Nanosieves Save Energy In Biofuel Production

Daily Science Journal (Feb. 13, 2008) — A new type of membrane, developed by scientists of the University of Twente in The Netherlands, can stand high temperatures for a long period of time. This ‘molecular sieve’ is capable of removing water out of e.g. solvents and biofuels. It is a very energy efficient alternative to existing techniques like distillation.

The cylinder is the carrier of a hybrid membrane: a layer of about 100 nanometer thickness. The insert shows a close-up of the layer showing the organic links and pores. From the left of the tube, only water molecules leave the sieve. (Credit: Image courtesy of University of Twente)

Even after testing during 18 months, the new membranes prove to be highly effective, while having continuously been exposed to a temperature of 150 ºC. Existing ceramic and polymer membranes will last considerably shorter periods of time, when exposed to the combination of water and high temperatures. The scientists managed to do this using a new ‘hybrid’ type of material combining the best of both worlds of polymer and ceramic membranes. The result is a membrane with pores sufficiently small to let only the smallest molecules pass through.

Ceramic membranes, made of silica, degrade because they react with water and steam. In the new membrane, part of the ceramic links is therefore replaced by organic links. By doing this, water doesn’t have the chance to ‘attack’ the membranes. Manufacturing the new hybrid membranes is simpler than that of ceramic membranes, because the material is flexible and will not show cracks. What they have in common with ceramic membranes is the rapid flow: an advantage of this is that the membrane surface can be kept small.

The hybrid membranes are suitable for ‘drying’ solvents and biofuels, an application for which there is a large potential market worldwide. The main advantage of membrane technology is that it consumes far less energy than common distillation techniques.

The scientists also foresee opportunities in separating hydrogen gas from gas mixtures. This implies a broad range of applications in sustainable energy. Apart from that, the hybrid membranes are suitable for desalinating water. Using a hybrid membrane that is much smaller than the current polymer membranes, the same result can be achieved.

The results have been achieved in a close cooperation of scientists from the Inorganic Materials Science Group of the MESA+ Institute for Nanotechnology (UT), the Energy Efficiency in Industry department of ECN and the University of Amsterdam. The invention has been patented worldwide.

The article ‘Hybrid ceramic nanosieves: stabilizing nanopores with organic links’ by Hessel Castricum, Ashima Sah, Robert Kreiter, Dave Blank, Jaap Vente and André ten Elshof has been published in Chemical Communications (ChemComm) of the Royal Society of Chemistry in de UK.

Adapted from materials provided by University of Twente.

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Biofuel Crops That Require Destroying Native Ecosystems Worsens Global Warming

Daily Science Journal (Feb. 12, 2008) — Turning native ecosystems into "farms" for biofuel crops causes major carbon emissions that worsen the global warming that biofuels are meant to mitigate, according to a new study by the University of Minnesota and the Nature Conservancy.

Aerial view of farmland in Indonesia. The conversion of peatlands for palm oil plantations in Indonesia ran up the greatest carbon debt, one that would require 423 years to pay off. (Credit: iStockphoto)

The carbon lost by converting rainforests, peatlands, savannas, or grasslands outweighs the carbon savings from biofuels. Such conversions for corn or sugarcane (ethanol), or palms or soybeans (biodiesel) release 17 to 420 times more carbon than the annual savings from replacing fossil fuels, the researchers said. The carbon, which is stored in the original plants and soil, is released as carbon dioxide, a process that may take decades. This "carbon debt" must be paid before the biofuels produced on the land can begin to lower greenhouse gas levels and ameliorate global warming.

The conversion of peatlands for palm oil plantations in Indonesia ran up the greatest carbon debt, one that would require 423 years to pay off. The next worst case was the production of soybeans in the Amazon, which would not "pay for itself" in renewable soy biodiesel for 319 years.

"We don't have proper incentives in place because landowners are rewarded for producing palm oil and other products but not rewarded for carbon management," said University of Minnesota Applied Economics professor Stephen Polasky, an author of the study. "This creates incentives for excessive land clearing and can result in large increases in carbon emissions.

"This research examines the conversion of land for biofuels and asks the question 'Is it worth it?'," said lead author Joe Fargione, a scientist for The Nature Conservancy. "And surprisingly, the answer is no."

Fargione began the work as a University of Minnesota postdoctoral researcher with Polasky, Regents Professor of Ecology David Tilman; he completed it after joining the Nature Conservancy. They, along with university researchers Jason Hill and Peter Hawthorne, also contributed to the work.

"If you're trying to mitigate global warming, it simply does not make sense to convert land for biofuels production," said Fargione. "All the biofuels we use now cause habitat destruction, either directly or indirectly. Global agriculture is already producing food for six billion people. Producing food-based biofuel, too, will require that still more land be converted to agriculture."

These findings coincide with observations that increased demand for ethanol corn crops in the United States is likely contributing to conversion of the Brazilian Amazon and Cerrado (tropical savanna). American farmers traditionally rotated corn crops with soybeans, but now they are planting corn every year to meet the ethanol demand and Brazilian farmers are planting more of the world's soybeans. And they're deforesting the Amazon to do it.

The researchers also found significant carbon debt in the conversion of grasslands in the United States and rainforests in Indonesia.

Researchers did note that some biofuels do not contribute to global warming because they do not require the conversion of native habitat. These include waste from agriculture and forest lands and native grasses and woody biomass grown on marginal lands unsuitable for crop production. The researchers urge that all fuels be fully evaluated for their impacts on global warming, including impacts on habitat conversion.

"Biofuels made on perennial crops grown on degraded land that is no longer useful for growing food crops may actually help us fight global warming," said Hill. "One example is ethanol made from diverse mixtures of native prairie plants. Minnesota is well poised in this respect."

"Creating some sort of incentive for carbon sequestration, or penalty for carbon emissions, from land use is vital if we are serious about addressing this problem," Polasky said.

"We will need to implement many approaches simultaneously to solve climate change. There is no silver bullet, but there are many silver BBs," said Fargione. "Some biofuels may be one silver BB, but only if produced without requiring additional land to be converted from native habitats to agriculture."

The work will be published in Science later this month and will be posted online Thursday, Feb. 7.

The work was supported by the University of Minesota's Initiative for Renewable Energy and the Environment and the National Science Foundation.

Adapted from materials provided by University of Minnesota.

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History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon

Daily Science Journal (Feb. 11, 2008) — John Wesley Powell wrote in 1895: “...what a conflict of water and fire there must have been [in western Grand Canyon]! Just imagine a river of molten rock running down over a river of melted snow.”

Toroweap Point in Grand Canyon national park. (Credit: iStockphoto/Natalia Bratslavsky)

Over 110 years later, a synthesis of new and existing dates on these lava flows shows that many are significantly younger than initially thought and all are less than 725 thousand years old. The geochronology data indicates four major episodes when lava flows either erupted into the canyon or flowed over the rim into it: 725-475 thousand years ago (ka), 400-275 ka, 225-150 ka, and 150-75 ka.

These flows formed lava dams in western Grand Canyon that had dramatic impact on the Colorado River.

This paper* presents light detection and ranging (lidar) data to establish the elevations of the tops and bottoms of basalt flow remnants along the river corridor. These data show the original extent of now-dissected intra-canyon flows and aid in correlation of flow remnants.

From 725 to 475 ka, volcanism built a high edifice within Grand Canyon in the area of the Toroweap fault, with dike-cored cinder cones on both rims and within the canyon itself. These large-volume eruptions helped drive the far-traveled basalt flows which flowed down-canyon over 120 km. A second episode of volcanism, from 400 to 275 ka, built a 215-m-high dam along the Hurricane fault, about 15 km downstream.

The ca. 200 and 100 ka flows (previously mapped as Gray Ledge) were smaller flows and lava cascades that entered the canyon from the north rim between the Toroweap and Hurricane faults.

The combined results suggest a new model for the spatial and temporal distribution of volcanism in Grand Canyon in which composite lava dams and edifices were generally leaky in proximal areas.

Available data suggest that the demise of volcanic edifices may have involved either large outburst-flood events or normal fluvial deposition at times when the river was established on top of basalt flows. These data highlight complex interactions of volcanism and fluvial processes in this classic locality.

This research, authored by Ryan Crow (University of New Mexico) et al. was published in the February issue of Geosphere, published by the Geological Society of America.

Adapted from materials provided by Geological Society of America.

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Magma And Volcanoes: Physicists Explain Dance Marathon Of Wispy Feature In Roiling Fluids

Daily Science Journal (Feb. 7, 2008) — Theoretical physicists at the University of Chicago are suggesting how thin spouts of magma in the Earth's mantle can persist long enough to form hotspot volcanism of the type that might have created the Hawaiian Islands.

University of Chicago physicists Wendy Zhang (left) and Laura Schmidt explain a feature of convecting fluids that colleagues have observed in laboratory experiments. The feature may help explain how hotspot volcanism created the Hawaiian Islands and other such landforms. (Credit: Dan Dry)

Their calculations also apply to tendrils only a few inches long that form in convecting fluids under laboratory conditions. University of Chicago graduate student Laura Schmidt and Wendy Zhang, an Assistant Professor in Physics, will detail their findings in the Feb. 1 issue of the journal Physical Review Letters.

The work was inspired by laboratory experiments conducted by Anne Davaille in France that mimic, in a simplified way, convecting bubbles of magma as they might look deep beneath the Earth's surface. "This is one robust feature of thermal convection," Zhang said.

"It's a useful thing to know because it's the kind of thing that happens in all sorts of different industries, in all sorts of different contexts." These include oil extraction, the chemical industry and in certain biotechnological applications.

Earth scientists also have theorized that mantle plumes form on a regional scale in the Earth's interior, sometimes breaking the surface to form small landmasses, including Hawaii and Iceland. Nevertheless, debate swirls around how, or even if, mantle plumes can account for such surface features.

Geophysicists often liken a pot of boiling water as a smaller, more rapid version of the convection that takes place in the mantle, the layer of Earth that lies between the surface crust and its core. But unlike a pot of water, the Earth's interior consists of layers with different properties.

In laboratory experiments, Anne Davaille, a geophysicist at the University of Paris 7, studies convection in a small tank by heating two layers of colored liquids of differing densities. She observed the formation and persistence of thin tendrils between the layers, which correspond to subsurface plumes measuring scores of miles across.

"It seems so thin and tenuous, how could it possibly manage to hold itself in place over time as everything else is going on around it?" Zhang asked. "Somehow, they manage to hold themselves together."

The tendrils persist for hours, even as experimental conditions change. "These tendrils have fluid flowing through them, and it starts to mix the two layers," Schmidt said. "When the two layers mix, then the viscosity of the layers changes as well."

Following a series of visits to Davaille's lab, Schmidt and Zhang sought to mathematically explain the phenomenon.

"When you look at the shape of these very thin tendrils, there's something very striking that Anne noticed right away," Zhang said. The tendrils seem to emerge from flow lines that resemble the flared-out end of a trumpet. This trumpet shape marked the location of a stagnation point. Both Davaille's experiments and Schmidt's calculations agree: The thinnest tendrils that persist have a stagnation point.

Schmidt had seen a similar stagnation point in experiments she conducted in the laboratory of Sidney Nagel, the Stein-Freiler Distinguished Service Professor in Physics at the University of Chicago. Those experiments involved unmixable fluids, such as water and oil, instead of the fresh water and salt water mixing in Davaille's laboratory.

Nevertheless, the experimental similarities provided Schmidt and Zhang insights that helped solve the problem. In previous studies, other theoreticians suggested how large flows might rise through the tendrils from the base of the hot spots, Schmidt said. She and Zhang approached the problem differently.

"We include the effect of the stagnation point," Schmidt explained. "Our tendrils are really a thin skin or thin layer of the surface between the fluids that is drawn up. It's not a bulk flow going up through the tendril."

Adapted from materials provided by University of Chicago, via EurekAlert!, a service of AAAS.

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Bio-crude Turns Cheap Waste Into Valuable Fuel

Daily Science Journal (Feb. 5, 2008) — CSIRO and Monash University have developed a chemical process that turns green waste into a stable bio-crude oil. The bio-crude oil can be used to produce high value chemicals and biofuels, including both petrol and diesel replacement fuels.

Forest waste can be converted into bio-crude oil. (Credit: Image courtesy of CSIRO Australia)

“By making changes to the chemical process, we’ve been able to create a concentrated bio-crude which is much more stable than that achieved elsewhere in the world,” says Dr Steven Loffler of CSIRO Forest Biosciences.

“This makes it practical and economical to produce bio-crude in local areas for transport to a central refinery, overcoming the high costs and greenhouse gas emissions otherwise involved in transporting bulky green wastes over long distances.”

The process uses low value waste such as forest thinnings, crop residues, waste paper and garden waste, significant amounts of which are currently dumped in landfill or burned.

“By using waste, our Furafuel technology overcomes the food versus fuel debate which surrounds biofuels generated from grains, corn and sugar,” says Dr Loffler.

“The project forms part of CSIRO’s commitment to delivering cleaner energy and reducing greenhouse gas emissions by improving technologies for converting waste biomass to transport fuels.”

The plant wastes being targeted for conversion into biofuels contain chemicals known as lignocellulose, which is increasingly favoured around the world as a raw material for the next generation of bio-ethanol.

Lignocellulose is both renewable and potentially greenhouse gas neutral. It is predominantly found in trees and is made up of cellulose; lignin, a natural plastic; and hemicellulose.

CSIRO and Monash University will apply to patent the chemical processes underpinning the conversion of green wastes to bio-crude oil once final laboratory trials are completed.

The research to date is supported by funding from CSIRO’s Energy Transformed Flagship program, Monash University, Circa Group and Forest Wood Products Australia.

National Research Flagships CSIRO initiated the National Research Flagships to provide science-based solutions in response to Australia’s major research challenges and opportunities. The nine Flagships form multidisciplinary teams with industry and the research community to deliver impact and benefits for Australia.

Adapted from materials provided by CSIRO Australia.

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Finding New Oil In Long-exhausted Oil Wells

Daily Science Journal (Feb. 3, 2008) — Under contemporary conditions, it is more economically sound not to look for new oil fields but to overhaul old ones. Oil reappears from time to time in old deposits and long ago exhausted oil wells.

The earth's crust is similar to a sandwich cake, consisting of hard layers and fractured-porous layers saturated by various fluids, including oil. In some places, the crust is penetrated by an extremely dense network of fissures and ruptures. Ruptures form cavities located almost horizontally and united into a network. All this complicated system is in constant motion due to tectonic forces’ action. The layers are moving, fissures are widening and acting as a rubber bulb: liquid starts coming into formed interstice from surrounding porous layers. In case of significant tectonic tensions, liquid moves at large distances.

This phenomenon attracts attention of multiple researchers. Specialists of the Institute of Oil and Gas Problems under the guidance of Academician Dmitrievsky offer their explanation.

According to the researchers’ opinion, this mechanism of liquid movement in the crust is the most intense and universal among all possible ones. It acts both in ruptures and in thin fractured layers, which stretch at significant distances. Vibrations in the crust drive fluids along all possible directions, including horizontal and even downward directions. Migration occurs along lengthy cavities and fractures systems, located at the depth of 10 to 15 kilometers.

Liquid movement caused by widening of internal cavities is of vibrating character. Oil sometimes rushes in or sometimes floods back. The mode and period of vibration depend on the size of perturbed area. In large porous layers, the vibration period makes about 10 thousand years. In the ruptures, the period is shorter and it varies from a thousand to hundreds and even dozens of years, if rupture zones are located at small depths.

The researchers have investigated the carbohydrates migration process from the petroliferous stratum into the upper layers in several regions. An example can be the Romashinskoye oilfield in Tatarstan. The volume of produced oil there has significantly exceeded the previously asserted reserves. According to the TATANEFT Joint Stock Company’s data, more than 65% of oil in Tatarstan is produced in old oilfields exhausted by 80%. However, supplementary exploration of the known deposits allowed to increment reserves of oil by one and a half times within the last 25 years. In the Romashinskoye oilfield, the researchers also discovered old exhausted drillings with regenerated inflow of oil and oil with water.

The space of oil pools and their reserves increase with increasing rupture network density. It is interesting to note that the depth of sedimentary covering in the zone of the gigantic Romashinskoye oilfield does not exceed 2 kilometers on average, and this mantle does not possess significant oil potential. Most likely, oil cames to these locations from the direction of Pre-Ural downfold.

In the researchers’ opinion, to overhaul old oil deposits is currently much more profitable and efficient than expensive geological exploration works at new locations.

Adapted from materials provided by Informscience.

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Making Accurate Predictions Of Tsunami Risks

Daily Science Journal (Feb. 2, 2008) — A new review of tsunami hazards concludes that the 2004 catastrophe was far from the worst possible in many Indian Ocean borderlands - and notes that warning systems to guard at-risk populations are still lagging.

Wave patterns generated by an earthquake just west of the Indonesian island of Sumatra. (Credit: Image courtesy of University of Southern California)

Costas Synolakis, director of the University of Southern California Tsunami Research Center is co-author of "Far-Field Tsunami Hazard From Mega-Thrust Earthquakes in the Indian Ocean," just published in the Geophysical Journal International.

Synolakis and co-author Emile Okal of Northwestern University evaluated all known potential tsunami-generating sources in the vast area between Africa, Asia, Australia and Antarctica, and then calculated the impact of the tsunamis they can generate, should they rupture. Their paper presents the geographical distribution of risk.

The pair examined eight scenarios, two along Southern Sumatra (in Indonesia), two in the North Andaman segment of the Sumatra Subduction Zone, two sources along the Makran Subduction Zone (south of western Pakistan) and two sources south of Java. (Indonesia)

According to Synolakis, a professor in the USC Viterbi School of Engineering's Sonny Astani Department of Civil and Environmental Engineering, "the most important lesson from the scenarios we investigated is that the patterns of far-field maximum amplitudes predicted by our simulations will not be a repeat of those observed in 2004." The differences result from differences in the directions in which the disturbances propagate, "and in many instances the results are counterintuitive."

Synolakis expressed high confidence in the reliability of the projections. "Even if the earthquakes, as they materialize in the future, have geometric characteristics that are slightly different from our hypothetical scenarios, the far field impact projections are robust to small initial perturbations arising from uncertainty in the rupture characteristics."

Among the paper's conclusions:

• The impact in the mid-ocean Maldive Islands from all scenarios appears to be similar or less than what was observed in 2004 - however the low-lying structure of the islands makes them more difficult to evacuate than other risk sites..
• The impact in Madagascar and the Mascarene Islands (Mauritius, Rodrigues and Réunion) and the Seychelles could be far greater than in 2004, particularly from earthquakes in Southern Sumatra and in South Java. Madagascar is found particularly vulnerable from South Sumatran tsunamis.
• Africa suffered in excess of 300 deaths in 2004, 300 of them in Somalia. Its east coast is vulnerable from south Sumatran tsunamis and in particular, Somalia remains at high risk due to the focusing effect of the Maldives ridge. The Comoro islands located between Tanzania and Madagascar would probably be affected more severely than in 2004.
• Large earthquakes in south Java would generate substantial levels of destruction in Northern Australia, despite the sparse level of development there.
• The Strait of Malacca area appears more vulnerable than in 2004, from earthquakes in the North Andaman. Bali and Lombok and could be severely affected by large events in south Java. In fact Bali was affected by the 1994 tsunami, whose trigger was smaller than the ones envisioned here.
• The Kerguelen Islands (49.5◦S; 69.5◦E), part of the French Southern and Antarctic Territories, are highly vulnerable. Other than the North Andaman scenarios, practically all other events affect the Kerguelens, where apparently the 2004 tsunami did not cause damage. The much larger offshore heights the simulations predict would put the scientific base there (60-100 persons) at risk

Many of these scenarios have never been examined before. Synolakis' USC colleague Jose Borrero and others examined the local impact from south Sumatran scenarios in a 2006 paper in the Proceedings of the National Academy of Sciences. Synolakis and Okal concentrated on basin-wide impacts not studied earlier.

The impact to the eastern coast of India and in Myanmar and Bangladesh from the North Andaman scenarios was examined in a paper recently published in Nature by Phil Cummins (2007) of Geoscience Australia. The impact the new paper predicts is slightly different, Synolakis says, but only in the geographical distribution of the carnage.

According to that paper, the Makran Coast of Baluchistan constitutes a subduction zone along which the Arabian plate sinks under the Eurasian one. This was the site of a major earthquake on 1945 November 27, which was accompanied by a significant regional tsunami, with run-up in the five to ten meter range.

Synolakis and Okal, who is a professor in Northwestern's Department of Earth and Planetary Science, examined different rupture scenarios and their affect on the Makran coast, Oman and the west coast of India. "They are substantial and need more detailed study," Synolakis said, making reference to a documented catastrophe that occurred 24 centuries ago: "While the tsunami impact could be inferred from Pliny's reports of the adventure sof the fleet of Alexander the Great returning from India at the Straits of Hormuz in 434 AD, it has not yet been examined to the extent it deserves given the commercial and military value of the Straits.

Synolakis and Okal agree with Cummins about a critical need for the area: a warning net.

"It is quite clear that a tested and true tsunami early warning system as now works in the Pacific by the Pacific Tsunami Warning Center needs to be urgently implemented in the Indian Ocean," said Synolakis. "This system should include hundreds of pre-computed detailed scenarios of inundation for all Indian Ocean nations to facilitate emergency planning for evacuation should any of these scenarios materialize. Public education is a must and local people and visitors should be made aware of tsunami hazards, no matter how unlikely they may be, just us Hawaii and Oregon are already doing."

Synolakis and Okal began work on the project almost in the immediate aftermath of Sumatra 2004 and was completed last year.

"Our work was triggered from three different two week classes we taught for UNESCO in 2006/2007 on tsunami hazard mitigations in the Indian Ocean," said Synolakis. "More than eighty professionals attended having been nominated by their governments and we tried to show them how to assess with us the local impact from adjacent sources. We tried to guide them towards understanding and evaluating transoceanic impact, but the computational tools they had then were just not optimal.

"The work we present here extends the synthesis of hundreds of inundation projections done by our students in these classes, with varying degrees of success. However, all the specific scenarios we used are the synthesis of extensive literature and archive review, a synthesis of the preliminary material we developed in the UNESCO classes and of course all the computations are new."

The National Science Foundation and the European Union - via a Transfer Grant - supported the research.

Adapted from materials provided by University of Southern California.

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Oil Exploration In Arctic Highly Risky: 'Response Gap' In Case Of Oil Spill, According To New Report

Daily Science Journal (Jan. 31, 2008) — Arctic marine conditions contribute to an oil spill “response gap” that effectively limits the ability to clean up after an oil spill.

A new report commissioned by WWF concludes that the only way to avoid the potentially devastating environmental risks is to ensure that no more of the Arctic is opened up to oil development until the response gap is closed.

“The ability to effectively clean up an arctic marine oil spill is a critical component of the risk equation,” said Dr Neil Hamilton, Director of the WWF International Arctic Programme. “The fact that a catastrophic spill might exceed the operating limits of existing oil spill response technologies is a strong argument for a moratorium until the response gap is filled.”

According to the report Oil Spill Response Challenges in Arctic Waters, arctic conditions can impact on both the probability that a spill will occur from oil and gas operations and the consequences of such a spill. The same conditions that contribute to oil spill risks (including lack of natural light, extreme cold, moving ice floes, high wind and low visibility) can also make spill response operations extremely difficult or totally ineffective.

“The Arctic offers the highest level of ecological sensitivity and the lowest level of capacity to clean up after an accident,” said James Leaton, Senior Policy Adviser, WWF-UK. “This combination makes it unacceptable to expose the Arctic to an unfettered scramble for oil.”

The report recognizes that significant efforts are ongoing to test and improve spill response technologies for use in arctic conditions. However, until such technologies are field-proven and market-ready, additional prevention and planning measures are required to eliminate oil spill risks during times when response operations are not feasible.

WWF has also called for an international mandatory instrument to regulate shipping in the Arctic, as shipping imposes great risks to the Arctic Environment. Routing, zero-discharge zones, areas to be avoided and obligations to keep a certain amount of “self-help” oil spill response equipment on board are among the needed measures.

The report can be downloaded at: http://assets.panda.org/downloads/nuka_oil_spill_response_report_final_jan_08.pdf

Adapted from materials provided by World Wildlife Fund.

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Innovative Method Improves Tsunami Warning Systems, Offers New Insights

ScienceDaily (Jan. 29, 2008) — A wave of new NASA research on tsunamis has yielded an innovative method to improve existing tsunami warning systems, and a potentially groundbreaking new theory on the source of the December 2004 Indian Ocean tsunami.

Using GPS data (purple arrows) to measure ground displacements, scientists replicated the December 2004 Indian Ocean tsunami, whose crests and troughs are shown here in reds and blues, respectively. The research showed GPS data can be used to reliably estimate a tsunami's destructive potential within minutes. (Credit: NASA/JPL)

In one study, published last fall in Geophysical Research Letters, researcher Y. Tony Song of NASA's Jet Propulsion Laboratory, Pasadena, Calif., demonstrated that real-time data from NASA's network of global positioning system (GPS) stations can detect ground motions preceding tsunamis and reliably estimate a tsunami's destructive potential within minutes, well before it reaches coastal areas. The method could lead to development of more reliable global tsunami warning systems, saving lives and reducing false alarms.

Conventional tsunami warning systems rely on estimates of an earthquake's magnitude to determine whether a large tsunami will be generated. Earthquake magnitude is not always a reliable indicator of tsunami potential, however. The 2004 Indian Ocean quake generated a huge tsunami, while the 2005 Nias (Indonesia) quake did not, even though both had almost the same magnitude from initial estimates. Between 2005 and 2007, five false tsunami alarms were issued worldwide. Such alarms have negative societal and economic effects.

Song's method estimates the energy an undersea earthquake transfers to the ocean to generate a tsunami by using data from coastal GPS stations near the epicenter. With these data, ocean floor displacements caused by the earthquake can be inferred. Tsunamis typically originate at undersea boundaries of tectonic plates near the edges of continents.

"Tsunamis can travel as fast as jet planes, so rapid assessment following quakes is vital to mitigate their hazard," said Ichiro Fukumori, a JPL oceanographer not involved in the study. "Song and his colleagues have demonstrated that GPS technology can help improve both the speed and accuracy of such analyses."

Song's method works as follows: an earthquake's epicenter is located using seismometer data. GPS displacement data from stations near the epicenter are then gathered to derive seafloor motions. Based upon these data, local topography data and new theoretical developments, a new "tsunami scale" measurement from one to 10 is generated, much like the Richter Scale used for earthquakes. Song proposes using the scale to make a distinction between earthquakes capable of generating destructive tsunamis from those unlikely to do so.

To demonstrate his methodology on real earthquake-tsunamis, Song examined three historical tsunamis with well-documented ground motion measurements and tsunami observations: Alaska in 1964; the Indian Ocean in 2004; and Nias Island, Indonesia in 2005. His method successfully replicated all three. The data compared favorably with conventional seismic solutions that usually take hours or days to calculate.

Song said many coastal GPS stations are already in operation, measuring ground motions near earthquake faults in real time once every few seconds. "A coastal GPS network established and combined with the existing International GPS Service global sites could provide a more reliable global tsunami warning system than those available today," he said.

The theory behind the GPS study was published in the December 20 issue of Ocean Modelling. Song and his team from JPL; the California Institute of Technology, Pasadena, Calif.; University of California, Santa Barbara; and Ohio State University, Columbus, Ohio, theorized most of the height and energy generated by the 2004 Indian Ocean tsunami resulted from horizontal, not vertical, faulting motions. The study uses a 3-D earthquake-tsunami model based on seismograph and GPS data to explain how the fault's horizontal motions might be the major cause of the tsunami's genesis.

Scientists have long believed tsunamis form from vertical deformation of seafloor during undersea earthquakes. However, seismograph and GPS data show such deformation from the 2004 Sumatra earthquake was too small to generate the powerful tsunami that ensued. Song's team found horizontal forces were responsible for two-thirds of the tsunami's height, as observed by three satellites (NASA's Jason, the U.S. Navy's Geosat Follow-on and the European Space Agency's Environmental Satellite), and generated five times more energy than the earthquake's vertical displacements. The horizontal forces also best explain the way the tsunami spread out across the Indian Ocean. The same mechanism was also found to explain the data observed from the 2005 Nias earthquake and tsunami.

Co-author C.K. Shum of Ohio State University said the study suggests horizontal faulting motions play a much more important role in tsunami generation than previously believed. "If this is found to be true for other tsunamis, we may have to revise some early views on how tsunamis are formed and where mega tsunamis are likely to happen in the future," he said.

Adapted from materials provided by NASA/Jet Propulsion Laboratory.

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Warmer Ocean Could Reduce Number Of Atlantic Hurricane Landfalls

Daily Science Journal (Jan. 25, 2008) — A warming global ocean — influencing the winds that shear off the tops of developing storms — could mean fewer Atlantic hurricanes striking the United States according to new findings by NOAA climate scientists. Furthermore, the relative warming role of the Pacific, Indian and Atlantic oceans is important for determining Atlantic hurricane activity.

Hurricane Katrina on Aug. 28, 2005. (Credit: NOAA)

The article, to be published on January 23 in Geophysical Research Letters, uses observations to show that warming of global sea surface temperatures is associated with a secular, or sustained long-term increase, of vertical wind shear in the main development region for Atlantic hurricanes. The increased vertical wind shear coincides with a downward trend in U.S. landfalling hurricanes.

“We looked at U.S. landfalling hurricanes because it is the most reliable Atlantic hurricane measurement over the long term,” says Chunzai Wang, a physical oceanographer and climate scientist with NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami and lead author on the article. “Using data extending back to the middle nineteenth century, we found a gentle decrease in the trend of U.S. landfalling hurricanes when the global ocean is warmed up. This trend coincides with an increase in vertical wind shear over the tropical North Atlantic and the Gulf of Mexico, which could result in fewer U.S. landfalling hurricanes.” For the article, Wang worked with Sang-Ki Lee of the Cooperative Institute for Marine and Atmospheric Studies-University of Miami.

In terms of hurricane strength, Wang notes, “The vertical wind shear is not the only factor affecting Atlantic hurricane activity, although it is an important one.” Other factors include atmospheric humidity, sea level pressure, and sea surface temperature.

This study also suggests that where the global ocean warming occurs is important for determining the vertical wind shear in the Atlantic hurricane main development region — within the 10°-20° North latitude belt that stretches from west Africa to Central America. Whether future global warming increases Atlantic hurricane activity will probably depend on the relative role induced by sustained long-term warming over the tropical oceans.

Observations from 1854 to 2006 show a warming of sea surface temperature occurring almost everywhere over the global ocean, with large warming in tropical regions of the Pacific, Atlantic, and Indian oceans. Warmer waters in the tropical Pacific, Indian and North Atlantic oceans produce opposite effects upon vertical wind shear; that is, warming in the tropical Pacific and Indian oceans increase vertical wind shear in the Atlantic hurricane main development region, while warming in the tropical North Atlantic decreases vertical wind shear. Overall, warming in the Pacific and Indian oceans is of greater impact and produces increased levels of vertical wind shear which suppresses Atlantic hurricane activity.

The National Oceanic and Atmospheric Administration, an agency of the U.S. Commerce Department, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of our nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 70 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.

Adapted from materials provided by National Oceanic And Atmospheric Administration.

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Seagull Blood Shows Promise For Monitoring Pollutants From Oil Spills

Daily Science Journal (Jan. 17, 2008) — Like the proverbial coal miners' canary-in-the-cage, seagulls may become living sentinels to monitor oil pollution levels in marine environments, report scientists in Spain.

Seagull blood shows promise for monitoring pollutants from oil spills in marine environments. (Credit: Courtesy of Alberto Velando, Universidade de Vigo, Spain)

In the study, Alberto Velando and colleagues note that researchers have known for years that large oil spills can increase levels of polycyclic aromatic hydrocarbons (PAHs) in marine environments.

Studies have linked these compounds to cancer in humans. While oil spills quickly kill large numbers of seabirds and other animals, scientists do not fully understand the non-lethal biological effects of these spills, the Spanish researchers say.

The researchers measured PAH levels in the blood of Yellow-legged gulls living in the vicinity of the oil spill caused by the 2002 shipwreck of the Prestige, one of Europe's largest oil spills.

Gulls exposed to the oil showed twice the levels of PAHs in their blood than unexposed birds, even though these levels were measured 17 months after the initial spill, the researchers say. The findings "give support to the nondestructive use of seabirds as biomonitors of oil pollution in marine environments," the article states.

The study "Monitoring Polycyclic Aromatic Hydrocarbon Pollution in Marine Environment after the Prestige Oil Spill by Means of Seabird Blood Analysis" is scheduled for the Feb. 1 issue of ACS' Environmental Science & Technology.

Adapted from materials provided by American Chemical Society.

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Natural Climate Changes Can Intensify Hurricanes More Efficiently Than Global Warming

Daily Science Journal (Dec. 13, 2007) — Natural climate variations, which tend to involve localized changes in sea surface temperature, may have a larger effect on hurricane activity than the more uniform patterns of global warming, a report in Nature suggests.

The multiple effects of warming oceans on hurricane intensity. (Credit: NOAA, GFDL)

In the debate over the effect of global warming on hurricanes, it is generally assumed that warmer oceans provide a more favorable environment for hurricane development and intensification. However, several other factors, such as atmospheric temperature and moisture, also come into play.

Drs. Gabriel A. Vecchi of the NOAA Geophysical Fluid Dynamics Laboratory and Brian J. Soden from the University of Miami Rosenstiel School of Marine & Atmospheric Science analyzed climate model projections and observational reconstructions to explore the relationship between changes in sea surface temperature and tropical cyclone 'potential intensity' - a measure that provides an upper limit on cyclone intensity.

They found that warmer oceans do not alone produce a more favorable environment for storms because the effect of remote warming can counter, and sometimes overwhelm, the effect of local surface warming. "Warming near the storm acts to increase the potential intensity of hurricanes, whereas warming away from the storms acts to decrease their potential intensity," Vecchi said.

Their study found that long-term changes in potential intensity are more closely related to the regional pattern of warming than to local ocean temperature change. Regions that warm more than the tropical average are characterized by increased potential intensity, and vice versa. "A surprising result is that the current potential intensity for Atlantic hurricanes is about average, despite the record high temperatures of the Atlantic Ocean over the past decade." Soden said. "This is due to the compensating warmth in other ocean basins."

"As we try to understand the future changes in hurricane intensity, we must look beyond changes in Atlantic Ocean temperature. If the Atlantic warms more slowly than the rest of the tropical oceans, we would expect a decrease in the upper limit on hurricane intensity," Vecchi added. "This is an interesting piece of the puzzle."

"While these results challenge some current notions regarding the link between climate change and hurricane activity, they do not contradict the widespread scientific consensus on the reality of global warming," Soden noted.

The journal article is entitled "Effect of Remote Sea Surface Temperature Change on Tropical Cyclone Potential Intensity."

Adapted from materials provided by University of Miami Rosenstiel School of Marine & Atmospheric Science, via EurekAlert!, a service of AAAS.

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Black Sea To Take Years To Recover From Oil Spill

Daily Science Journal (Nov. 29, 2007) — The oil spill that wreaked havoc in the Kerch Strait leading to the Black Sea in early November will take at least 5 to 10 years for the marine environment to recover, says WWF.

According to WWF specialists, the 2000-tonne spill has badly affected the local fishing industry. Fish caught in the Kerch Strait are not safe for consumption.

The spill has also threatened birds. About 11 endangered species inhabit the area around the strait, including the Dalmatian pelican and great black-headed gull, and many more migrating birds will be wintering in this area in the coming months.

Thanks to the efforts of clean-up crews, including WWF staff and members, some birds have been rescued. However, these activities can only help save a very small percentage of the thousands of affected birds. Two dolphins have also been found washed up on shore where clean-up operations are being conducted, but their chances of survival are slim. The Black Sea is home to common and bottlenose dolphins.

“Although it is practically impossible to completely eliminate the damage caused by the large oil spill,” said Igor Chestin, CEO of WWF-Russia, “we believe that to avoid such disasters in the future drastic changes need to be made in the oil transportation system; oil pollution laws need to be enacted.”

To avoid such accidents in the future, WWF and other environmental NGOs are developing recommendations for the Russian government, which include:

• Local volunteers should be trained to respond to oil spills (WWF has already been training clean-up teams on the Russian coast of the Barents Sea for several years).

• Oil export via the river-sea corridor should be stopped, and river vessels not suited for marine conditions should be instructed to enter ports.

• Russia should develop a legislative base for oil spills, similar to the US Oil Pollution Act adopted after the Exxon Valdez oil spill in 1989, and should set up an independent agency responsible for environmental protection.

According to Alexey Knizhnikov, head of WWF-Russia’s oil and gas project, there is a prepared draft law introducing the “polluter pays” principle and environmental insurance. However, they have not been approved by the State Duma (Russia’s lower house of parliament).

“If these draft law is approved, many problems will be solved, as companies will feel more responsible for the risks they take,” says Knizhnikov.

“We hope that this accident will spur the process in adopting these laws and creating such an agency.”

Adapted from materials provided by World Wildlife Fund.

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Oiled-bird Being Rescued In San Francisco

Daily Science Journal (Nov. 12, 2007) — UC Davis wildlife experts are leading the rescue of oiled birds in San Francisco today after a container ship spilled nearly 60,000 gallons of heavy bunker fuel oil into the bay.

Veterinarians assess the health status of oiled birds that are being brought in from beaches and the bay waters. (Credit: UC Davis (archival photo))

Three veterinarians and a veterinary technician arrived at Fort Mason Wednesday to organize the rescue effort and begin treating injured birds.

By 1 p.m. November 8, there were 21 seabirds being treated, all of them surf scoters, according to UC Davis veterinarian Michael Ziccardi, director of the California Oiled Wildlife Care Network.

Jonna Mazet, a UC Davis veterinarian and international authority on the rescue and treatment of oiled wildlife, has said in the past that for every oiled seabird that is found washed ashore, an estimated 10 to 100 birds died at sea.

The UC Davis rescue team is working in a custom-built recovery and rehabilitation trailer. There, they assess the health status of oiled birds that are being brought in from beaches and the bay waters.

Then the birds are put in boxes and driven to the San Francisco Bay Oiled Wildlife Care and Education Center in Cordelia (just outside Fairfield), where they will receive the world's most advanced veterinary care for oiled wildlife.

At the center, the first order of business is not to remove oil from the birds. Instead, it is to warm the birds and nourish them. Once stabilized, they will be better able to withstand the stresses of being washed.

The Cordelia center is a 12,000-square-foot, $2.7 million facility capable of caring for up to 1,000 sick birds. It is the major Northern California rescue center in the statewide Oiled Wildlife Care Network, which comprises nine rescue facilities and 25 organizations prepared to care for oiled wildlife on short notice.

At each California rescue center, UC Davis wildlife veterinarians work in partnership with local, trained wildlife rehabilitators. At the Cordelia center, those rehabilitators are staff members of the International Bird Rescue Research Center.

At this time, a standing corps of trained volunteers is being called up to staff the rescue center.

The Oiled Wildlife Care Network is managed statewide by the UC Davis Wildlife Health Center, a unit of the UC Davis School of Veterinary Medicine.

The network is funded by the Office of Spill Prevention and Response of the California Department of Fish and Game. The Fish and Game monies come from interest on the $50 million California Oil Spill Response Trust Fund, built from assessments on the oil industry.

In addition to giving veterinary care, the network funds basic research into the effects of oil on wildlife and applied research into treatments that will improve survival.

Adapted from materials provided by University of California, Davis.

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Double Star TC-1 Completes Its Mission ; Details Of Solar Particles Penetrating The Earth's Environment Revealed

Daily Science Journal (Oct. 19, 2007) — TC-1, one of the two satellites of the CNSA/ESA Double Star mission, was decommissioned on 14 October as its designed orbit lifetime came to an end. The satellite re-entered Earth’s atmosphere and turned to dust during its descent.

Flying in formation around the Earth, they relay detailed information about how solar wind affects our planet in 3D. The satellites are called Rumba, Salsa, Samba and Tango. (Credit: ESA)

Along with its twin TC-2, TC-1 is the first satellite built and operated by the Chinese National Space Administration (CNSA) in cooperation with ESA. Along with its twin and the four Cluster satellites, TC-1 has helped accomplish much during its lifetime.

The four years during which Double Star was operational brought in new perspectives concerning the boundaries of the magnetosphere and the fundamental processes that are playing a role in the transport of mass, momentum and energy into the magnetosphere. Thanks to the measurements of TC-1, there was a chance to observe the evolution of structures and physical processes at small scales with Cluster, and then on large scales with Double Star.

Here we list some of the most interesting results where TC-1 played a crucial role.

Space is fizzy

Above our heads, at the bow shock, where the Earth’s magnetic field meets the constant stream of gas from the Sun, thousands of bubbles of superheated gas, or ion density holes, are constantly growing and popping. These bubbles were discovered by Cluster and Double Star together, and the discovery allowed scientists to better understand the interaction between the solar wind and the Earth’s magnetic field.

Celestial chorus further away

Chorus emissions are waves naturally generated in space close to the magnetic equator. They play an important role in creating killer electrons that can damage solar panels and electronic equipments of satellites and are a hazard for astronauts. It was found that these waves are created further away from Earth during high geomagnetic activity. This information is crucial to be able to forecast their impact.

Oscillations of Earth’s natural cloak of magnetism

The four Cluster satellites and TC-1 unexpectedly found themselves engulfed by waves of electrical and magnetic energy as they travelled through Earth’s night-time shadow. Something had set the tail of Earth’s natural cloak of magnetism oscillating, like waves created by a boat travelling across a lake. The data collected gave scientists an important clue to the effects of space weather on Earth’s magnetic field.

"Double Star has demonstrated mutual benefit and fostered scientific cooperation in space research between China and Europe. But there is still much more to come as the full, high-resolution data archive becomes available," says Philippe Escoubet, ESA’s Cluster and Double Star Project Scientist.

Adapted from materials provided by European Space Agency.

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Details Of Solar Particles Penetrating The Earth's Environment Revealed

Co-ordinated efforts by China/ESA’s Double Star and ESA’s Cluster spacecraft have allowed scientists to zero in on an area where energetic particles from the Sun are blasting their way through the Earth’s magnetic shield. Solar material penetrating the Earth's magnetic shield can represent a hazard to both astronauts and satellites.

This sketch shows the orbits of the Cluster and Double Star (TC-1) spacecraft on 8 May 2004, when the five satellites observed magnetic channels created by the merging of the Sun and the Earth's magnetic fields. Such events, called 'Flux Transfer Events,' allow solar particles to break through the Earth's magnetic shield and penetrate the Earth's environment. (Image courtesy of European Space Agency)

On 8 May 2004, one of the two Double Star satellites (TC-1) and all four Cluster spacecraft found themselves in the firing line. For about 6 hours, the Cluster spacecraft were buffeted every 8 minutes by intense flows of electrically charged particles released by the Sun. The Double Star TC-1 spacecraft had it even rougher, being blasted every four minutes for eight hours.

During such events, magnetic channels created by the merging of the Sun and the Earth’s magnetic fields allow solar particles to break through the Earth’s magnetic shield and penetrate the Earth’s environment. Physicists call the occurrence of these magnetic channels Flux Transfer Events. Each magnetic channel appears like a curve shaped tube that can be anything from 5000 to 25000 kilometres in diameter. One end of the magnetic flux tube is connected to Earth while the other end is connected to the solar wind.

The basic physical mechanism responsible for the occurrence of flux transfer events is called magnetic reconnection. In the 1950s, space physicists believed that magnetic reconnection let solar particles break through at a steady rate. That view changed in the late 1970s, when several studies showed that the magnetic reconnection could also be intermittent and take place in pulses, lasting a few minutes. Each pulse produces a magnetic flux tube (a Flux Transfer Event).

On 8 May 2004, these magnetic flux tubes swept over Cluster and Double Star again and again. As the Cluster and Double Star data clearly showed, the same location underwent magnetic reconnection several times, creating new successive magnetic flux tubes to channel more charged particles towards the Earth. The observations stopped probably because the spacecraft moved out of range and not because the reconnection region weakened in any way.

The data from the five spacecraft allowed scientists led by Aurélie Marchaudon of the Laboratoire de Physique et Chimie de l’Environnement, Centre Nationale de la Recherche Scientifique (CNRS) and Université d’Orléans, Orléans, France to triangulate the location of the magnetic reconnection region, and to deduce its size. They found that the reconnection site was located on the daylight west side of the Earth’s magnetic shield and was around 25000 kilometres across. A computer simulation of the event, conducted by Jean Berchem of the University of California Los Angeles (UCLA) and his team, confirmed the possibility of magnetic reconnection occurring at that location.

Although intermittent reconnection has been observed in the past, this was one of the longest series of continuous observations ever taken of a magnetic reconnection region in the Earth’s magnetosphere. Perhaps most surprising is that 8 May 2004 was just relatively a normal day for the Earth’s magnetic field. There were no large magnetic storms on Earth, or spectacular aurorae to fill the night sky. However, Cluster and Double Star revealed that energetic particles from the Sun were blasting their way through the Earth’s magnetic shield and penetrating the Earth’s environment.

Each day, Cluster and Double Star return more observations that allow scientist to understand the invisible magnetic turbulence high above our heads.

Adapted from materials provided by European Space Agency.

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2004 Sumatra Tsunami And Storm-generated Waves On North America's Atlantic Coast Were Concurrent

Daily Science Journal (Aug. 16, 2007) — The Sumatra-Andaman earthquake generated a catastrophic tsunami that caused heavy damage and fatalities in coastal areas around the Indian Ocean. The tsunami, which struck on 26 December 2004, also propagated throughout the world's oceans, making it the first such event to be scrutinized with continuous observations of widespread oceanic monitoring networks.

Thomson et al. analyze more than 100 tide gauge records from the Atlantic coast of North America and find that the tsunami was identified in most outer tide gauges from Florida to Nova Scotia. Maximum heights for northern regions were between 32 and 39 centimeters (1.0 and 1.3 feet), while southern regions experienced wave heights between 15 and 33 centimeters (0.49 and 1.1 feet).

However, along the shores of Maine and Nova Scotia, the arrival of the tsunami coincided with the presence of tsunami-like waves generated by a major storm tracking northward along the U.S. eastern seaboard. The combined waves reached heights in excess of 1 meter (3.3 feet).

The authors warn that, although the northern Atlantic Ocean has low tsunami hazards, tsunamis from distant seismic events could threaten coastal infrastructure and habitat when the waves coincide with winter storm waves.

Title: Double jeopardy: Concurrent arrival of the 2004 Sumatra tsunami and storm-generated waves on the Atlantic coast of the United States and Canada

Authors: Richard E. Thomson: Institute of Ocean Sciences, Sidney, British Columbia, Canada;

Alexander B. Rabinovich: Institute of Ocean Sciences, Sidney, British Columbia, Canada; also at P.P. Shirshov Institute of Oceanology, Moscow, Russia;

Maxim V. Krassovski: School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada.

Source: Geophysical Research Letters (GRL) paper 10.1029/2007GL030685, 2007

Adapted from materials provided by American Geophysical Union, via EurekAlert!, a service of AAAS.

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Strong Storms Linked With Rising Sea Surface Temperatures

Daily Science Journal (Aug. 15, 2007) — Researchers at the Georgia Institute of Technology have released a study supporting the findings of several studies last year linking an increase in the strength of hurricanes around the world to a global increase in sea surface temperature. The new study strengthens the link between the increase in hurricane intensity and the increase in tropical sea surface temperature. It found that while factors such as wind shear do affect the intensity of individual storms or storm seasons, they don't account for the global 35-year increase in the number of the most intense hurricanes.

A new Georgia Tech study strengthens the link between an increasing number of intense hurricanes, like Hurricane Katrina, and rising sea surface temperatures. (Photo courtesy: NOAA)

Last summer, the journals Nature and Science published studies claiming to show a very strong link between rising tropical sea surface temperatures and an increase in the strength of hurricanes. The Nature study, by Kerry Emanuel at the Massachusetts Institute of Technology, concluded that cyclonic storms in the North Atlantic and North Pacific oceanic basins were increasing in strength and duration. That increase, Emanuel concluded, was due to increasing sea surface temperatures caused, in part, by global warming.

A month later, the journal Science published research linking an increase in sea surface temperatures over the past 35 years to a near doubling in the number of the strongest hurricanes, those labeled Category 4 or 5. The study, authored by Peter Webster, Judith Curry and Hai-Ru Chang at Georgia Tech and Greg Holland at the National Center for Atmospheric Research, examined hurricanes in all oceanic basins that play host to cyclonic storms around the world.

This latest study sought to determine whether factors other than sea surface temperatures could be significantly contributing to this 35-year trend. Georgia Tech researchers Carlos Hoyos and Paula Agudelo, along with Curry and Webster examined three factors: vertical wind shear (changes in wind speed and direction with height); humidity in the lower atmosphere; and zonal stretching deformation, which is the tendency of the winds to rotate in a cyclonic direction.

"If you examine the intensification of a single storm, or even the statistics on intensification for a particular season, factors like wind shear can play an important role," said Curry, professor and chair of the School of Earth and Atmospheric Sciences at Georgia Tech. "However, there is no global trend in wind shear or the other factors over the 35-year period."

Curry said they did see a small but significant trend in increasing wind shear strength in the North Atlantic, but that the sea surface temperatures were the dominant influence on the increase in both global hurricane intensity as well as the intensity of the North Atlantic hurricanes.

"With this new paper, we firm up the link between the increase in sea surface temperatures and hurricane intensity, which has been a key issue in the debate about whether global warming is causing an increase in hurricane intensity," said Curry.

The study appears online in the March 16 edition of Science Express.

The study was supported by the Climate Dynamics Division of the National Science Foundation.

Adapted from materials provided by Georgia Institute of Technology.

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Satellite Tracking Will Help Answer Questions About Penguin Travels

Daily Science Journal (Aug. 10, 2007) — You could understand if a half-dozen Magellanic penguins developed a "big bird is watching" phobia before this month is over, but the surveillance really will be for their own good.

The feathers of three Magellanic penguins blackened with oil, seen along Argentina's Atlantic coast in October 2005. (Credit: Dee Boersma)

University of Washington scientists will attach satellite tracking devices to the backs of six penguins that have been treated at two centers in northern Argentina after their feathers were fouled with oil. The birds will be released into the Atlantic Ocean and their movements traced using satellites and the Internet.

The idea is to plug a critical gap in the knowledge of the Magellanics' annual life cycle, their movements on the journey from their winter feeding grounds back to their breeding colonies along the southern Argentina coast and the Islas Malvinas, or Falkland Islands.

"We're missing that information. We know what happens when they leave the breeding grounds but we don't know what happens on the return trip," said Elizabeth Skewgar, a University of Washington doctoral student in biology.

"We want to model the energy requirements for these birds so that we understand what it takes to return to the breeding grounds and still have enough energy to reproduce. Human fisheries competing for the same food could make migration even more difficult for them."

The project is led by Dee Boersma, a UW biology professor who for 25 years has headed the Magellanic Penguin Project at Punta Tombo, Argentina, the birds' largest breeding colony in South America.

"We need to know how penguins use the ocean so we can make their migration route safe through a combination of national marine parks, marine protected areas and ocean zoning," Boersma said.

During the week of Aug. 20, the scientists will select six adult male penguins from rehabilitation centers at San Clemente del Tuyu and Mar del Plata, coastal towns more than 500 miles north of Punta Tombo. Epoxy and special tape will be used to attach a transmitter to each bird before it is released into the Atlantic. The tags are about the size of many common cellular telephones and weigh less than 3.5 ounces.

"We want to put the transmitters on healthy, robust birds that we think are likely to get back and start breeding," Boersma said. "The point is to follow them back to their colony and see where they might be running into petroleum."

Through late October the birds' movements will be tracked by the Argos satellite system, operated by the National Oceanic and Atmospheric Administration and the French space agency. A satellite will pass overhead every two hours and chart the penguins' positions, then transmit the information back to the researchers, who will use it to update a public tracking map on the Internet at http://www.penguinstudies.org.

The transmitters will be active for 36 hours at a time and then will be off for 36 hours, a means of preserving the two double-A batteries in each transmitter for the life of the project. The researchers have no way of knowing whether the birds will go to southern Argentina or the Malvinas, or whether they will follow a straight course to the breeding grounds or take a circuitous route.

"After we release them, they could just hang out at Mar del Plata for a month. It's all up to them," Boersma said. "We're hoping the males we tag will be in a hurry to get to their colony and start breeding."

The satellite tracking also will be instrumental in pinpointing the birds after they arrive at the breeding grounds. Punta Tombo alone is home to some 400,000 penguins during breeding season.

"Tracking the locations by satellite is only accurate to within 5 kilometers, so it really is like trying to find a needle in a haystack," Boersma said.

Locating the penguins once they reach the breeding ground is important so the researchers can assess the birds' physical condition after the long journey.

"We'll know how much weight they gained or lost on their journey," Boersma said.

After its mate arrives, a male fasts until the female lays two eggs, then he returns to the ocean to feed, sometimes swimming hundreds of miles in search of fish such as anchovies that are staples of the penguin diet. After about two weeks the male returns to the nest to incubate the eggs while the female goes in search of food.

The birds' energy can be drastically sapped if they become coated with oil, and that can mean death. Last year, a team of scientists that included Boersma reported they had found 19 groups rehabilitating oiled seabirds along the Atlantic coast from central Brazil to central Argentina, indicating a much larger problem than generally had been believed. It remains uncertain where the oil comes from -- it could be from a combination of sources, including seepage from offshore oil rigs and ballast water from passing ships.

"We know that birds show up oiled back at our colony, so that means they're getting oiled somewhere between where they winter and Punta Tombo," Boersma said.

Others involved in the work are Sergio Rodriguez Heredia of the Fundacion Mundo Marino in San Clemente del Tuyu, Karen Griot of Fundacion Mar del Plata Aquarium and Valeria Ruoppolo of the International Fund for Animal Welfare's Penguin Network.

The research will be included in Skewgar's doctoral dissertation. The work is being funded by the Wildlife Conservation Society, with support from the tourism office of the Argentine Province of Chubut.

Adapted from materials provided by University of Washington.

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Oil Spill Clean-up Agents Threaten Coral Reefs

Daily Science Journal (Jul. 31, 2007) — In a setback for efforts to protect endangered coral reefs from oil spills, researchers in Israel report that oil dispersants -- the best tool for treating oil spills in tropical areas --are significantly more toxic to coral than the oil they are used to clean up. Their study, which urges caution in the use of these materials, is scheduled for the August 1 issue of ACS' Environmental Science & Technology.

Oil-spill clean-up agents are a threat to coral reefs, researchers say. Credit: (Credit: Courtesy of Shai Shafir, The Hebrew University of Jerusalem)

Called the 'rainforests of the sea,' coral reefs are an endangered ecosystem and are disappearing at an alarming rate due to numerous threats, including over-fishing, global warming and pollution, particularly oil spills. Besides hosting a rich diversity of marine organisms, these habitats are also potential sources of life-saving medicines and food for humans. Scientists looking for better ways to protect this important habitat have recently focused on the environmental impact of oil dispersants, detergents used break down oil spills into smaller, less harmful droplets.

In the new report, Shai Shafir and colleagues evaluated the effects of both crude oil and six commercial oil dispersants under laboratory conditions on the growth and survival of two important species of reef corals. The dispersants and dispersed oil droplets were significantly more toxic to the coral than the crude oil itself, the scientists report. The dispersants caused "significant harm," including rapid, widespread death and delay in growth rates, to the coral colonies tested even at doses recommended by the manufacturers, they add.

"Decision-making authorities should carefully consider these results when evaluating possible use of oil dispersants as a mitigation tool against oil pollution near coral reef areas," the report said.

Article: "Short and Long Term Toxicity of Crude Oil and Oil Dispersants to Two Representative Coral Species"

Adapted from materials provided by American Chemical Society, via EurekAlert!, a service of AAAS.

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Cluster Hits The Magnetic Bull's-eye

Daily Science Journal (Jul. 19, 2006) — The European Space Agency's spacecraft constellation Cluster has hit the magnetic bull's-eye. The four spacecraft surrounded a region within which the Earth’s magnetic field was spontaneously reconfiguring itself.

This artist's impression shows the four Cluster spacecraft encompassing a 'magnetic null' region. A magnetic null region is a three dimensional zone where the magnetic fields break and reconnect. (Credits: Dr. Xiao/Chinese Academy of Sciences (Beijing))

This is the first time such an observation has been made and gives astronomers a unique insight into the physical process responsible for the most powerful explosions that can occur in the Solar System: the magnetic reconnection.

When looking at the static pattern of iron filings around a bar magnet, it is difficult to imagine how changeable and violent magnetic fields can be in other situations.

In space, different regions of magnetism behave somewhat like large magnetic bubbles, each containing electrified gas known as plasma. When the bubbles meet and are pushed together, their magnetic fields can break and reconnect, forming a more stable magnetic configuration. This reconnection of magnetic fields generates jets of particles and heats the plasma.

At the very heart of a reconnection event, there must be a three dimensional zone where the magnetic fields break and reconnect. Scientists call this region the null point but, until now, have never been able to positively identify one, as it requires at least four simultaneous points of measurements.

On 15 September 2001, the four Cluster spacecraft were passing behind the Earth. They were flying in a tetrahedral formation with separations between the spacecraft of over 1 000 kilometres. As they flew through the Earth’s magnetotail, which stretches out behind the night-time side of our planet, they surrounded one of the suspected null points.

The data returned by the spacecraft have been extensively analysed by an international team of scientists led by Dr. C. Xiao from Chinese Academy of Sciences, Prof. Pu from Peking University, Prof. Wang from Dalian University of Technogy. Xiao and his colleagues used the Cluster data to deduce the three-dimensional structure and size of the null point, revealing a surprise.

The null point exists in an unexpected vortex structure about 500 kilometres across. "This characteristic size has never been reported before in observations, theory or simulations," say Xiao, Pu and Wang.

This result is a major achievement for the Cluster mission as it gives scientists their first look at the very heart of the reconnection process.

Throughout the Universe, magnetic reconnection is thought to be a fundamental process that drives many powerful phenomena, such as the jets of radiation seen escaping from distant black holes, and the powerful solar flares in our own Solar system that can release more energy than a billion atomic bombs.

On a smaller scale, reconnection at the dayside boundary of the Earth’s magnetic field allows solar gas through, triggering a specific type of aurora called 'proton aurora'.

Understanding what sparks magnetic reconnection will also help scientists trying to harness nuclear fusion for energy production. In tokamak fusion reactors, spontaneous magnetic reconfigurations rob the process of its controllability. By understanding how magnetic fields reconnect, fusion scientists hope to be able to design better reactors that prevent this from taking place.

Having identified one null point, the team now hopes to score future bull’s-eyes to compare nulls and see whether their first detection possessed a configuration that is rare or common.

Adapted from materials provided by European Space Agency.

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