Posts tagged solar
Solar eruption could be like an attack on the Earth
Dec 9th
CU-Boulder scientist: 2012 solar storm
points up need for society to prepare
points up need for society to prepare
A massive ejection of material from the sun initially traveling at over 7 million miles per hour that narrowly missed Earth last year is an event solar scientists hope will open the eyes of policymakers regarding the impacts and mitigation of severe space weather, says a University of Colorado Boulder professor.
The coronal mass ejection, or CME, event was likely more powerful than the famous Carrington storm of 1859, when the sun blasted Earth’s atmosphere hard enough twice to light up the sky from the North Pole to Central America and allowed New Englanders to read their newspapers at night by aurora light, said CU-Boulder Professor Daniel Baker. Had it hit Earth, the July 2012 event likely would have created a technological disaster by short-circuiting satellites, power grids, ground communication equipment and even threatening the health of astronauts and aircraft crews, he said.
CMEs are part of solar storms and can send billions of tons of solar particles in the form of gas bubbles and magnetic fields off the sun’s surface and into space. The storm events essentially peel Earth’s magnetic field like an onion, allowing energetic solar wind particles to stream down the field lines to hit the atmosphere over the poles.
Fortunately, the 2012 solar explosion occurred on the far side of the rotating sun just a week after that area was pointed toward Earth, said Baker, a solar scientist and the director of CU-Boulder’s Laboratory for Atmospheric and Space Physics. But NASA’s STEREO-A, satellite that was flying ahead of the Earth as the planet orbited the sun, captured the event, including the intensity of the solar wind, the interplanetary magnetic field and a rain of solar energetic particles into space.
“My space weather colleagues believe that until we have an event that slams Earth and causes complete mayhem, policymakers are not going to pay attention,” he said. “The message we are trying to convey is that we made direct measurements of the 2012 event and saw the full consequences without going through a direct hit on our planet.”
Baker will give a presentation on the subject at the 46th Annual Fall Meeting of the American Geophysical Union held in San Francisco Dec. 9 to Dec. 13.
While typical coronal mass ejections from the sun take two or three days to reach Earth, the 2012 event traveled from the sun’s surface to Earth in just 18 hours. “The speed of this event was as fast or faster than anything that has been seen in the modern space age,” said Baker. The event not only had the most powerful CME ever recorded, but it would have triggered one of the strongest geomagnetic storms and the highest density of particle fluctuation ever seen in a typical solar cycle, which last roughly 11 years.
“We have proposed that the 2012 event be adopted as the best estimate of the worst case space weather scenario,” said Baker, who chaired a 2008 National Research Council committee that produced a report titled Severe Space Weather Events – Understanding Societal and Economic Impacts. “We argue that this extreme event should be immediately employed by the space weather community to model severe space weather effects on technological systems such as the electrical power grid.
“I liken it to war games — since we have the information about the event, let’s play it through our various models and see what happens,” Baker said. “If we do this, we would be a significant step closer to providing policymakers with real-world, concrete kinds of information that can be used to explore what would happen to various technologies on Earth and in orbit rather than waiting to be clobbered by a direct hit.”
Even though it occurred about 150 years ago, the Carrington storm was memorable from a natural beauty standpoint as well as its technological impacts, he said. The event disrupted telegraph communications — the Internet of the Victorian Age — around the world, sparking fires at telegraph offices that caused several deaths, he said.
A 1989 geomagnetic storm caused by a CME from a solar storm in March 1989 resulted in the collapse of Hydro-Quebec’s electricity transmission system, causing 6 million people to lose power for at least nine hours, said Baker. The auroras from the event could be seen as far south as Texas and Florida.
“The Carrington storm and the 2012 event show that extreme space weather events can happen even during a modest solar cycle like the one presently underway,” said Baker. “Rather than wait and pick up the pieces, we ought to take lessons from these events to prepare ourselves for inevitable future solar storms.”
CU media release.
CU’s Mars mission off the ground
Nov 19th
NASA’s Mars mission led by CU-Boulder
successfully launches from Florida
successfully launches from Florida
A $671 million NASA mission to Mars led by the University of Colorado Boulder thundered into the sky today from Cape Canaveral, Fla., at 1:28 p.m. EST, the first step on its 10-month journey to Mars.
Known as the Mars Atmosphere and Volatile EvolutioN mission, the MAVEN spacecraft was launched aboard an Atlas V rocket provided by United Launch Alliance of Centennial, Colo. The mission will target the role the loss of atmospheric gases played in changing Mars from a warm, wet and possibly habitable planet for life to the cold dry and inhospitable planet it appears to be today.
MAVEN spacecraft hauls CU research into space
“Our team is incredibly excited,” said Bruce Jakosky, MAVEN’s principal investigator who is at CU-Boulder’s Laboratory for Atmospheric and Space Physics (LASP). “Everything went absolutely perfectly, exactly as we had planned when we accepted the challenge to develop this mission five years ago. Now it’s on to Mars.”
The spacecraft is carrying three instrument suites. LASP’s Remote Sensing Package will determine global characteristics of the upper atmosphere and ionosphere, while the Neutral Gas and Ion Mass Spectrometer, provided by the NASA Goddard Space Flight Center in Greenbelt, Md., will measure the composition of neutral gases and ions.
The Particles and Fields Package, built by the University of California, Berkeley, with some instrument elements from LASP and NASA Goddard, contains six instruments to characterize the solar wind and the ionosphere of Mars.
NASA selected the MAVEN mission for flight in 2008. Scientists think Mars was much more Earth-like roughly four billion years ago, and want to know how the climate changed, where the water went and what happened to the atmosphere, said Jakosky, also a professor in CU-Boulder’s geological sciences department.
CU-Boulder also is providing science operations and directing education and public outreach efforts. NASA Goddard provided two of the science instruments and manages the project. In addition to building the spacecraft, Lockheed Martin will perform mission operations. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., is providing program management via the Mars Program Office, as well as navigation support, the Deep Space Network and the Electra telecommunications relay hardware and operations.
MAVEN is slated to begin orbiting Mars in September 2014. For more information about MAVEN visit http://lasp.colorado.edu/home/maven/ and http://www.nasa.gov/maven.
-CU-
CU study: Global warming no hoax in the Eastern Canadian Arctic
Oct 23rd
Average summer temperatures in the Eastern Canadian Arctic during the last 100 years are higher now than during any century in the past 44,000 years and perhaps as long ago as 120,000 years, says a new University of Colorado Boulder study.
The study is the first direct evidence the present warmth in the Eastern Canadian Arctic exceeds the peak warmth there in the Early Holocene, when the amount of the sun’s energy reaching the Northern Hemisphere in summer was roughly 9 percent greater than today, said CU-Boulder geological sciences Professor Gifford Miller, study leader. The Holocene is a geological epoch that began after Earth’s last glacial period ended roughly 11,700 years ago and which continues today.
Miller and his colleagues used dead moss clumps emerging from receding ice caps on Baffin Island as tiny clocks. At four different ice caps, radiocarbon dates show the mosses had not been exposed to the elements since at least 44,000 to 51,000 years ago.
Since radiocarbon dating is only accurate to about 50,000 years and because Earth’s geological record shows it was in a glaciation stage prior to that time, the indications are that Canadian Arctic temperatures today have not been matched or exceeded for roughly 120,000 years, Miller said.
“The key piece here is just how unprecedented the warming of Arctic Canada is,” said Miller, also a fellow at CU-Boulder’s Institute of Arctic and Alpine Research. “This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere.”
A paper on the subject appeared online Oct. 23 in Geophysical Research Letters, a journal published by the American Geophysical Union. Co-authors include CU-Boulder Senior Research Associate Scott Lehman, former CU-Boulder doctoral student and now Prescott College Professor Kurt Refsnider, University of California Irvine researcher John Southon and University of Wisconsin, Madison Research Associate Yafang Zhong. The National Science Foundation provided the primary funding for the study.
Miller and his colleagues compiled the age distribution of 145 radiocarbon-dated plants in the highlands of Baffin Island that were exposed by ice recession during the year they were collected by the researchers. All samples collected were within 1 meter of the ice caps, which are generally receding by 2 to 3 meters a year. “The oldest radiocarbon dates were a total shock to me,” said Miller.
Located just east of Greenland, the 196,000-square-mile Baffin Island is the fifth largest island in the world. Most of it lies above the Arctic Circle. Many of the ice caps on the highlands of Baffin Island rest on relatively flat terrain, usually frozen to their beds. “Where the ice is cold and thin, it doesn’t flow, so the ancient landscape on which they formed is preserved pretty much intact,” said Miller.
To reconstruct the past climate of Baffin Island beyond the limit of radiocarbon dating, Miller and his team used data from ice cores previously retrieved by international teams from the nearby Greenland Ice Sheet.
The ice cores showed that the youngest time interval from which summer temperatures in the Arctic were plausibly as warm as today is about 120,000 years ago, near the end of the last interglacial period. “We suggest this is the most likely age of these samples,” said Miller.
The new study also showed summer temperatures cooled in the Canadian Arctic by about 5 degrees Fahrenheit from roughly 5,000 years ago to about 100 years ago – a period that included the Little Ice Age from 1275 to about 1900.
“Although the Arctic has been warming since about 1900, the most significant warming in the Baffin Island region didn’t really start until the 1970s,” said Miller. “And it is really in the past 20 years that the warming signal from that region has been just stunning. All of Baffin Island is melting, and we expect all of the ice caps to eventually disappear, even if there is no additional warming.”
Temperatures across the Arctic have been rising substantially in recent decades as a result of the buildup of greenhouse gases in Earth’s atmosphere. Studies by CU-Boulder researchers in Greenland indicate temperatures on the ice sheet have climbed 7 degrees Fahrenheit since 1991.
A 2012 study by Miller and colleagues using radiocarbon-dated mosses that emerged from under the Baffin Island ice caps and sediment cores from Iceland suggested that the trigger for the Little Ice Age was likely a combination of exploding tropical volcanoes – which ejected tiny aerosols that reflected sunlight back into space – and a decrease in solar radiation.
-CU-
