bluuebunny/crossref_metadata_2025 huggingface dataset:
Binary L12 Intermetallics: A Statistical‐Thermodynamic Modeling of Ordering Phenomena, Behavior and Properties
Authors: Semenova Olga
Published: September 2012

The main objective of this paper is aimed towards a correct statistical‐thermodynamic modeling and description of the effects and changes associated with the creation of different defects in the crystal structure and their connection and influence on the properties of the binary L12 intermetallic systems. This was done by the using of a General Defect Correlation Model (GDCM), employing applications of the Bragg‐Williams‐Gorsky mean‐field approximation. The obtained results are compared to a model based on the Wagner‐Schottky approach with application of the grand canonical ensemble for non‐interacting point defects for description of the arrangement of anti‐structure and vacancy defects. The basic concept includes the evaluation of such characteristics of the intermetallic materials with L12 structures as the virtual critical temperatures of order‐disorder transformations, the pair‐wise interaction and defect formation energies, thermodynamic activities and defect concentrations, and also descriptions of long‐ranged (LRO) and short‐ranged (SRO) atomic correlations in the crystal lattice (including the possible correlation of nearest neighbor point defect combinations), which is difficult to obtain by other methods. The model calculations also are tested using experimental data on thermodynamic and structural properties.
Molecular Polyselenide Anions Sandwiched between Cationic Extended Metal Hydroxides: Synthesis and Structures of [Sr2Sn(OH)6(H2O)6]Se4 and [Sr2Sn(OH)6(H2O)5]Se3·H2O
Authors: Wang Xiqu , Wang Haiyin H. , Makarenko Boris , Jacobson Allan J.
Published: September 2012

Two new strontium tin hydroxy polyselenides [Sr2Sn(OH)6(H2O)6]Se4 (1) and [Sr2Sn(OH)6(H2O)5]Se3·H2O (2) were synthesized from hydrothermal reactions. Their structures were determined from single‐crystal X‐ray data measured at 218 K. Compound 1 crystallized in the space group P$\bar{1}$ with a = 5.935(1), b = 8.440(1), c = 9.464(2) Å, α = 97.292(2)°, β = 104.957(2)°, γ = 110.328(2)°. Compound 2 crystallized also in the space group P$\bar{1}$ with a = 10.658(2), b = 11.082(2), c = 15.797(2) Å, α = 73.303(4)°, β = 74.942(4)°, γ = 64.627(3)°. Both compounds have structures containing infinite cationic layers of hydrated metal hydroxides built from Sn(OH)6 octahedra and Sr(OH, H2O)n polyhedra. Molecular Se42– and Se32– anions are located in the interlayer spaces of 1 and 2, respectively. The Se42– anions of 1 adopt a flat zigzag conformation with a torsion angle of 0°.
Geochemical Behaviour of Vanadium, Chromium, Cobalt, Nickel, and Copper during Progressive Chloritization of Biotites in Granites
Authors: Viswanathan S. , Singh Yamuna , Mahabaleswar B.
Published: September 2012

Evaluation of the vanadium, chromium, cobalt, nickel, and copper contents of five biotites, chloritized to varying degrees, from a magmatic granitic series of the 2700-million-year-old Giants Range Batholith of Northeastern Minnesota, USA, on the southern margin of the Canadian Shield, determined by wavelength-dispersive x-ray fluorescence spectrometry, shows that, during progressive chloritization of biotites in granites, the content of vanadium decreases and the contents of chromium, cobalt, nickel, and copper increase. The results emphasise the need for great caution when interpreting whole-rock trace-element data in petrological research.
Efficacy of Electrical Resistivity Tomography Technique in Mapping Shallow Subsurface Anomaly
Authors: Kumar Dewashish
Published: September 2012

Electrical Resistivity Tomography is a versatile, fast and cost effective technique for mapping the shallow subsurface anomaly. It covers a wide spectrum of resistivity ranging from <1 Ohm.m to several thousands of Ohm.m. In this paper applications and utility of two-dimensional Electrical Resistivity Tomography (ERT) technique are discussed to look into huge data density coverage, different signal strengths of data from subsurface and their implications in resolving the aquifer zones, related geological structures etc. of the substratum ranging from alluvium to tectonically disturbed hard rock ridge region of the country. The major advantages and flexibility of ERT over conventional resistivity methods are also discussed.
Fractal Analysis of Magnetite Grains – Implications for Interpreting Deformation Mechanism
Authors: Mamtani Manish A.
Published: September 2012

In the present study, the grain size (d) and shape of 225 magnetite grains, that crystallized at T>600°C in a syntectonic granite (Godhra Granite, India) are evaluated and implications of data to decipher deformation mechanism of magnetite are discussed. Fractal (ruler) dimension (D) analysis of magnetite grains is performed and it is demonstrated that they show fractal behaviour. Smaller magnetite grains tend to be more serrated than the larger ones, which is manifested in the higher fractal (ruler) dimension (D) of the former. Assuming a natural strain rate ranging between 10-10 s-1 and 10-14 s-1, the grain size data fall dominantly in the dislocation creep field of the existing deformation mechanism map of magnetite for 630°C. However, SEM-EBSD studies reveal that subgrains are absent in the magnetite grains and they did not undergo dislocation creep. Thus it is inferred that the shape of magnetite grains was not controlled by dislocation creep. It is concluded that the higher serration and increased fractal dimension of finer magnetite grains implies the importance of diffusion creep as an important deformation mechanism at high-T for magnetite in polymineralic rocks.
Petrographic and Depositional Characteristics of Tadkeshwar Lignite Deposits (Cambay Basin), Gujarat
Authors: Singh Alpana , Thakur O. P. , Singh B. D.
Published: September 2012

Tadkeshwar lignite deposits are one of the important Lower Tertiary lignite deposits of Cambay Basin, Gujarat. These lignites are rich in huminite macerals followed by liptinite and inertinite with moderate to high proportions of associated mineral matter. Under fluorescence mode these are found to be rich in liptinite macerals, in particular the liptodetrinite and resinite. The type of huminite suggests that the lignite is formed from mixed vegetal source, i.e. woody forest vegetation and herbs, shrubs. The composition of macerals indicates the deposition of lignite in sub-aqueous condition in wet-reducing environment with intermittent exposure and subsidence of the peat surface. The rank of the Main and the Leader seams, determined through reflectance measurement, indicate that the lignite is less mature. The considerable amount of perhydrous huminite may have contributed to the lower reflectance values in some of the samples. Low rank and appreciable amount of mineral matter make the lignite suitable for its utilization in thermal power plants, however when upgraded or mixed with better quality coals it can be used for other industries.
Characterization of Bauxite Deposits from Kachchh Area, Gujarat
Authors: Jadhav G. N. , Sharma N. , Sen Priyanka
Published: September 2012

The bauxites deposits of Kachchh area in Gujarat are investigated to characterize them based on mineralogical and petrographic studies. The major bauxitic mineral in these occurrences is gibbsite, with minor concentration of boehmite and diaspore. Apart from the bauxitic minerals, the other associate minerals are kaolin, calcite, alunite and the iron ore minerals such as hematite and goethite and titanium rich anatase. The iron ore minerals (hematite and goethite) are 10-50microns in size and are disseminated throughout the oolitic and pisolitic bauxitic minerals. At places the goethite exhibits colloform texture. The preservation of basaltic texture in some of the samples indicate that the insitu nature of these bauxites, which are formed by the alteration of calcic plagioclase from the parent basalt. Although, the basalt occurs as the main parent rock for these bauxites, the presence of calcite in some of the samples represent the possibility of having a limestone parent rock at least in some of the bauxite occurrences.
Hydrogeology of a Buried Channel, Village Shenoli, District Satara, Maharashtra
Authors: Sinha A. K. , Singh R. P. , Khanna P. P.
Published: September 2012

A buried channel has been located, in the basaltic terrain, near village Shenoli, District Satara, Maharashtra. It is composed of a gritty mass formed of a semi-consolidated material. The resistivity value of the semi-consolidated formation is 6.30 Ohm - m whereas the resistivity values of the vesicular basalts range between 18 and 32 Ohm-m. The specific capacity, unit area specific capacity, specific capacity index, transmissivity and hydraulic conductivity, with respect of the buried channel, are 609.07 LPM/m of drawdown, 12.12 LPM/m3, 95.47 LPM/ m2, 353.26 m2/day and 55.37 m/day, respectively whereas the values of these parameters for basalt aquifers range from 67 to 117 LPM/m of drawdown, 0.7 to 4.27 LPM/ m3, 14.08 to 31.04 LPM/m2, 33.5 to 73.71 m2/day and 9.44 to 18.32 m/day, respectively. A comparison of the well characteristics and aquifer parameters reveal that the buried channel with semi-consolidated formation has distinctly better groundwater yielding properties.

The groundwater from the semi-consolidated formation has distinctly different quality. The electrical conductivity (EC) of the water from the basalt aquifers ranges between 417 and 555 micro mhos/cm with a modal value of 430 micro mhos/cm, which is 960 micro mhos/cm at 25° C for the semi-consolidated material forming the buried channel. The plots on the Trilinear diagram show that all the samples fall in field 5 where alkaline earths exceed alkalies and weak acids exceed strong acids but it is clear that the proportion of alkalies and weak acids in the water from the buried channel aquifer is higher than the water from the basalt aquifers.
Interpretation of Aero-Magnetic Data and Satellite Imagery to Delineate Structure – A Case Study for Uranium Exploration from Gwalior Basin, India
Authors: Markandeyulu A. , Patra I. , Raju B.V.S.N. , Chaturvedi A. K. , Parihar P. S.
Published: September 2012

The Paleo-Meso Proterozoic Gwalior basin (E – W), lying to NW fringe of Bundelkhand massif is represented by litho-package of lower arenaceous Par Formation and upper chemogenic Morar Formation. It is bounded by Indo-Gangetic alluvium in north and east, Kaimur sediments in west and Bundelkhand granitoids in south. Gwalior Basin has been the exploration target for uranium mineralization right from early 60's. Surface radioactivity anomalies due to uranium has been reported in both Par and Morar Formations of Gwalior Group and Vindhyan sediments. Besides presence of syngenetic uranium in the system, presence of post-depositional faults and fractures are the favorable factors. Aeromagnetic survey was carried out by AMD in 2002 with N-S lines of 500 m interval covering 9406 line km. The data with sampling interval of 0.1 sec was corrected for spikes, diurnal variation, IGRF, heading and lag. Final processed images are prepared after suitable leveling and gridding. First vertical derivative of TMI-RTP and tilt-angle derivative images are used to map the litho-contacts, lineaments and structural features. Numerous NE-SW trending low amplitude and NW-SE trending high amplitude magnetic linears corroborate with quartz reefs and basic dykes respectively. Besides, E-W to WNW-ESE and ENE-WSW trending fractures are also evident from the processed image maps. Further, the Euler’s depth solution of gridded aeromagnetic data calculated for structural indices of 0 and 1 are very consistent in locating the position of the causative sources. Based on the amplitude and textural character of processed aeromagnetic data, alteration zone is delineated well within the Morar Formation. Enhanced Thematic Mapper (ETM+) image with 30m resolution was merged with IRS PAN 1D (5.8 m resolution) for better spatial/radiometric resolution to extract litho-contacts and lineament patterns. Merged PAN band-4 after linear contrast and edge enhancement techniques deciphered detailed lineament pattern, which corroborate the magnetic data. Merged ETM+ (RGB 751) and PC (PC1-PC2-PC5) images depict litho-logical contrast. Integration of aeromagnetic and satellite imagery data helped in understanding the structural fabric of the Gwalior Basin and to identify favorable loci of uranium mineralization.
Paleoenvironment of Deposition of the Dupi Tila Formation, Lalmai Hills, Comilla, Bangladesh
Authors: Roy Mrinal Kanti , Ahmed Syed Samsuddin , Bhattacharjee Tapas Kumar , Mahmud Sultan , Moniruzzaman MD. , Haque MD. Masidul , Saha Sudip , Molla MD. Ismail , Roy Pulin Chandra
Published: September 2012

The Dupi Tila Formation is composed of yellow to light brown medium to very fine moderately hard to loose sandstone, siltstone, silty clay, mudstone and shale with some conglomerates with clasts of petrified wood. The lithofacies of matrix supported conglomerate, trough cross bedded conglomerate, massive sandstone, trough cross bedded sandstone, planar cross bedded sandstone, ripple cross laminated sandstone-siltstone, flaser laminated sandstone-shale, lenticular laminated sandstone-siltstone-shale, parallel laminated sandstone-siltstone, wavy laminated shale, parallel laminated blue shale, and mudstone are delineated within this formation. Based on the grain size, sedimentary structures, water depth and genesis of individual facies, facies are grouped into three types of facies associations like (i) coarse-grained conglomerate facies association in relation to tractive current deposits of alluvial fan set up at the base of litho-succession (FAC), (ii) medium to fine-grained sandstone-siltstone-mudstone facies association or facies association in relation to strong tide (FAT) characterizing the middle part of litho-succession, (iii) very fine-grained sandstone-siltstone-mudstone facies association in relation to less frequent weak tide or heterolithic facies association (FAHL) characterizing upper part of litho-succession and shallow marine facies association (FASM) composing the uppermost litho-succession. Presence of gluconite indicates that the depositional environment was shallow to deep marine. The dominant paleoflow direction during the deposition of Dupi Tila Formation was toward southeast to southwestern direction. The rivers were of braided type at the piedmont alluvial depositional set up at the lower part, which later changed to estuarine–tidal flat type environmental set up in the middle part to upper part and paleo-environment was shallow marine in the uppermost part.
Geological Modeling and Short-term Production Planning of Dimension Stone Quarries Based on Market Demand
Authors: Abdollahisharif J. , Bakhtavar E. , Alipour A. , Mokhtarian M.
Published: September 2012

In order to obtain minimum amount of ore wastage and maximum profitability in dimension stone quarries an optimal short-term production planning procedure has been established here according to the market demand. As the base of this procedure geological modelling has been first created and smoothing of ore-body boundaries was done. Then, an economical block model has been provided. In the next step, all probable shapes of minable-blocks were specified and their priorities in assignment were done according to desired size of the blocks by market demand. Finally, searching from a base sub-block was started in order to find the optimal plan. The procedure has been used for a dimension marble quarry located in northwest of Iran. It demonstrates a decrease about 26% of ore wastage and 21.3% of diamond wire assumption with comparing to the existent traditional procedure.
Characterization of Clay Minerals in the Sundarban Mangroves River Sediments by SEM/EDS
Authors: Rajkumar K. , Ramanathan AL. , Behera P. N.
Published: September 2012

Clay minerals, byproducts of chemical weathering, are important group of minerals found in rivers, estuaries, and marine sedimentary environments, which include mudstones, clay stones, and shales. In the present study, FTIR and SEM investigation on the clay minerals in Sundarban mangrove core sediments collected from Moipith Matla and Belamati Island are carried out. The study indicated the dominant association of kaolinite with subordinate amount of quartz, illite and chlorite. The abundance of kaolinite, illite chlorite and clay with quartz helps in increasing sediment in the islands region. The geochemical and mineralogical evolution of mangrove sediments are results of the interaction of biotic and abiotic parameters, whose balance is conditioned by the climate that governs the hydrologic regime, the sedimentation dynamics and the organic matter. This study on the charaterstation of clay provides us with substantial impact in the water holding capacity, productivity and mineralogical and chemical transformation in order to establish much more and intermediate equilibrium between marine influence and continental contribution, as part of the estuarine environment, than to the tropical climate conditions.
A New Method for Determining Why Length of Life is More Unequal in Some Populations Than in Others
Authors: Nau Claudia , Firebaugh Glenn
Published: September 2012

Why is there greater variability in individual longevity in some populations than in others? We propose a decomposition method designed to address that question by quantifying the effects of population differences in the spread, allocation, and timing of the principal causes of death. Applying the method to the United States and Sweden, we find that spread effects account for about two-thirds of the greater variance in age at death among American adults, meaning that two-thirds of the U.S.-Sweden difference would persist if the two countries differed only with respect to within-cause variance among adults. The remainder of the difference is due largely to allocation effects, with the greater incidence of homicides and fatal traffic accidents alone accounting for more than one-fourth of the greater variance in age at death among adults in the United States.
Equilibrium self‐association of tropomyosin
Authors: Stafford Walter F. , Lee Eunhee , Graceffa Philip
Published: September 2012

It has recently been reported that tropomyosin exists exclusively as a dimer in physiological salt conditions. It is shown in the present work using analytical ultracentrifugation that, on the contrary, tropomyosin is in equilibrium between monomer, dimer and tetramer with a weak tendency to dimerize and tetramerize. Such a finding has consequences for the assembly of the tropomyosin–actin complex.
Cdk5‐mediated phosphorylation of CRMP‐2 enhances its interaction with CaV2.2
Authors: Brittain Joel M. , Wang Yuying , Eruvwetere Omotore , Khanna Rajesh
Published: September 2012

Crmp2
physically interacts with
Cav2.2
by anti tag coimmunoprecipitation (View interaction)
Role of poly(ADP‐ribose) polymerases in the regulation of inflammatory processes
Authors: Bai Péter , Virág László
Published: September 2012

PARP enzymes influence the immune system at several key points and thus modulate inflammatory diseases. PARP enzymes affect immune cell maturation and differentiation and regulate the expression of inflammatory mediators such as cytokines, chemokines, inducible nitric oxide synthase and adhesion molecules. Moreover, PARP enzymes are key regulators of cell death during inflammation‐related oxidative and nitrosative stress. Here we provide an overview of the different inflammatory diseases regulated by PARP enzymes.
The value of plasma osteopontin levels as a predictive factor of disease stage and recurrence in patients with bladder urothelial carcinoma: A prospective study
Authors: Park Min‐Gu , Oh Mi‐Mi , Yoon Jong‐Hyun , Park Jae‐Young , Park Hong‐Seok , Moon Du‐Geon , Yoon Duck‐Ki
Published: September 2012

This study was performed in order to determine the value of plasma osteopontin (OPN) levels as a predictive factor of disease stage and recurrence in patients with bladder urothelial carcinoma (UC). Data from 50 patients diagnosed to have bladder UC after transurethral resection of bladder tumor (TURBT) from 2009 to 2010 were evaluated prospectively. Blood tests were performed before and after TURBT, and plasma OPN levels were measured using enzyme‐linked immunosorbent assay. Differences in OPN levels according to clinicopathologic variables were analyzed statistically. Significant differences in plasma OPN levels were observed between groups with and without muscle invasion (89.16 vs. 67.08 ng/mL, p = 0.041). Comparison according to tumor grade found no significant difference between high and low grade groups (p = 0.115). Mean plasma OPN levels decreased after TURBT without statistical significance (p = 0.571). Between groups with recurrence and those without recurrence, OPN levels of the group with recurrence were higher without statistical significance (p = 0.161). Comparison of plasma OPN levels according to performance of radical cystectomy (RC) showed significant differences; patients who underwent RC showed higher levels of plasma OPN (95.58 vs. 70.37 ng/mL, p = 0.030). Comparison according to T stage after RC showed significant differences in OPN levels (T1: 67.45, T2: 86.60 and T3: 95.23 ng/mL, respectively, p = 0.006). The group with lymph node invasion showed significantly higher levels of OPN, compared to the group without invasion (153.24 vs. 68.03 ng/mL, p = 0.017). Preoperative plasma OPN levels correlated to muscle invasion of bladder UC and pathological stage after RC.
The Compleat Economic Voter: New Theory and British Evidence
Authors: Lewis-Beck Michael S. , Nadeau Richard , Foucault Martial
Published: September 2012

Almost all the prolific work done on economic voting has been based on the classic reward–punishment model, which treats the economy as a valence issue. The economy is a valence issue, but it is much more than that. This article explores two other dimensions of economic voting – position and patrimony. Investigating a 2010 British survey containing relevant measures on these three dimensions, the authors estimate their impact on vote intention, using a carefully specified system of equations. According to the evidence reported, each dimension of economic voting has its own independent effect. Moreover, together, they reveal a ‘compleat’ economic voter, who wields considerable power over electoral choice in Britain. This new result confirms and extends recent work on American and French elections.
Delegation without borders: On individual rights, constitutions and the global order
Authors: BROUSSEAU ERIC , SGARD JEROME , SCHEMEIL YVES
Published: September 2012

Political and economic rights are envisaged as the outcome of an ongoing bargain between citizens and their rulers. Over the long run, this constitutive process shapes the development of both the economy and the state. Globalization, however, corresponds to a period where both the market and civil society extend far beyond the borders of the initial political compact. Hence, citizens may not only ask that cross-border transactions be made easier; they may also challenge the institutional cohesion and integrity of the classical, Westphalian state, i.e., its legal and judicial order, and its bureaucratic capabilities. We are proposing a schematic description of how this political process may gradually exit the national perimeter and deliver four possible models of international or global governance, depending upon the potential structuring of coalitions between the potential winners of the globalization both in the elite and in society, and the losers; national games being ultimately arbitrated by the international competition among elites, but also by the possible formation of global coalitions of citizens and merchants.
Associations of Psychological, Functional, and Biological Factors with Age Changes in the Self-Perceived Health of Old Persons
Authors: Despot Lucanin Jasminka , Lucanin Damir
Published: September 2012

This research investigates the associations of psychological and biological factors with the self-perceived health of old persons. Participants were 411 residents of 11 retirement homes in Zagreb, Croatia: 104 men, 307 women, aged 56–96 years (average 79) at baseline, mobile, and not diagnosed with dementia. The variables measured, at baseline and at 2-year follow-up, were sociodemographics, self-perceived health, functional ability, cognitive function, depression, and social participation. Biochemical variables were measured from vein blood sample at baseline. Cross-sectional and longitudinal analyses explained 33%–38% of self-perceived health variance. Functional ability, depressive symptoms, and age were significant predictors of self-perceived health in all analyses. Two biological cardiovascular risk factors variables – glucose and urea – were significantly associated with self-perceived health.
Promoting Active Aging Through University Programs for Older Adults
Authors: Fernández-Ballesteros Rocío , Molina María Ángeles , Schettini Rocío , del Rey Ángel Luis
Published: September 2012

Throughout history, formal education has been “age-based,” in the sense that primary, secondary, further, and higher education have been planned and implemented with the main objective of preparing citizens for working life. However, gerontological research on cognitive plasticity in the latter half of the 20th century provided evidence of learning potential throughout the lifespan and into old age. The II International Plan of Action on Aging recognizes the importance of older adults in contributing to social and economic development, remaining active and having the right to benefit from lifelong learning (LLL) policies. Consequently, universities have been opened up to older adults, and university programs for older adults have been developed. Our general hypothesis is that those older adults who follow a university program will improve the core of active aging, which involves cognitive, emotional, and social factors. The quasiexperimental group was 82 older adults who followed the University Program for Older Adults at the Autonomous University of Madrid from 2007 to 2010. These were then compared with a control group (N = 76) over the same period. Pre/post comparisons show that participants obtain significant benefits, attributable to the program, in that they maintain their cognitive performance evaluated through the Digit-Symbol Test, their health (assessed through the number of illnesses reported), and their level of activity (information-seeking and social activities), and increase their level of positive affect. At the end of the Program, significantly more of those who enrolled on it were classified as “active agers,” compared to the control group.
On Geropsychology in the Czech Republic
Authors: Stepankova Hana , Jarolimova Eva , Dragomirecka Eva , Sobotkova Irena , Sulova Lenka , Bezdicek Ondrej , Nikolai Tomas , Pulkrabkova Alice , Bergerova Marie , Vacha Tomas , Kolda Pavel , Holmerova Iva
Published: September 2012

This work provides an overview of psychology of aging and old age in the Czech Republic. Historical roots as well as recent activities are listed including clinical practice, cognitive rehabilitation, research, and the teaching of geropsychology.
An objective methodology for merging satellite‐ and model‐based soil moisture products
Authors: Yilmaz M. T. , Crow W. T. , Anderson M. C. , Hain C.
Published: September 2012

An objective methodology that does not require any user‐defined parameter assumptions is introduced to obtain an improved soil moisture product along with associated uncertainty estimates. This new product is obtained by merging model‐, thermal infrared remote sensing‐, and microwave remote sensing‐based soil moisture estimates in a least squares framework where uncertainty estimates for each product are obtained using triple collocation. The merged anomaly product is validated against in situ based soil moisture data and shows higher correlations with observations than individual input products; however, it is not superior to a naively merged product acquired by averaging the products using equal weighting. The resulting combined soil moisture estimate is an improvement over currently available soil moisture products due to its reduced uncertainty and can be used as a standalone soil moisture product with available uncertainty estimates.
Cenozoic seawater Sr/Ca evolution
Authors: Sosdian Sindia M. , Lear Caroline H. , Tao Kai , Grossman Ethan L. , O'Dea Aaron , Rosenthal Yair
Published: September 2012

Records of seawater chemistry help constrain temporal variations in geochemical processes that impact the global carbon cycle and climate through Earth's history. Here we reconstruct Cenozoic seawater Sr/Ca (Sr/Casw) using fossil Conus and turritellid gastropod Sr/Ca. Combined with an oxygen isotope paleotemperature record from the same samples, the gastropod record suggests that Sr/Caswwas slightly higher in the Eocene (∼11.4 ± 3 mmol/mol) than today (∼8.54 mmol/mol) and remained relatively stable from the mid‐ to late Cenozoic. We compare our gastropod Cenozoic Sr/Casw record with a published turritellid gastropod Sr/Casw record and other published biogenic (benthic foraminifera, fossil fish teeth) and inorganic precipitate (calcite veins) Sr/Caswrecords. Once the uncertainties with our gastropod‐derived Sr/Casw are taken into account the Sr/Casw record agrees reasonably well with biogenic Sr/Caswrecords. Assuming a seawater [Ca] history derived from marine evaporite inclusions, all biogenic‐based Sr/Casw reconstructions imply decreasing seawater [Sr] through the Cenozoic, whereas the calcite vein Sr/Casw reconstruction implies increasing [Sr] through the Cenozoic. We apply a simple geochemical model to examine the implications of divergence among these seawater [Sr] reconstructions and suggest that the interpretation and uncertainties associated with the gastropod and calcite vein proxies need to be revisited. Used in conjunction with records of carbonate depositional fluxes, our favored seawater Sr/Ca scenarios point to a significant increase in the proportion of aragonite versus calcite deposition in shelf sediments from the Middle Miocene, coincident with the proliferation of coral reefs. We propose that this occurred at least 10 million years after the seawater Mg/Ca threshold was passed, and was instead aided by declining levels of atmospheric carbon dioxide.
Evidence for external forcing on 20th‐century climate from combined ocean‐atmosphere warming patterns
Authors: Sedláček Jan , Knutti Reto
Published: September 2012

Of the additional energy absorbed by the Earth over the past decades, by far the largest fraction is taken up by the oceans. Yet most attribution studies focus on the surface warming, and only few have used patterns of ocean warming to attribute changes to external forcing or internal variability. Here we use the combined observed evidence from warming of the atmosphere and ocean with the latest climate model simulations to demonstrate that both the depth profiles and spatial warming patterns near the surface are very heterogeneous when resulting from internal unforced variability. In the 20th‐century simulations on the other hand, the observed spatial pattern is smooth, and the warming decreases almost gradually with depth in the ocean, consistent with observations and a penetration of the surface warming to intermediate depth by diffusion and advection. We argue that such physically motivated arguments combining different lines of evidence and types of observations offer insight that is complementary to optimal fingerprint attribution methods. We conclude that the simultaneous global warming of the atmosphere and mixed layer alone is uninformative for attribution, but the magnitude of ocean heat uptake, the homogeneity of the spatial pattern as well as the distribution of warming below the mixed layer strongly argue for the 20th‐century warming being largely externally forced.
Arctic sea ice reduction and European cold winters in CMIP5 climate change experiments
Authors: Yang Shuting , Christensen Jens H.
Published: September 2012

European winter climate and its possible relationship with the Arctic sea ice reduction in the recent past and future as simulated by the models of the Climate Model Intercomparison Project phase 5 (CMIP5) is investigated, with focus on the cold winters. While Europe will warm overall in the future, we find that episodes of cold months will continue to occur and there remains substantial probability for the occurrence of cold winters in Europe linked with sea ice reduction in the Barents and Kara Sea sector. A pattern of cold‐European warm‐Arctic anomaly is typical for the cold events in the future, which is associated with the negative phase of the Arctic Oscillation. These patterns, however, differ from the corresponding patterns in the historical period, and underline the connection between European cold winter events and Arctic sea ice reduction.
Automated mapping of Earth's annual minimum exposed snow and ice with MODIS
Authors: Painter Thomas H. , Brodzik Mary J. , Racoviteanu Adina , Armstrong Richard
Published: September 2012

Global snow and ice have been diminishing during the Anthropocene but we still lack a complete mapping of annual minimum exposed snow and ice with a consistent, repeatable algorithm. The Global Land Ice Measurements from Space (GLIMS) project has compiled digital glacier outlines and related metadata for the majority of the world's glaciers but inconsistency among product algorithms and time periods represented precludes the production of a consistently derived global data set. Here we present the MODIS Persistent Ice (MODICE) algorithm that leverages the time series of fractional snow and ice cover from the MODIS Snow Covered Area and Grain size (MODSCAG) algorithm. The end product of MODICE is a consistently derived map of annual minimum exposed snow and ice. Comparisons of MODICE with GLIMS glacier outlines derived from SPOT, ASTER, and Landsat Thematic Mapper show strong agreement with the higher resolution outlines subject to uncertainties with spatial resolution, deep mountain shadows, and GLIMS interpretation errors.
The MJO‐Kelvin wave transition
Authors: Sobel A. H. , Kim D.
Published: September 2012

As the Madden‐Julian oscillation (MJO) moves eastward from the Indian to the Pacific ocean, it typically accelerates, becomes less strongly coupled to convection, and becomes more similar to a dry Kelvin wave. This transition is analyzed using observations of outgoing longwave radiation and ERA Interim reanalyses of surface pressure and 850 hPa zonal wind. Two individual example events as well as composites are shown. The transitions are well defined, with distinct disturbances on either side of the transition whose identities as MJO or Kelvin waves are clear. In some cases there appears to be a pre‐existing Kelvin wave passing through the MJO from the west to the east, but this feature is not apparent in the composites. The transitions occur at different longitudes in different events, over a wide range from the eastern Indian to the central Pacific oceans.
Dependence of plasma sheet energy fluxes and currents on solar wind‐magnetosphere coupling
Authors: Kaufmann Richard L.
Published: September 2012

The epsilon solar wind‐magnetosphere coupling function was used to estimate the rate at which energy from the solar wind was being dissipated in the inner magnetosphere and ionosphere. The Geotail CPI ion and electron data sets showed that the average percentage of this energy that was carried earthward by energetic particles at |z| < 2.5 RE in the central plasma sheet increased from approximately zero at x = −28 RE to 25% at x = −10 RE when epsilon was high. Much of this increase was attributed to the adiabatic energization of particles as flux tubes collapsed following reconnection events. The Geotail magnetometer and CPI ion data sets also were used to estimate the average electric fields and currents. These parameters provided an alternative viewpoint from which to examine particle energization. The parallel volume current density exhibited a stronger dependence on epsilon than did the perpendicular sheet current density. During disturbed times, a maximum of the parallel current density at a fixed x, y location existed at a distance of ∼3 RE from the neutral sheet. A strong dawn‐dusk asymmetry was seen in the long‐term averaged region 1 field‐aligned currents. The ratio of upgoing dusk side to downgoing dawn side currents at the same x was ∼1.7 throughout the portion of the plasma sheet that could be studied, and was seen during both quiet and disturbed conditions. Previous papers showed that most of this excess upgoing dusk side parallel current was closed through connections to a dusk side downgoing region 0 current system.
Identifying the causes of the poor decadal climate prediction skill over the North Pacific
Authors: Guemas V. , Doblas‐Reyes F. J. , Lienert F. , Soufflet Y. , Du H.
Published: September 2012

While the North Pacific region has a strong influence on North American and Asian climate, it is also the area with the worst performance in several state‐of‐the‐art decadal climate predictions in terms of correlation and root mean square error scores. The failure to represent two major warm sea surface temperature events occurring around 1963 and 1968 largely contributes to this poor skill. The magnitude of these events competes with the largest observed temperature anomalies in the twenty‐first century that might be associated with the long‐term warming. Understanding the causes of these major warm events is thus of primary concern to improve prediction of North Pacific, North American and Asian climate. The 1963 warm event stemmed from the propagation of a warm ocean heat content anomaly along the Kuroshio‐Oyashio extension. The 1968 warm event originated from the upward transfer of a warm water mass centered at 200 m depth. For being associated with long‐lived ocean heat content anomalies, we expect those events to be, at least partially, predictable. Biases in ocean mixing processes present in many climate prediction models seem to explain the inability to predict these two major events. Such currently unpredictable warm events, if occurring again in the next decade, would substantially enhance the effect of long‐term warming in the region.
Diurnal variations in convective storm activity over contiguous North China during the warm season based on radar mosaic climatology
Authors: Chen Mingxuan , Wang Yingchun , Gao Feng , Xiao Xian
Published: September 2012

Diurnal variations in the formation and development of convective storms over contiguous North China during the warm season were studied using reflectivity from six China Next Generation Weather Radars between 2008 and 2011. Our results, including temporal and spatial analysis of hourly storm frequency through the warm season, and inter‐month comparisons during June, July and August, indicate that most storms initiate over the northwestern mountains in the afternoon as a result of solar heating, with the highest frequency in June, and the lowest in August. Storms propagate from the mountains to the southeastern foothills and plains, with the highest rates occurring in June, and the lowest in August. In the late afternoon, there is a remarkably high storm frequency over the foothills and plains, which indicates a significant topographic control on the southeastward propagation and intensification of storms during the warm season. Storm activity occurs mainly on the plains through the night, with the highest frequency in July and the lowest in June, as a result of a favorable nocturnal convection mechanism. The region‐averaged hourly storm frequencies for the warm season, and also for each month in JJA, are all bimodally distributed, with peak frequencies occurring in late afternoon and during the night, with the highest frequency recorded in the late afternoon during June and July, but at night in August. In general, the mean storm frequency is highest during the day and night in July, and lowest from afternoon to evening in August, but from nighttime to the next morning in June.
Nested high‐resolution modeling of the impact of urbanization on regional climate in three vast urban agglomerations in China
Authors: Wang Jun , Feng Jinming , Yan Zhongwei , Hu Yonghong , Jia Gensuo
Published: September 2012

In this paper, the Weather Research and Forecasting Model, coupled to the Urban Canopy Model, is employed to simulate the impact of urbanization on the regional climate over three vast city agglomerations in China. Based on high‐resolution land use and land cover data, two scenarios are designed to represent the nonurban and current urban land use distributions. By comparing the results of two nested, high‐resolution numerical experiments, the spatial and temporal changes on surface air temperature, heat stress index, surface energy budget, and precipitation due to urbanization are analyzed and quantified. Urban expansion increases the surface air temperature in urban areas by about 1°C, and this climatic forcing of urbanization on temperature is more pronounced in summer and nighttime than other seasons and daytime. The heat stress intensity, which reflects the combined effects of temperature and humidity, is enhanced by about 0.5 units in urban areas. The regional incoming solar radiation increases after urban expansion, which may be caused by the reduction of cloud fraction. The increased temperature and roughness of the urban surface lead to enhanced convergence. Meanwhile, the planetary boundary layer is deepened, and water vapor is mixed more evenly in the lower atmosphere. The deficit of water vapor leads to less convective available potential energy and more convective inhibition energy. Finally, these combined effects may reduce the rainfall amount over urban areas, mainly in summer, and change the regional precipitation pattern to a certain extent.
A mysterious plasma wave emission and the determination of plasma densities in Neptune's inner magnetosphere
Authors: Moses S. L. , Coronti F. V.
Published: September 2012

One of the strongest plasma wave signals observed during the Voyager 2 encounter with Neptune is a narrowband emission between 3.0 and 4.3 kHz that was detected over a period of roughly 2 hours around closest approach. The emission occurs below the electron cyclotron frequency and the low‐frequency cutoff of the radio continuum radiation. Of the naturally occurring signals in the Earth's auroral zone and in Jupiter's magnetosphere this emission most resembles trapped Z mode waves found near the left‐hand cutoff frequency. Using this identification, we obtain a plasma density profile that is independent of the plasma temperature. These densities greatly exceed those measured by the plasma science instrument on Voyager but are lower than estimates based on other models of Neptunian plasma wave phenomenology. If this wave mode is not a natural emission, it might arise from an unusual interaction of the spacecraft with the cold, dense ambient plasma.
The albedo, effective temperature, and energy balance of Neptune, as determined from Voyager data
Authors: Pearl J. C. , Conrath B. J.
Published: September 2012

Data from the Voyager infrared spectrometer and radiometer (IRIS) investigation are used in determining the albedo, effective temperature, and energy balance of Neptune. From broadband radiometric observations made at phase angles of 14° and 134°, together with measurements at intermediate phase angles from the literature, an orbital mean value for the bolometric Bond albedo, Ā = 0.290 ± 0.067, is obtained; this yields an equilibrium temperature Teq = 46.6 ± 1.1 K. From thermal spectra obtained over latitudes from pole to pole an effective temperature = 59.3 ± 0.8 K is derived. This represents a substantial improvement over previously determined values. The energy balance of Neptune is therefore E = 2.61 ± 0.28, which is in agreement with previous results. The reduced uncertainty in this value is due to the improved determination of the effective temperature.
Theory of ring sweeping of energetic particles
Authors: Paranicas C. P. , Cheng A. R.
Published: September 2012

Because the effective “area” of the Neptunian rings is larger than that of the inner moons, the sweeping of energetic particles by the rings is perhaps the dominant process for particle loss in the magnetosphere within 5 RN. In this paper we describe a theory for calculating the absorption probability of energetic charged particles by the rings. We include the effects of a large tilt and an offset between the planet and dipole centers. We find that the probability of absorption for protons is so high that the sweeping lifetime is only a few times the gradient‐curvature drift period. For electrons the sweeping lifetime is even less. The pitch angle dependence for sweeping manifests itself strongly only at large equatorial pitch angles. Lower‐energy particles have higher absorption rates by the rings.
Evidence of auroral plasma cavities at Uranus and Neptune from radio burst observations
Authors: Farrell W. M. , Desch M. D. , Kaiser M. L. , Calvert W.
Published: September 2012

Radio bursts originating from the stronger magnetic polar regions of both Uranus and Neptune were detected by the planetary radio astronomy experiment during the Voyager 2 encounters with the planets. It has previously been demonstrated that these bursts are beamed into a broad, hollow emission pattern from their auroral sources. We now show that the bursts at both planets also manifest similar detailed patterns, with the waves beamed into two separate and distinct radiation cones at intermediate wave frequencies. This double‐cone emission pattern is predicted by relativistic cyclotron resonance theory, and application of this theory to the observed emission pattern yields the plasma density structure within the radio source region. Calculations indicate that at both Uranus and Neptune the plasma‐to‐cyclotron frequency ratio can drop well below 0.01 within the active region. Such low values indicate that the southern auroral zones at both planets contain an auroral plasma cavity that is similar to that found in Earth's nightside auroral zone.
Low‐energy ions near Neptune
Authors: Richardson John D. , Belcher John W. , Zhang Ming , McNutt Ralph L.
Published: September 2012

This paper provides a synopsis of the ion observations near Neptune, from the upstream solar wind through the magnetosheath, magnetosphere, and back out through the magnetosheath to the solar wind. The main emphasis is on the magnetosphere; complete density and temperature profiles are shown for this region. Observations are consistent with the presence of two ion species, H+ and N+, which increase in density and temperature with decreasing distance from Neptune. Calculations of the flux tube content and energy invariant imply that N+ escapes directly from Triton's ionosphere, whereas H+ is created by ionization of a large neutral H cloud emanating from Triton and extending inward to 8RN. Inside L=8, substantial plasma losses occur, precipitation into Neptune's atmosphere is one loss mechanism, and charge exchange with a hypothesized Neptune‐centered H cloud may also be important Given expected source rates of about lxlO25 ions/s, transport times must be very fast, of the order of 105 s at L=10.
Satellite sweeping of energetic particles at Neptune
Authors: Paranicas C. P. , Cheng A. F.
Published: September 2012

The calculation of the absorption rate of charged particles by planetary satellites introduced by Paonessa and Cheng (1987) is generalized to include an arbitrary offset of the dipole center from the planet center, appropriate for Neptune. The absorption rates calculated for particles of fixed L shell, energy, and pitch angle reflect the features of the complicated geometry of the dipole and the moons. This absorption probability is found to be insignificant compared with that of the rings at L shells to which both sets of absorbers map. However, at larger radii the sweeping rate is controlled by the moons, and the corresponding absorption features provide a starting point for understanding the Voyager energetic particle observations.