Even psychological placebos have an effect

The color green can have a positive effect on the personal condition, as long as this effect was previously attributed to it.

Placebo effects do not only occur in medical treatment -- placebos can also work when psychological effects are attributed to them. Psychologists from the University of Basel reported these findings in the journal Scientific Reports, based on three studies with over 400 participants.

Psychotherapy and placebos are both psychological interventions that not only have comparable effects, but that are also based on very similar mechanisms. Both forms of treatment are heavily influenced by the relationship between patients and those treating them, as well as by the expectations of recovery. Whereas placebo research mostly focuses on a biomedical model -- an inert pill is provided with a medical rationale, which produces a corresponding effect -- little is known about the effect of placebos provided with a psychological rationale.

"Green is calming"

Placebos can also have effects when specific psychological effects are attributed to them. This is the conclusion that researchers from the Division of Clinical Psychology and Psychotherapy at the University of Basel reached in three independent experiments with 421 healthy participants. The accompanying explanation -- the narrative -- played a key role when dispensing the placebos, as did the relationship between the researchers and the participants.

The researchers used the color green as the placebo in the video experiments, examining it both with and without a psychological narrative ("green is calming because it activates early conditioned emotional schemata"), as well as in the context of a neutral or a friendly relationship.

After viewing the videos, the participants assessed their subjective condition with questionnaires over several days. The results showed that the placebo had a positive effect on the participants' well-being when it was prescribed together with a psychological narrative and in the context of a friendly relationship. The observed effect was strongest after administering the placebo but remained evident for up to one week.

Ethical implications

"The observed effects were comparable with those of psychotherapeutic interventions in the same populations," says principal investigator Professor Jens Gaab. The fact that psychological placebos can have significant effects is not only important for understanding psychological interventions: "It challenges both research and clinical practice to address these mechanisms and effects, as well as their ethical implications."

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A warming world increases air pollution

Climate change is warming the ocean, but it's warming land faster and that's really bad news for air quality all over the world, says a new University of California, Riverside study.

The study, published February 4 in Nature Climate Change, shows that the contrast in warming between the continents and sea, called the land-sea warming contrast, drives an increased concentration of aerosols in the atmosphere that cause air pollution.

Aerosols are tiny solid particles or liquid droplets suspended in the atmosphere. They can come from natural sources, like dust or wildfires, or human-made sources such as vehicle and industrial emissions. Aerosols affect the climate system, including disturbances to the water cycle, as well as human health. They also cause smog and other kinds of air pollution that can lead to health problems for people, animals, and plants.

"A robust response to an increase in greenhouse gases is that the land is going to warm faster than the ocean. This enhanced land warming is also associated with increased continental aridity," explained first author Robert Allen, an associate professor of earth sciences at UC Riverside.

The increase in aridity leads to decreased low cloud cover and less rain, which is the main way that aerosols are removed from the atmosphere.

To determine this, the researchers ran simulations of climate change under two scenarios. The first assumed a business-as-usual warming model, in which warming proceeds at a constant, upward rate. The second model probed a scenario in which the land warmed less than expected.

In the business-as-usual scenario, enhanced land warming increased continental aridity and, subsequently, the concentration of aerosols that leads to more air pollution. However, the second model -- which is identical to the business-as-usual model except the land warming is weakened -- leads to a muted increase in continental aridity and air pollution. Thus, the increase in air pollution is a direct consequence of enhanced land warming and continental drying.

The results show that the hotter Earth gets, the harder it's going to be to keep air pollution down to a certain level without strict control over the sources of aerosols.

Because the researchers wanted to understand how greenhouse gas warming affects air pollution, they assumed no change to human-made, or anthropogenic, aerosol emissions.

"That's probably not going to be true because there's a strong desire to reduce air pollution, which involves reducing anthropogenic aerosol emissions," cautioned Allen. "So this result represents an upper bound."

But it also suggests that if the planet keeps warming, larger reductions in anthropogenic aerosol emissions will be required to improve air quality.

"The question is what level of air quality are we going to accept," said Allen. "Even though California has some of the strictest environmental laws in the country we still have relatively poor air quality, and it's much worse in many countries."

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Think pink: Fluorescent pink flying squirrel in UV light at night

Photographs of a flying squirrel with visuals from the human eye and under ultraviolet light.

The North American flying squirrel fluoresces pink at night under ultraviolet light, but the purpose of the pink color is still a mystery to researchers.

Allison Kohler, a graduate student in the Texas A&M University wildlife and fisheries department in College Station, helped make this discovery as well as affirm other flying squirrels do in fact fluoresce pink.

Kohler's undergraduate professor Dr. Jon Martin, associate professor of forestry at Northland College in Wisconsin, was doing an exploratory forest survey with an ultraviolet flashlight in his backyard. Initially, he was looking at different lichens, mosses and plants to see what fluoresced. By chance, a flying squirrel happened to be at his bird feeder. When he saw it under the ultraviolet light, it was hot pink.

A team to investigate this discovery was formed and included Martin, Kohler and two of Martin's colleagues at Northland College: Dr. Paula Anich, associate professor of natural resources, and Dr. Erik Olson, assistant professor of natural resources.

With access to a museum collection at the Minnesota Science Museum, Martin asked Kohler to take the lead on the project and develop a protocol to help further investigate exactly what it was they had found.

"I looked at a ton of different specimens that they had there," Kohler said. "They were stuffed flying squirrels that they had collected over time, and every single one that I saw fluoresced hot pink in some intensity or another."

In order to expand the search, the team went to the Field Museum of Natural History in Chicago and gathered more specimens. In all, they researched over 100 specimens ranging across numerous states, all confirming their "pink theory." They also looked at five additional live specimens.

"We tested all three of the North American flying squirrel species: the Northern flying squirrel, the Southern flying squirrel and the Humboldt's flying squirrel, and all three of them fluoresced," she said.

After comparing the flying species to other squirrels, like the American red squirrel and gray squirrel, the team found that the pink color is unique to the flying squirrel.

The reasons for the squirrels to fluoresce pink is still under investigation, but communication and camouflage are two top contenders for why this might be happening, the team has hypothesized.

"They could be communicating with members of their own species by showing off their fluorescence to each other, or it might be a sort of mating display," Kohler said. "The other hypothesis is that they could be using this fluorescence as an anti-predator trait to communicate with other species, avoiding predation by other species by blending in or dealing with their potentially ultraviolet-saturated environments."

As the research develops, she said, the importance of this find will present itself more clearly. Kohler plans to continue her research while pursuing her master's degree at Texas A&M. Further research will look firmly at the implications of the team's find.

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Retreating snow line reveals organic molecules around young star

The distribution of dust is shown in orange and the distribution of methanol, an organic molecule, is shown in blue.

Astronomers using ALMA have detected various complex organic molecules around the young star V883 Ori. A sudden outburst from this star is releasing molecules from the icy compounds in the planet forming disk. The chemical composition of the disk is similar to that of comets in the modern Solar System. Sensitive ALMA observations enable astronomers to reconstruct the evolution of organic molecules from the birth of the Solar System to the objects we see today.

The research team led by Jeong-Eun Lee (Kyung Hee University, Korea) used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect complex organic molecules including methanol (CH3OH), acetone (CH3COCH3), acetaldehyde (CH3CHO), methyl formate (CH3OCHO), and acetonitrile (CH3CN). This is the first time that acetone was unambiguously detected in a planet forming region or protoplanetary disk.

Various molecules are frozen in ice around micrometer-sized dust particles in protoplanetary disks. V883 Ori's sudden flare-up is heating the disk and sublimating the ice, which releases the molecules into gas. The region in a disk where the temperature reaches the sublimation temperature of the molecules is called the "snow line." The radii of snow lines are about a few astronomical units (au) around normal young stars, however, they are enlarged almost 10 times around bursting stars.

"It is difficult to image a disk on the scale of a few au with current telescopes," said Lee. "However, around an outburst star, ice melts in a wider area of the disk and it is easier to see the distribution of molecules. We are interested in the distribution of complex organic molecules as the building blocks of life."

Ice, including frozen organic molecules, could be closely related to the origin of life on planets. In our Solar System, comets are the focus of attention because of their rich icy compounds. For example, the European Space Agency's legendary comet explorer Rosetta found rich organic chemistry around the comet Churyumov-Gerasimenko. Comets are thought to have been formed in the outer colder region of the proto-Solar System, where the molecules were contained in ice. Probing the chemical composition of ice in protoplanetary disks is directly related to probing the origin of organic molecules in comets, and the origin of the building blocks of life.

Thanks to ALMA's sharp vision and the enlarged snow line due to the flare-up of the star, the astronomers obtained the spatial distribution of methanol and acetaldehyde. The distribution of these molecules has a ring-like structure with a radius of 60 au, which is twice the size of Neptune's orbit. The researchers assume that inside of this ring the molecules are invisible because they are obscured by thick dusty material, and are invisible outside of this radius because they are frozen in ice.

"Since rocky and icy planets are made from solid material, the chemical composition of solids in disks is of special importance. An outburst is a unique chance to investigate fresh sublimates, and thus the composition of solids." says Yuri Aikawa at the University of Tokyo, a member of the research team.

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The Caucasus: Complex interplay of genes and cultures

This is a of the Maykop culture from the burial mound Marinskaya 5.

An international research team, coordinated by the Max Planck Institute for the Science of Human History (MPI-SHH) and the Eurasia Department of the German Archaeological Institute (DAI) in Berlin, is the first to carry out systematic genetic investigations in the Caucasus region. The study, published in Nature Communications, is based on analyses of genome-wide data from 45 individuals in the steppe and mountainous areas of the North Caucasus. The skeletal remains, which are between 6,500 and 3,500 years old, show that the groups living throughout the Caucasus region were genetically similar, despite the harsh mountain terrain, but that there was a sharp genetic boundary to the adjacent steppe areas in the north.

The Caucasus, an area that today includes parts of Russia, Azerbaijan, Armenia, Georgia, Iran and Turkey, is a crucial intersection for the history of Europe, both genetically and culturally. Today it is one of the regions of the world with the highest linguistic diversity, and in the past, populations from the Caucasus were instrumental in shaping the genetic components of today's Europeans. During the Bronze Age, important technological innovations, developed in the Caucasus and beyond, were transported to Europe through this region, such as the first highly effective metal weapons and the wheel and wagon.

"We assume that in the wake of the Neolithic period, sometime before 5,000 BC when a more sedentary lifestyle with domesticated animals and plants was established, populations from the southern Caucasus spread over the mountains to the north and there met with nomadic populations from the Eurasian steppe," says Dr. Wolfgang Haak, group leader for molecular anthropology at the MPI-SHH and leader of the study. "The genetic boundary corresponds in principle to the ecological and geographical regions: the mountains and the steppe. Today, on the other hand, the Caucasus mountains themselves are more of a barrier to gene flow."

Over the centuries, an interaction zone was formed, where the traditions of the Mesopotamian civilization and those of the Caucasus met with the cultures of the steppe. This intertwining is evident in the cultural exchange and transfer of technological and social innovations, as well as the occasional exchange of genes, which the study shows also took place between groups of quite distinct genetic backgrounds.

Cultural contact zone, genetic border region
The skeletal remains studied come from different Bronze Age cultures. The Maykop culture in particular, based on its spectacular grave goods, which had close parallels in the south, was long regarded as a population that had migrated to the North Caucasus from Mesopotamia.

The current paleogenetic study paints a more nuanced picture of mobility during the Bronze Age. People with a distinct southern Caucasus ancestry were already north of the mountain ridges by the 5th millennium BC. It is highly likely that these groups formed the basis for the local Early Bronze Age Maykop culture of the 4th millennium BC. Intriguingly, the Maykop individuals tested are genetically distinct from the groups in the adjacent steppes to the north.

"The genetic results do not support scenarios of large-scale migrations from the south during the Maykop period, or even from the northwest, as was postulated by some archaeologists. These findings have major implications for our understanding of the local development of North Caucasus cultures in the 4th millennium BC," explains Prof. Dr. Dr. h.c. Svend Hansen, Director of the DAI's Eurasia-Department.

By the 3rd millennium BC, pastoralist groups from the steppe were bringing about a fundamental change in the population of Europe. The current study confirms parallel changes in the Caucasus along the southern border of the steppe zone. "During the 3rd and 2nd millennium BC, however, the people living in the Northern Caucasus all shared a similar genetic makeup even though they can be recognized (archaeologically) as different cultural groups," says Sabine Reinhold, co-director of the archaeological team. "Individuals belonging to Yamnaya or Catacomb cultural complexes, according to archaeological analyses of their graves, are genetically indistinguishable from individuals from the North Caucasian culture in the foothills and in the mountains. Local or global cultural attributions were apparently more important than common biological roots."

Subtle gene flow from the west contributed to the formation of early Yamnaya groups

The massive population shifts in the 3rd millennium BC, in connection with the expansion of the groups from the steppe who were part of what is known as the Yamnaya culture, have long been associated with the transfer of significant technological innovations from Mesopotamia to Europe. Recent studies at the DAI's Eurasia department on the spread of early wagons or metal weapons have shown, however, that an intensive exchange between Europe, the Caucasus and Mesopotamia began much earlier. However, can evidence of these technological exchanges also be provided by the genetic interactions revealed in the current study? And if so, in which direction do they point?

The genomes of the Yamnaya individuals from the steppe bordering the Caucasus indeed show subtle genetic traces that are also characteristic of the neighboring farming populations of south-eastern Europe. Detailed analysis now shows that this subtle gene flow cannot be linked to the Maykop population, but must have come from the west.

"These are exciting and surprising findings, which highlight the complexity of the processes that lead to the formation of Bronze Age steppe pastoralist," says Chuan-Chao Wang, population geneticist postdoc at the MPI-SHH and first author of the study, now professor at Xiamen University in China.

Hansen adds, "These subtle genetic traces from the west are indeed remarkable and suggest contact between people in the steppes and western groups, such as the Globular Amphora culture, between the 4th and the 3rd millennium BC."

It appears that the world of the 4th millennium BC was well-connected long before the major expansion of steppe pastoralist and related groups. In this wide-ranging network of contacts, people not only spread and exchanged know-how and technological innovations, but occasionally also exchanged genes, and not only in one direction.

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First discovered fossil feather did not belong to iconic bird Archaeopteryx

The isolated Archaeopteryx feather is the first fossil feather ever discovered. Top image, the feather as it looks today under white light. Middle image, the original drawing from 1862 by Hermann von Meyer. Bottom image, Laser-Stimulated Fluorescence (LSF) showing the halo of the missing quill. Scale bar is 1cm.

A 150-year-old fossil feather mystery has been solved by an international research team including Dr Michael Pittman from the Department of Earth Sciences, The University of Hong Kong. Dr Pittman and his colleagues applied a novel imaging technique, Laser-Stimulated Fluorescence (LSF), revealing the missing quill of the first fossil feather ever discovered, dethroning an icon in the process.

This fossil feather was found in the Solnhofen area of southern Germany in 1861. The isolated feather was used to name the iconic fossil bird Archaeopteryx and was closely identified with its skeletons. Unlike the feather impressions preserved in some Archaeopteryx fossils, the isolated feather is preserved as a dark film. The detailed 1862 description of the feather mentions a rather long quill visible on the fossil, but this is unseen today. Even recent x-ray fluorescence and UV imaging studies did not end the debate of the "missing quill." The original existence of this quill has therefore been debated and it was unclear if the single feather represented a primary, secondary, or primary covert feather.

The results of this study are described in the journal Scientific Reports, and underscore the potential and scientific importance of Laser-Stimulated Fluorescence, which is being developed by Thomas G Kaye of the Foundation for Scientific Advancement, USA and Dr Pittman. "My imaging work with Tom Kaye demonstrates that important discoveries remain to be made even in the most iconic and well-studied fossils," says Dr Pittman.

With the help of the LSF images, the team finally solved the 150-year-old missing quill mystery. The now completely visible feather allowed detailed comparisons with the feather impressions of Archaeopteryx and with living birds. Before this LSF work, the feather was thought to represent a primary covert from Archaeopteryx, but this study shows that it differs from coverts of modern birds by lacking a distinct s-shaped centerline. The team also ruled out that the feather represented a primary, secondary, or tail feather of Archaeopteryx. Instead, the new data indicates that the isolated feather came from an unknown feathered dinosaur and that its attribution to Archaeopteryx was wrong. "It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill," says Daniela Schwarz, co-author in the study and curator for the fossil reptiles and bird collection of the Museum für Naturkunde, Berlin. This discovery also demonstrates that the diversity of feathered dinosaurs was likely higher around the ancient Solnhofen Archipelago than previously thought. "The success of the LSF technique here is sure to lead to more discoveries and applications in other fields. But, you'll have to wait and see what we find next!'' added Tom Kaye, the study's lead author.

From Science Daily

Researcher unearths an ice age in the African desert

Drumlins, hills formed in places once covered by glaciers, were discovered in Namibia by WVU's Graham Andrews.

A field trip to Namibia to study volcanic rocks led to an unexpected discovery by West Virginia University geologists Graham Andrews and Sarah Brown.

While exploring the desert country in southern Africa, they stumbled upon a peculiar land formation -- flat desert scattered with hundreds of long, steep hills. They quickly realized the bumpy landscape was shaped by drumlins, a type of hill often found in places once covered in glaciers, an abnormal characteristic for desert landscapes.

"We quickly realized what we were looking at because we both grew up in areas of the world that had been under glaciers, me in Northern Ireland and Sarah in northern Illinois," said Andrews, an assistant professor of geology. "It's not like anything we see in West Virginia where we're used to flat areas and then gorges and steep-sided valleys down into hollows."

After returning home from the trip, Andrews began researching the origins of the Namibian drumlins, only to learn they had never been studied.

"The last rocks we were shown on the trip are from a time period when southern Africa was covered by ice," Andrews said. "People obviously knew that part of the world had been covered in ice at one time, but no one had ever mentioned anything about how the drumlins formed or that they were even there at all."

Andrews teamed up with WVU geology senior Andy McGrady to use morphometrics, or measurements of shapes, to determine if the drumlins showed any patterns that would reflect regular behaviors as the ice carved them.

While normal glaciers have sequential patterns of growing and melting, they do not move much, Andrews explained. However, they determined that the drumlins featured large grooves, which showed that the ice had to be moving at a fast pace to carve the grooves.

These grooves demonstrated the first evidence of an ice stream in southern Africa in the late Paleozoic Age, which occurred about 300 million years ago.

"The ice carved big, long grooves in the rock as it moved," Andrews said. "It wasn't just that there was ice there, but there was an ice stream. It was an area where the ice was really moving fast."

McGrady used freely available information from Google Earth and Google Maps to measure their length, width and height.

"This work is very important because not much has been published on these glacial features in Namibia," said McGrady, a senior geology student from Hamlin. "It's interesting to think that this was pioneer work in a sense, that this is one of the first papers to cover the characteristics of these features and gives some insight into how they were formed."

Their findings also confirm that southern Africa was located over the South Pole during this period.

"These features provide yet another tie between southern Africa and south America to show they were once joined," Andrews said.

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Much of the surface ocean will shift in color by end of 21st century

A new MIT study finds that over the coming decades climate change will affect the ocean’s color, intensifying its blue regions and its green ones.

Climate change is causing significant changes to phytoplankton in the world's oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean's color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean's color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world's oceans will shift in color, due to climate change.

The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton -- and life in general -- in those waters, compared with today. Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.

"The model suggests the changes won't appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles," says lead author Stephanie Dutkiewicz, a principal research scientist at MIT's Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. "That basic pattern will still be there. But it'll be enough different that it will affect the rest of the food web that phytoplankton supports."

Dutkiewicz's co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier of the University of California at Davis.

Chlorophyll count

The ocean's color depends on how sunlight interacts with whatever is in the water. Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out. Hence, relatively barren open-ocean regions appear as deep blue from space. If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.

Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions. As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.

Since the late 1990s, satellites have taken continuous measurements of the ocean's color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn't necessarily have reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to "natural variability" -- normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.

"An El Niño or La Niña event will throw up a very large change in chlorophyll because it's changing the amount of nutrients that are coming into the system," Dutkiewicz says. "Because of these big, natural changes that happen every few years, it's hard to see if things are changing due to climate change, if you're just looking at chlorophyll."

Modeling ocean light

Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change's effect on phytoplankton by looking at satellite measurements of reflected light alone.

The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification. This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean's currents and mixing.

This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.

"Sunlight will come into the ocean, and anything that's in the ocean will absorb it, like chlorophyll," Dutkiewicz says. "Other things will absorb or scatter it, like something with a hard shell. So it's a complicated process, how light is reflected back out of the ocean to give it its color."

When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean's color as environmental conditions change in the future.

"The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change," Dutkiewicz says.

A signal in blues and greens

As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 -- what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases -- they found that wavelengths of light in the blue/green waveband responded the fastest.

What's more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.

"Chlorophyll is changing, but you can't really see it because of its incredible natural variability," Dutkiewicz says. "But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that's where we should be looking in satellite measurements, for a real signal of change."

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, our blue planet may look visibly altered.

Read more at Science Daily

Variations in seafloor create freak ocean waves

Nick Moore is an assistant professor of mathematics at Florida State.

Florida State University researchers have found that abrupt variations in the seafloor can cause dangerous ocean waves known as rogue or freak waves -- waves so catastrophic that they were once thought to be the figments of seafarers' imaginations.

"These are huge waves that can cause massive destruction to ships or infrastructure, but they are not precisely understood," said Nick Moore, assistant professor of mathematics at Florida State and author of a new study on rogue waves.

The study is published in the journal Physical Review Fluids, Rapid Communication.

Once regarded as a myth, these waves have stumped the scientific community for several decades.

Over the years, researchers across the globe have examined a number of different factors they thought might contribute to these waves, including the seafloor, wind excitation and a phenomenon called Benjamin-Feir where deviations from a periodic waveform are reinforced by nonlinearity.

Most of the studies that focused on the seafloor considered only gentle slopes, and the few studies that pushed the slopes to greater extremes relied primarily on computer simulations.

"There was a relative underrepresentation of real-world data that you can get from laboratory experiments, where you can carefully control the various factors," Moore said. "Often you need this real-world data to see whether the computer simulations are giving you sensible predictions at all."

Moore's laboratory experiments were the first to examine the effect of abrupt seafloor variations on wave statistics.

Along with FSU's Geophysical Fluid Dynamics Institute Director Kevin Speer and now-former FSU student Tyler Bolles, Moore created a long chamber with a variable bottom. Using a motor to generate randomized waves, the research team tracked thousands of waves to see if any patterns emerged.

After the waves passed through several feet of a constant depth, they encountered a step in the bottom of the tank that represented an abrupt change in the seafloor. Moore and his colleagues found that initially the waves appeared normal, following a traditional bell curve. But when they passed over the step, the structures of the waves significantly changed.

The altered waves followed what's called a gamma distribution, a mathematics function describing certain patterns that defy the bell curve in a particular way.

"It is surprising how well the gamma distribution describes the waves measured in our experiments," Moore said. "As a mathematician, that is screaming to me that there is something fundamental to understand."

The experiments and the emergence of this gamma distribution have spurred new investigations into the origin of rogue waves.

"We have to understand them on a fundamental level first by developing new mathematics," Moore said. "The next step is to use that new mathematics to try to predict where and when these extreme events will occur."

Read more at Science Daily

European waters drive ocean overturning, key for regulating climate

New research shows the Atlantic meridional overturning circulation, which regulates climate, is primarily driven by waters west of Europe.

A new international study finds that the Atlantic meridional overturning circulation (MOC), a deep-ocean process that plays a key role in regulating Earth's climate, is primarily driven by cooling waters west of Europe.

In a departure from the prevailing scientific view, the study shows that most of the overturning and variability is occurring not in the Labrador Sea off Canada, as past modeling studies have suggested, but in regions between Greenland and Scotland. There, warm, salty, shallow waters carried northward from the tropics by currents and wind, sink and convert into colder, fresher, deep waters moving southward through the Irminger and Iceland basins.

Overturning variability in this eastern section of the ocean was seven times greater than in the Labrador Sea, and it accounted for 88 percent of the total variance documented across the entire North Atlantic over the 21-month study period.

These findings, unexpected as they may be, can help scientists better predict what changes might occur to the MOC and what the climate impacts of those changes will be, said Susan Lozier, the Ronie-Rochele Garcia-Johnson Professor of Earth and Ocean Sciences at Duke University's Nicholas School of the Environment.

"To aid predictions of climate in the years and decades ahead, we need to know where this deep overturning is currently taking place and what is causing it to vary," said Lozier, who led the international observational study that produced the new data.

"Overturning carries vast amounts of anthropogenic carbon deep into the ocean, helping to slow global warming," said co-author Penny Holliday of the National Oceanography Center in Southampton, U.K. "The largest reservoir of this anthropogenic carbon is in the North Atlantic."

"Overturning also transports tropical heat northward," Holliday said, "meaning any changes to it could have an impact on glaciers and Arctic sea ice. Understanding what is happening, and what may happen in the years to come, is vital."

Scientists from 16 research institutions from seven countries collaborated on the new study. They published their peer-reviewed findings Feb. 1 in Science.

"I cannot say enough about the importance of this international collaboration to the success of this project," Lozier said. "Measuring the circulation in the subpolar North Atlantic is incredibly challenging so we definitely needed an 'all hands on deck' approach."

This paper is the first from the $32 million, five-year initial phase of the OSNAP (Overturning in the Subpolar North Atlantic Program) research project, in which scientists have deployed moored instruments and sub-surface floats across the North Atlantic to measure the ocean's overturning circulation and shed light on the factors that cause it to vary. Lozier is lead investigator of the project, which began in 2014.

"As scientists, it is exciting to learn that there are more pieces to the overturning puzzle than we first thought," said co-author Johannes Karstensen of the GEOMAR Helmholtz Centre for Ocean Research Kiel, in Germany.

Read more at Science Daily