Tagged: Earth Observation Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 9:57 am on January 16, 2019 Permalink | Reply
    Tags: , Delay Tolerant Networks, Earth Observation, , , ESA's Discovery and Preparation Programme, ESA's OPS-SAT CubeSat, European Data Relay System (EDRS), Space Internet   

    From European Space Agency: “Space Internet” 

    ESA Space For Europe Banner

    From European Space Agency

    15 January 2019

    The European Data Relay System (EDRS) uses advanced laser technology to relay information collected by lower orbiting satellites to the Earth via geostationary nodes.

    Every day satellites collect a wealth of information about Earth, but they must send it down to the ground before we can make use of it. Sometimes this data can be lost, damaged, or delayed, but our access to it could be improved using Delay Tolerant Networks (DTNs) – a new way of communicating with spacecraft.

    Imagine the inconvenience of only being able to send a message to a friend when your phones are directly facing each other with a perfect connection. Fortunately, the internet allows us to circumnavigate this problem by passing data to in-between nodes, and if your friend’s phone isn’t connected to the internet, the data is stored until it can be transferred to them.

    ESA’s Aeolus satellite sending data to a ground station in Sweden (artist’s impression)

    ESA ADM-Aeolus satellite

    Currently communication with Earth observation satellites does not benefit from this internet-like transmission and storage of information through in-between nodes. Earth observation satellites only send data down to Earth when they are directly overhead a ground station. When a satellite isn’t facing a ground station, data starts queuing up. There is no system that automatically sort the queue to prioritise the sending of urgent data – information captured about natural disasters, perhaps – from the ordinary.

    Delay Tolerant Networks offer a solution in the form of using relay spacecraft and other ground stations. These would act as intermediate nodes that would be able to hold on to data and pass it on as soon as the next ‘hop’ is available, ensuring its safe delivery by relaying it up to a spacecraft or down to a ground station at just the right time. DTNs provide a new way of transmitting information, creating the foundation for a ‘space internet’.

    So far, DTNs have mostly been explored in the context of deep space – when distant planetary orbiters and rovers need to use intermediary nodes to communicate with Earth. But a team of researchers supported by ESA’s Discovery and Preparation Programme recently investigated the possible benefits of Delay Tolerant Networking for Earth observation.

    The team, made up of representatives from GMV INSYEN, German Aerospace Center (DLR), Solenix Deutschland and the University of Bologna analysed how DTNs could improve our communication with Earth observation spacecraft.

    Different types of Delay Tolerant Networks

    Sebastian Martin, responsible for the project from ESA’s side, explains further, “DTNs allow information to be sent through a network that does not have a direct route from the starting point to the final receiver of information. In-between ‘nodes’ receive information and store it until they can send it on to a neighbour. In addition, DTNs can automatically schedule when to store information and when to forward it over different possible routes.”

    The team began by investigating how one of the existing Copernicus Sentinel missions could benefit from DTN technology. They then modelled a futuristic scenario with a full system of DTN-enabled Earth observation satellites, ground stations and control centres. In both scenarios, they found that the data automatically reached their destination via optimal routes and that the network correctly handled data with different priorities.

    Sentinel-2 transmitting data by laser.Sentinel-2 carries an innovative high-resolution multispectral imager with 13 spectral bands for a new perspective of our land and vegetation. Once its data are acquired, they are sent to the core Sentinel ground stations in Italy, Spain and Norway. For continual data delivery, the satellite is also equipped with a laser terminal to transmit data to satellites in geostationary orbit carrying the European Data Relay System (EDRS). These satellites then transmit the Sentinel-2 data to the ground. Complementing the Sentinel ground-station network, EDRS ensures the timely availability of large volumes of data. Sentinel-1 carries the same laser terminal.

    They also looked into a second benefit of DTNs. When existing Earth observation satellites pass over ground stations on their orbits around Earth, a short amount of time at the beginning and the end of its pass is not used to transfer information. This is because there is a risk of data getting lost when the satellite is low over the horizon with a poor connection with the ground station. Using DTNs, it is possible to automatically check for lost data and get it resent. This means it is safer for satellites to attempt to send information as soon as the ground station is in sight, possibly resulting in more data being transferred during each pass of the satellite.

    Data can also be lost for other reasons, like bad weather. Optical communications, for example, can be severely affected by cloud cover, so to avoid loss of data it is necessary to wait for clear skies to send information. DTN networks would support this data being sent at any time, as lost data would be automatically detected and resent.

    A third advantage of DTNs is that data can be automatically prioritised. Michael Staub, who managed the project from GMV INSYEN, explains, “The DTNs that we created successfully sorted data depending on its priority, meaning that important observations – for example those made during natural disasters – would be sent as quickly as possible, even if other data joined the queue first.”

    This study is one step further in our understanding of how DTNs could revolutionise space communications. Next, experts will investigate how DTNs can be implemented technically, what data types would profit most, the potential impact on operations and operators, and where new markets and users could benefit from this technology.

    ESA Ops-sat Cubesat

    One option being considered for testing DTNs is ESA’s OPS-SAT CubeSat. The 30-centimetre high demonstrator will test out a large variety of technologies, including DTNs, to provide information useful for larger future missions. Eventually, the more spacecraft and ground stations using DTN technology, the more benefits the technology will bring.

    “Through this study, we have shown that DTNs would be very beneficial for Earth observation scenarios,” concludes Staub. “The networks we propose will enable organisations and commercial entities to interoperate, including encouraging the sharing of each other’s facilities and resources.”

    With space exploration becoming more complex, current communication networks become increasingly inadequate. DTNs would facilitate the next generation of space missions.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

  • richardmitnick 10:59 am on December 27, 2018 Permalink | Reply
    Tags: , Earth Observation, Mysterious Anomaly Under Africa Is Weakening Earth's Magnetic Field, ,   

    From Science Alert and U Rochester: “Mysterious Anomaly Under Africa Is Weakening Earth’s Magnetic Field” 


    From Science Alert

    27 DEC 2018

    (NASA Hubble Space Telescope/Flickr)

    Above our heads, something is not right. Earth’s magnetic field is in a state of dramatic weakening – and according to mind-boggling research from earlier this year, this phenomenal disruption is part of a pattern lasting for over 1,000 years.

    Earth’s magnetic field doesn’t just give us our north and south poles; it’s also what protects us from solar winds and cosmic radiation – but this invisible force field is rapidly weakening, to the point scientists think it could actually flip, with our magnetic poles reversing.

    As crazy as that sounds, this actually does happen over vast stretches of time. The last time it occurred was about 780,000 years ago, although it got close again around 40,000 years back.

    When it takes place, it’s not quick, with the polarity reversal slowly occurring over thousands of years.

    Nobody knows for sure if another such flip is imminent, and one of the reasons for that is a lack of hard data.

    The region that concerns scientists the most at the moment is called the South Atlantic Anomaly – a huge expanse of the field stretching from Chile to Zimbabwe. The field is so weak within the anomaly that it’s hazardous for Earth’s satellites to enter it, because the additional radiation it’s letting through could disrupt their electronics.

    “We’ve known for quite some time that the magnetic field has been changing, but we didn’t really know if this was unusual for this region on a longer timescale, or whether it was normal,” physicist Vincent Hare from the University of Rochester in New York said in February this year.

    One of the reasons scientists don’t know much about the magnetic history of this region of Earth is it lacks what’s called archeomagnetic data – physical evidence of magnetism in Earth’s past, preserved in archaeological relics from bygone ages.

    One such bygone age belonged to a group of ancient Africans, who lived in the Limpopo River Valley – which borders Zimbabwe, South Africa, and Botswana: regions that fall within the South Atlantic Anomaly of today.

    Approximately 1,000 years ago, these Bantu peoples observed an elaborate, superstitious ritual in times of environmental hardship.

    During times of drought, they would burn down their clay huts and grain bins, in a sacred cleansing rite to make the rains come again – never knowing they were performing a kind of preparatory scientific fieldwork for researchers centuries later.

    “When you burn clay at very high temperatures, you actually stabilise the magnetic minerals, and when they cool from these very high temperatures, they lock in a record of the earth’s magnetic field,” one of the team, geophysicist John Tarduno explained.

    As such, an analysis of the ancient artefacts that survived these burnings reveals much more than just the cultural practices of the ancestors of today’s southern Africans.

    “We were looking for recurrent behaviour of anomalies because we think that’s what is happening today and causing the South Atlantic Anomaly,” Tarduno said.

    “We found evidence that these anomalies have happened in the past, and this helps us contextualise the current changes in the magnetic field.”

    Like a “compass frozen in time immediately after [the] burning”, the artefacts revealed that the weakening in the South Atlantic Anomaly isn’t a standalone phenomenon of history.

    Similar fluctuations occurred in the years 400-450 CE, 700-750 CE, and 1225-1550 CE – and the fact that there’s a pattern tells us that the position of the South Atlantic Anomaly isn’t a geographic fluke.

    “We’re getting stronger evidence that there’s something unusual about the core-mantel boundary under Africa that could be having an important impact on the global magnetic field,” Tarduno says.

    The current weakening in Earth’s magnetic field – which has been taking place for the last 160 years or so – is thought to be caused by a vast reservoir of dense rock called the African Large Low Shear Velocity Province, which sits about 2,900 kilometres (1,800 miles) below the African continent.

    “It is a profound feature that must be tens of millions of years old,” the researchers explained in The Conversation last year.

    “While thousands of kilometres across, its boundaries are sharp.”

    This dense region, existing in between the hot liquid iron of Earth’s outer core and the stiffer, cooler mantle, is suggested to somehow be disturbing the iron that helps generate Earth’s magnetic field.

    There’s a lot more research to do before we better understand what’s going on here.

    As the researchers explain, the conventional idea of pole reversals is that they can start anywhere in the core – but the latest findings suggest what happens in the magnetic field above us is tied to phenomena at special places in the core-mantle boundary.

    If they’re right, a big piece of the field weakening puzzle just fell in our lap – thanks to a clay-burning ritual a millennia ago. What this all means for the future, though, no-one is certain.

    “We now know this unusual behaviour has occurred at least a couple of times before the past 160 years, and is part of a bigger long-term pattern,” Hare said.

    “However, it’s simply too early to say for certain whether this behaviour will lead to a full pole reversal.”

    The findings are reported in Geophysical Review Letters.

    See the full Science Alert article here .

    From U Rochester: “Earth’s magnetic field fluctuations explained by new data”

    February 27, 2018

    Earth’s geomagnetic field surrounds and protects our planet from harmful space radiation. (CC BY-SA 2.0 photo / Flickr user NASA Goddard Space Flight Center)

    Using new data gathered from sites in southern Africa, University of Rochester researchers have extended their record of Earth’s magnetic field back thousands of years to the first millennium.

    The record provides historical context to help explain recent, ongoing changes in the magnetic field, most prominently in an area in the Southern Hemisphere known as the South Atlantic Anomaly.

    “We’ve known for quite some time that the magnetic field has been changing, but we didn’t really know if this was unusual for this region on a longer timescale, or whether it was normal,” says Vincent Hare, who recently completed a postdoctoral associate appointment in the Department of Earth and Environmental Sciences (EES) at the University of Rochester, and is lead author of a paper published in Geophysical Research Letters [link is above].

    Weakening magnetic field a recurrent anomaly

    The new data also provides more evidence that a region in southern Africa may play a unique role in magnetic pole reversals.

    he magnetic field that surrounds Earth not only dictates whether a compass needle points north or south, but also protects the planet from harmful radiation from space. Nearly 800,000 years ago, the poles were switched: north pointed south and vice versa. The poles have never completely reversed since, but for the past 160 years, the strength of the magnetic field has been decreasing at an alarming rate. The region where it is weakest, and continuing to weaken, is a large area stretching from Chile to Zimbabwe called the South Atlantic Anomaly.

    In order to put these relatively recent changes into historical perspective, Rochester researchers—led by John Tarduno, a professor and chair of EES—gathered data from sites in southern Africa, which is within the South Atlantic Anomaly, to compile a record of Earth’s magnetic field strength over many centuries. Data previously collected by Tarduno and Rory Cottrell, an EES research scientist, together with theoretical models developed by Eric Blackman, a professor of physics and astronomy at Rochester, suggest the core region beneath southern Africa may be the birthplace of recent and future pole reversals.

    “We were looking for recurrent behavior of anomalies because we think that’s what is happening today and causing the South Atlantic Anomaly,” Tarduno says. “We found evidence that these anomalies have happened in the past, and this helps us contextualize the current changes in the magnetic field.”

    The researchers discovered that the magnetic field in the region fluctuated from 400-450 AD, from 700-750 AD, and again from 1225-1550 AD. This South Atlantic Anomaly, therefore, is the most recent display of a recurring phenomenon in Earth’s core beneath Africa that then affects the entire globe.

    “We’re getting stronger evidence that there’s something unusual about the core-mantel boundary under Africa that could be having an important impact on the global magnetic field,” Tarduno says.

    A pole reversal? Not yet, say researchers.

    The magnetic field is generated by swirling, liquid iron in Earth’s outer core. It is here, roughly 1800 miles beneath the African continent, that a special feature exists. Seismological data has revealed a denser region deep beneath southern Africa called the African Large Low Shear Velocity Province. The region is located right above the boundary between the hot liquid outer core and the stiffer, cooler mantle. Sitting on top of the liquid outer core, it may sink slightly, disturbing the flow of iron and ultimately affecting Earth’s magnetic field.

    A major change in the magnetic field would have wide-reaching ramifications; the magnetic field stimulates currents in anything with long wires, including the electrical grid. Changes in the magnetic field could therefore cause electrical grid failures, navigation system malfunctions, and satellite breakdowns. A weakening of the magnetic field might also mean more harmful radiation reaches Earth—and trigger an increase in the incidence of skin cancer.

    Hare and Tarduno warn, however, that their data does not necessarily portend a complete pole reversal.

    “We now know this unusual behavior has occurred at least a couple of times before the past 160 years, and is part of a bigger long-term pattern,” Hare says. “However, it’s simply too early to say for certain whether this behavior will lead to a full pole reversal.”

    Even if a complete pole reversal is not in the near future, however, the weakening of the magnetic field strength is intriguing to scientists, Tarduno says. “The possibility of a continued decay in the strength of the magnetic field is a societal concern that merits continued study and monitoring.”

    This study was funded by the US National Science Foundation.

    See the full U Rochester article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 2:50 pm on December 19, 2018 Permalink | Reply
    Tags: , Earth Observation, , Kīlauea Eruption’s Media Frenzy, Nine tips about how to debunk geohazard misinformation in real time from a scientist,   

    From Eos: “Lessons Learned from Kīlauea Eruption’s Media Frenzy” 

    From AGU
    Eos news bloc

    From Eos

    18 December 2018
    Jenessa Duncombe

    The Kīlauea eruption earlier this year unleashed a media bonanza. Here are nine tips about how to debunk geohazard misinformation in real time from a scientist frequently tapped for expert comments.

    A fountain of lava from Kīlauea’s fissure 8 in May 2018. Credit: iStock.com/Frizi

    One hundred interviews in 1 month: That’s how many volcanologist Ken Rubin and his colleagues at the University of Hawai‘i gave during the Kīlauea Volcano eruption in May earlier this year.

    Rubin was working as a professor in Earth science in Honolulu, Hawaii, when, in April, magma supply increased to the volcano, causing an upper lava lake to overflow. Earthquakes followed, changing the plumbing of the volcano, and the magma drained out of the primary vent. The eruption had begun.

    Over the next 4 months, 20 eruptive fissures would open in the area, some of which led to hundreds of homes being destroyed. The event was a focus of national and international news, and as the crisis escalated, misinformation started to fly.

    Rubin and his colleagues stepped up to be available for media interviews while geologists at the Hawaiian Volcano Observatory were busy monitoring the situation. Last week, Rubin gave a presentation at AGU’s Fall Meeting 2018 detailing what he learned from stepping into the media spotlight.

    Here are nine takeaways from Rubin’s talk:

    1.People want immediate access to information in the 24-hour news cycle. “The public has an expectation of that right now,” Rubin said. But agencies like the U.S. Geological Survey (USGS) aren’t always equipped to communication so frequently. “The USGS puts out awesome products,” he said, “but they come out once a day, and that’s just too slow in an event like this.”

    2.Without continuous information coming from official channels, citizens scientists and local news channels fill the void. That’s how people found out about the start of the eruption, said Rubin, from a drone video of a fissure taken from a resident’s backyard and posted to social media. News organizations can pick up these sources and distribute them, for better or for worse.

    3.Unofficial sources can lead to exaggerated or misconceived news. The most doomsday rumor flying around during the Kīlauea eruption, said Rubin, was the idea that half of Kīlauea was going to break off into the ocean and cause a tsunami that would wipe out the west coast of the United States. “There is no evidence in the geological record that this has ever happened,” Rubin noted. Other myths included refrigerator-sized lava bombs and acid pouring into the ocean from the volcano.

    What is a researcher to do, knowing the media landscape today? Rubin offered this advice:

    4.Provide historical context. “None of these hazards were new to this event. They’ve happened multiple times over the 35-year history of the eruption.” In the early days of the eruption, he created a map of past lava deposits from 1955 and 1960 in the area to give historical perspective.

    5.When possible, push content as much as possible out on social media. Rubin put the historical map out on his social media, and his posts were often picked up by news organizations, which he could reference during live interviews.

    6.Put parameters around the real danger of the situation. “Despite most of what you heard from the national and international media that the hazards were very widespread, they were extremely local,” explained Rubin. “It really only impacted people in the immediate area.” Harm that did befall people, such as one man whose leg was broken from a lava bomb, happened to those who did not follow evacuation orders.

    7.Understand that debunking misinformation will be a huge part of your job. “A lot of the role of a knowledgeable scientist is to debunk these bizarre theories, while being interviewed live in real time by CNN,” Rubin said. Keep tabs on the present rumors and prepare a response.

    8.Make a script and stick with it. Rubin and his colleagues created daily scripts for speaking with the media.

    9.Have endurance. “It is a pain in the butt,” Rubin said. Journalists will call “at all hours,” he said, and often one interview will bring an onslaught of new calls. Respond quickly to requests but also learn to set boundaries.

    Rubin ended his talk with a call to researchers to step up to the plate when events demand their expertise.

    “Having knowledgeable scientists involved in the information flow is the only way, in my opinion, to help keep the misinformation to a minimum,” he said.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Eos is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

  • richardmitnick 12:14 pm on December 19, 2018 Permalink | Reply
    Tags: , Discovery of recent Antarctic ice sheet collapse raises fears of a new global flood, Earth Observation, Glaciologists worry about the present-day stability of the West Antarctic Ice Sheet,   

    From Science Magazine: “Discovery of recent Antarctic ice sheet collapse raises fears of a new global flood” 

    From Science Magazine

    Dec. 18, 2018
    Paul Voosen

    A 30-kilometer crack angles across the Pine Island Glacier, a vulnerable part of the West Antarctic Ice Sheet. NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team/Flickr

    Some 125,000 years ago, during the last brief warm period between ice ages, Earth was awash. Temperatures during this time, called the Eemian, were barely higher than in today’s greenhouse-warmed world. Yet proxy records show sea levels were 6 to 9 meters higher than they are today, drowning huge swaths of what is now dry land.

    Scientists have now identified the source of all that water: a collapse of the West Antarctic Ice Sheet. Glaciologists worry about the present-day stability of this formidable ice mass. Its base lies below sea level, at risk of being undermined by warming ocean waters, and glaciers fringing it are retreating fast. The discovery, teased out of a sediment core and reported last week at a meeting of the American Geophysical Union in Washington, D.C., validates those concerns, providing evidence that the ice sheet disappeared in the recent geological past under climate conditions similar to today’s. “We had an absence of evidence,” says Anders Carlson, a glacial geologist at Oregon State University in Corvallis, who led the work. “I think we have evidence of absence now.”

    If it holds up, the finding would confirm that “the West Antarctic Ice Sheet might not need a huge nudge to budge,” says Jeremy Shakun, a paleoclimatologist at Boston College. That, in turn, suggests “the big uptick in mass loss observed there in the past decade or two is perhaps the start of that process rather than a short-term blip.” If so, the world may need to prepare for sea level to rise farther and faster than expected: Once the ancient ice sheet collapse got going, some records suggest, ocean waters rose as fast as some 2.5 meters per century.

    As an analogy for the present, the Eemian, from 129,000 to 116,000 years ago, is “probably the best there is, but it’s not great,” says Jacqueline Austermann, a geophysicist at Columbia University’s Lamont-Doherty Earth Observatory. Global temperatures were some 2°C above preindustrial levels (compared with 1°C today). But the cause of the warming was not greenhouse gases, but slight changes in Earth’s orbit and spin axis, and Antarctica was probably cooler than today. What drove the sea level rise, recorded by fossil corals now marooned well above high tide, has been a mystery.

    Scientists once blamed the melting of Greenland’s ice sheet. But in 2011, Carlson and colleagues exonerated Greenland after identifying isotopic fingerprints of its bedrock in sediment from an ocean core drilled off its southern tip. The isotopes showed ice continued to grind away at the bedrock through the Eemian. If the Greenland Ice Sheet didn’t vanish and push up sea level, the vulnerable West Antarctic Ice Sheet was the obvious suspect. But the suspicion rested on little more than simple subtraction, Shakun says. “It’s not exactly the most compelling or satisfying argument.”

    Carlson and his team set out to apply their isotope technique to Antarctica. First, they drew on archived marine sediment cores drilled from along the edge of the western ice sheet. Studying 29 cores, they identified geochemical signatures for three different bedrock source regions: the mountainous Antarctic Peninsula; the Amundsen province, close to the Ross Sea; and the area in between, around the particularly vulnerable Pine Island Glacier.

    Armed with these fingerprints, Carlson’s team then analyzed marine sediments from a single archived core, drilled farther offshore in the Bellingshausen Sea, west of the Antarctic Peninsula. A stable current runs along the West Antarctic continental shelf, picking up ice-eroded silt along the way. The current dumps much of this silt near the core’s site, where it builds up fast and traps shelled microorganisms called foraminifera, which can be dated by comparing their oxygen isotope ratios to those in cores with known dates. Over a stretch of 10 meters, the core contained 140,000 years of built-up silt.

    For most of that period, the silt contained geochemical signatures from all three of the West Antarctic bedrock regions, the team reported, suggesting continuous ice-driven erosion. But in a section dated to the early Eemian, the fingerprints winked out: first from the Pine Island Glacier, then from the Amundsen province. That left only silt from the mountainous peninsula, where glaciers may have persisted. “We don’t see any sediments coming from the much larger West Antarctic Ice Sheet, which we’d interpret to mean that it was gone. It didn’t have that erosive power anymore,” Carlson says.

    He concedes that the dating of the core is not precise, which means the pause in erosion may not have taken place during the Eemian. It is also possible that the pause itself is illusory—that ocean currents temporarily shifted, sweeping silt to another site.

    More certainty is on the way. Next month, the International Ocean Discovery Program’s JOIDES Resolution research ship will begin a 3-month voyage to drill at least five marine cores off West Antarctica.

    JOIDES Resolution research ship

    “That’s going to be a great test,” Carlson says. Meanwhile, he hopes to get his own study published in time to be included in the next United Nations climate report. In the 2001 and 2007 reports, West Antarctic collapse was not even considered in estimates of future sea level; only in 2013 did authors start to talk about an Antarctic surprise, he says. Research is due by December 2019. “We gotta beat that deadline.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 10:52 am on December 19, 2018 Permalink | Reply
    Tags: Early data suggest that Antarctica’s Dotson ice shelf has lost more than 390 feet (120 meters) in thickness since 2003, Earth Observation, Measuring the height of sea ice to within an inch, NASA ICEsat-2,   

    From University of Washington: “UW glaciologist gets first look at NASA’s new measurements of ice sheet elevation” 

    U Washington

    From University of Washington

    December 14, 2018
    Hannah Hickey

    The horizontal blue line is the travel path for ICESat-2. The lower line shows some of its first measurements. This satellite can capture steep terrain and measure elevation much more precisely than its predecessor. NASA’s Earth Observatory/Joshua Stevens

    Less than three months into its mission, NASA’s Ice, Cloud and land Elevation Satellite-2, or ICESat-2, is already exceeding scientists’ expectations, according to the space agency.

    NASA ICEsat-2

    The satellite is measuring the height of sea ice to within an inch, tracing the terrain of previously unmapped Antarctic valleys and measuring other interesting features in our planet’s elevation.

    Benjamin Smith, a glaciologist with the University of Washington and member of the ICESat-2 science team, shared the first look at the satellite’s performance at the American Geophysical Union’s annual meeting Dec. 11 in Washington, D.C.

    Mountain valleys “have been really difficult targets for altimeters in the past, which have often used radar instead of lasers and they tend to show you just a big lump where the mountains are,” Smith told the BBC. “But we can see very steeply sloping surfaces; we can see valley glaciers; we’ll be able to make out very small details.”

    With each pass of the ICESat-2 satellite, the mission is adding to the data sets that track Earth’s rapidly changing ice. Researchers are ready to use the information to study sea level rise resulting from melting ice sheets and glaciers, and to improve sea ice and climate forecasts.

    In topographic maps of the Transantarctic Mountains, which divide east and west Antarctica, there are places where other satellites cannot see, Smith said. Some instruments don’t orbit that far south, while others only pick up large features or the highest points and so miss minor peaks and valleys. Since launching ICESat-2, in the past three months scientists have started to fill in those details.

    “It’s spectacular terrain,” Smith said. “We’re able to measure slopes that are steeper than 45 degrees, and maybe even more, all through this mountain range.”

    As ICESat-2 orbits over Antarctica, the photons reflect from the surface and show high ice plateaus, crevasses in the ice 65 feet (20 meters) deep, and the sharp edges of ice shelves dropping into the ocean. These first measurements can help fill in the gaps of Antarctic maps, Smith said, but the key science of the ICESat-2 mission is yet to come. As researchers refine knowledge of where the instrument is pointing, they can start to measure the rise or fall of ice sheets and glaciers.

    Early data suggest that Antarctica’s Dotson ice shelf has lost more than 390 feet (120 meters) in thickness since 2003, Smith told the Associated Press.

    “Very soon, we’ll have measurements that we can compare to older measurements of surface elevation,” Smith said. “And after the satellite’s been up for a year, we’ll start to be able to watch the ice sheets change over the seasons.”

    Mission managers expect to release the data to the public in early 2019.

    The first ICESat satellite operated between 2003 and 2009. The more sophisticated ICESat-2 launched Sept. 15, 2018, from Vandenberg Air Force Base in California. Its laser instrument, called ATLAS (Advanced Topographic Laser Altimeter System), sends pulses of light to Earth. The instrument then times, to within a billionth of a second, how long it takes individual photons to return to the satellite. ATLAS has fired its laser more than 50 billion times since going live Sept. 30, and all the metrics from the instrument show it is working as it should, NASA scientists say. IceBridge, an aircraft-based NASA campaign, operated between the two satellite missions.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Washington is one of the world’s preeminent public universities. Our impact on individuals, on our region, and on the world is profound — whether we are launching young people into a boundless future or confronting the grand challenges of our time through undaunted research and scholarship. Ranked number 10 in the world in Shanghai Jiao Tong University rankings and educating more than 54,000 students annually, our students and faculty work together to turn ideas into impact and in the process transform lives and our world. For more about our impact on the world, every day.
    So what defines us —the students, faculty and community members at the University of Washington? Above all, it’s our belief in possibility and our unshakable optimism. It’s a connection to others, both near and far. It’s a hunger that pushes us to tackle challenges and pursue progress. It’s the conviction that together we can create a world of good. Join us on the journey.

  • richardmitnick 8:30 am on November 27, 2018 Permalink | Reply
    Tags: , Earth Observation, , Yellowstone's Eternal Scenes are Changing Before Our Eyes   

    From The New York Times: “Your Children’s Yellowstone Will Be Radically Different” 

    New York Times

    From The New York Times

    NOV. 15, 2018
    Marguerite Holloway
    Photographs and time-lapse video by Josh Haner

    On a recent fall afternoon in the Lamar Valley, visitors watched a wolf pack lope along a thinly forested riverbank, ten or so black and gray figures shadowy against the snow. A little farther along the road, a herd of bison swung their great heads as they rooted for food in the sagebrush steppe, their deep rumbles clear in the quiet, cold air.

    In the United States, Yellowstone National Park is the only place bison and wolves can be seen in great numbers. Because of the park, these animals survive. Yellowstone was crucial to bringing back bison, reintroducing gray wolves, and restoring trumpeter swans, elk, and grizzly bears — all five species driven toward extinction found refuge here.

    Bison in Yellowstone.

    But the Yellowstone of charismatic megafauna and of stunning geysers that four million visitors a year travel to see is changing before the eyes of those who know it best. Researchers who have spent years studying, managing, and exploring its roughly 3,400 square miles say that soon the landscape may look dramatically different.

    Over the next few decades of climate change, the country’s first national park will quite likely see increased fire, less forest, expanding grasslands, shallower, warmer waterways, and more invasive plants — all of which may alter how, and how many, animals move through the landscape. Ecosystems are always in flux, but climate change is transforming habitats so quickly that many plants and animals may not be able to adapt well or at all.

    Yellowstone National Park, established in 1872, is one of the Unesco World Heritage sites threatened by climate change. It is home to some of the country’s oldest weather stations, including one at Mammoth Hot Springs. Data from the park and surrounding area has helped scientists understand and track climate change in the Western United States.

    Since 1948, the average annual temperature in the Greater Yellowstone Ecosystem — an area of 34,375 square miles that includes the park, national forests, and Grand Teton National Park — has risen about 2 degrees Fahrenheit. Researchers report that winter is, on balance, 10 days shorter and less cold.

    The Grand Prismatic Spring from above

    “For the Northern Rockies, snowpack has fallen to its lowest level in eight centuries,” said Patrick Gonzalez, a forest and climate change scientist at the University of California, Berkeley.

    Because snow is a cornerstone of the park’s ecology, the decline is alarming to some ecologists.

    The Grand Prismatic Spring.

    Summers in the park have become warmer, drier and increasingly prone to fire. Even if rainfall increases in the future, it will evaporate more quickly, said Michael Tercek, an ecologist who has worked in Yellowstone for 28 years.

    “By the time my daughter is an old woman, the climate will be as different for her as the last ice age seems to us,” Dr. Tercek said.

    Yellowstone’s unusual landscape — of snow and steam, of cold streams and hot springs — is volcanic. Magma gives rise to boiling water and multihued thermophiles, bacteria that thrive at high temperatures.

    In 1883, The New York Times described the park as an “almost mystical wonderland.”

    For many visitors, Yellowstone represents American wilderness: a place with big, open skies where antelope and bison still roam.

    “You run into visitors and they thank you for the place,” said Ann Rodman, a park scientist. “They are seeing elk and antelope for the first time in their lives.”

    An elk at Mammoth Hot Springs

    Ms. Rodman, who has been working in Yellowstone for 30 years, has pored over temperature and weather data. The trends surprised her, as well as the urgency.

    “When I first started doing it, I really thought climate change was something that was going to happen to us in the future,” she said. “But it is one of those things where the more you study it, the more you realize how much is changing and how fast.”

    “Then you begin to go through this stage, I don’t know if it is like the stages of grief,” Ms. Rodman said. “All of a sudden it hits you that this is a really, really big deal and we aren’t really talking about it and we aren’t really thinking about it.”

    Ann Rodman, a scientist at Yellowstone.

    Ms. Rodman has seen vast changes near the town of Gardiner, Mont., at the north entrance to Yellowstone. Some non-nutritious invasive plants like cheatgrass and desert madwort have replaced nutritious native plants. Those changes worry Ms. Rodman and others: Give invasives an inch and they take miles.

    Cheatgrass has already spread into the Lamar Valley. “This is what we don’t want — to turn into what it looks like in Gardiner,” Ms. Rodman said. “The seeds come in on people’s cars and on people’s boots.”

    Pronghorn antelope, with cheatgrass in the background.

    Cheatgrass can thrive in disturbed soils and can ignite “like tissue paper,” she said. It takes hold after fires, preventing native plants from regrowing.

    If cheatgrass and its ilk spread, bison and elk could be affected. Cheatgrass, for instance, grows quickly in the spring. “It can suck the moisture out of the ground early,” Ms. Rodman said. “Then it is gone, so it doesn’t sustain animals throughout the summer the way native grasses would.”

    In recent years, elk have lost forage when drier, hotter summers have shortened what ecologists call the green wave, in which plants become green at different times at different elevations, said Andrew J. Hansen of Montana State University.

    Some elk now stay in valleys outside the park, nibbling lawns and alfalfa fields, Dr. Hansen said. And where they go, wolves follow. “It is a very interesting mix of land-use change and climate change, possibly leading to quite dramatic shifts in migration and to thousands of elk on private land,” he said.

    Drier summers also mean that fires are a greater threat. The conditions that gave rise to the fires of 1988, when a third of the park burned, could become common.

    By the end of the century, “the weather like the summer of ’88 will likely be there all the time rather than being the very rare exception,” said Monica G. Turner of the University of Wisconsin-Madison. “As the climate is warming, we are getting fires that are happening more often. We are starting to have the young forests burn again before they have had a chance to recover.”

    Evergreen forest damaged by bark beetles.

    rees, and new growth, after a forest fire.

    In 2016, a wildfire swept through trees in a section near the Madison River that had burned in 1988. Because young trees don’t have many cones on them, Dr. Turner said, they don’t have as many seeds to release to form new forest. The cones they do have are close to the ground, which means they are less likely to survive the heat.

    Repeated fires could lead to more grassland. “The structure of the forests is going to change,” Dr. Turner said. “They might become sparse or not recover if we keep doing a double and triple whammy.”

    Forests shade waterways, and those too are experiencing climate-related changes. “We can very definitely see warming trends during the summer and fall,” said Daniel J. Isaak of the United States Forest Service. “Stream and river flows are declining as snowpack declines.” As fish become concentrated in smaller areas, Dr. Isaak said, disease can increase in a population because transmission is easier.

    Sour Creek

    In 2016, the Yellowstone River — famous for its fly fishing and its cutthroat trout, which thrive in colder waters — was closed to anglers for 183 miles downstream from the park after an outbreak of kidney disease killed thousands of fish. “The feeling was that this was a canary in the coal mine,” said Dan Vermillion of Sweetwater Travel Company, a fly-fishing operation in Livingston, Mont.

    Lower flows and warmer water are one consequence of spring arriving earlier. Quickly melting snow unleashing torrents is another. Flooding has affected the nesting of water birds like common loons, American white pelicans, and double-crested cormorants. “All their nesting is on lakes and ponds, and water levels are fluctuating wildly, as it does with climate change,” said Douglas W. Smith, a park biologist.

    And Yellowstone’s trumpeter swans are declining. By the early 20th century, hunters had wiped out most of the enormous birds in the continental United States, killing them for food and fashionable feathers. But 70 or so swans remained in the Yellowstone region, some of them safe inside the park. Those birds helped restore trumpeters nationwide. Now only two trumpeter pairs live in the park, and they have not bred successfully for several years.

    Part of the reason, said Dr. Smith and a colleague, Lauren E. Walker, may be the loss of nests and nesting sites during spring floods. A pair on Swan Lake, just south of Mammoth Hot Springs, has spurned the floating nest that the Park Service installed to help the birds.

    “Heritage-wise this is a really important population,” Dr. Walker said. “If this is no longer a reliable spot, what does that mean for the places that may have more human disturbance?”

    On the shores of Yellowstone Lake, dozens of late-season visitors watched two grizzly bears eating a carcass, while a coyote and some ravens circled, just a hundred or so yards from the road. “If they run this way,” the ranger called out, “get in your cars.”

    Grizzlies are omnivores, eating whatever is available, including the fat- and protein-packed nuts of the whitebark pine. That pine is perhaps the species most visibly affected by climate change in Yellowstone and throughout the West. Warmer temperatures have allowed a native pest, the mountain pine beetle, to better survive winter, move into high elevations and have a longer reproductive season. In the last 30 years, an estimated 80 percent of the whitebark pines in the park have died by fire, beetle, or fungal infection.

    For want of the whitebark pine, a great deal could be lost. The trees are a foundation species, meaning they play a central role in the structure of the ecosystem. They colonize exposed mountain sites, allowing other plants to get a root-hold. Their wide canopies protect snowpack from the sun. They are also a keystone species. They provide food for birds like the Clark’s nutcracker, which, in turn, create whitebark pine nurseries by caching nuts. And they are an important food source for squirrels, foxes, and grizzlies.

    When pine nuts are not plentiful, bears consume other foods, including the elk or deer innards left by hunters outside the park. And that can bring the Yellowstone-area grizzlies, relisted as threatened this September, into conflict with people.

    The loss of the pines “has far-reaching implications for the entire ecosystem,” said Jesse A. Logan, a retired Forest Service researcher.

    “The rest of the landscape, even in the mountainous West, has been so altered that Yellowstone becomes even more important,” Dr. Logan said.

    Yellowstone provides a refuge for people seeking and delighting in a sense of wilderness. It offers a landscape unlike any other: a largely intact ecosystem rich in wildlife and rich in geothermal features. Yellowstone’s unusual beauty was forged by volcanic heat; heat from humanity could be its undoing.

    Map showing Snow-telemetry (SNOTEL) weather stations in and near Yellowstone National Park. Left: Background shows average number of days per water year (October–September) with SWE greater than 0 cm. Right: Background shows average annual peak (greatest) SWE (cm). Data source = SNODAS [20]. Both panels are averaged over water years ending 2005– 2014, which was the length of record available for this data source. Gray areas = Lakes.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 2:40 pm on November 17, 2018 Permalink | Reply
    Tags: Airbus Zephyr S, Earth Observation, , HAPS – missions to the edge of space to watch over Earth, High Altitude Pseudo Satellite, , Potential High Altitude Pseudo Satellite Design   

    From European Space Agency: “HAPS – missions to the edge of space to watch over Earth” 

    ESA Space For Europe Banner

    From European Space Agency

    15 November 2018

    Lighter-than-air Stratobus, Thales Alenia Space/Briot
    Thales Alenia Space’s Stratobus airship can carry up to 250 kg of payload, its electric engines flying against the breeze to hold itself in position, and relying on fuel cells at night. Its first flight is projected for 2021.

    Is it a bird? Is it a plane? No, it’s a High-Altitude Pseudo-Satellite (HAPS) — an uncrewed airship, plane or balloon watching over Earth from the stratosphere. Operating like satellites but from closer to Earth, HAPS are the ‘missing link’ between drones flying close to Earth’s surface and satellites orbiting in space.

    They float or fly high above conventional aircraft and offer continuous day-and-night coverage of the territory below. Target applications include search and rescue missions, disaster relief, environmental monitoring and agriculture.

    ESA’s Directorates of Telecommunication, Earth Observation and Navigation are working together to establish a HAPS Programme. The Agency will hold its second HAPS4ESA workshop on 12–14 February 2019, and the future of HAPS was discussed at yesterday’s Φ-week session at ESA’s Earth observation centre in Frascati, Italy.


    Airbus Zephyr S , Airbus
    The Airbus Zephyr S is a High Altitude Pseudo Satellite (HAPS) that flew for more than 25 days on its maiden flight in 2018. HAPS float or fly high above conventional aircraft and offer continuous day-and-night coverage of the territory below. Target applications include search and rescue missions, disaster relief, environmental monitoring and agriculture.

    Additionally, ESA is performing other HAPS studies through its Discovery and Preparation Programme, identifying how HAPS could bring value to satellite communications and Earth observation in terms of performance or cost, to highlight gaps in current HAPS technologies, and plan moves towards operational services.

    “HAPS could give us prolonged high-resolution coverage of specific regions of Earth,” explains Juan Lizarraga Cubillos, leading both studies from ESA. “They could also help provide tactica and emergency communications and broadband internet services.”

    By combining the expertise of telecommunications company HISPASAT and aircraft maker Airbus, the TELEO – High-Altitude Pseudo-Satellites for Telecommunication and Complementary Space Applications – team found that aerodynamic HAPS, taking the form of aircraft, could complement traditional satellite networks.

    HAPS could also improve security for major events – for example the Olympic Games or G7 meetings– and emergency situations, by providing secure communication bubbles over areas of interest.

    High Altitude Pseudo Satellite, ESA
    In the future, High Altitude Pseudo Satellites could be used as relays between satellites and ground stations to improve data transfer.

    Juan Carlos Martin Quirós from HISPASAT explains, “Because HAPS can be rapidly deployed compared to satellites, in addition to being low-cost and flexible, they could be extremely useful in telecommunications services.”

    The TELEO team also looked at disaster management and maritime traffic safety and security.

    “At Airbus we have demonstrated that aerodynamic HAPS are a practical reality – a Zephyr S was flown this year carrying prototypes of passive Earth observation payloads,” explains Steffen Kuntz from Airbus.

    Potential High Altitude Pseudo Satellite Design, ESA
    Design for a High Altitude Pseudo Satellite (HAPS) arising from a Discovery and Preparation study. The study, HAPPIEST, investigated the role of HAPS in future telecommunications networks, looking at where they could complement and fill gaps in existing satellite networks and applications.

    The HAPPIEST – High-Altitude Pseudo-Satellites: Proposal of Initiatives to Enhance Satellite Communication – team from the University of León, Thales Alenia Space, Elecnor Deimos and Airobotics mainly focused on the potential of ‘aerostatic’ HAPS in the form of stratospheric balloons – able to carry more payload and generate more power than aerodynamic HAPS.

    HAPPIEST investigated the role of HAPS in future telecommunications networks, to complement and fill gaps in existing satellite networks and applications.

    HAPS looks promising – both economically and technically – in response to natural disasters or in supporting field activities in areas lacking infrastructure, such as remote areas or the deep sea. Additionally, HAPS could be useful as an intermediate relay step between a satellite and a ground station, easing the transfer of data and reducing the ground and satellite infrastructure required.

    High-altitude pseudo-satellites, ESA Earth Observation Graphics Bureau

    High Altitude Pseudo-Satellites, or HAPS, are platforms that float or fly at high altitude like conventional aircraft but operate more like satellites – except that rather than working from space they can remain in position inside the atmosphere for weeks or even months, variously enabling precise monitoring and surveillance, high-bandwidth communications or back up to existing satellite navigation services.

    “We found that HAPS don’t really compete with terrestrial networks in highly developed areas, or with satellite networks where the areas of interest are large”, explains Jesus Gonzalo, leading the project from the University of León. “But HAPS efficiently complement the networks in between, where the target area is limited and changing and where ground infrastructure is inexistent or unavailable.”

    Based on their research, the HAPPIEST team designed a HAPS measuring 181 metres long, with a take-off mass of 16 metric tons for an operational payload of 250 kg, envisaged for the 2025 timeframe.

    Looking ahead, ESA is already running five more studies with the objective of developing business cases or innovative new applications and services to be enabled by HAPS. Several further studies are planned for the near future, especially in using HAPS as intermediaries between satellites and ground stations.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    The European Space Agency (ESA), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA50 Logo large

  • richardmitnick 9:58 am on November 16, 2018 Permalink | Reply
    Tags: ACC- Antarctic Circumpolar Current, , , Earth Observation,   

    From CSIROscope: “Explainer: how the Antarctic Circumpolar Current helps keep Antarctica frozen” 

    CSIRO bloc

    From CSIROscope

    16 November 2018
    Helen Phillips
    Benoit Legresy
    Nathan Bindoff

    The Antarctic Circumpolar Current, or ACC, is the strongest ocean current on our planet. It extends from the sea surface to the bottom of the ocean, and encircles Antarctica.

    It is vital for Earth’s health because it keeps Antarctica cool and frozen. It is also changing as the world’s climate warms. Scientists like us are studying the current to find out how it might affect the future of Antarctica’s ice sheets, and the world’s sea levels.

    The ACC carries an estimated 165 million to 182 million cubic metres of water every second (a unit also called a “Sverdrup”) from west to east, more than 100 times the flow of all the rivers on Earth. It provides the main connection between the Indian, Pacific and Atlantic Oceans.

    The tightest geographical constriction through which the current flows is Drake Passage, where only 800 km separates South America from Antarctica. While elsewhere the ACC appears to have a broad domain, it must also navigate steep undersea mountains that constrain its path and steer it north and south across the Southern Ocean.

    Scientists deploying a vertical microstructure profiler (VMP-2000), which measures temperature, salinity, pressure and turbulence, from RV Investigator in the Antarctic Circumpolar Current, November 2018. Photo credit: Nathan Bindoff.

    What is the Antarctic Circumpolar Current?

    A satellite view over Antarctica reveals a frozen continent surrounded by icy waters. Moving northward, away from Antarctica, the water temperatures rise slowly at first and then rapidly across a sharp gradient. It is the ACC that maintains this boundary.

    Map of the ocean surface temperature as measured by satellites and analysed by the European Copernicus Marine Services. The sea ice extent around the antarctic continent for this day appears in light blue. The two black lines indicate the long term position of the southern and northern front of the Antarctic Circumpolar Current.

    The ACC is created by the combined effects of strong westerly winds across the Southern Ocean, and the big change in surface temperatures between the Equator and the poles.

    Ocean density increases as water gets colder and as it gets more salty. The warm, salty surface waters of the subtropics are much lighter than the cold, fresher waters close to Antarctica. We can imagine that the depth of constant density levels slopes up towards Antarctica.

    The westerly winds make this slope steeper, and the ACC rides eastward along it, faster where the slope is steeper, and weaker where it’s flatter.

    Fronts and bottom water

    In the ACC there are sharp changes in water density known as fronts. The Subantarctic Front to the north and Polar Front further south are the two main fronts of the ACC (the black lines in the images). Both are known to split into two or three branches in some parts of the Southern Ocean, and merge together in other parts.

    Scientists can figure out the density and speed of the current by measuring the ocean’s height, using altimeters. For instance, denser waters sit lower and lighter waters stand taller, and differences between the height of the sea surface give the speed of the current.

    Map of how fast the waters around Antarctica are moving in an easterly direction. It is produced using 23 years of satellite altimetry (ocean height) observations as provided by the European Copernicus Marine Services. Author provided.

    The path of the ACC is a meandering one, because of the steering effect of the sea floor, and also because of instabilities in the current.

    The ACC also plays a part in the meridional (or global) overturning circulation, which brings deep waters formed in the North Atlantic southward into the Southern Ocean. Once there it becomes known as Circumpolar Deep Water, and is carried around Antarctica by the ACC. It slowly rises toward the surface south of the Polar Front.

    Once it surfaces, some of the water flows northward again and sinks north of the Subarctic Front. The remaining part flows toward Antarctica where it is transformed into the densest water in the ocean, sinking to the sea floor and flowing northward in the abyss as Antarctic Bottom Water. These pathways are the main way that the oceans absorb heat and carbon dioxide and sequester it in the deep ocean.

    Changing current

    The ACC is not immune to climate change. The Southern Ocean has warmed and freshened in the upper 2,000 m. Rapid warming and freshening has also been found in the Antarctic Bottom Water, the deepest layer of the ocean.

    Waters south of the Polar Front are becoming fresher due to increased rainfall there, and waters to the north of the Polar Front are becoming saltier due to increased evaporation. These changes are caused by human activity, primarily through adding greenhouse gases to the atmosphere, and depletion of the ozone layer. The ozone hole is now recovering but greenhouse gases continue to rise globally.

    Winds have strengthened by about 40% over the Southern Ocean over the past 40 years. Surprisingly, this has not translated into an increase in the strength of the ACC. Instead there has been an increase in eddies that move heat towards the pole, particularly in hotspots such as Drake Passage, Kerguelen Plateau, and between Tasmania and New Zealand.

    We have observed much change already. The question now is how this increased transfer of heat across the ACC will impact the stability of the Antarctic ice sheet, and consequently the rate of global sea-level rise.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    SKA/ASKAP radio telescope at the Murchison Radio-astronomy Observatory (MRO) in Mid West region of Western Australia

    So what can we expect these new radio projects to discover? We have no idea, but history tells us that they are almost certain to deliver some major surprises.

    Making these new discoveries may not be so simple. Gone are the days when astronomers could just notice something odd as they browse their tables and graphs.

    Nowadays, astronomers are more likely to be distilling their answers from carefully-posed queries to databases containing petabytes of data. Human brains are just not up to the job of making unexpected discoveries in these circumstances, and instead we will need to develop “learning machines” to help us discover the unexpected.

    With the right tools and careful insight, who knows what we might find.

    CSIRO campus

    CSIRO, the Commonwealth Scientific and Industrial Research Organisation, is Australia’s national science agency and one of the largest and most diverse research agencies in the world.

  • richardmitnick 7:17 pm on November 15, 2018 Permalink | Reply
    Tags: "Younger Dryas" cooling event, , Earth Observation, , Hiawatha Glacier, Hidden beneath Hiawatha is a 31-kilometer-wide impact crater big enough to swallow Washington D.C., Massive crater under Greenland’s ice points to climate-altering impact in the time of humans,   

    From Science Magazine: “Massive crater under Greenland’s ice points to climate-altering impact in the time of humans” 

    From Science Magazine

    A 1.5-kilometer asteroid, intact or in pieces, may have smashed into an ice sheet just 13,000 years ago.

    Nov. 14, 2018
    Paul Voosen

    On a bright July day 2 years ago, Kurt Kjær was in a helicopter flying over northwest Greenland—an expanse of ice, sheer white and sparkling. Soon, his target came into view: Hiawatha Glacier, a slow-moving sheet of ice more than a kilometer thick. It advances on the Arctic Ocean not in a straight wall, but in a conspicuous semicircle, as though spilling out of a basin. Kjær, a geologist at the Natural History Museum of Denmark in Copenhagen, suspected the glacier was hiding an explosive secret. The helicopter landed near the surging river that drains the glacier, sweeping out rocks from beneath it. Kjær had 18 hours to find the mineral crystals that would confirm his suspicions.

    What he brought home clinched the case for a grand discovery. Hidden beneath Hiawatha is a 31-kilometer-wide impact crater, big enough to swallow Washington, D.C., Kjær and 21 co-authors report today in a paper in Science Advances. The crater was left when an iron asteroid 1.5 kilometers across slammed into Earth, possibly within the past 100,000 years.

    Though not as cataclysmic as the dinosaur-killing Chicxulub impact, which carved out a 200-kilometer-wide crater in Mexico about 66 million years ago, the Hiawatha impactor, too, may have left an imprint on the planet’s history.

    Artist’s reconstruction of Chicxulub crater soon after impact, 66 million years ago.

    The timing is still up for debate, but some researchers on the discovery team believe the asteroid struck at a crucial moment: roughly 13,000 years ago, just as the world was thawing from the last ice age. That would mean it crashed into Earth when mammoths and other megafauna were in decline and people were spreading across North America.

    The impact would have been a spectacle for anyone within 500 kilometers. A white fireball four times larger and three times brighter than the sun would have streaked across the sky. If the object struck an ice sheet, it would have tunneled through to the bedrock, vaporizing water and stone alike in a flash. The resulting explosion packed the energy of 700 1-megaton nuclear bombs, and even an observer hundreds of kilometers away would have experienced a buffeting shock wave, a monstrous thunder-clap, and hurricane-force winds. Later, rock debris might have rained down on North America and Europe, and the released steam, a greenhouse gas, could have locally warmed Greenland, melting even more ice.

    The news of the impact discovery has reawakened an old debate among scientists who study ancient climate. A massive impact on the ice sheet would have sent meltwater pouring into the Atlantic Ocean—potentially disrupting the conveyor belt of ocean currents and causing temperatures to plunge, especially in the Northern Hemisphere. “What would it mean for species or life at the time? It’s a huge open question,” says Jennifer Marlon, a paleoclimatologist at Yale University.

    A decade ago, a small group of scientists proposed a similar scenario [Science]. They were trying to explain a cooling event, more than 1000 years long, called the Younger Dryas, which began 12,800 years ago, as the last ice age was ending. Their controversial solution was to invoke an extraterrestrial agent: the impact of one or more comets. The researchers proposed that besides changing the plumbing of the North Atlantic, the impact also ignited wildfires across two continents that led to the extinction of large mammals and the disappearance of the mammoth-hunting Clovis people of North America. The research group marshaled suggestive but inconclusive evidence, and few other scientists were convinced. But the idea caught the public’s imagination despite an obvious limitation: No one could find an impact crater.

    Proponents of a Younger Dryas impact now feel vindicated. “I’d unequivocally predict that this crater is the same age as the Younger Dryas,” says James Kennett, a marine geologist at the University of California, Santa Barbara, one of the idea’s original boosters.

    But Jay Melosh, an impact crater expert at Purdue University in West Lafayette, Indiana, doubts the strike was so recent. Statistically, impacts the size of Hiawatha occur only every few million years, he says, and so the chance of one just 13,000 years ago is small. No matter who is right, the discovery will give ammunition to Younger Dryas impact theorists—and will turn the Hiawatha impactor into another type of projectile. “This is a hot potato,” Melosh tells Science. “You’re aware you’re going to set off a firestorm?”

    It started with a hole. In 2015, Kjær and a colleague were studying a new map of the hidden contours under Greenland’s ice. Based on variations in the ice’s depth and surface flow patterns, the map offered a coarse suggestion of the bedrock topography—including the hint of a hole under Hiawatha.

    Kjær recalled a massive iron meteorite in his museum’s courtyard, near where he parks his bicycle. Called Agpalilik, Inuit for “the Man,” the 20-ton rock is a fragment of an even larger meteorite, the Cape York, found in pieces on northwest Greenland by Western explorers but long used by Inuit people as a source of iron for harpoon tips and tools. Kjær wondered whether the meteorite might be a remnant of an impactor that dug the circular feature under Hiawatha. But he still wasn’t confident that it was an impact crater. He needed to see it more clearly with radar, which can penetrate ice and reflect off bedrock.

    Kjær’s team began to work with Joseph MacGregor, a glaciologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who dug up archival radar data. MacGregor found that NASA aircraft often flew over the site on their way to survey Arctic sea ice, and the instruments were sometimes turned on, in test mode, on the way out. “That was pretty glorious,” MacGregor says.

    The radar pictures more clearly showed what looked like the rim of a crater, but they were still too fuzzy in the middle. Many features on Earth’s surface, such as volcanic calderas, can masquerade as circles. But only impact craters contain central peaks and peak rings, which form at the center of a newborn crater when—like the splash of a stone in a pond—molten rock rebounds just after a strike. To look for those features, the researchers needed a dedicated radar mission.

    Coincidentally, the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, had just purchased a next-generation ice-penetrating radar to mount across the wings and body of their Basler aircraft, a twin-propeller retrofitted DC-3 that’s a workhorse of Arctic science. But they also needed financing and a base close to Hiawatha.

    Kjær took care of the money. Traditional funding agencies would be too slow, or prone to leaking their idea, he thought. So he petitioned Copenhagen’s Carlsberg Foundation, which uses profits from its global beer sales to finance science. MacGregor, for his part, enlisted NASA colleagues to persuade the U.S. military to let them work out of Thule Air Base, a Cold War outpost on northern Greenland, where German members of the team had been trying to get permission to work for 20 years. “I had retired, very serious German scientists sending me happy-face emojis,” MacGregor says.

    NASA and German aircraft used radar to see the contours of an impact crater beneath the ice of Hiawatha Glacier. JOHN SONNTAG/NASA

    Three flights, in May 2016, added 1600 kilometers of fresh data from dozens of transits across the ice—and evidence that Kjær, MacGregor, and their team were onto something. The radar revealed five prominent bumps in the crater’s center, indicating a central peak rising some 50 meters high. And in a sign of a recent impact, the crater bottom is exceptionally jagged. If the asteroid had struck earlier than 100,000 years ago, when the area was ice free, erosion from melting ice farther inland would have scoured the crater smooth, MacGregor says. The radar signals also showed that the deep layers of ice were jumbled up—another sign of a recent impact. The oddly disturbed patterns, MacGregor says, suggest “the ice sheet hasn’t equilibrated with the presence of this impact crater.”

    But the team wanted direct evidence to overcome the skepticism they knew would greet a claim for a massive young crater, one that seemed to defy the odds of how often large impacts happen. And that’s why Kjær found himself, on that bright July day in 2016, frenetically sampling rocks all along the crescent of terrain encircling Hiawatha’s face. His most crucial stop was in the middle of the semicircle, near the river, where he collected sediments that appeared to have come from the glacier’s interior. It was hectic, he says—”one of those days when you just check your samples, fall on the bed, and don’t rise for some time.”

    In that outwash, Kjær’s team closed its case. Sifting through the sand, Adam Garde, a geologist at the Geological Survey of Denmark and Greenland in Copenhagen, found glass grains forged at temperatures higher than a volcanic eruption can generate. More important, he discovered shocked crystals of quartz. The crystals contained a distinctive banded pattern that can be formed only in the intense pressures of extraterrestrial impacts or nuclear weapons. The quartz makes the case, Melosh says. “It looks pretty good. All the evidence is pretty compelling.”

    Now, the team needs to figure out exactly when the collision occurred and how it affected the planet.

    The Younger Dryas, named after a small white and yellow arctic flower that flourished during the cold snap, has long fascinated scientists. Until human-driven global warming set in, that period reigned as one of the sharpest recent swings in temperature on Earth. As the last ice age waned, about 12,800 years ago, temperatures in parts of the Northern Hemisphere plunged by as much as 8°C, all the way back to ice age readings. They stayed that way for more than 1000 years, turning advancing forest back into tundra.

    The trigger could have been a disruption in the conveyor belt of ocean currents, including the Gulf Stream that carries heat northward from the tropics. In a 1989 paper in Nature, Kennett, along with Wallace Broecker, a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory, and others, laid out how meltwater from retreating ice sheets could have shut down the conveyor. As warm water from the tropics travels north at the surface, it cools while evaporation makes it saltier. Both factors boost the water’s density until it sinks into the abyss, helping to drive the conveyor. Adding a pulse of less-dense freshwater could hit the brakes. Paleoclimate researchers have largely endorsed the idea, although evidence for such a flood has been lacking until recently.

    Then, in 2007, Kennett suggested a new trigger. He teamed up with scientists led by Richard Firestone, a physicist at Lawrence Berkeley National Laboratory in California, who proposed a comet strike at the key moment [PNAS]. Exploding over the ice sheet covering North America, the comet or comets would have tossed light-blocking dust into the sky, cooling the region. Farther south, fiery projectiles would have set forests alight, producing soot that deepened the gloom and the cooling. The impact also could have destabilized ice and unleashed meltwater that would have disrupted the Atlantic circulation.

    The climate chaos, the team suggested, could explain why the Clovis settlements emptied and the megafauna vanished soon afterward. But the evidence was scanty. Firestone and his colleagues flagged thin sediment layers at dozens of archaeological sites in North America. Those sediments seemed to contain geochemical traces of an extraterrestrial impact, such as a peak in iridium, the exotic element that helped cement the case for a Chicxulub impact. The layers also yielded tiny beads of glass and iron—possible meteoritic debris—and heavy loads of soot and charcoal, indicating fires.

    The team met immediate criticism. The decline of mammoths, giant sloths, and other species had started well before the Younger Dryas. In addition, no sign existed of a human die-off in North America, archaeologists said. The nomadic Clovis people wouldn’t have stayed long in any site. The distinctive spear points that marked their presence probably vanished not because the people died out, but rather because those weapons were no longer useful once the mammoths waned, says Vance Holliday, an archaeologist at The University of Arizona in Tucson. The impact hypothesis was trying to solve problems that didn’t need solving.

    The geochemical evidence also began to erode. Outside scientists could not detect the iridium spike in the group’s samples. The beads were real, but they were abundant across many geological times, and soot and charcoal did not seem to spike at the time of the Younger Dryas. “They listed all these things that aren’t quite sufficient,” says Stein Jacobsen, a geochemist at Harvard University who studies craters.

    Yet the impact hypothesis never quite died. Its proponents continued to study the putative debris layer at other sites in Europe and the Middle East. They also reported finding microscopic diamonds at different sites that, they say, could have been formed only by an impact. (Outside researchers question the claims of diamonds.)

    Now, with the discovery of Hiawatha crater, “I think we have the smoking gun,” says Wendy Wolbach, a geochemist at De-Paul University in Chicago, Illinois, who has done work on fires during the era.

    The impact would have melted 1500 gigatons of ice, the team estimates—about as much ice as Antarctica has lost because of global warming in the past decade. The local greenhouse effect from the released steam and the residual heat in the crater rock would have added more melt. Much of that freshwater could have ended up in the nearby Labrador Sea, a primary site pumping the Atlantic Ocean’s overturning circulation. “That potentially could perturb the circulation,” says Sophia Hines, a marine paleoclimatologist at Lamont-Doherty.

    Leery of the earlier controversy, Kjær won’t endorse that scenario. “I’m not putting myself in front of that bandwagon,” he says. But in drafts of the paper, he admits, the team explicitly called out a possible connection between the Hiawatha impact and the Younger Dryas.

    Banded patterns in the mineral quartz are diagnostic of shock waves from an extraterrestrial impact. ADAM GARDE, GEUS

    The evidence starts with the ice. In the radar images, grit from distant volcanic eruptions makes some of the boundaries between seasonal layers stand out as bright reflections. Those bright layers can be matched to the same layers of grit in cataloged, dated ice cores from other parts of Greenland [Science]. Using that technique, Kjær’s team found that most ice in Hiawatha is perfectly layered through the past 11,700 years. But in the older, disturbed ice below, the bright reflections disappear. Tracing the deep layers, the team matched the jumble with debris-rich surface ice on Hiawatha’s edge that was previously dated to 12,800 years ago. “It was pretty self-consistent that the ice flow was heavily disturbed at or prior to the Younger Dryas,” MacGregor says.

    Other lines of evidence also suggest Hiawatha could be the Younger Dryas impact [PNAS]. In 2013, Jacobsen examined an ice core from the center of Greenland, 1000 kilometers away. He was expecting to put the Younger Dryas impact theory to rest by showing that, 12,800 years ago, levels of metals that asteroid impacts tend to spread did not spike. Instead, he found a peak in platinum, similar to ones measured in samples from the crater site. “That suggests a connection to the Younger Dryas right there,” Jacobsen says.

    For Broecker, the coincidences add up. He had first been intrigued by the Firestone paper, but quickly joined the ranks of naysayers. Advocates of the Younger Dryas impact pinned too much on it, he says: the fires, the extinction of the megafauna, the abandonment of the Clovis sites. “They put a bad shine on it.” But the platinum peak Jacobsen found, followed by the discovery of Hiawatha, has made him believe again. “It’s got to be the same thing,” he says.

    Yet no one can be sure of the timing. The disturbed layers could reflect nothing more than normal stresses deep in the ice sheet. “We know all too well that older ice can be lost by shearing or melting at the base,” says Jeff Severinghaus, a paleoclimatologist at the Scripps Institution of Oceanography in San Diego, California. Richard Alley, a glaciologist at Pennsylvania State University in University Park, believes the impact is much older than 100,000 years and that a subglacial lake can explain the odd textures near the base of the ice. “The ice flow over growing and shrinking lakes interacting with rough topography might have produced fairly complex structures,” Alley says.

    A recent impact should also have left its mark in the half-dozen deep ice cores drilled at other sites on Greenland, which document the 100,000 years of the current ice sheet’s history. Yet none exhibits the thin layer of rubble that a Hiawatha-size strike should have kicked up. “You really ought to see something,” Severinghaus says.

    Brandon Johnson, a planetary scientist at Brown University, isn’t so sure. After seeing a draft of the study, Johnson, who models impacts on icy moons such as Europa and Enceladus, used his code to recreate an asteroid impact on a thick ice sheet. An impact digs a crater with a central peak like the one seen at Hiawatha, he found, but the ice suppresses the spread of rocky debris. “Initial results are that it goes a lot less far,” Johnson says.

    In 2016, Kurt Kjær looked for evidence of an impact in sand washed out from underneath Hiawatha Glacier. He would find glassy beads and shocked crystals of quartz.

    Even if the asteroid struck at the right moment, it might not have unleashed all the disasters envisioned by proponents of the Younger Dryas impact. “It’s too small and too far away to kill off the Pleistocene mammals in the continental United States,” Melosh says. And how a strike could spark flames in such a cold, barren region is hard to see. “I can’t imagine how something like this impact in this location could have caused massive fires in North America,” Marlon says.

    It might not even have triggered the Younger Dryas. Ocean sediment cores show no trace of a surge of freshwater into the Labrador Sea from Greenland, says Lloyd Keigwin, a paleoclimatologist at the Woods Hole Oceanographic Institution in Massachusetts. The best recent evidence, he adds, suggests a flood into the Arctic Ocean through western Canada instead [Nature Geoscience].

    An external trigger may be unnecessary in any case, Alley says. During the last ice age, the North Atlantic saw 25 other cooling spells, probably triggered by disruptions to the Atlantic’s overturning circulation. None of those spells, known as Dansgaard-Oeschger (D-O) events, was as severe as the Younger Dryas, but their frequency suggests an internal cycle played a role in the Younger Dryas, too. Even Broecker agrees that the impact was not the ultimate cause of the cooling. If D-O events represent abrupt transitions between two regular states of the ocean, he says, “you could say the ocean was approaching instability and somehow this event knocked it over.”

    Still, Hiawatha’s full story will come down to its age. Even an exposed impact crater can be a challenge for dating, which requires capturing the moment when the impact altered existing rocks—not the original age of the impactor or its target. Kjær’s team has been trying. They fired lasers at the glassy spherules to release argon for dating, but the samples were too contaminated. The researchers are inspecting a blue crystal of the mineral apatite for lines left by the decay of uranium, but it’s a long shot. The team also found traces of carbon in other samples, which might someday yield a date, Kjær says. But the ultimate answer may require drilling through the ice to the crater floor, to rock that melted in the impact, resetting its radioactive clock. With large enough samples, researchers should be able to pin down Hiawatha’s age.

    Given the remote location, a drilling expedition to the hole at the top of the world would be costly. But an understanding of recent climate history—and what a giant impact can do to the planet—is at stake. “Somebody’s got to go drill in there,” Keigwin says. “That’s all there is to it.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

  • richardmitnick 11:26 am on November 15, 2018 Permalink | Reply
    Tags: , As an indicator of the impacts of climate change Arctic sea ice is hard to beat, “Right now the prediction is that in about 20 years we will see an [Arctic] ice-free summer, Earth Observation, Reports on the ground indicate the ice is melting at a much faster rate than predicted by global climate models, Simulation Versus Observation, The effects of changes in the Arctic are no longer confined to the region and in fact spread to the mid-latitudes — often in the form of cold weather outbreaks, The importance of anthropogenic forcing,   

    From UC Santa Barbara: “Simulation Versus Observation” 

    UC Santa Barbara Name bloc
    From UC Santa Barbara

    November 13, 2018
    Sonia Fernandez
    (805) 893-4765

    The gap between simulated prediction and real-life observation in Arctic sea ice melt can be attributed to complicated internal drivers.

    Arctic sea ice

    As an indicator of the impacts of climate change, Arctic sea ice is hard to beat. Scientists have observed the frozen polar ocean advance and retreat at this most sensitive region of the Earth over decades for insight on the potential ripple effects on assorted natural systems: global ocean circulation, surrounding habitats and ecosystems, food sources, sea levels and more.

    Despite efforts to make model simulations more closely mirror actual observations of Arctic sea ice melt, however, a gap has opened: Reports on the ground indicate the ice is melting at a much faster rate than predicted by global climate models.

    “Based on this phenomenon, people have different opinions,” said UC Santa Barbara climate scientist Qinghua Ding, an assistant professor in the campus’s Earth Research Institute. The consensus of the climate science community, he said, is leaning toward the idea that the discrepancy is due to flawed modeling. “It’s something like the model has some bias; it has some low sensitivity to anthropogenic forcing,” he explained.

    Ding and his group disagree. In a study titled Fingerprints of internal drivers of Arctic sea ice loss in observations and model simulations, published in the journal Nature Geoscience, the group says the models are just fine. About 40 to 50 percent of sea ice loss over the last three decades, they argue, is attributable to significant but as yet little-understood internal drivers — among them effects that originate partially as far away as the tropics.

    “Actually, we’re comparing apples to oranges,” Ding said of the discrepancy between real-time observation and simulated Arctic ice melt driven by anthropogenic forcing. The average of models, he explained, accounts only for what effects are a result of historical radiative forcing — calculations based mostly on levels of greenhouse gases — but don’t rely on, for instance, the short-term variations in sea surface temperatures, humidity, atmospheric pressure and other factors both local and connected to other phenomena elsewhere on Earth. Such higher-frequency events often show up as noise in the repeated, individual runs of the simulations as scientists look for general long-term trends.

    “Any one run of a model will have random noise,” said Bradley Markle, a postdoctoral scholar in Ding’s research group. “If you take 20 or 30 runs of a model, they will each have their own random noise, but they will cancel each other out.” The resulting value is the average of all the simulation runs without the random variability. But that random variability may also be impacting what is being observed out on the ice, in addition to the forced signal.

    Due to their nature, internal variabilities are also likely to result in periods in which Arctic ice melt will appear to slow or even reverse, but in the bigger picture, climate scientists still see the eventual complete melting of Arctic sea ice for part of the year.

    “There are so many reasons we focus on Arctic sea ice, but one of the main things people really care about is the timing of the ice-free summer,” said Ding, referring to a time when the northern pole will no longer be the frozen frontier it has been even in the summer.

    “Right now, the prediction is that in about 20 years, we will see an ice-free summer,” Ding said. More than just a climate issue, he continued, the ice-free summer is also a societal issue, given the effects on fisheries and other food sources as well as natural resources and habitats that benefit from a frozen polar ocean. One of the things this discrepancy between simulation and observation indicates, he said, is that predictions about when this ice-free summer occurs will have to be tempered with some acknowledgement of the effects of internal variabilities.

    “There’s a large uncertainty associated with this time window,” Ding said. “As we consider internal variabilities, plus CO2 forcing, we should be more cautious about the timing of the ice-free summer.”

    For Markle, this situation highlights the disconnect that often occurs when talking about long-term climate trends versus short-term observations. Over the course of our human timescales of hours to days, we experience atmospheric temperature changes over several degrees, so a mean global temperature rise of one or two degrees doesn’t seem all that significant.

    “Likewise, year-to-year temperature variability, such as that associated with these tropical internal variations, can be several degrees in annual average temperature in a specific area, so near the same magnitude as the centuries-long global warming signal,” he said.

    An example of this relatively short-term climate variability is the well-known El Niño Southern Oscillation (ENSO), the constant tipping between the El Niño and counterpart La Niña weather systems that brings both drought and rain, scarcity and abundance to different parts of the world. More extreme ENSO-driven weather behavior is expected as the Earth’s climate seeks equilibrium in the face of an average global temperature increase of even a couple degrees.

    “Just for reference, 20,000 years ago there was an ice sheet covering most of Canada during the height of the last ice age — that was a four- or five-degree annual average temperature change,” Markle said, “but it’s a huge difference.”

    Ding’s research group continues to investigate the mysterious and complex internal drivers that affect Arctic sea ice, particularly those that originate in the warm, wet tropics.

    “We’re mostly interested in the period from the early 2000s to the present day, where we see such strong melting,” said graduate student Ian Baxter, who also works with Ding. It’s known, he added, that the effects of changes in the Arctic are no longer confined to the region and in fact spread to the mid-latitudes — often in the form of cold weather outbreaks. The group is interested in how effects in the tropics could spread beyond that region and affect the Arctic.

    “We’re trying to lay out a mechanism through which that happens,” Baxter said.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    UC Santa Barbara Seal
    The University of California, Santa Barbara (commonly referred to as UC Santa Barbara or UCSB) is a public research university and one of the 10 general campuses of the University of California system. Founded in 1891 as an independent teachers’ college, UCSB joined the University of California system in 1944 and is the third-oldest general-education campus in the system. The university is a comprehensive doctoral university and is organized into five colleges offering 87 undergraduate degrees and 55 graduate degrees. In 2012, UCSB was ranked 41st among “National Universities” and 10th among public universities by U.S. News & World Report. UCSB houses twelve national research centers, including the renowned Kavli Institute for Theoretical Physics.

Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc
%d bloggers like this: