 1967. Why we need more monitoringCrisis was averted during the Cold War largely because of the space monitoring that was already in place. The US Air Force had established solar observatories after the Second World War, which allowed space weather forecasters and the US Department of Defense to understand that the “jamming” was from a natural source. Nowadays, as we become even more dependent on communications technology, an extreme space weather event could have even more severe consequences. Therefore, as technology advances, so must our knowledge of the near-Earth space environment, a goal that many cooperative space weather researchers and organisations around the world are continually striving to achieve. Brett Carter, RMIT Research Fellow in Space Weather and Ionospheric Physics, RMIT University and Delores Knipp, Research professor, University of Colorado This article was originally published on The Conversation. Read the original article. Ever wonder what it's like to be a rocket scientist? Check out this podcast with contributor Ian Cohen! As funding has become harder and harder to get, more science is being done with smaller missions called CubeSats. These 10cm by 10cm satellites are a relatively cheap way to get into space and gather data which is fantastic. It also has created a platform where students are able to be involved directly in the process of a satellite mission. Contributor Quintin Shiller and Lauren Blum gave an interview on their highly successful CubeSat mission, The Colorado Student Space Weather Experiment, and you can listen to it here. Both are now PhD's and working at NASA Goddard on upcoming CubeSat missions. Eyes in the sky: Cutting NASA Earth observations would be a costly mistakeDavid Titley, Pennsylvania State UniversityDonald Trump’s election is generating much speculation about how his administration may or may not reshape the federal government. On space issues, a senior Trump advisor, former Pennsylvania Rep. Bob Walker, has called for ending NASA earth science research, including work related to climate change. Walker contends that NASA’s proper role is deep-space research and exploration, not “politically correct environmental monitoring.” This proposal has caused deep concern for many in the climate science community, including people who work directly for NASA and others who rely heavily on NASA-produced data for their research. Elections have consequences, and it is an executive branch prerogative to set priorities and propose budgets for federal agencies. However, President-elect Trump and his team should think very carefully before they recommend canceling or defunding any of NASA’s current Earth-observing missions. We can measure the Earth as an entire system only from space. It’s not perfect – you often need to look through clouds and the atmosphere – but there is no substitute for monitoring the planet from pole to pole over land and water. These data are vital to maintaining our economy, ensuring our safety both at home and abroad, and quite literally being an “eye in the sky” that gives us early warning of changes to come. To paraphrase Milton Friedman, there’s no free lunch. If NASA is not funded to support these missions, additional dollars will need to flow into NOAA and other agencies to fill the gap. Shared missionsThe National Aeronautics and Space Act of 1958, which created NASA, explicitly listed “the expansion of human knowledge of phenomena in the atmosphere and space” as one of the new agency’s prime objectives. Other federal agencies have overlapping missions, which is normal, since there are few neatly defined stovepipes in the real world. The National Oceanic and Atmospheric Administration, which is part of the Department of Commerce, works to “understand and predict changes in climate, weather, oceans, and coasts.” And the U.S. Geological Survey, a bureau of the Interior Department, is charged with “characterizing and understanding complex Earth and biological systems.” These primary earth science agencies have a pretty clear division of labor. NOAA and USGS fund and operate a constellation of weather- and land-observing satellites, while NASA develops, prototypes and flies higher-risk, cutting-edge science missions. When these technologies have been proven, and Congress funds them, NASA transfers them to the other two agencies. For example, in the NOAA-NASA partnership to develop the next generation of operational weather-observing satellites, NASA took the lead in prototyping and reducing risk by building the Suomi NPP satellite. That satellite, now five years old, is improving our daily weather forecasts by sending terabytes of data every day to supercomputers at NOAA. Its images also help with tasks as diverse as navigating in the Arctic through the Northwest Passage and monitoring the tragic wildfires near Gatlinburg, Tennessee. The experience NASA gained by developing the new technologies is now incorporated into NOAA’s Joint Polar Satellite System, whose first launch is scheduled for next year. When I served as NOAA’s chief operating officer, I met regularly with my NASA counterpart to ensure that we were not duplicating efforts. Sometimes these relationships are even more complex. As oceanographer of the Navy, I worked with NOAA, NASA and the government of France to ensure joint funding and mission continuity for the JASON-3 ocean surface altimeter system. The JASON satellites measure the height of the ocean’s surface, track sea level rise and help the National Weather Service (which sits within NOAA) forecast tropical cyclones that threaten U.S. coastlines. It is vital for these agencies to coordinate, but each plays an important individual role, and they all need funding. NOAA does not have enough resources to build and operate a number of NASA’s long-term space-based Earth observing missions. For its part, NASA focuses on new techniques and innovations, but is not funded to maintain legacy operational spacecraft while simultaneously pushing the envelope by developing new technologies. The value of space observationTo many members of the earth science community, organizational issues between NASA and NOAA are secondary to the real problem: lack of sufficient and sustained funding. NASA and NOAA are working jointly to patch together a space-based Earth observing system, but do not receive sufficient resources to fully meet the mission. An administration that truly wanted to improve this situation could do so by developing a comprehensive Earth observing strategy and asking Congress for enough money to execute it. That would include maintaining NASA’s annual Earth science budget at around US$2 billion and increasing NOAA’s annual satellite budget by $1-2 billion. There’s a reason why space is called “the ultimate high ground” and our country spends billions of dollars each year on space-based assets to support our national intelligence community. In addition to national security, NASA missions contribute vital information to many other users, including emergency managers and the Federal Emergency Management Agency (FEMA), farmers, fishermen and the aviation industry. While NASA’s Earth observation satellites support numerous research scientists in government labs and universities, they also provide constant real-time data on the state of space weather, the atmosphere and the oceans – information that is critical to U.S. Navy and Department of Defense operations worldwide. Six years ago while I was serving as oceanographer of the Navy, I was asked to estimate how much more money the Navy would need to spend if we did not have our NASA and NOAA partners. The answer was, very conservatively, $2 billion per year just to maintain the capability that we had. That figure has almost certainly increased. If the Trump administration cuts NASA’s earth science funding, that capability will need to come from some other set of agencies. Has the new team thought seriously about which agencies should have their budgets increased to make up this gap? Finally a few thoughts about the elephant in the room: climate change. Mr. Walker has said that “we need good science to tell us what the reality is,” a statement virtually everyone would agree with. The way to have good science is to fund a sustained observation system and ensure the scientific community has free and full access to the data that these satellites produce. Not funding observation systems, or restricting access to their data, will not change the facts on the ground. Ice will continue to melt, and our atmosphere and oceans will continue to warm. Such a policy would greatly increase risks to our economy, and even to many Americans’ lives. In the business world, this stance would be considered gross negligence. In government the stakes are even higher. David Titley, Professor of Practice in Meteorology & Director Center for Solutions to Weather and Climate Risk, Adjunct Senior Fellow, Center for New American Security, Pennsylvania State University This article was originally published on The Conversation. Read the original article. In our last post we heard from Christine from UCLA, one of the large groups of space physicists in the United States. Today we'll hear from a few of the scientists at the Laboratory of Atmospheric and Space Sciences (LASP) at the University of Colorado Boulder, another of the large space physics groups. I'd write more about them but I think they do a better job in the video below :). |
AuthorA bunch of us Space Nerds Archives
July 2017
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