Scientists Find the Coldest Place on Earth

Posted December 11th, 2013 at 7:53 pm (UTC+0)
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This image shows the location of record low temperature measurements for Antarctica. (Ted Scambos, National Snow and Ice Data Center) The red dots show where the record satellite-measured surface temperatures and the earlier record low air temperature occurred. Shades of gray are a compilation of the lowest MODIS-sensor land surface temperature readings made by NASA's Aqua satellite during 2003-2013, with darker grays representing the coldest areas. Landsat 8 thermal images acquired in July and August of 2013 provided more detail on the coldest areas (purple squares). Elevation of the Antarctic surface is shown in green lines, and a blue lines provide an outline of the Antarctic continent, its islands, and the edge of its floating ice sheet.

This image shows the location of record low temperature measurements for Antarctica. (Ted Scambos, National Snow and Ice Data Center)

Winter officially arrives in the Northern Hemisphere in about 10 days (12/21/13).  Here in the Washington, DC area, temperatures have already been dropping below 0° C at times.

While some of us are already complaining about the recent icy temperatures we know it could be a lot worse!

Scientists from NASA and the U.S. Geological Survey (USGS), using a variety of sophisticated devices, such as those on the Landsat 8 satellite launched earlier this year (see related story), have found the coldest place on Earth.

Temperatures at spots along a 1,000 km strip of a remote and desolate ice plateau in East Antarctica have been measured between −92° to −93.2° C.

Project researchers made the temperature measurements between 2003 and 2013.

They used the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, an instrument installed on NASA’s Terra and Aqua satellites as well as the Advanced Very High Resolution Radiometer (AVHRR) which is aboard several National Oceanic and Atmospheric Administration satellites.

NASA Video – The Coldest Place in the World (NASA)

During the 2013 Southern Hemisphere winter (6/21/13 – 9/23/13) their temperature measurements were augmented with data that was taken by equipment aboard the new Landsat 8 Earth observing satellite.

The newly recorded coldest temperature of -93.2° C was set on August 10, 2010 and it beats a record from more than 30 years ago when it was −89.2° C on July 21, 1983 at the Vostok Research Station in East Antarctica.

Ted Scambos the lead scientist at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder also joined the NASA/USGS team for this project. “I’ve never been in conditions that cold and I hope I never am,” said Scambos. “I am told that every breath is painful and you have to be extremely careful not to freeze part of your throat or lungs when inhaling.”

An Atlas-V rocket with the Landsat Data Continuity Mission (LDCM) spacecraft onboard is seen as it launches on Monday, Feb. 11, 2013 at Vandenberg Air Force Base, Calif. (Photo: NASA/Bill Ingalls)

An Atlas-V rocket with the Landsat Data Continuity Mission (LDCM) spacecraft onboard is seen as it launches on Monday, Feb. 11, 2013 at Vandenberg Air Force Base, Calif. (Photo: NASA/Bill Ingalls)

These record temperatures in East Antarctica are much colder than a few other areas where sub-freezing temperatures are normal.

The project scientists found that the lowest recorded temperature in the United States was in Alaska coming in at −62° C.  In northern Asia cold temperatures have dipped to -68° C, while a temperature of -75° C was measured at the peak of the Greenland Ice Sheet.

According to NASA the coldest permanently inhabited place on Earth is located in northeastern Siberia, where temperatures dropped to -67.8° in the towns of Verkhoyansk – 1802 and Oymyakon – 1933.

The new record cold temperatures were found by the scientists in several 5 by 10 km pockets where the topography of the area shapes shallow hollows of about 2 to 4 meters deep.

These small dips in Antarctic landscape are close to an ice ridge that runs between the ice-dome peaks of Dome A (Argus) and Dome F (Fuji) which are located on the East Antarctic Ice Sheet.  An ice-dome has been described as a mass of ice located on an ice-sheet that has been shaped into a dome.

The researchers say that the cold air begins near the snow surface. Since cold air is thought to be much denser that the air above, this already cold air then moves down into those hollows making the air even colder, under ideal conditions.

“The record-breaking conditions seem to happen when a wind pattern or an atmospheric pressure gradient tries to move the air back uphill, pushing against the air that was sliding down,” Scambos said. “This allows the air in the low hollows to remain there longer and cool even further under the clear, extremely dry sky conditions. When the cold air lingers in these pockets it reaches ultra-low temperatures,” he added.

The researchers happened to notice the record low temperatures while they were studying some unusual cracks on East Antarctica’s ice surface that could be several hundred years old.

Satellite image shows a portion of the East Antarctic Ice Sheet (NASA)

Satellite image shows a portion of the East Antarctic Ice Sheet (NASA)

The scientists say that they suspect that a layer in the atmosphere above the ice plateau reaches a certain minimum temperature and is preventing the ice plateau’s surface from getting any colder.

“There seems to be a physical limit to how cold it can get in this high plateau area and how much heat can escape,” Scambos said. “The levels of carbon dioxide, nitrogen oxide, traces of water vapor and other gases in the air may impose a more or less uniform limit on how much heat can radiate from the surface.”

The researchers say that they will continue to refine their map of Earth’s coldest places using Landsat 8 data.

“It’s a remarkable satellite and we’ve repeatedly been impressed with how well it works, not just for mapping temperature but for mapping crops and forests and glaciers all over the world,” Scambos said.

Fresh Water Once Flowed in Ancient Mars Lake

Posted December 9th, 2013 at 9:09 pm (UTC+0)
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Artist's concept as to where water may have once flowed in ancient Gale Crater lake (NASA/JPL)

Artist’s concept as to where water may have once flowed in ancient Gale Crater lake (NASA/JPL)

NASA’s Mars Science LaboratoryCuriosity Rover – was sent to Mars some 16 months ago with a major objective of finding evidence of a past environment that would be well suited to supporting microbial life.

Today, a team of mission researchers, writing in a series of papers published in the journal Science, said that they found evidence of what was once an ancient fresh water lake on Mars that might have been capable of supporting life.

The findings were also announced this morning by members of the research team who addressed the annual meeting of the American Geophysical Union in San Francisco.

The researchers studied a set of sedimentary rock outcrops that were found in an area on the floor of Gale Crater called Yellowknife Bay, near the Mars equator.

These sedimentary rocks that probably formed from ancient Martian mud or clay have suggested to researchers that there was at least one lake that welled up with what could have been drinkable water inside of Gale Crater some 3.6 million years ago, and that the lake could have lasted for tens or even hundreds of thousands of years.

“Shortly after we landed, Curiosity found evidence that liquid water had flowed across the surface long ago in Gale crater,” said Jim Bell, from Arizona State University and an author of four of the papers. “These new results, however, come from the first drilling activities ever performed on Mars, and they show that in addition to surface water, there was likely an active groundwater system in Gale crater that significantly weathered ancient rocks and minerals.”

The mudstones analyzed by the research team are normally formed in calm conditions and produced by very fine sediment grains settling on each other layer-by-layer, in still water.

A mosaic of images taken by Curiosity showing a view of Yellowknife Bay Formation, where rock samples were taken that indicated a freshwater lake once flowed within Gale Crater (NASA/JPL)

A mosaic of images taken by Curiosity showing a view of Yellowknife Bay Formation, where rock samples were taken that indicated a freshwater lake once flowed within Gale Crater (NASA/JPL)

The team’s analysis of Yellowknife Bay’s clay-rich lake-bed region showed that a calm and fresh water lake that contained basic but crucial biological elements such as carbon, hydrogen, oxygen, nitrogen and sulfur existed at least once inside the Gale Crater.

According to the team, a lake with these conditions could provide an ideal environment for simple microbial life.  The researchers think that a lake like this could have provided perfect conditions for simple bacterial life such as chemolithoautotrophs, which are rock-eating microbes that live on and derive their energy from mineral compounds.

The researchers pointed out that they did not find signs of ancient life itself on Mars.

“It is exciting to think that billions of years ago, ancient microbial life may have existed in the lake’s calm waters, converting a rich array of elements into energy. The next phase of the mission, where we will be exploring more rocky outcrops on the crater’s surface, could hold the key to whether life did exist on the red planet,” said another of the paper’s co-authors, Sanjeev Gupta from Imperial College London, who is also a member of the MSL mission team.

The researchers will continue to use the Mars roving science laboratory to continue exploring Gale Crater for even more evidence of ancient lakes or other habitable environments.

New-found Planet Defies Scientific Theory

Posted December 6th, 2013 at 8:14 pm (UTC+0)
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Artist's conception of HD106906b a young planet in a distant orbit around its host star. (NASA/JPL-Caltech)

Artist’s conception of HD106906b a young planet in a distant orbit around its host star. (NASA)

A newly-discovered  planet outside of our solar system has scientists rethinking how planets form.

The international research team said the new exoplanet, with the registration number HD 106906b,  is not only huge, weighing 11 times Jupiter’s mass, but also orbits its sun from a distance of 650 au’s – astronomical units or 97,238,615,955 km.  In comparison, the distance from the Sun to Pluto at its farthest orbital point – is 7,375,623,552 km.

“This system is especially fascinating because no model of either planet or star formation fully explains what we see,” said Vanessa Bailey, a graduate student at Tucson’s University of Arizona who led the research team.

The location and attributes of this giant exoplanet defy conventional planet formation theories.

It is thought that planets forming within a solar system usually do so at a relatively closer distance to their home stars.  Among other planet formation theories one indicates that there shouldn’t be enough of the primordial material with the mass needed to create a planet the size and weight of HD 106906b at a distance so far from its sun.

HD 106906b is only about 13 million years old.  In comparison, scientists believe Earth was born about 4.5 billion years ago, which makes our planet 350 times older than HD 106906 b.

This is a discovery image of planet HD 106906b in thermal infrared light from MagAO/Clio2, processed to remove the bright light from its host star, HD 106906A. The circle around the star indicates distance from Neptune to our sun. (Vanessa Bailey)

This is a discovery image of planet HD 106906b in thermal infrared light from MagAO/Clio2, processed to remove the bright light from its host star, HD 106906A. The circle around the star indicates distance from Neptune to our sun. (Vanessa Bailey)

The exoplanet is so young, according to the researchers, that it still glows with the left-over heat from its formation. The planet temperature is about 1,500 degrees Celsius and cooler than its sun, so HD 106906b emits most of its energy within the infrared spectrum rather than visible light.

The team used the new Magellan Adaptive Optics (MagAO) system and the Clio2 thermal infrared camera, which was mounted to the 6.5 meter-diameter Magellan telescope located in Chile’s Atacama Desert.

The MagAO system was developed by University of Arizona scientists to allow Earth-based telescopes take sharper images of the night sky than ever before. (see a related story)  This new optical system can counteract the blurring effects of the atmosphere by floating a very thin curved glass mirror that vibrates a 1,000 times per second  on a magnetic field that is set about 9 meters above the telescope’s primary mirror.

This atmospheric correction system allowed the research team to detect the weak heat emitted from the exoplanet without it being interfered with by the overpowering heat from its much hotter sun.

Scientists have thought that planets like Earth, which are relatively close to their suns,  form when remnant material from a star’s formation–such as dust and gas–gathers together.

But, according to the scientists, that method of planet formation may act too slowly for the giant planets located far from their sun to form.

The Magellan Telescope with MagAO’s Adaptive Secondary Mirror (ASM) mounted at the top looking down on the 6.5m (21 foot) diameter Primary Mirror. (Yuri Beletsky, LCO/Magellan Staff)

The Magellan Telescope with MagAO’s Adaptive Secondary Mirror (ASM) mounted at the top looking down on the 6.5m (21 foot) diameter Primary Mirror. (Yuri Beletsky, LCO/Magellan Staff)

Another theory suggests that these giant planets can form as the result of a fast, direct collapse of the primordial disk material. But the team says that in the case of HD 106906b, which is so far from its sun, any disks of planet forming material usually don’t have enough mass to create a planet.

Scientists have also developed and offered other theories including one that speculates how mini-binary star systems are formed.

“A binary star system can be formed when two adjacent clumps of gas collapse more or less independently to form stars, and these stars are close enough to each other to exert a mutual gravitation attraction and bind them together in an orbit,” said Bailey. “It is possible that in the case of the HD 106906 system the star and planet collapsed independently from clumps of gas, but for some reason the planet’s progenitor clump was starved for material and never grew large enough to ignite and become a star.”

Bailey and her team have outlined their research and discovery in a paper that will be published in a future issue of The Astrophysical Journal Letters.

Real-time Flu Forecasting Proves Successful in Large-scale Test

Posted December 3rd, 2013 at 9:02 pm (UTC+0)
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(mcfarlandmo via wikimedia commons)

(mcfarlandmo via Wikimedia commons)

A flu forecasting system that uses some of the same techniques as modern weather forecasting was not only able to  predict the timing of the 2012-2013 influenza season, but was able to do so nine weeks before the flu season peaked.

Columbia University researchers say there were able to correctly predict that flu activity in the southeastern United States would peak in December 2012, and that the rest of nation wouldn’t see its flu season crest until the first weeks of 2013.

A study published in Nature Communications revealed the results of the researcher’s first large-scale demonstration, which tested the forecasting system in 108 U.S. cities.  The World Health Organization (WHO) says between 250,000 to 500,000 people worldwide die from influenza.  In the United States, between 3,000 to 49,000 people die from the flu every year, according to the Centers for Disease Control (CDC). The CDC says about 45 percent of Americans receive annual flu inoculations.

The demonstration of Columbia University’s flu-predicting system follows the team’s study last year that predicted, in retrospect, the peak of the New York City flu season for each year between 2003 and 2008.

Predictions made in last year’s study were the initial test of the system and were limited to one city.  The researchers said the new and expanded demonstration made its predictions in real-time for a number of cities throughout the country.

A microscopic image of the H1N1 ('swine flu') influenza virus - In 2009, the World Health Organization declared this new strain as a pandemic.

A microscopic image of the H1N1 (‘swine flu’) influenza virus . (wikimedia commons)

The timing of flu season can vary from year to year and from region to region.  Influenza usually arrives any time between December and April, but when it does hit, a city can go from having no, or very few cases, to thousands within a short time period.

“Having greater advance warning of the timing and intensity of influenza outbreaks could prevent a portion of these influenza infections by providing actionable information to officials and the general public,” said  study author Jeffrey Shaman,  assistant professor  at Columbia University’s Mailman School of Public Health.

This advance warning could provide people with information that might encourage them to get their flu vaccination, become more aware of their own personal health,  and perhaps exercise extra caution when they’re around people who sneeze and cough.

The prediction system could also help health authorities prepare for an upcoming influenza outbreak.  It could help inform their decisions on how many vaccines and antiviral drugs to stockpile, and whether to take other measures such as closing local schools in the event of a virulent outbreak.

To test their prediction system on a large scale, the researchers began to perform weekly estimates for 108 US cities in November 2012.  The results of their weekly estimates were posted online and shared with the CDC.

They found that by the end of 2012, or four weeks into the flu season, their forecasting system had made accurate predictions in 63 percent of the cities they measured. That accuracy increased as the flu season moved forward. By the fourth week, the forecast system had accurately predicted the peak of the flu season in 70 percent of the country.

The flu forecasts were able to provide precise lead-times of up to nine weeks in advance of the peak, instead of the usual two-to-four weeks offered by other prediction methods that use historical data instead of real-time data.

A flu shot may sting a little bit but the US CDC recommends a yearly flu vaccine as the first and most important step in protecting ourselves against flu viruses. (Photo: US Navy)

A flu shot may sting a little bit but the US CDC recommends a yearly flu vaccine as the first and most important step in protecting ourselves against flu viruses. (Photo: US Navy)

In reviewing the results of their measurements, the researchers noticed regional differences regarding the accuracy of the system.

“We were able make better predictions in smaller cities. Population density may also be important,” said Shaman. “It suggests that in a city like New York, we may need to predict at a finer granularity, perhaps at the borough level. In a big sprawling city like Los Angeles, we may need to predict influenza at the level of individual neighborhoods.”

Shaman and his colleagues are gearing up for the 2013-2014 flu season and will be ready to put their forecasting system back into action as soon as it begins.

“Right now there are few cases of the flu, but as soon as the needle starts to move, we will start making predictions,” said Shaman.

Flu forecasts this season will be more available to the public because they will be posted on a soon-to-be launched website hosted by Columbia’s Mailman School of Public Health.

Rainy-day Drivers Become Precipitation Gauges

Posted November 29th, 2013 at 8:39 pm (UTC+0)
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A windshield wiper at work on a rainy day (Basheer Tome via Flickr/Creative Commons)

A windshield wiper at work on a rainy day (Basheer Tome via Flickr/Creative Commons)

German scientists plan to use moving vehicles to measure precipitation on rainy days, after noticing that drivers control the speed of their windshield wipers according to the intensity of rainfall—faster for heavy rain and slower for light rain or drizzle.

Writing in Hydrology and Earth System Sciences, the University of Hanover scientists say they will use cars equipped with GPS systems as mobile rain measuring devices.

The amount of rainfall can vary quite a bit within even small parts of a region. The scientists said that while standard rain gauges can provide accurate measurements, some parts of the world may have very few of these gauges in place and those they do have are spread out over a large area.

As a result, the measurements made by the rain gauges aren’t able provide the detailed information that would reflect that variation, information that could be vital to help predict and prevent flooding.

“If moving cars could be used to measure rainfall the network density could be improved dramatically,” said Uwe Haberlandt, project leader for the RainCars project, an initiative that was conceived after a brainstorming session between the scientists.

To test the idea, the researchers went to work in a laboratory equipped with a rain simulator that mimicked both light and heavy rainfall. They placed cars equipped with different types of windshield wiper systems, into their rain simulator to determine the relationship between wiper speed and rainfall intensity.

For their first experiment, they placed a person inside each of the cars to manually adjust the speed of the wipers for the best windshield visibility.

“The experiments have shown that the front visibility is a good indicator for rainfall intensity,” says Ehsan Rabiei, the paper’s lead author.

But the researchers also found that measurements made with this method might not be dependable since they would rely on the visibility perception of the individual making the manual wiper speed adjustments.

Moving on to their next rain simulator experiment, the researchers tested optical sensors used by some new wiper systems that allow the systems to operate automatically. These sensors use infrared laser beams that can detect rain drops collecting on the device’s surface. Each sensor reading, according to the researchers, corresponds to a specific amount of water – in other words, the more readings made by the sensors, the more intense the rainfall.

“The optical sensors measure the rain on the windshield in a more direct and continuous manner so, currently, they would be the better choice for rain sensors in cars,” said Haberlandt.

The researchers also found that speed isn’t the only factor that can impact rain measurements.

Here's a car that's being tested under the research group's rain simulator (www.ikg.uni-hannover.de, Daniel Fitzner)

Here’s a car that’s being tested under the research group’s rain simulator (www.ikg.uni-hannover.de, Daniel Fitzner)

“Our experiments so far were carried out in an ideal and controlled environment. In nature there are external effects like wind, spray from other cars or shielding trees that can affect the readings, and rainfall characteristics are different from the rain simulator,” said Rabiei.

The research team’s goal isn’t so much about a higher accuracy of measuring rainfall, as it is about being able to increase the number of available measurement points.

A study published in 2010 by two members of the team showed that a system using a higher number of gauges that perhaps weren’t so accurate still provided more reliable rainfall readings than one that used a smaller number of much more accurate gauges.

The researchers said that they are already back at work conducting field experiments that use cars to measure the amount of real rainfall in and around their home city of Hanover.

They’re conducting these experiments with the help of volunteers, a taxi company and a car company, and say that they would like to see more people involved in this work.

Volunteers, Home Computers Help Identify Gamma Ray Pulsars

Posted November 26th, 2013 at 5:45 pm (UTC+0)
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A gamma-ray pulsar is a compact neutron star that accelerates charged particles to speeds that are described only by the theory of relativity in a strong magentic field. The process produces gamma radiation seen in violet. (© NASA/Fermi/Cruz de Wilde)

A gamma-ray pulsar is a compact neutron star that accelerates charged particles to speeds that are described only by the theory of relativity in a strong magnetic field. The process produces gamma radiation seen in violet. (NASA/Cruz de Wilde)

A network of 40,000 volunteer researchers, along with 200,000 personal computers worldwide, has helped scientists from the Max Planck Institutes for Gravitational Physics and Radio Astronomy – the Albert Einstein Institute (AEI) discover four gamma-ray pulsars.

Pulsars are compact and rapidly rotating neutron stars which are the remains of stars that have exploded.

The discoveries made by this unique collaboration were made possible by an online computing project called Einstein@Home, which was launched back in 2005 as a joint program from the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee and the AEI in Hannover, Germany.

The volunteers were from countries such as Australia, Canada, France, Germany, Japan and the USA, and used data from NASA’s Fermi Gamma-Ray Space Telescope, according to the AEI.

“Our innovative solution for the compute intensive search for gamma-ray pulsars is the combination of particularly efficient methods along with the distributed computing power of Einstein@Home,” said AEI’s Holger Pletsch, who’s also the lead author of the study. “The volunteers from around the world enable us to deal with the huge computational challenge posed by the Fermi data analysis. In this way, they provide an invaluable service to astronomy.”

The online computer project connects 200,000 home and office computers to a global supercomputer.  Since identifying these new gamma-ray pulsars requires a lot of computing power, the combined computing ability provided by the Einstein@Home network of personal computers, along with the supercomputer, provides scientists with an efficient yet more cost effective way to conduct their research.

A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth's mass into a sphere about 20 kilometers across. This illustration compares the size of a neutron star to the area around Hannover, Germany (© NASA's Goddard Space Flight Center)

A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth’s mass into a sphere about 20 kilometers across. This illustration compares the size of a neutron star to the area around Hanover, Germany (NASA)

“The first-time discovery of gamma-ray pulsars by Einstein@Home is a milestone – not only for us but also for our project volunteers. It shows that everyone with a computer can contribute to cutting-edge science and make astronomical discoveries,” said Bruce Allen from AEI and the principal investigator of Einstein@Home. “I’m hoping that our enthusiasm will inspire more people to help us with making further discoveries.”

Pulsars have usually been detected by the beam of electromagnetic radiation or radio waves they emit when the signal points toward Earth. But, according to AEI officials, the four pulsars discovered through this collaborative effort are only visible in gamma-rays and not radio waves.

AEI officials said special follow-up observations of all four new pulsar discoveries will be conducted with radio telescopes located at Germany’s Max Planck Institute for Radio Astronomy and the Parkes Observatory in Australia.  Scientists hope these observations will confirm that radio waves won’t be detected in the pulsars.

Data gathered by the Fermi Gamma-Ray Space Telescope, which was launched from the Cape Canaveral Air Force Base on June 11, 2008 is also credited with helping scientists to discover thousands of gamma-ray sources that they said had been previously unknown.   According to AEI those gamma-ray sources may also include hundreds of yet undiscovered pulsars.

The Sun is About to Flip Its (Magnetic) Poles

Posted November 15th, 2013 at 9:37 pm (UTC+0)
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The Sun photographed by the Atmospheric Imaging Assembly (AIA 304) of NASA's Solar Dynamics Observatory (SDO). This is a false-color image of the Sun observed in the extreme ultraviolet region of the spectrum. (NASA/SDO (AIA))

The Sun photographed by NASA’s Solar Dynamics Observatory (SDO). (NASA/SDO (AIA))

Here at Science World, one of our favorite topics is the sun. We’ve been able to provide you with a number of informational pieces regarding events and phenomena such as the ebb and flow of the sun’s activity throughout its roughly 11 year solar cycle.

As the sun goes through this process – from when it’s least active (solar minimum) to its most active (solar maximum) and back again – it undergoes what scientists describe as a “complete makeover” when its magnetic field reverses or flips its polarity.  The sun’s magnetic north becomes its south and vice versa, causing effects that can ripple throughout our solar system.

Scientists say that our sun, which is nearing the peak of its current solar cycle, is about to flip its magnetic poles. The current solar cycle that began in 2008 or 2009 is the 24th since scientists started tracking them back in 1755.  Compared to previous solar cycles, researchers have said that the current cycle appears to be weaker than any other before it, perhaps the weakest in 100 years.

While not much is known about the actual mechanics behind this polarity flip, solar scientists at Stanford University’s Wilcox Solar Observatory are keeping an eye on the sun’s magnetic field, monitoring and measuring it every day, as they have done since 1975.

Large field-of-view image of sunspots. The image has been colored yellow for aesthetic reasons. (Royal Swedish Academy of Sciences)

Large field-of-view image of sunspots. The image has been colored yellow for aesthetic reasons. (Royal Swedish Academy of Sciences)

The daily monitoring efforts allow these researchers to observe and identify the magnetic polarity reversal as it actually takes place on the sun’s surface.  This upcoming shift in the Sun’s poles will be the fourth the observatory has watched.

While we laypeople tend to label the sun’s magnetic poles as north and south, Todd Hoeksema, a solar physicist and Director of the Wilcox Solar Observatory, suggests that we think of the poles as positive and negative. “It’s best not to think of it like a big bar magnet.  That works OK for Earth but not the Sun.  Think of the Sun as having a large number of smaller magnetic fields scattered over the surface,” he said.

Of course, hearing that the sun is about undergo a significant event like a pole reversal can alarm some people who may wonder if they might be in danger.  But, according to Hoeksema we have nothing to worry about.

“When it happened about eleven or twelve years ago, you probably didn’t even notice,” he said.

Hoeksema explains that the pole reversal process takes place over time throughout the solar cycle where sunspots come up at the Sun’s mid-latitudes (equator) and spread out toward its poles.  Gradually, as the magnetic flux (a measurement of the quantity of magnetism) that comes up with the sunspots moves pole-ward it erodes the existing polar fields and replaces them with magnetic fields that have the opposite polarity.

Illustration of the sun's magnetic field lines extending out (NASA/SVS)

Illustration of the sun’s magnetic field lines extending out (NASA/SVS)

“What we’re seeing recently is more activity in the (sun’s) southern hemisphere and that’s the pole that’s just about to switch or is switching right now,” said Hoeksema.

He also pointed out that the sun’s northern pole switched about a year ago in the summer of 2012.

The sun’s two hemispheres (north and south) aren’t in perfect synchronization with each other and the number of sunspots that emerge in each of the hemispheres can be different.

Because of this, according to Hoeksema, the sun’s ‘new’ polarity that moves poleward is generally different in the north and south in both timing and strength which causes one geographic pole to change its magnetic field direction before the other.

Since it is at or near its peak of activity, the sun is has been pumping out a lot of energy particles throughout the solar system via the solar wind. Because of this outpouring of sun particles, according to Hoeksema, we’re actually being shielded from the high energy particles that come at us from other parts of the galaxy.

Todd Hoeksema from Stanford University monitors the sun's magnetic field at Stanford's Wilcox Solar Observatory. (Photo: Linda A. Cicero /Stanford News Service)

Todd Hoeksema from Stanford University monitors the sun’s magnetic field at Stanford’s Wilcox Solar Observatory. (Photo: Linda A. Cicero /Stanford News Service)

Along with their ground-based Wilcox Solar Observatory at Stanford, Hoeksema and his fellow scientists also use some sophisticated observational tools in space, too.  One is as an instrument aboard NASA’s Solar Dynamic Observatory (SDO) called the ‘Helioseismic and Magnetic Imager’ (HMI) which allows the team to measure the sun’s magnetic field every 45 seconds.

These measurements help scientists zero in on where and what kind of solar activity is taking place on the Sun, something that Hoeksema and his colleagues hope will help scientists better predict potentially dangerous space weather.

Dr. Todd Hoeksema joins us this weekend on the radio edition of “Science World.”  To listen to our conversation either tune into the show (see right column for scheduled times) or check out the interview below.

Also check out the video below.

Solar physicist Todd Hoekserma explains sun’s magnetic reversal (Stanford University)

Global Precipitation Changes Linked to Human-induced Climate Change

Posted November 12th, 2013 at 7:43 pm (UTC+0)
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A rainy day in Chicago (Bernt Rostad via Flickr/Creative Commons)

A rainy day in Chicago (Bernt Rostad via Flickr/Creative Commons)

A new study shows changes in precipitation are affected by human activities and can’t be explained by natural phenomena, such as El Niños and La Niñas.

Scientists from the Lawrence Livermore National Laboratory in California published the study in the Proceedings of the National Academy of Sciences.

The researchers suggest two mechanisms will probably cause changes in the distribution and intensity of precipitation worldwide because of human release of greenhouse gases that trap heat and deplete the ozone.

First, there are some thermodynamic changes, caused by the increasing global temperatures, which will likely result in already wet regions of the world getting wetter while the dry areas will become drier.

The researchers also think increased temperatures could change global atmospheric circulation patterns – movement of air at all levels of the atmosphere – which might move storm tracks and push current subtropical dry zones toward the poles.

“Both these changes are occurring simultaneously in global precipitation and this behavior cannot be explained by natural variability alone,” said Kate Marvel, the study’s lead author. “External influences such as the increase in greenhouse gases are responsible for the changes.”

To reach their conclusions, the researchers compared various climate model predictions with global observations from 1979-2012 that were provided by the Global Precipitation Climatology Project.

(Flóra Soós via Flickr/Creative Commons)

(Flóra Soós via Flickr/Creative Commons)

The scientists found natural climate phenomena alone couldn’t explain the ongoing changes in global precipitation patterns. They also noted that any fluctuations in climate brought on by natural causes could either intensify or shift precipitation towards the poles, but it’s very rare for both to take place together naturally.

“In combination, man-made increases in greenhouse gases and stratospheric ozone depletion are expected to lead to both an intensification and redistribution of global precipitation,” said Céline Bonfils, another co-author of the study. “The fact that we see both of these effects simultaneously in the observations is strong evidence that humans are affecting global precipitation.”

The researchers said their studies helped them identify a “fingerprint pattern” that can explain the simultaneous changes in precipitation locations and intensity brought on by external forces such as warming caused by human activities.

“We have shown that the changes observed in the satellite era are externally forced and likely to be from man,” Bonfils said.

Science Images

Posted November 8th, 2013 at 6:00 pm (UTC+0)
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This is a magnification of a nerve cell. The green fibrous material surrounding the yellow core are the branches of the cell. Scientists recently were able to identify a chain reaction that allows the cell to repair of these branches when they are severed. (Yongcheol Cho, PhD)

This is a magnification of a nerve cell. The green fibrous material surrounding the yellow core are the branches of the cell. Scientists recently were able to identify a chain reaction that allows the cell to repair of these branches when they are severed. (Yongcheol Cho, PhD)

This hybrid image of the Boomerang nebula, called the “coldest place in the universe”, was taken with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope and the Hubble Space Telescope. The red in the image are cold gas molecules. (NRAO/AUI/NSF/NASA/STScI/JPL-Caltech)

This hybrid image of the Boomerang nebula, called the “coldest place in the universe”, was taken with the Atacama Large Millimeter/submillimeter Array (ALMA) telescope and the Hubble Space Telescope. The red in the image are cold gas molecules. (NRAO/AUI/NSF/NASA/STScI/JPL-Caltech)

The Heterospilus is one 277 new wasp species that was recently found in Costa Rica by researchers from the University of Illinois at Urbana-Champaign. This image shows a female of the Heterospilus species. (Alexander Wild)

The Heterospilus is one 277 new wasp species that was recently found in Costa Rica by researchers from the University of Illinois at Urbana-Champaign. This image shows a female of the Heterospilus species. (Alexander Wild)

Scientists recently discovered a rocky exoplanet called Kepler-78B that orbits its star every eight and a half hours at a distance of less than 1,609,344 km. This is an artist’s conception of that scorching hot lava world. According to current theories of planet formation, it couldn't have formed so close to its star, nor could it have moved there. (David A. Aguilar/CfA)

Scientists recently discovered a rocky exoplanet called Kepler-78B that orbits its star every eight and a half hours at a distance of less than 1,609,344 km. This is an artist’s conception of that scorching hot lava world. According to current theories of planet formation, it couldn’t have formed so close to its star, nor could it have moved there. (David A. Aguilar/CfA)

Recent testing of a new climate-studying instrument that was carried with the help of a helium balloon that lifted it into the atmosphere (HySICS Team/LASP)

Recent testing of a new climate-studying instrument that was carried with the help of a helium balloon that lifted it into the atmosphere (HySICS Team/LASP)

A Soyuz spacecraft carrying three new crewmembers for the International Space Station along with the Olympic Flame for the Sochi 2014 Winter Games blasts off from the Baikonur cosmodrome, in Kazakhstan on Thursday, Nov. 7, 2013. (AP/Dimitry Lovetsky)

A Soyuz spacecraft carrying three new crewmembers for the International Space Station along with the Olympic Flame for the Sochi 2014 Winter Games blasts off from the Baikonur cosmodrome, in Kazakhstan on Thursday, Nov. 7, 2013. (AP/Dimitry Lovetsky)

Sphyrna gilberti, a new species of scalloped hammerhead shark was recently found off the South Carolina coast. Researchers nicknamed it the Carolina Hammerhead. (University of South Carolina)

Sphyrna gilberti, a new species of scalloped hammerhead shark was recently found off the South Carolina coast. Researchers nicknamed it the Carolina Hammerhead. (University of South Carolina)

An X3.3 class solar flare taken by NASA's Solar Dynamics Observer at 5:12 p.m. EST Nov. 5, 2013. This composite image is made up of light blended from the 131 and 193 wavelengths. (NASA/SDO)

An X3.3 class solar flare taken by NASA’s Solar Dynamics Observer at 5:12 p.m. EST Nov. 5, 2013. This composite image is made up of light blended from the 131 and 193 wavelengths. (NASA/SDO)

Fossil Reveals New Species of Ancient Platypus

Posted November 5th, 2013 at 7:15 pm (UTC+0)
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Obdurodon tharalkooschild, a middle to late Cenozoic giant toothed platypus.  Fossil found in the World Heritage fossil deposits of Riversleigh, Australia. Unlike today's platypus this ancient species had teeth - see inset. (Peter Schouten)

Obdurodon tharalkooschild, a middle to late Cenozoic giant toothed platypus. Unlike today’s platypus, this ancient species had teeth (see inset). (Peter Schouten)

Australian scientists say they’ve found the fossil of a new species of  giant platypus that walked the Earth between 5 and 15 million years ago.

Up until now, the fossil record of the platypus indicated that only one species of the animal lived on Earth at any one time. The new study suggests this new extinct giant platypus species, called Obdurodon tharalkooschild, is a side-branch of the platypus family, rather than its direct ancestor.

The platypus is a mammal with a duck-like bill, thick fur that’s much like an otter’s, and a tail similar to a beaver’s. It has webbed feet and reproduces by laying eggs rather than giving birth like other mammals.

The animal was so odd that in 1798 when Captain John Hunter, then the governor of New South Wales, Australia, sent a pelt of a platypus along a sketch of the animal to scientists in Great Britain, the British researchers at first thought it was a joke or a hoax.

The Australian researchers were able to identify this new species of platypus from a single fossilized tooth found in the Riversleigh World Heritage Area of northwest Queensland, Australia.

Monotremes (platypuses and echidnas) are the last remnant of an ancient radiation of mammals unique to the southern continents,” said Rebecca Pian, lead author of the study. “A new platypus species, even one that is highly incomplete, is a very important aid in developing understanding about these fascinating mammals.”

The fossilized tooth’s size leads researchers to believe this ancient platypus was about a meter in length, two times the length of today’s platypus. Today, the male platypus grows to a length of about 50 cm while females grow to about 43 cm in length.

A modern day platypus swimming underwater at the Sydney Aquarium (wehunts via Flickr/Creative Commons)

A modern day platypus swimming underwater at the Sydney Aquarium (wehunts via Flickr/Creative Commons)

“Like other platypuses, it was probably a mostly aquatic mammal and would have lived in and around the freshwater pools in the forests that covered the Riversleigh area millions of years ago,” said Dr. Suzanne Hand of the University of New South Wales, a co-author of the study.

The ancient Obdurodon tharalkooschild was able to eat its prey with a set of well-developed teeth, unlike today’s platypus which has horny pads in its mouth instead.

The extinct platypus probably ate a varied menu that included not only crayfish and other freshwater crustaceans, but also small vertebrates such as lungfish, frogs, and small turtles.

The researchers named  the prehistoric animal Obdurodon, Greek for “lasting (obdurate) tooth,”  because its teeth are unlike today’s platypus species.  Tharalkooschild was given in honor of a story told by Indigenous Australians about the creation and origin of the platypus.

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