ALBERT

Description: ABSTRACT A 175 years long homogenized composite record of monthly mean temperatures is presented for Oslo, the capital of Norway. The early raw data have been digitised and quality controlled, and monthly means have been calculated. Some early original observations carried out in a Wild screen (1877–1936) were found to be spuriously high because of inappropriate sheltering from sunlight. These spurious temperatures were not used in the composite record, but alternative temperatures measured (1837–1933) by thermometers placed outside windows at the Astronomical Observatory were used instead. No inhomogeneity was detected in the latter series after adding an instrument correction of +0.3 °C, but the start year of the correction remains uncertain. The more recent part of the composite record used the long-term series (1937 to present) from Blindern in Oslo, the premises of The Norwegian Meteorological Institute. Two small inhomogeneities were detected in the Blindern series, possibly caused by a weak urban heat island effect or growing/cutting of trees. The study revealed that the annual mean temperature has increased by 1.5 °C in the period 1838–2012. The most pronounced increase in annual temperature occurred during the last 50 years, and in the early 20th century that ended with a local maximum in the 1930s. The temperature has increased significantly in all seasons; however, the temperature increase in summer was less than a half of that in winter and spring, which were the seasons with largest increase. In addition the monthly mean temperature of the coldest month in each year has increased two times faster than the warmest one. The most significant temperature variations were associated to ∼ 5-year time scales in its early part, but since 1930 and up to present, the dominant time scales were 10–20 years.

Description: Invertebrates in estuaries could be at a greater risk of parasitism as climate change causes sea levels to rise. A new paper published 8 December in Proceedings of the National Academy of Sciences of the United States of America (doi:10.1073/pnas.1416747111) describes how rapid sea level rise in the Holocene affected the population of parasitic flatworms called trematodes.

Description: ABSTRACT The onset, retreat and the length of growing season in the north-eastern region of Sri Lanka were investigated using daily rainfall data for the period 1961 to 2000. Data from three weather stations situated in the coastal belt in the northern and eastern parts of Sri Lanka (Jaffna, Trincomalee and Batticaloa) that receive rainfall predominantly from the northeast monsoon were selected for this study. A method based on cumulative rainy days was utilized in the determination of the onset and retreat dates. It is shown that there is substantial interannual variability in onset and retreat dates. The mean onset and retreat dates fall on the standard week 38.3 ± 2.7 and 53.0 ± 2.9, respectively. The mean duration of the growing season is 14.7 ± 3.4 weeks. The retreat date and thus the length of growing season could be extended by 2 weeks if the probability of occurrence of rain during the onset is favourable for the retreat. The results indicate that there has been no significant trend in the onset and retreat dates during the last 40 years in the dry zone of Sri Lanka. The onset date and the length of growing season are weakly correlated with early onset dates leading to longer growing seasons. The study concludes that rainy days could be used successfully to determine the mean rainfall onset and retreat dates in the dry zone of Sri Lanka.

Description: ABSTRACT A 256-year composite monthly rainfall record representative of the lowlands around Carlisle, northwest England is presented, providing the third longest instrumental record of rainfall available in the UK and expanding the sparse network of long homogenous rainfall series. This article describes the construction of the rainfall record for the period 1757–2012 and presents analyses of long-term annual and seasonal variability, with a particular focus on wet/dry extremes. Three primary rainfall records from Carlisle underpin the reconstruction, with others selected based on length of record and proximity to the primary recording stations. Linear regression and adjustment factors were applied to create a homogenous continuous rainfall record, assessed by cross-comparison with other long-term UK rainfall records. Double-mass curve and standard normal homogeneity tests using long records representative of Manchester and Appleby confirmed that the Carlisle record is homogenous, but includes a period of uncertainty during the period 1886–1911, which is within the recognized instrumental phase of recording. Analysis of the series shows long-term temporal rainfall variability, with seasonal rainfall totals showing a significant increase in winter rainfall. An increasing trend in annual rainfall was also identified but is not significant. Several previously documented notable extreme wet (e.g. winter 1834) and dry (e.g. summer 1995) seasons were identified, along with several additional seasons (e.g. winter 1764 and summer 1891) that can be considered as extreme and occurred during the more poorly understood 18th and early 19th centuries. These results allow recent extremes to be placed within the context of long-term natural variability. At the decadal timescale seasonal rainfall totals are highly variable. The wettest season fluctuates between autumn and summer until the late 20th century (1990s), when winter became wetter than any other season for the first time on record.

Description: ABSTRACT Policymakers, governments and aid agencies require operational environmental monitoring in support of evidence-based policy-making and resource deployment in crisis situations. For Africa, this is only feasible at sub-continental scale with a large network of automated meteorological stations, a large number of highly coordinated field observers or with satellite remote sensing. The challenge with satellite data lies in the derivation of meaningful environmental indicators. This article describes a conceptual framework for understanding satellite-derived indicators of rainfall and vegetation greenness trends over Africa. It attributes observed vegetation changes to climatic (i.e. rainfall linked) and non-climatic drivers. A decade of annual rainfall and vegetation data over sub-Saharan Africa was analysed using satellite-based rainfall estimates [Famine Early Warning System Rainfall Estimation 2.0 (FEWSNET RFE 2.0)] from National Oceanic and Atmospheric Administration's (NOAA's) Climate Prediction Centre and the Normalized Difference Vegetation Index (NDVI) obtained from the Satellite Pour l'Observation de la Terre Vegetation (SPOT-VGT) sensor. Rainfall and vegetation greenness trends were analysed for 759 administrative regions of sub-Saharan Africa to identify those regions that have experienced a negative, positive or stable rainfall/vegetation trend over the period 2001–2010. The character of the relationship between the annual rainfall and max NDVI trends were examined to identify areas where the changes in greenness could be attributed to climatic (rainfall) and non-climatic (human land use or ecological disturbance) changes. Regions where increasing rainfall was associated with vegetation greening were found in West Africa, Central African Republic, West Cameroon and northeastern part of South Africa, whereas areas with evidence of ‘climatic vegetation degradation’ were located in Southern Madagascar, Nigeria, Kenya and the Garden Route region of South Africa.

Description: ABSTRACT The North African climate is analysed for August during a 32-year period using the European Centre for Medium Range Weather Forecast (ECMWF) global data set to investigate the intensity variability at 600 mb of the subtropical highs, Africa easterly jet (AEJ) with two embedded local wind maxima, and African easterly waves over North Africa and the Arabian Peninsula. The variability of these synoptic weather systems is higher in East Africa. The most noticeable variability of intensity occurred with easterly waves. Maintenance of easterly waves from the Arabian Peninsula into East Africa is dependent on strong zonal gradients from the AEJ through shear vorticity. These zonal gradients were induced by the strengthening of the subtropical highs and the presence of a westerly jet in Central Africa and south of the Arabian Peninsula. During positive ENSO periods, these systems are generally weaker while in negative periods are stronger. The focus of this research is to investigate the role of the Arabian High and eastern local wind maximum (LWM E ) on complementing the Saharan High and western local wind maximum (LWM W ). It is found that an intense local wind maximum in East Africa helps maintain the easterly waves and their westward propagation from the Arabian Peninsula.

Description: Herein, we report on the crystal structures of Nb 2 AlC and TiNbAlC—actual composition (Ti 0.45 ,Nb 0.55 ) 2 AlC—compounds determined from Rietveld analysis of neutron diffraction patterns in the 300–1173 K temperature range. The average linear thermal expansion coefficients of a Nb 2 AlC sample in the a and c directions are, respectively, 7.9(5) × 10 −6 and 7.7(5) × 10 −6  K −1 on one neutron diffractometer and 7.3(3) × 10 −6 and 7.0(2) × 10 −6  K −1 on a second diffractometer. The respective values for the (Ti 0.45 ,Nb 0.55 ) 2 AlC composition—only tested on one diffractometer—are 8.5(3) × 10 −6 and 7.5(5) × 10 −6  K −1 . These values are relatively low compared to other MAX phases. Like other MAX phases, however, the atomic displacement parameters (APDs) show that the Al atoms vibrate with higher amplitudes than the Ti and C atoms, and more along the basal planes than normal to them. When the predictions of the APDs obtained from density functional theory are compared to the experimental results, good quantitative agreement is found for the Al atoms. In case of the Nb and C atoms, the agreement was more qualitative.

Description: In this study, lithium disilicate (LS 2 ) glass samples with different particle sizes ranging from less than 105 to 850 μm were prepared. These specimens were inserted in a Pt-Rh DSC crucible and heated to 850°C at different rates (ϕ = 0.5–30 K/min) to identify their crystallization peaks. The activation energies for the overall crystallization ( E ) and the Avrami coefficient ( n ) were evaluated using different nonisothermal models. Specifically, n was evaluated using the Augis–Benett model and the Ozawa method, and E was evaluated using the Kissinger and Ligero methods. As expected, the coarse particles mainly crystallized in the volume, while surface crystallization was predominant in the samples with particle sizes of less than 350 μm. This result was confirmed through SEM analysis of the double stage heat-treated samples. In contrast with previous studies, our results demonstrated that the activation energy decreased as the particle size increased. In addition, no clear correlation between the peak intensity (δ T p ) and the particle size was observed.

Description: About an hour and a half before the launch of the Orbital Sciences Corporation's Antares rocket and Cygnus cargo spacecraft at 6:22 p.m. on 28 October, Jeff Goldstein arrived at his vantage point on Arbuckle Neck Road in Assawoman, Va. It was just 1.5 miles from launchpad 0A at NASA's Wallops Flight Facility. Goldstein, director of the National Center for Earth and Space Science Education (NCESSE) had come with about 35 elementary school through college students, as well as some parents, teachers, and school administrators, to watch the liftoff that would deliver the students' microgravity experiments to the International Space Station (ISS).

Description: Americans are very worried about the threat of natural disasters—but don't seem to be prepared for one. This conclusion comes from Chapman University's recent Survey on American Fears, released on 21 October. The survey asked 1500 Americans to rank how worried they were about several types of natural disasters and then how prepared they were for each.

Description: Microbial communities in thawing permafrost contribute a significant amount to atmospheric methane, a greenhouse gas many times more potent than carbon dioxide. A new paper published in Nature on 23 October describes how a newly discovered microbe— Methanoflorens stordalenmirensis —adds another layer to the complicated relationship between the world's permafrost fields and greenhouse gas (GHG) emissions.

Description: Crowdsourcing—“the act of taking a job traditionally performed by a designated agent [expert] and outsourcing it to an undefined, generally large group of people” [ Howe, 2009]—has fundamentally changed and enhanced the collection and dissemination of data. Crowdsourcing has proven effective for rapid data collection, especially where in-depth knowledge of a topic or discipline is not a necessity.

Description: I am a counter by nature. I count things as an effective way to occupy my mind. How many people are in this room? How many are women? How many are wearing glasses? How many people are using a Mac versus a PC?

Description: Ethics education is an increasingly important component of the pre-professional training of geoscientists. Geoethics encompasses the values and professional standards required of geoscientists to work responsibly in any geoscience profession and in service to society. Funding agencies (e.g., the National Science Foundation, the National Institutes of Health) require training of graduate students in the responsible conduct of research; employers are increasingly expecting their workers to have basic training in ethics; and the public demands the highest standards of ethical conduct by scientists. However, there is currently no formal course of instruction in ethics in the geoscience curriculum, and few faculty members have the experience, resources, and sometimes willingness required to teach ethics as a component of their geoscience courses.

Description: U.S. hydrocarbon production is on the rise, meaning that transporting hydrocarbons—whether by pipelines, trucks, or trains—is as well. However, increasing environmental concerns, mixed with other issues such as energy independence and landowner rights, is making this transportation a hot-button issue.

Description: Lava from Iceland's Bardarbunga volcano, which began erupting on 29 August, now covers 60 square kilometers of the Holuhraun lava field. Scientists have arrived in droves to study the ongoing fissure eruptions.

Description: In the early years of the 20th century, physicist Bernard Brunhes, then director of the Geophysical Observatory of Puy de Dôme (now Observatoire de Physique du Globe de Clermont), measured for the first time reverse magnetization in samples from a basaltic lava flow and from the underlying backed argillaceous sediments from the village of Pontfarein (now Pont Farin) in the Cantal volcanic district (Auvergne, France).

Description: During the latter half of the Cenozoic, starting during the Pliocene, the eastern equatorial Pacific (EEP) underwent a change from warm, wet climate conditions—which scientists refer to as “permanent El Niño”—to more moderate conditions like those observed today. Although scientists can track this change using marine proxy records, they are still puzzled as to why the sudden shift occurred.

Description: Scientists who study the physics of inland and coastal water bodies met in Trento, Italy in July for the 17th in a series of workshops that seek to expand cooperation with researchers in related fields. The workshops aim to facilitate the dialogue among physical limnologists, modelers, and colleagues from other disciplines, such as biologists, chemists, and engineers. This year's workshop was attended by 47 participants from 17 different countries.

Description: Saturn's magnetosphere exhibits phenomena with 10.7-hour periodicity that scientists do not fully understand. One proposed explanation is that twin vortices in the upper atmosphere at Saturn's north and south poles generate currents that drive the magnetosphere periodicity.

Description: On 9 December a dynamic, new, broadly inclusive, and freely accessible Earth and space science news website will launch: Eos.org. This new site is inspired by AGU's vision to galvanize our community of Earth and space scientists to collaboratively advance and communicate our science.

Description: The motion of the Earth's mantle is controlled in part by how mantle minerals respond to changes in temperature and pressure. The chemical and physical shifts that minerals undergo as they are heated and squeezed cause some to sink down toward the core and others to rise up toward the surface. This buoyant pressure and gravitational sinking, in turn, affect the convection of the mantle and the large-scale cycling of the Earth.

Description: Because the Earth's population is slated to hit 9 billion in the next century, food scarcity has become an increasingly important topic of study. Food availability is widely examined, but D'Odorico et al. point out that reliance on trade to distribute food has not been sufficiently quantified.

Description: As a glacier slides slowly into the sea, buoyancy eventually trumps gravity, and the sheet of ice floats. The place where the ice starts leaving the ground is called the grounding line, and this line can shift as the mass of the glacier shifts with precipitation or climate. Studying the movement of the grounding line through time helps scientists determine the stability of the glacier and its mass budget—the balance of how much mass the glacier is gaining or losing.

Description: The Edmond M. Dewan Young Scientist Scholarship fund has reached its goal of $25,000. Those who donated to the fund share AGU's mission in taking an active role in educating and nurturing the next generation of scientists and ensuring a sustainable future for society. Thanks to the generosity of more than 100 members of the AGU and science community, a deserving graduate student of atmospheric or space physics will receive financial assistance to further his or her research and advance his or her research and future career.

Description: Throughout the western United States, scientists have noticed that warming has reduced snow accumulation and led to earlier snowmelt, a change that could have dire consequences for the region's ecology and industries. Specifically, previous research has found that the rain-snow transition zone—the area where precipitation is dominated by rain versus snow in the winter—has shifted significantly in the past few decades.

Description: Coastal Oregon is home to a number of slow, recurrent landslides. During bouts of heavy rain, water gets into the soil, reducing friction and causing the ground to slip. Often, these landslides creep along at a barely perceptible rate—less than a centimeter per day. Yet the landslides are a lurking threat, as past events that have damaged infrastructure and cut communities off for months at a time have demonstrated.

Description: Surface ice on oceans and lakes can cause major problems onshore and offshore. Specifically, surface waves interacting with ice can create hazardous conditions for cargo ships, damage coastal structures, and carry important nutrients away from the shore.

Description: In this letter, 2-μm Pb 0.97 La 0.02 (Zr 0.75 Sn 0.18 Ti 0.07 )O 3 antiferroelectric thick film with tetragonal structure was prepared. The effects of operating electric field, temperature, and frequency on the thermal–electrical energy harvesting capacity of the film were studied by using the Olsen cycle. The results demonstrated that giant energy harvesting effect could be realized in the antiferroelectric thick film. The maximum harvestable energy density per cycle of the film was about 7.8 J/cm 3 at 1 kHz, which was the largest reported value to date. The corresponding energy harvesting efficiency was 0.53%. Moreover, the film had a low leakage current density (about 7.3 × 10 −7 and 3.9 × 10 −5  A/cm 2 at 25 and 200°C, respectively), which was favorable for its application in the devices of the thermal–electrical energy harvesting.

Description: Discharged energy properties of PbO–SrO–Na 2 O–Nb 2 O 5 –SiO 2 glass-ceramics with crystallization time from 1 to 1000 min were investigated by measuring their hysteresis loops (described as quasi-static measuring method) and pulse-discharge current-time curves (described as dynamic measuring method). The results show the same trend for both measuring methods: With the increment of crystallization time, the discharged energy density increases gradually, while the energy efficiency decreases. The highest energy efficiencies were obtained in the sample with crystallization time of 1 min, which are 96.3% and 82.4%, corresponding quasi-static and dynamic measurement, respectively. The reduction of energy efficiency with crystallization time is attributed to combined effect of ferroelectric polarization and interfacial polarization, and part of the corresponding energy could not release in the pulse-discharge process.

Description: ABSTRACT The purpose of this paper is to describe the variability of sunshine duration and air temperature and to assess the relationship between these variables. The paper is based on daily means of air temperature and daily sunshine duration totals from the 1884–2012 period. The variability analyses of these variables for the whole period is supplemented by additional trend analyses for two separate time periods described in the literature as dimming (1958–1985) and brightening (1985–2012). All the data come from the Jagiellonian University Research Station in Krakow. In Krakow, there is a decrease in the number of sunshine hours in the 1950s to 1980s period followed by an increase in the last two decades of the 20th century. The long-term course of air temperature in Krakow confirms the results obtained in other places in the world and exhibits increasing warming of the climate. The temperature increase is visible in each month but is highest in winter (exceeding 1.5 °C per 100 years). Therefore, it may be assumed that the increase in air temperature, which has been particularly strong since the 1980s, showed the full effect of global warming in the brightening period that was previously masked by global dimming as shown in the sunshine duration records. The time course of air temperature for the whole study period (1884–2012) shows a statistically significant positive linear trend. The present warming is influenced probably by the air-quality improvement (brightening period) and an increase in sunshine duration in the years 1980–2012.

Description: The relationship between long-term variations in summer temperature in Japan since the early 20th century and the large-scale atmospheric circulation field was analysed. The combined influence of various circulation predictors on temperature variations was analysed via a multicomponent canonical correlation analysis (CCA). The positive phase of the first CCA mode is related to a positive temperature anomaly across Japan, characterized by a weak blocking high over the Okhotsk Sea, and a strong North Pacific subtropical high (NPSH) over Japan. The positive phase of the second CCA mode corresponds to a positive temperature anomaly in southwestern Japan, and a negative anomaly in northern Japan, characterized by an anticyclonic circulation anomaly over eastern China and a cyclonic anomaly over the northwestern Pacific. By investigating the temporal changes in CCA scores, we detected an abrupt increase in the first CCA score in the early 1910s and a long-term increasing trend in the second CCA score since the early 20th century. The abrupt increase in the first CCA score indicates an abrupt increase in temperature throughout Japan. By investigating changes in the circulation field associated with this abrupt warming, we determined that intensification of zonal flow over the Okhotsk Sea was responsible. The increasing trend of the second CCA score indicates an increase in the regional difference in summer temperatures between northern and southwestern Japan. After investigating changes in the circulation field before and after the mid-20th century, we suggest that the southwestward shift of the NPSH and the weakening of anticyclonic circulation anomalies over the northwestern Pacific were responsible for this increase in the regional temperature difference.

Description: ABSTRACT The vegetation green-up date (GUD) is widely expected to advance to an earlier date in the year in response to increasing spring temperature. However, although it is well known that climatic warming has been more intensive at higher latitudes than at lower latitudes in the Northern Hemisphere, it is not known whether this greater climatic warming at higher latitudes has led to a greater advance of vegetation GUD during the past few decades. We have first determined GUD from the satellite-derived greenness vegetation index for all the vegetated land between 30 and 75°N from 1982 to 2008, and then investigated the latitudinal pattern of the inter-annual trend of GUD and its relation to pre-season temperature. The results show a generally greater GUD advance in lower latitudes, in spite of the faster increase in pre-season temperature in higher latitudes. We find that 88% of the latitudinal variability in the GUD trend can be explained by the sensitivity of the GUD response to pre-season temperature. The GUD change has also resulted in a northward shift of GUD isolines by 1°–4° between 50 and 65°N during the period. These findings highlight the sensitivity of vegetation response to temperature in shaping the spatial pattern of spring phenological change and suggest that temperate ecosystems may experience greater phenological change if the current latitudinal pattern of climatic warming continues.

Description: As part of the Amazon Web Services Hack-A-Thon, this year's AGU Fall Meeting attendees will be challenged to create an idea for a Web product based on climate change data for individual cities.

Description: The rate of ocean acidification in coral reefs outpaces the rise in carbon dioxide (CO 2 ) in Earth's atmosphere, indicating that anthropogenic carbon emissions alone are not to blame for the threat to coral reefs, a new study shows.

Description: New lead-free perovskite solid solution ceramics of (1  − x )( Bi 1/2 Na 1/2 ) TiO 3 – x Ba ( Ni 1/2 Nb 1/2 ) O 3 [(1− x )BNT– x BNN, x  =   0.02–0.06) were prepared and their dielectric, ferroelectric, piezoelectric, and electromechanical properties were investigated as a function of the BNN content. The X-ray diffraction results indicated that the addition of BNN has induced a morphotropic phase transformation from rhombohedral to pseudocubic symmetry approximately at x  =   0.045, accompanying an evolution of dielectric relaxor behavior as characterized by enhanced dielectric diffuseness and frequency dispersion. In the proximity of the ferroelectric rhombohedral and pseudocubic phase coexistence zone, the x  =   0.045 ceramics exhibited optimal piezoelectric and electromechanical coupling properties of d 33 ~121 pC/N and k p ~0.27 owing to decreased energy barriers for polarization switching. However, further addition of BNN could cause a decrease in freezing temperatures of polar nanoregions till the coexistence of nonergodic and ergodic relaxor phases occurred near room temperature, especially for the x  =   0.05 sample which has negligible negative strains and thus show the maximum electrostrain of 0.3% under an external electric field of 7 kV/mm, but almost vanished piezoelectric properties. This was attributed to the fact that the induced long-range ferroelectric order could reversibly switch back to its original ergodic state upon removal of external electric fields.

Description: Light transmission in polycrystalline magnesium fluoride was studied as a function of the mean grain size at different wavelengths. The mean grain size was varied by annealing hot-pressed billets in argon atmosphere at temperatures ranging from 600°C to 800°C for 1 h. The grain-size and grain-orientation distributions were characterized by electron back scatter diffraction. The scattering coefficients were calculated from the in-line transmittance measured at various wavelengths. The scattering coefficient of polycrystalline magnesium fluoride increased linearly with the mean grain size and inversely with the square of the wavelength of light. It is shown that these trends are consistent with theoretical models based on both a limiting form of the Raleigh–Gans–Debye (RGD) theory of particle scattering and light retardation theories that take refractive index variations along the light path. Quantitative predictions of the theories are, however, subject to uncertainly due to the restrictive assumptions made in the theories and difficulties in representing the microstructure in the theoretical models. In particular, grain-size distribution has a significant influence on the scattering coefficient calculated using particle scattering models.

Description: Determining the absolute chronology of ceramic artifacts has significant implications for archeological and historical research. Wilson, Hall et al . recently suggested a new technique for direct absolute dating of archeological ceramics based on a moisture-induced chemical reaction, called rehydroxylation (RHX) dating. RHX dating proceeds by measuring the mass of chemically combined water in the ceramics in the form of OH hydroxyls, and the mass gain rate at the Effective Lifetime Temperature (ELT) that the ceramics experienced over its lifetime. To date, ELT determinations have been based on estimates of the ceramic's lifetime temperature history; taking into account weather and climate data and the depth at which the artifact was found. The uncertainty in determining the ELT can be a major component of the overall dating uncertainty. Here, we propose an alternative method which relies minimally on weather and climate data, and provides more precise determinations of the ELT and the ceramic age . The proposed method (SAS: Same Age Samples) involves a minimum of four measurements of the RHX mass gain rate constant for two ceramic samples of the same age at two temperatures. We show via simulations that the proposed SAS method can determine the ELT with a precision of 0.2 K which is comparable to the best ELT determination based on lifetime temperature history, and also comparable to available microbalance temperature resolutions of around 0.1 K. The corresponding percent age error is then 1.4%, or 43 yr for a 3000-yr-old ceramic. The proposed SAS method should be tested with ceramic samples of different ages, whose ELT are well-known.

Description: Glasses in the Na 2 O–CaO–SrO–ZnO–SiO 2 system have previously been investigated for suitability as a reagent in Al-free glass polyalkenoate cements (GPCs). These materials have many properties that offer potential in orthopedics. However, their applicability has been limited, to date, because of their poor strength. This study was undertaken with the aim of increasing the mechanical properties of a series of these Zn-based GPC glasses by doping with nitrogen to give overall compositions of: 10Na 2 O–10CaO–20SrO–20ZnO–(40−3 x )SiO 2 – x Si 3 N 4 ( x is the no. of moles of Si 3 N 4 ). The density, glass-transition temperature, hardness, and elastic modulus of each glass were found to increase fairly linearly with nitrogen content. Indentation fracture resistance also increases with nitrogen content according to a power law relationship. These increases are consistent with the incorporation of N into the glass structure in threefold coordination with silicon resulting in extra cross-linking of the glass network. This was confirmed using 29 Si MAS-NMR which showed that an increasing number of Q 2 units and some Q 3 units with extra bridging anions are formed as nitrogen content increases at the expense of Q 1 units. A small proportion of Zn ions are found to be in tetrahedral coordination in the base oxide glass and the proportion of these increases with the presence of nitrogen.

Description: ABSTRACT In this study, we investigated the impact of the spring North Pacific Oscillation (NPO) on typhoon frequency over the Western North Pacific (WNP, north of the equator and west of dateline). To reduce the statistical uncertainty, all the data we used have been excluded the El Nino/Southern Oscillation signals. We found that the spring NPO positively correlated with the annual typhoon number over the WNP (hereafter TNWNP) during the period 1968–2010, with a correlation coefficient of 0.62 (above the 99% significance level). When the Northern Low and Southern High pattern over the north Pacific weakens, the TNWNP tends to increase. A positive phase of spring NPO is associated with the tropical circulation and sea surface temperature (SST) anomalies in the North Pacific, which may lead to unfavorable dynamical and thermal conditions for typhoon genesis over the WNP during JJAS. The negative anomaly of SST over the WNP, associated with the positive spring NPO anomaly, is connected to the tropical atmospheric circulations from spring to summer via good oceanic seasonal persistence and air–sea interaction. Thus, the spring NPO-related variability of the tropical atmospheric circulation as well as the SST can affect typhoon activity over the WNP. In addition, the spring NPO can also be adopted as a predictor for the summer rainfall in South China, since the spring NPO can modulate the WNP SST and western Pacific subtropical high from spring to summer.

Description: Although it is not possible to predict when an earthquake will occur, many earthquakes have been found to have had some precursor activity. To study precursors of stick-slip behavior, Johnson et al . conducted laboratory experiments on a sheared granular material under normal stress ranging from 2 to 8 megapascals as an analog for a fault under tectonic stress. They found that acoustic emissions and microslips are a precursor to larger movements. Very similar results were obtained in a discrete element simulation of sheared beads. These types of experiments could help scientists better understand when earthquakes are more likely to occur. As shown by a number of researchers, very similar activity preceding faulting can occur in the Earth.

Description: In Arctic seafloor sediments, methane, a potent greenhouse gas, is trapped in chemical structures called hydrates. Methane hydrates form at low-temperature, high-pressure conditions, and methane can be released if the temperature rises. Previous studies have raised concern that global climate change could lead to release of significant amounts of methane from Arctic hydrates.

Description: A 308-year ice core record provides new data on climate variability in coastal West Antarctica and shows that a clear warming trend has occurred in recent decades. To study climate over the past 3 centuries, Thomas et al . analyzed stable isotopes in the ice core, which provide a record of past temperatures. They observed that climate variability in coastal West Antarctica is strongly driven by sea surface temperatures and atmospheric pressure in the tropical Pacific.

Description: When tectonic plates collide, the less buoyant plate will, in some cases, be forced beneath the other. At such subduction zones the sinking tectonic plate, known as a slab, does not follow a simple path from the surface to the deeper mantle. Instead, new research by Fukao and Obayashi suggests that subducting slabs pass through four largely distinct stages as they penetrate toward the core. To systematically catalog the stages of slab subduction, the authors analyzed roughly 10 million observations of the subsurface that were part of a tomographic study that used primary seismic waves to detect the structure of slabs in subduction zones around the Pacific.

Description: It is an honor and privilege to accept the David Perlman Award. Though I have never met Dave, he is a legend, and I can only hope to have a reporting career half as distinguished and a third as long as his own.

Description: It's my pleasure to nominate Paul Voosen, the former science reporter for Greenwire , for the David Perlman award. Last November, as Superstorm Sandy pounded the East Coast of the United States, Paul found himself stranded for several days in Miami, mourning a recently deceased family member.

Description: Some of the most dramatic effects of climate change have been observed in the Earth's polar regions. In Greenland, ice loss from the Greenland ice sheet has accelerated in recent years [ Shepherd et al ., 2012]. Outlet glaciers are changing their behavior rapidly, with many thinning, retreating, and accelerating [ Joughin et al ., 2004]. The loss of ice weighing on the crust and mantle below has allowed both to rebound, resulting in high rock uplift rates [ Bevis et al ., 2012]. Changes in ice cover and meltwater production influence sea level and climate feedbacks; they are expected to contribute to increasing vulnerability to geohazards such as landslides, flooding, and extreme weather.

Description: Suzette Kimball, who has served as acting director of the U.S. Geological Survey (USGS) since February 2013, will be nominated to be director of the agency, U.S. president Barack Obama announced on 9 January. If Kimball's nomination is confirmed by the U.S. Senate, she will lead the science agency, which has more than 8000 employees and an annual budget of more than $1.1 billion.

Description: With titles like “Correlates of avian building strikes at a glass façade museum surrounded by avian habitat” and “Electrospray ionization FT-ICR/MS investigation of zinc sulfate clusters,” a series of posters presented at AGU's Fall Meeting on 12 December 2013 might seem like a session covering general contributions from AGU members. However, something was unique about the posters: Most were created and presented by high school students.

Description: This study presents a thermodynamic analysis to predict the type of initial, amorphous oxide overgrowth (i.e., am - Al 2 O 3 or am - SiO 2 ) on bare Al – Si alloy substrates. This analysis have taken into account the energies associated with both its interfaces (interface between the Al – Si alloy substrate and the thin oxide film and interface between the thin oxide film and vacuum) along with the bulk Gibbs free energy of oxide formation. This developed analysis is then applied for various parameters, such as, Si alloying element content at the substrate/oxide interface, the growth temperature, the oxide film thickness (up to 1 nm), and various low-index crystallographic surfaces of the substrate. It is found that am - SiO 2 overgrowth is thermodynamically preferred for a combination of lower oxide film thickness, lower growth temperature, and lower Si alloying content at the alloy/oxide interface. This is because of the overcompensation of the lower energies of both the interfaces over the bulk Gibbs free energy. Furthermore, it is found that for all cases, am - Al 2 O 3 forms a more stable interface with Al – Si alloy than am - SiO 2.

Description: A writer needs two distinct qualities to produce an article like “The Calm Before the Wave,” the piece on tsunamis for which Tim Folger is being honored with the 2013 Walter Sullivan Award. Like any good science writer, he needs the ability to sort through a large mass of scientific information and transform it into a clear, compelling narrative. But he also needs an empathic eye and ear—the ability to feel his way into the lives of people whose stories are utterly different from his own and to see and hear the telling details that will make those people come alive on the page.

Description: ABSTRACT Climate change is almost certain to affect snow and ice processes. Even at lower latitudes, changes in snow cover at high altitudes can significantly affect catchment hydrology. This article uses data from a transient Regional Climate Model projection (HadRM3Q0) for 1950–2099 (A1B emissions) to drive hydrological models for three nested catchments on the river Dee in north-east Scotland, to assess potential changes in flood frequency and timing using annual maxima and moving-window analyses. Some results are also shown for an upland catchment in northern England. Modelling is performed both with and without a snow module, to demonstrate the effects of snowfall/melt and how these change through time and vary between catchments. Modelled changes in flood magnitude and timing are nonlinear, with most changes for daily mean flows not significant. For longer duration (30-day) flows with snow there are significant decreases in peak magnitude, particularly for the smaller higher altitude Dee catchments, with peaks occurring months earlier in future (changes without snow are generally not significant). There is a general convergence in results with and without snow later in the period, as snow processes become less important, but convergence occurs at different times for different catchments and occurs differently for daily and 30-day peak flows due to the differential effects of snow at different durations. This not only highlights the importance of including snow processes for such catchments, particularly for longer duration flows, but also highlights the complexity of interactions: Physical catchment properties, the balance between precipitation occurrence and temperature, and how this balance alters as the climate changes will each be critical in determining the impact on the magnitude and timing of peak flows, making it hard to generalize results.

Description: ABSTRACT This article is the first of two companion articles providing details of the development of two separate models for statistically downscaling monthly precipitation. The first model was developed with National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis outputs and the second model was built using the outputs of Hadley Centre Coupled Model version 3 GCM (HadCM3). Both models were based on the multi-linear regression (MLR) technique and were built for a precipitation station located in Victoria, Australia. Probable predictors were selected based on the past literature and hydrology. Potential predictors were selected for each calendar month separately from the NCEP/NCAR reanalysis data, considering the correlations that they maintained with observed precipitation. Based on the strength of the correlations, these potential predictors were introduced to the downscaling model until its performance in validation, in terms of Nash–Sutcliffe Efficiency (NSE), was maximized. In this manner, for each calendar month, the final sets of potential predictors and the best downscaling models with NCEP/NCAR reanalysis data were identified. The HadCM3 20th century climate experiment data corresponding to these final sets of potential predictors were used to calibrate and validate the second model. In calibration and validation, the model developed with NCEP/NCAR reanalysis data displayed NSEs of 0.74 and 0.70, respectively. The model built with HadCM3 outputs showed NSEs of 0.44 and 0.17 during the calibration and validation periods, respectively. Both models tended to under-predict high precipitation values and over-predict near-zero precipitation values, during both calibration and validation. However, this prediction characteristic was more pronounced by the model developed with HadCM3 outputs. A graphical comparison of observed precipitation, the precipitation reproduced by the two downscaling models and the raw precipitation output of HadCM3, showed that there is large bias in the precipitation output of HadCM3. This indicated the need of a bias-correction, which is detailed in the second companion article.

Description: Deformation processes involve systems of tens to hundreds of kilometers moving at highly variable rates. Because direct kinematic observations have proven difficult, geoscientists are sometimes found in the lab creating analogs, or laboratory models of the Earth. The main scope—and a key challenge—of laboratory modeling of Earth systems is to provide a quantitative approach for understanding geological processes. Since the last decade, various image analysis techniques in laboratory modeling have been designed and used to constrain the kinematics of the simulated processes at an unprecedented resolution. These techniques prove to be the key quantification tools in experimental modeling, not only allowing mechanical analysis of the experiments but also producing experimental data sets that are directly comparable to geophysical and geodetic data in nature and numerical models.

Description: Continental scientific drilling is an important tool for exploring natural and anthropogenic processes on Earth. In past decades the results obtained from lake drilling projects contributed significantly to a better understanding of short-term and long-term climate change and natural hazards.

Description: Sintered nanoceramics of Pr -doped lanthanum hafnate, La 2 Hf 2 O 7 : Pr , were prepared by means of a high-pressure sintering technique using nanopowders made by Pechini method. Structure, morphology, and spectroscopic properties of the ceramics compared to the starting powder are presented and discussed. Emission and excitation spectra recorded at room temperature as well as at 7 K using synchrotron radiation are presented together with results of luminescence kinetics measurements. In ceramics, at 7 K, the Pr 3+ luminescence from 3 P 0 (blue-green, green, and red region) and 1 D 2 (red) levels is accompanied by a broad-band emission located in the 380–530 nm range of wavelengths, whereas powders gives only the Pr 3+ -related luminescence. Depending on the excitation wavelength, the broad-band emission maximum moves between 430 and 470 nm indicating superposition of at least two components. In sintered nanoceramics, the lifetimes of Pr 3+ emissions from 3 P 0 and 1 D 2 levels were by 10%–20% shorter compared to the powder. The existence of different luminescence centers was proved by the selective emission decays examination. The fast 5 d → 4 f luminescence of Pr 3+ was not observed from either of the two types of La 2 Hf 2 O 7 :Pr materials.

Description: We, Kevin's friends and colleagues, are pleased to have prepared his nomination package. Across the broad and expansive climate science community, there are very few people who have a history of sustained engagement like Kevin. Whereas many people have worked to convey the importance of climate change, Kevin has tirelessly done so for decades. In addition, the breadth of his activities is astonishing. It includes innumerable interviews on radio, on television, and in printed media over the past 30 years. He has also taken on many leadership communication roles within the scientific community, including the Intergovernmental Panel on Climate Change to name just one.

Description: Ted Flinn and John LaBrecque followed remarkably, perhaps eerily, similar career paths. Ted started as a seismologist, John as a tectonician and sea-going geophysicist. Both decided to rededicate their efforts toward supporting the geophysical community, recognizing that it depends ever more critically on global, space-based measurements and observations. Ted did that a decade after the 1968 Williamstown conference, and John did it a decade after the 1988 Coolfont conference. Both of these history-making conferences focused on the geophysical uses of space assets to study the planet.

Description: Chapman conferences are intended for deeper discussions of specific topical areas of scientific interest. This Chapman conference was organized to review and discuss new strategies to observe and understand processes and drivers in the biogeosphere, particularly those related to coupled biogeochemical and hydrological processes in terrestrial systems. The topics presented at the meeting included transport and exchange processes of organic and gaseous compounds across the soil-water and soil-plant interfaces, monitoring strategies of soil-mediated processes and drivers from the local to the catchment scale, and the impact of soil formation and functions on ecosystem services. These topics were addressed and intensively discussed by participants covering the fields of soil systems sciences, hydrology, and biogeosciences.

Description: It is a great pleasure and an honor to give the citation for the 2013 Athelstan Spilhaus awardee, Iain Stewart, professor of geoscience communication at the University of Plymouth, recognizing his truly exceptional work over the last decade in communicating geoscience to the general public. Iain has been making documentaries for the BBC, National Geographic, and Discovery for nearly a decade. These programs have huge international audiences and wide-reaching impact.

Description: I am delighted to be recognized with this prize. I want to first thank AGU and the prize committee and, especially, Nature's Own for establishing this prize in a field that has become contentious and highly political. It did not used to be this way. Following the media frenzy with the 2007 Intergovernmental Panel on Climate Change (IPCC) report, there was hope at the 2009 Conference of Parties meeting in Copenhagen that an international framework agreement on climate change might be achieved. It was not to be. Planned actions to address issues of climate change were undermined by huge funding of misinformation by vested interests. It was not helped by so-called “climategate” in which many emails illegally hacked from a computer server at the University of East Anglia in the United Kingdom were released, cherry picked, distorted, and misused by climate change deniers. Minor errors in the IPCC report were blown out of all proportion and ineffectively addressed. I was caught up in all this, and one of my many emails went viral: the “travesty” quote in which I bemoaned the inability to close the global energy balance associated with short-term climate variability but which was misinterpreted as saying there was no global warming. These examples highlight failures of communication.

Description: Solomon Hsiang is representative of a new generation in the geosciences community, whose work spans several disciplines, drawing on methods and concepts from far outside the traditional physical science domain in order to make progress on difficult questions at the intersection of natural science, social science, and public policy. Broadly speaking, by examining how humanity has responded to climate variability and change in the distant and recent past, Sol's research elucidates the question of how humanity may respond to a changing climate in the future. Combining large, independent sets of social science, meteorological, and climatological data and analyzing them with tools more common in microeconomics than natural science, Sol, still at an early stage of his career, has made critical contributions to an incipient revolution in our understanding of the sensitivity and adaptability of humans and their social arrangements to climate variability and change. Such insights will greatly improve the information base from which effective public policy is developed.

Description: Thanks to AGU and our citationist, Richard Alley, for this joint award to Erna and myself. While it is, of course, personally gratifying, we also consider it an acknowledgement that “science journalism” has broadened out from print to include video in all forms—from PBS primetime to YouTube anytime—and also social media and spoken-word presentations. We're pleased that this is one more way in which AGU is validating the participation of its members in all forms of public outreach. We're gratified that our efforts in this regard have been supported by NSF, NASA, and NOAA, among other government agencies, and are happy to acknowledge their “priceless” role as funders. As one of our current collaborators, former NASA chief scientist Waleed Abdalati, likes to say, “The science isn't done until it's shared”…and there are more and more ways in which that sharing can be done.

Description: On 24 August 2013 a sudden burst of gas erupted from the ground near Rome's airport, about 15 kilometers southwest of the city. The eruption produced a crater that was initially about half a meter wide but that gradually increased in size and eventually reached a diameter of about 3 meters.

Description: Dr. Chelle Gentemann is a worthy recipient of the Charles S. Falkenberg Award. Through her leadership at both national and international levels, Chelle has contributed significantly to improving the accuracy, accessibility, and utility of satellite-derived fields of sea surface temperature (SST) for a wide range of applications, including numerical weather forecasting, operational oceanography, and climate research.

Description: Thank you, Cinna, for your kind and generous citation and for your friendship. It is a great recognition having been selected for the 2013 International Award. I feel honored, especially considering the international breadth of AGU, fostering scientific excellence and promoting research in Earth and space sciences worldwide. AGU has evolved over the years, becoming increasingly international and multidisciplinary, providing the intellectual framework and networking for research collaboration. I have been privileged to serve as International Secretary of the Union, which together with work in the committees permitted me to better appreciate the range of activities and the programs AGU does to serve its membership and the geophysics community.

Description: The meaning of “interdisciplinary” has evolved over my career. When I started my science research career, it meant bridging atmospheric and ocean science and embracing the science of the Earth system and its interacting components. Thus, I found a home at AGU submitting science abstracts to atmospheric science, oceanography, or hydrology sessions. In fact, my first research paper appeared in Journal of Geophysical Research (JGR)-Atmospheres , and a letter to the editor and response appeared in JGR-Oceans . It also meant getting scientists in these disciplines talking to each other. I organized a seminar series at Rice University under the umbrella of an Earth Systems Institute that included the Departments of Space Physics and Astronomy, Geology and Geophysics, Biology, and Hydrology. I also began working with Dr. Patricia Reiff, a space physicist with a passion for science education.

Description: It is really wonderful to receive this award and the recognition of AGU for my work. I've been a member of the Union since my Ph.D. days, 25 years or so ago, when I was working on earthquake faulting in Greece and Turkey. Its meetings were always the place that showcased geoscience at its most novel and exciting. It was the breadth of what was on offer that was so exhilarating. My doctoral studies had already opened up fairly wide vistas for me since my interest in Holocene earthquake activity also required an understanding of the Mediterranean's rich cultural history and the vagaries of millennial-scale climate fluctuations. Later, my research would distract me into farther-flung realms, such as volcanic faulting on Mount Etna, paleotsunamis along Aegean shores, even postglacial earthquakes in northern Scotland! Kindly colleagues would occasionally advise me to focus my efforts on a single substantive area of research, cautioning that my flighty research forays weren't conducive to climbing the academic ladder. I'm sure they were correct. Or would have been proved so if I hadn't been rescued by television.

Description: I am honored to receive this award, created by Peter Schlosser, nominated by my postdoc advisor Michael Oppenheimer, and alongside my thesis advisor Mark Cane, recipient of this year's Maurice Ewing Medal—all role models and original pioneers in “the application and use of Earth and space sciences to solve societal problems.”

Description: A question about how to predict the runoff from a basin where there is no history of flow measurements is probably featured in almost every hydrology graduate student's oral examinations. It has certainly been one of the longest-standing problems for the profession. The International Association of Hydrological Sciences Prediction in Ungauged Basins initiative [ Wagener et al ., 2004] has focused researchers and meetings on the topic, culminating in this book, which assembles the thoughts gathered over the last decade.

Description: From Cosmos to Mars and Pluto and back home, Geoffrey Haines-Stiles and Erna Akuginow have invested their careers reporting the best modern science in novel, compelling, and accessible ways through documentaries, live events, print, and new media. They are outstanding recipients of the AGU Robert C. Cowen Award for Sustained Achievement in Science Journalism.

Description: Clouds' effects on climate are significant and complex. Many cloud processes occur at small scales and are difficult to calculate in large-scale models, so general circulation models typically use parameterizations to represent a range of cloud properties.

Description: ABSTRACT This article is the second of a series of two articles. In the first article, two models were developed with National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis and HadCM3 outputs, for statistically downscaling these outputs to monthly precipitation at a site in north-western Victoria, Australia. In that study, it was seen that the downscaling model developed with NCEP/NCAR reanalysis outputs performs much better than the model developed with HadCM3 outputs. Furthermore, it was found that there is large bias in HadCM3 outputs which needs to be corrected. In this article, the downscaling model developed with NCEP/NCAR reanalysis outputs was used to downscale HadCM3 20th century climate experiment outputs to monthly precipitation over the period 1950–1999. In all four seasons, the precipitation downscaled with HadCM3 20th century outputs, displayed a large scatter and the majority of precipitation was overestimated. The precipitation downscaled with HadCM3 outputs was bias-corrected against the observed precipitation pertaining to the period 1950–1999, using three techniques: (1) equidistant quantile mapping (EDQM), (2) monthly bias-correction (MBC) and (3) nested bias-correction (NBC). Although all these bias-correction techniques were able to adequately correct the statistics of downscaled precipitation, the magnitude of the scatter of precipitation remained almost the same. Considering the performances and its ability to correct the cumulative distribution of precipitation, EDQM was selected for the bias-correction of future precipitation projections. HadCM3 outputs for the A2 and B1 greenhouse gas scenarios were introduced to the downscaling model and the downscaled precipitation for the period 2000–2099 was bias-corrected with the EDQM technique. Both A2 and B1 scenarios indicated a rise in the average of future precipitation in winter and a drop in it in summer and spring. These scenarios showed an increase in the maximum monthly precipitation in all seasons and an increase in percentage of months with zero precipitation in summer, autumn and spring.

Description: Nine AGU members are among the 102 researchers that U.S. president Barack Obama announced on 23 December as recipients of the Presidential Early Career Awards for Scientists and Engineers, the highest honor bestowed by the U.S. government on science and engineering professionals in the early stages of their independent research careers.

Description: An 8 January decision by the White House to propose an extension of the International Space Station's (ISS) operation until at least 2024 would allow for increased research on board the floating laboratory, a longer planning horizon for commercial activities, and a continuation of international cooperation in space, administration officials said. The proposal, which has received initial support from some key members of Congress, would be the second extension for ISS under the Obama administration and would accommodate increased research related to long-duration human space flight, Earth science, and other areas. ISS, which in the United States is authorized under the NASA Authorization Act of 2010, was last extended in 2010 and costs about $3 billion annually to operate.

Description: Since 2011, the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) and three major river forecasting centers of the National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) have discontinued a long-standing practice of publishing consensus water supply forecasts in western U.S. river basins.

Description: Atmospheric and Space Electricity (ASE)

Description: Hawaii's Kīlauea volcano has been erupting since 1983. Starting in 2003, researchers noticed an inflation of the magma chamber beneath the volcano; this inflation accelerated in 2006. In June 2007, the volcano's eruption peaked with a burst of activity known as the Father's Day event. In the buildup to those eruptions, according to new research by Wauthier et al ., a pair of large-magnitude earthquakes hit, with an epicenter beneath the volcano. Earthquakes are common around the volcano, which sits on Hawaii's Big Island, but with magnitudes of 4.7 and 4.1, the two 2007 earthquakes were among the most powerful recorded in the region since records began in 1959.

Description: When the temperature rises on Baffin Island, in the Canadian high Arctic, ancient Polytrichum mosses are exposed from beneath melting glacier ice. Within a few years of exposure the mosses are quickly eroded away by snow and wind, but trapped beneath the ice, they can remain, frozen, for thousands of years.

Description: Since the first up-close observations of Saturn, made by the Pioneer 11 probe in 1979, a great deal has been learned about the dynamics of the gas giant's magnetosphere. In-depth observations made by the Cassini orbiter, which has been circling Saturn since 2004, have revealed fundamental differences between the behavior of Saturn's magnetosphere and that of the Earth's magnetosphere. Earth's magnetospheric plasma is largely populated by ions captured from the solar wind, whereas Saturn's plasma comes predominantly from water vapor that spews from massive geysers on the southern end of its icy moon Enceladus. Ionized water vapor from Enceladus streams out at 12 to 250 kilograms per second, yet observations show that the concentration of plasma in Saturn's magnetosphere is at a relatively steady level. This discrepancy has left researchers searching for potential plasma loss mechanisms. In a review, Thomsen highlights the progress made in recent years in understanding this question.

Description: ABSTRACT Hailstorms have become a serious meteorological risk in mid-latitude countries because of their small-scale development and short time span, and their forecasting remains problematic. Moreover, the lack of reliable hailstorm databases is an important handicap for Numerical Weather Prediction (NWP) model validation, time trend studies and establishment of hailstorm relationships with global warming and climate change. However, this can be overcome by ascertaining physical relationships between favourable synoptic patterns and mesoscale trigger factors for hailstorm development in a local study area. North-eastern Spain is one of the European regions with largest number of hailstorm days (HD) observed in the summer. Since 2001, from May through September, reliable databases of hailstorm occurrence in the middle Ebro Valley have been constructed, which include intensity, temporal frequency and spatial coordinate data. June and July 2006 had the largest number of HD in 2001–2010. With the objective of analysing meteorological factors responsible for this anomaly, atmospheric patterns at low and mid-tropospheric levels were studied. We determined a set of special synoptic configurations, with an evident deviation from climatic values generating anomalies of 850 hPa temperature relative to the characteristic values of 2001–2010 and 1950–2010. An analysis of these anomalies detected a positive trend of 850 hPa temperature and geopotential height in the western Mediterranean area. As a consequence, the characteristic synoptic circulation has changed since 1950, towards low-level patterns favouring adequate thermodynamic environments for hailstorm development in north-eastern Spain. Finally, after a cluster analysis, we studied periodicities in the monthly 850 hPa temperature field to improve knowledge for seasonal forecasting of hailstorms.

Description: We have investigated the electromechanical response of potassium sodium niobate ( K 0.5 Na 0.5 NbO 3 or KNN) thick films. The high-field strain hysteresis loops and weak-field converse piezoelectric d 33 coefficient of the films were measured and compared with those of KNN bulk ceramics under the same electric field conditions. The converse d 33 values of the thick films and bulk ceramics were equal to 82.5 and 138 pm/V, respectively, at 0.4 kV/mm. The fundamental difference between the piezoelectric response of the KNN films and the ceramics was studied in terms of the effective (“clamped”) piezoelectric d 33 coefficient. The reduction in the piezoelectric d 33 coefficient of the KNN films, resulting from the clamping by the substrate, was compared to lead-based ferroelectric thick films, including Pb ( Zr , Ti ) O 3 (PZT) and (1 −  x ) Pb ( Mg 1/3 Nb 2/3 ) O 3 − x PbTiO 3 (PMN-PT). We propose a possible explanation, based on the particular elastic properties of KNN, for the small relative difference observed between the “clamped” and “unclamped” (“bulk”) d 33 of KNN, in comparison with lead-based systems.

Description: Lead zirconate titanate (PbZr 1 −  x Ti x O 3 , PZT)/epoxy composites with one- dimensional epoxy in PZT matrix (called 3-1 type piezocomposites) have been fabricated by tert-butyl alcohol (TBA)-based directional freeze casting of PZT matrix and afterward infiltration of epoxy. The composites with PZT volume fraction ranging from 0.36 to 0.69 were obtained by adjusting initial solid loading in freeze-casting slurry. The effect of poling voltage on piezoelectric properties of the composites was studied for various volume fraction of PZT phase. With the increasing of PZT volume fraction, relative permittivity (ε r ) increased linearly and piezoelectric coefficient ( d 33 and d 31 ) increased step by step. The resultant composites with 0.57 PZT volume fraction possessed the highest hydrostatic piezoelectric strain coefficient ( d h ) value (184 pC/N), voltage coefficient ( g h ) value (13.6 × 10 −3  V/m Pa), and hydrostatic figure of merit (HFOM) value (2168 × 10 −15  Pa −1 ).

Description: Multiphase borosilicate glass-ceramics represent one candidate to contain radioactive nuclear waste separated from used nuclear fuel. In this work, the thermophysical properties from room temperature to 1273 K were investigated for four different borosilicate glass-ceramic compositions containing waste loadings from 42 to 60 wt% to determine the sensitivity of these properties to waste loading, as-fabricated microstructure, and potential evolutions in microstructure brought about by temperature transients. The thermal expansion, specific heat capacity, thermal diffusivity, and thermal conductivity are presented. The impact of increasing waste loading is shown to have a small but measurable effect on the thermophysical properties between the four compositions, contrasted to a much greater impact observed when transitioning from predominantly crystalline to amorphous systems. Thermal cycling below 1273 K was not found to measurably impact the thermophysical properties of the compositions investigated here.

Description: The 27 February release of an environmental review of geological and geophysical (G&G) survey activities off the mid- and South Atlantic outer continental shelf is a key step toward potentially opening the area to oil and gas exploration, according to industry and environmental groups. That is a prospect industry groups favor and environmental groups say will harm marine life.

Description: Scientific discovery, technological revolutions, and complex global challenges are commonplace in the modern era. People are bombarded with news about climate change, pandemics, and genetically modified organisms, and scientific literacy has never been more important than in the present day. Yet only 29% of American adults have sufficient understanding to be able to read science stories reported in the popular press [ Miller, 2010], and American students consistently rank below other nations in math and science [ National Center for Education Statistics, 2012].

Description: In the shadow of the Matterhorn, the broad form of the Matter Valley—like so many throughout the Alps—is interrupted by a deep U-shaped glacial trough. Carved into a landscape reflecting millennia of tectonic uplift and river erosion, growing evidence suggests the 100-meter-deep U-shaped groove was produced shortly after a shift toward major cycles of Alpine glaciation almost a million years ago. Subsequent glaciations may have therefore had little effect on the landscape.

Description: The U.S. Senate confirmed Kathryn Sullivan as under secretary of commerce for oceans and atmosphere on 6 March. She also becomes administrator of the National Oceanic and Atmospheric Administration (NOAA).

Description: The proposed federal budget for fiscal year (FY) 2015, released by the White House on 4 March, would provide small increases for a number of science agencies, although some, including NASA, would see a dip in funding. Overall, the budget proposes $135.4 billion for federal research and development (R&D) activities, an increase of $1.7 billion (1.2%) over the FY 2014 enacted levels.

Description: We report a novel oscillatory pressure-assisted hot-pressing process for preparing high-quality ceramics. Compared with the samples prepared by conventional pressureless sintering (PS) and hot-pressing (HP), the zirconia ceramic prepared by oscillatory pressure-assisted hot-pressing (OPAHP) exhibited a higher density, smaller grain size, and more homogeneous structure. More remarkably, the strength of the OPAHP sample reached 1556 MPa, which is much higher than the samples prepared by other two techniques. The results suggest that OPAHP is a more effective technique for preparing high-quality zirconia, which is likely applicable to other material systems.

Description: The formation of a homogeneous Bi 8 TiO 14 phase was successfully achieved in a specimen calcined at 600°C. However, a Bi 4 Ti 3 O 12 secondary phase also developed in specimens calcined at temperatures higher than 600°C, probably because of Bi 2 O 3 evaporation. For specimens sintered above 800°C, a small amount of the Bi 8 TiO 14 phase melted during sintering, with the liquid phase contributing to the densification of the specimens; however, Bi 4 Ti 3 O 12 and Bi 12 TiO 20 secondary phases were still formed in these specimens. The microwave dielectric properties of the Bi 8 TiO 14 phase were considerably affected by variations in the microstructure of the specimens. When the sintering temperature exceeded 825°C, the amount of secondary phases increased, and this decreased the density and Q×f values of the specimens. Bi 8 TiO 14 ceramics sintered at 825°C exhibited promising microwave dielectric properties, with ε r = 47.4, Q×f  =   5370 GHz, and τ f = −16.01 ppm/°C.

Description: A new solid solution of (1− x ) Pb ( Mg 1/2 W 1/2 ) O 3 – x Pb ( Zn 1/2 W 1/2 )O 3 has been prepared in the form of ceramics by solid-state reaction with composition x up to 30%. It is found that with the substitution of Zn 2+ for Mg 2+ on the B site of the of complex perovskite structure the antiferroelectric (AFE) Curie temperature T C of PMW increases from 40°C ( x  = 0) to 67°C ( x  = 30%), indicating an enhancement of antiferroelectric order, whereas, at the same time, the phase transition becomes more diffuse due to a higher degree of chemical inhomogeneity. X-ray diffraction analysis indicates that the crystal structure adopts an orthorhombic space group ( Pmcn ) with a decrease in lattice parameter a, but an increase in b and c as the Zn 2+ concentration increases. The low dielectric constant (~ 10 2 ), low dielectric loss (tanδ ≈ 10 −3 ), linear-field-induced polarization, and significantly high breakdown field (~ 125 kV/cm) at room temperature make this family of dielectric materials a promising candidate for ceramic insulators.

Description: ABSTRACT Tree-ring-based climate reconstructions are typically derived from either (1) a single species from one or multiple locations or (2) multiple species from multiple locations. Here, we investigate the ability of using multiple co-occurring canopy-dominant species from a single location for climate reconstructions based in the eastern United States. Using a variety of techniques, we first compare the climate signals of three canopy-dominant species ( Quercus rubra, Quercus alba, Liriodendron tulipifera ) at an old-growth forest in southern Indiana. We then determine if a composite time series of these co-occurring species increases or decreases the reconstruction model skill. Climate–growth correlation analysis of the species reveals strong and consistent relationships with summer [June–August (JJA)] Palmer Drought Severity Index (PDSI) during the period 1895–2012. We first use a split-sample reconstruction technique to compare the performance of species reconstruction models. We then use a nested technique to build a composite chronology against which to compare the individual species chronologies. The composite chronology of all three species accounts for up to 38% of the mean variation in JJA PDSI, and verification statistics indicate robust statistical skill from 1870 to 2012. The composite chronology reconstruction also outperforms each individual species model, indicating that using multiple co-occurring species increases reconstruction skill, at least from a single study site. Furthermore, model performance is improved by using nested reconstruction techniques, and implicates the potential ability to use multiple co-occurring species across multiple locations in the eastern United States.

Description: Secretary of the Interior Sally Jewell released a new strategy on 10 April 2014 to advance landscape-scale, science-based management of America's public lands and wildlife. The strategy will implement mitigation policies and practices at the Department of the Interior that can encourage infrastructure development while protecting natural and cultural resources.

Description: The U.S. Geological Survey (USGS) has released the latest edition of its National Land Cover Database (NLCD 2011), the nation's most comprehensive look at land surface conditions. The database divides the lower 48 states into 9 billion geographic cells, providing consistent information about land conditions on regional and nationwide scales.

Description: Energetic protons emitted in bursts from the Sun pose a potential hazard for spacecraft, satellites, humans in space, and aircraft at high latitudes. Researchers have now verified that a set of sensors used to measure solar proton events are correctly intercalibrated to provide early warning of the events.

Description: ABSTRACT Phenology can be used to track plant responses to climate change. In China, several studies have found the earlier trends of spring phenophases over the past 50 years. However, few studies put these phenological changes into historical perspective. Based on specific phenophases records from historical diaries and Chinese Phenological Observation Network, we developed spring phenology index (SPI) time series in temperate and subtropical regions of eastern China from 1850 to 2009. We firstly compare the temporal change of SPI and seasonal temperature anomaly. Subsequently, we search for common shifts in phenological and temperature time series by applying the moving t -test method, and discuss temperature sensitivity of SPI by using the moving linear regression method for both regions. Results show that the SPI in temperate region revealed lower interannual variability than in subtropical region, while the seasonal temperature variability was higher in temperate region. In temperate region, the timing of significant shift towards earlier SPI (in 1979) coincides with the timing of shift in spring temperature time series. The temperature sensitivities of SPI differ among the two regions. The mean sensitivity of SPI to spring temperature in subtropical region (−3.7 days °C −1 ) is stronger than in temperate region (−2.5 days °C −1 ). The temperature sensitivity of SPI varies among consecutive 30-year periods. In recent three decades, temperature sensitivity of spring phenophases became stronger in both regions.