bluuebunny/crossref_metadata_2025 huggingface dataset:
On Shifted Weibull-Pareto Distribution
Authors: Alzaghal Ahmad , Ghosh Indranil , Alzaatreh Ayman
Published: June 2016

The Lomax distribution, known as Pareto (type II) distribution, is a heavy tail probability distribution used extensively in business, economics and in actuarial modeling. The Weibull-Pareto distribution defined by Alzaatreh et al. (2013a) has shown high bias and standard error for the ML estimates when the parameter $c>>1$. In this paper we use the Lomax distribution to construct the Weibull-Lomax distribution. It is observed that the Weibull-Lomax distribution performs significantly better in terms of the ML estimations. Some structural properties of the Weibull-Lomax distribution are discussed.
Evaluation of the Quality of Composite Maize-Wheat Chinchin Enriched with Rhynchophorous phoenicis
Authors: Dong Ojinnaka, , T. C. Emeh, , S. U. Okorie,
Published: June 2016

The purpose of this research was to develop and evaluate a snack product (chin-chin) from composite maize-wheat flour blends enriched with edible palm weevil (Rhyhnchophorus phoenicis) paste. The maize-wheat chin-chin enriched with R. phoenicis were subjected to acceptability test using twenty member semi-trained panelist. The moisture, fat, protein and carbohydrate compositions of the snack samples had significant differences in their values. Sample 5M5R90W (containing 5% maize flour and Rhyhnchophorus phoenicis paste and 90% wheat flour) had the highest protein value of 19.05% while the least value 9.39% was obtained by sample 100M0R0W (100% maize flour alone). Sample 100M0R0W containing 100% maize flour also had the highest carbohydrate value of 75.24%. There was no significant difference in the ash and crude fiber contents of the chin-chin samples enriched with edible palm weevil paste. There were significant differences (P ≤ 0.05) in the functional properties of maize-wheat composite flour blends. Their wettability values ranged from 46.67 – 200 while the swelling index, bulk density and oil absorption capacity showed no significant difference in their values. The result of the mineral analysis showed phosphorus, magnesium and sodium had significant differences in their values in the range of 317.55 – 376.75mg/100g; 5.60 -13.60mg/100g;59.0 – 70.3mg/100g, respectively. There were no significant differences in the sensory attributes of the chin-chin samples. The result showed that an acceptable chin-chin product can be processed with the inclusion of the larva of edible palm weevil with maize-wheat composite flour to enhance the nutritional quality of the product.
Sensory, Physicochemical and Microbiological Characteristics of Venison Jerky Cured with NaCl and KCl
Authors: Tangkham Wannee , LeMieux Frederick
Published: June 2016

Traditionally, jerky is produced from sliced whole muscle marinated in a high sodium chloride (NaCl) concentration and dried. Because a high salt diet has been linked to hypertension, salt substitutes are often recommended as a healthier alternative. However, potassium chloride (KCl), a popular salt substitute may impart an undesired bitterness and metallic aftertaste. The objective of this study was to evaluate specific attributes of venison jerky prepared in three different (NaCl/KCl) salt solutions. Through sensory testing, each preparation was evaluated for consumer product acceptance and purchase intent. Additionally, the venison jerky was assayed for physicochemical characteristics and microbial counts. Using a 9-point hedonic scale, sixty-eight consumers evaluated the jerky for acceptability of flavor, texture, taste, saltiness, bitterness and overall liking. Physicochemical characteristics were evaluated for moisture content, pH, color and TBAR. Jerky was assayed for microbial counts via aerobic plate count, Escherichia coli, Staphylococcus aureus and Campylobacter spp. Results show that jerky prepared with 100% KCl received the most desirable score (8.75), compared to jerky prepared with 100% NaCl (6.28), and jerky prepared with 50% NaCl + 50% KCl (6.13). Acceptability and purchase intent questionnaires indicate jerky prepared with 100% KCl ranked the highest at 86.8% and 70.6%, respectively. Jerky prepared with 100% KCl had the lowest moisture content, TBAR, and a* values (P<0.05). No E. coli, S. aureus and Campylobacter spp. were detected over the 28 day period. Our study suggests that jerky prepared with KCl represents a low sodium alternative to traditional jerky.
Morphological and Biochemical Characterization of Soybean Nodulating Rhizobia Indigenous to Zambia
Authors: Kapembwa Rachael , Mweetwa Alice M. , Ngulube Munsanda , Yengwe Jones , Yengwe Jones
Published: June 2016

Soybean [Glycine max (L.) Merrill] is known for nitrogen fixation by rhizobia present in the soil with which it establishes an efficient symbiosis. In Zambia, current rhizobial inoculants used in soybeans production are based on non-indigenous strains; this creates a need to isolate local strains that can be used for the development of local inoculants for soybeans in Zambian soils. This paper reports the isolation and characterization of rhizobial isolates from virgin and cultivated soils of the three agro-ecological regions of Zambia. Rhizobia were isolated using the Trap Method and characterized using selected morphological and biochemical markers. A total of 61 isolates were isolated on Yeast Extract Mannitol (YEM) agar medium. Isolates varied in colony form, color, margin and texture. From the 61 isolates from the three regions, 87 % were circular, 8 % irregular and 5 % punctuate in form with 100 % convex elevation. The isolates had 88% entire, 10% undulate and 2 % lobate colony margins with different colors – 56 % cream, 24 % white, 11 % yellow, 5 % transparent and 3 % pink. Transparent colonies were peculiar to Region I and III while pink colonies were peculiar to Region III. All isolates produced mucous, were gram negative and rod shaped, a characteristic of rhizobial cells. None of the isolates could tolerate extremes of pH (4 and 9) in growth medium but grew well at pH 6.8. All isolates utilized glucose as a source of carbon. Based on the Bromothymol Blue (BTB) assay, 59 isolates were fast growing while two isolates from cultivated soils of region II were slow growing. The fast growing 59 isolates showed an acidic reaction changing the medium from green to yellow, while the others showed an alkaline reaction. Based on the results, the 59 fast-growers could be Ensifer fredii or/and Rhizobium tropici rather than Bradyrhizobium. However, further tests to confirm these findings using ketolactose, genetic characterization and inclusion of reference strains, are still needed and are being recommended here.
Legal Constraints on the Indeterminate Control of ‘Dangerous’ Sex Offenders in the Community: The Dutch Perspective
Authors: Struijk Sanne , Mevis Paul
Published: June 2016

Legal Constraints on the Indeterminate Control of ‘Dangerous’ Sex Offenders in the Community: The Dutch Perspective

In the Netherlands, the legal possibilities for post-custodial supervision have been extended considerably in recent years. A currently passed law aims to further increase these possibilities specifically for dangerous (sex) offenders. This law consists of three separate parts that may all result in life-long supervision. In the first two parts, the supervision is embedded in the conditional release after either a prison sentence or the safety measure ‘ter beschikking stelling’ (TBS). This paper focuses on the third part of the law, which introduces an independent supervisory safety measure as a preventive continuation of both a prison sentence and the TBS measure. Inevitably, this new independent sanction raises questions about legitimacy and necessity, on which this paper reflects from a human rights perspective. Against the background of the existing Dutch penal law system, the content of the law is thoroughly assessed in view of the legal framework of the Council of Europe and the legal principles of proportionality and less restrictive means. In the end, we conclude that the supervisory safety measure is not legitimate nor necessary (yet). Apart from the current lack of (empirical evidence of) necessity, we state that there is a real possibility of an infringement of Article 5(4) ECHR and Article 7 ECHR, a lack of legitimising supervision ‘gaps’ in the existing penal law system, and finally a lack of clear legal criteria. Regardless of the potential severity of violent (sex) offenses, to simply justify this supervisory safety measure on the basis of ‘better safe than sorry’ is not enough.
Text Optiona:l Visual Storytelling with Wordless Picturebooks
Authors: Gibson Jennifer
Published: June 2016

Wordless picturebooks are on the rise and are increasingly revered by readers and critics. In many countries, including the United States, wordless picturebooks have become a sub-genre unto themselves—a publishing trend resulting in author/illustrators who even specialize in this type of book.
Why Storytelling Matters: Unveiling the Literacy Benefits of Storytelling
Authors: Agosto Denise E.
Published: June 2016

Storytelling is a long-standing tradition in US public and school libraries. Storytelling, not to be confused with story reading, involves telling a story from memory without the aid of a book or written script. Some tellers memorize their stories; others memorize the characters and events and freely tell their stories, varying them with each telling.
Perennially Popular: The Appeal of Classic Fairy Tales for Children
Authors: Dewan Pauline
Published: June 2016

Fairy tales were not initially intended for children. “Originally told at fireside gatherings or in spinning circles by adults to adult audiences,” as Maria Tatar points out, “fairy tales joined the canon of children’s literature (which is itself of recent vintage) only in the last two to three centuries.”
En systematik for ideudviklingsformater
Authors: Due Brian Lystgaard
Published: June 2016

Inden for medie- og kommunikationsforskningen har der været sporadisk fokus på de ideudviklingsprocesser, der ligger bag udviklingen af medie- og kommunikationsløsninger. Men præcis viden om, hvordan ideer på møder i kommunikationsafdelinger fremsættes og behandles i autentisk interaktion mangler. Gennem en række eksempler udvikles i artiklen en sammenhængende systematik for, hvilke formater deltagere bruger når de 1) fremsætter ideer, responderer 2a) positivt (affilierende) eller 2b) negativt (disaffilierende), og hvordan ideer 3a) accepteres eller 3b) kritikhåndteres. Artiklen bygger på data fra tre forskellige danske kommunikationsafdelinger, der har arbejdet med at udvikle nye kommunikationsprodukter. Artiklen præsenterer en række formater, der er blevet fremanalyseret med videoetnografisk og konversationsanalytisk metode. Artiklens formål er at give et overblik over de mest almindelige formater under ideudviklingsmøder.
Análisis económico de la erosión del suelo: Valoración de los efectos externos en la cuenca del Alto Genil
Authors: Colombo Sergio , Calatrava Requena Javier
Published: June 2016

The paper presents the economic evaluation of the soil erosion off-farm effects by means of the Choice Experiment method. After a review of the main studies that consider, under a socio-economic point of view, the soil erosion problem an application of the choice experiment to monetary evaluation of the off-farm effects of soil erosion in the Alto Genil watershed (Granada province) is described. The choice experiment method allows the estimation of the values of the most important soil erosion impacts, so that to provide public-decisors with useful information regarding land management. Also, the welfare change experimented by citizens, due to the implementation of soil erosion reduction policies, is investigated. These evaluations will be compared with the subsidy that the regional government grants to farmers that adopt soil conservation measures.
Factores determinantes del precio de la carne de ternera: Un análisis hedónico
Authors: Gracia Royo Azucena , Pérez y Pérez Luis
Published: June 2016

Beef market has been affected by recent food products crises. The consumer’s decision is being related to the price and this one by the product characteristics and by other factors which can in fluence the consumer’s utility. The objective of the paper is to analyse the economic value of the beef attributes influencing the consumer’s purchase decision using an hedonic prices methodology. Data come from two surveys carried out on 540 consumers in Zaragoza City in the years 2001 and 2002. In the econometric estimation, a flexible functional form is assumed, the Box-Cox transformation. This approach solves the functional form problem. Results show that the consumers’ assessment on the beef attributes does not change from one year to another and that the designation of origin is the most important characteristic determining the beef price.
Productividad total de los factores en la agricultura chilena: 1961-1996
Authors: Olavarría Jaime A. , Bravo-Ureta Boris , Cocchi Horacio
Published: June 2016

The main objective of this paper is to determine the productivity growth in the Chilean Agricultural sector during the 1961-1996 period. Total Factor Productivity (TFP) was calculated using the Törnqvist index, which is a discrete approximation to the Divisia index. The data used to estimate these indexes are prices and quantities for 51 crops, and for four inputs —labor, land, capital and intermediate factors. The rate of annual growth for the period 1961-96 was 2,69% and –0,09%, for products and inputs, respectively. Therefore, the TFP grew at an average annual rate of 2,78%. Given a significant annual variability in TFP growth, an analysis was carried out for seven sub-periods corresponding to different political regimes. TFP grew at an annual average of 1,83% with Alessandri (1961-64), 3,12% under the period of Frei Montalva (1965-70), 1,52% during the Allende years (1971-73), 6,11% during the first part of the Pinochet regime and –0,28% in the second period of Pinochet (1981-89), 3,12% during Aylwin (1990-93) and 5,28% under Frei Ruiz-Tagle (1994-96). The results suggest that the land reform program implemented in the 1960s did not have a negative effect on TFP growth, as has been previously argued by some authors.
Análisis de la convergencia en productividad agraria en las regiones europeas
Authors: Castillo Valero Juan Sebastián , Cuerva Narro Mª Carmen
Published: June 2016

In this paper, we intend to analyze the regional convergence of the agricultural sector in Europe. More specifically, we want to show the relevance of the agricultural sector in explaining territorial inequalities within the European Union. For that purpose, we will analyze the evolution of inequality and convergence in European agriculture by using data on Gross Value Added per employee in the period spanning from 1985 to 1997. Empirical results provide evidence of the existence of absolute convergence among regional agricultural sectors. However, we have found empirical evidence of the existence of several stationary states due to the specific peculiarities of each economy. This result can be interpreted in terms of the existence of convergence clubs and center-periphery models. Moreover, we show that the CAP is a relevant variable in explaining convergence through the protection of Mediterranean and Continental products. We have found that physical capital and infrastructure, as well as accumulation of capital, are the primary sources of convergence. This result is compatible with a neoclassical model in which convergence is due to decreasing returns of physical capital, whilst also showing the importance of the territorial dimension of public investment.
El valor de la flexibilidad en la valoración de inversiones acuícolas
Authors: Pardo Sempere Loreto , Rodríguez Alcaide José Javier
Published: June 2016

The loud initial investments that are necessary to start aquaculture activities, united to the so expanded period of the cycle of production and to the risk that this activity entails, are situations that appoint the future of the activity whose continuity requires necessarily of its economic viability. For it, it is important to pay attention to those studies that justify this economic viability capturing important aspects such like the managerial flexibility or the strategic value embedded in each project of investment, often perceived as critical success factors. From this perspective, it shows the need and the opportunity of this investigation, based on the application of Real Options method to value projects, considering the value of the strategic options embedded in them and that traditional discounted cash flow models does not capture. In short it is applied to a project of investment in a sea bream Sparus aurata offshore fish farm. After the election of the model of cage, the project was valued considering the strategic options to delay or abandon the project according to the events along 10 years. This valuation allowed concluding that the project is highly viable, considering the option to delay from only upon the 9th year analysis, if the preceding years are always unfavourable, being its probability very low. The option to abandon does not have value in this project of investment.
Evaluación de preferencias hacia las mandarinas en el mercado británico. Aplicación de las subastas Vickrey
Authors: Martínez-Carrasco L. , Vidal F. , Poole N.
Published: June 2016

The objective of this work is to analyse British consumer preferences towards five varieties of mandarins (two of them from Spain) under three different information conditions: visual inspection, peeling and consumption. Therefore, the paper deals with the purchase process from two perspectives: before and after experiencing the product and considering both search and experience attributes. Besides, it is intended to study the market possibilities of the Spanish varieties in British market. The research employed the second price Vickrey experimental auction method using two treatments applied to different subgroups of the total sample. Half of the groups evaluated the fruit characteristics at each stage of the experimental process before making the auction bids while the other half of the groups offered bids without giving an evaluation of the fruit. Main results are: (1) significant changes in evaluation and willingness to pay for mandarins as consumer move forward the purchase-consumption process, (2) both experimental groups behaved similarly, (3) juiciness, sweetness and acidity are the attributes most closely correlated with the overall evaluation of the different varieties, (4) Spanish varieties are well evaluated, but only after consumption. The main recommendation for Spanish citrus producer is to find a way to communicate Spanish mandarin excellence in some search attributes, which cannot be evaluated by visual inspection, but are significant at post-purchase valuation.
Nuevos acuerdos regionales de comercio en Latinoamérica y disposición a negociar: El caso de la agricultura
Authors: Valdés Alberto , Foster William
Published: June 2016

This article analyses past trade trends and agricultural protectionism in Latin American agriculture, by examining observed changes in Latin American agriculture and trade policies over the last 20 years that have led to what the authors call the«New Open Regionalism». It also discussed the conflicting interests and various trading positions taken up by Latin American countries in multilateral trade talks, as a result of the strong heterogeneity between net agricultural exporters and importers. The authors show that the repeated failure of the Doha round of trade talks opens the door for bilateral or sub-regional free trade agreements, concluding with the prediction that regional integration in Latin America will come about as a result of agreements between various sub-regional trade blocs. The weakness of internal demand makes the development of the region’s agri-food sector highly dependent on exports, the growth of which is one of the main economic drivers in these countries, particularly net exporters. In addressing the issue of the distribution of profits from trade liberalization, the authors propose a variety of schemes that have already proved their effectiveness in countries such as Mexico, Turkey, Brazil, Colombia, Nicaragua and Honduras.
Pobreza, degradación ambiental y liberalización del comercio: Hacia una intervención de políticas «second best»
Authors: Pascual Unai , Martínez-Espiñeira Roberto
Published: June 2016

Forest based agricultural systems in the tropics are being opened up to international trade at an unprecedented rate.This is the case of tropical agriculture in Mexico under the North American Free Trade Agreement (NAFTA), which is also having significant impacts on the decentralized land use decisions of small-scale farmers and on the natural resource base on which they depend. This paper develops a bioeconomic model of a typical forest-land based farming system that is integrated with the non-farm labour sector, as typically found in tropical regions. The data used to generate the simulations were gathered in two communities of Yucatan (Mexico) in 1998-2000. Through a systemdynamics framework, the agro-ecological and farming economic subsystems are integrated and the current situation of price liberalization that is negatively affecting soil capital and income levels is compared to a scenario that precludes an «optimal path to extinction» through careful policy intervention. This second-best case is based on a targeted policy mix that seeks to maintain the system viable for as long as possible above an irreducible poverty level. The policy intervention involves, simultaneoulsy, subsidizing off-farm wage rates, intensification of land use, and the control of households’ rights to the forest commons. The model shows that such policy intervention can result in a large positive discounted net payoff basedon the increased incomes for the farming community after deducting the implementation costs of such intervention.
Propuesta para corregir las externalidades en el mercado de café: Un impuesto sobre el té y el café regular y una subvención sobre el café de Comercio Justo
Authors: Galarraga Ibon , Markandya Anil
Published: June 2016

This paper justifies the need to introduce a tax on regular coffee drinkers in the UK to subsidise the fair trade/organic coffee production. This policy will allow to take full account of the negative external effect of regular coffee production while internalising the positive effect of fair trade initiatives. Designing such a policy is possible and the benefits of it can be calculated. This paper shows how.
Route Choice Model Based on Game Theory for Commuters
Authors: Yang Licai , Shi Yunfeng , Hao Shenxue , Wu Lei
Published: June 2016

The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decisionexactly and the provided route is reliable.
Impact of a New Concept of Universal Service Obligations on Revenue Increase in the Post of Serbia
Authors: Dobrodolac Momčilo , Ralević Predrag , Švadlenka Libor , Radojičić Valentina
Published: June 2016

The European postal directives and Serbian legislation as well define the quality standards for universal service obligations at the aggregate level, i.e. for all postal items transferred by the postal operator. This paper proposes a new concept where the transit time is defined by the customer and specified for each shipment. The paper considers three different models of this new concept. However, the one where a customer could choose between two alternatives: D+1 and D+3 transfer, is analysed in details. By using the attitudes of examined customers, forecasting methods and analysis of revenues from the past, it is assessed at what price the new postal service should be offered to achieve the highest revenue. The proposed methodology was tested and verified in the case of the Post of Serbia. The results indicate that the best would be to offer the service D+1 at the 40% increased price compared to the existing prices.
Long period preservation of marine products using electrostatic field
Authors: Okumura Takamasa , Yaegashi Taro , Yamada Kazuki , Ito Takanori , Takahashi Katsuyuki , Aisawa Sumio , Takaki Koichi , Yamazaki Shigeyoshi , Syuto Bunei
Published: June 2016

The effect of an AC electric field on the freshness of marine products was experimentally investigated. An AC voltage of 10 kV with 50 Hz in frequency was generated with a transformer and applied to a plane electrode set in an incubator. The biological material was the gonad of purple sea urchin. The AC electric field with 50 Hz in frequency was applied to the gonad at −1 °C for 7 days. Freshness was evaluated by measuring protein release and lactate dehydrogenase (LDH) activity. The results showed that the protein release and LDH activity in the gonad were suppressed by applying the AC electric field, compared with that without the AC electric field. Moreover, the gonad was treated with the AC electric field at −5 °C for 3 days and then preserved at 0 °C for 1 day without the field. This electrical field treatment of the gonad prolonged the freshness date for more than 10 days under 4 °C preservation condition. In addition, the permeability of the cell membrane was suppressed by applying the AC electric field. Concerning the relationship between permeability and AC electric field, the conformational change of bovine serum albumin (BSA) induced by the AC electric field was evaluated on the basis of UV absorption spectra. The results revealed that the secondary and/or higher-order structure gradually changes with preservation period. The conformational change of the BSA molecule was induced by applying the AC electric field.
Audio segmentation using Flattened Local Trimmed Range for ecological acoustic space analysis
Authors: Vega Giovany , Corrada-Bravo Carlos J. , Aide T. Mitchell
Published: June 2016

The acoustic space in a given environment is filled with footprints arising from three processes: biophony, geophony and anthrophony. Bioacoustic research using passive acoustic sensors can result in thousands of recordings. An important component of processing these recordings is to automate signal detection. In this paper, we describe a new spectrogram-based approach for extracting individual audio events. Spectrogram-based audio event detection (AED) relies on separating the spectrogram into background (i.e., noise) and foreground (i.e., signal) classes using a threshold such as a global threshold, a per-band threshold, or one given by a classifier. These methods are either too sensitive to noise, designed for an individual species, or require prior training data. Our goal is to develop an algorithm that is not sensitive to noise, does not need any prior training data and works with any type of audio event. To do this, we propose: (1) a spectrogram filtering method, the Flattened Local Trimmed Range (FLTR) method, which models the spectrogram as a mixture of stationary and non-stationary energy processes and mitigates the effect of the stationary processes, and (2) an unsupervised algorithm that uses the filter to detect audio events. We measured the performance of the algorithm using a set of six thoroughly validated audio recordings and obtained a sensitivity of 94% and a positive predictive value of 89%. These sensitivity and positive predictive values are very high, given that the validated recordings are diverse and obtained from field conditions. The algorithm was then used to extract audio events in three datasets. Features of these audio events were plotted and showed the unique aspects of the three acoustic communities.
Horizontal mixing in the Southern Ocean from Argo float trajectories
Authors: Roach Christopher J. , Balwada Dhruv , Speer Kevin
Published: June 2016

We provide the first observational estimate of the circumpolar distribution of cross‐stream eddy diffusivity at 1000 m in the Southern Ocean using Argo float trajectories. We show that Argo float trajectories, from the float surfacing positions, can be used to estimate lateral eddy diffusivities in the ocean and that these estimates are comparable to those obtained from RAFOS floats, where they overlap. Using the Southern Ocean State Estimate (SOSE) velocity fields to advect synthetic particles with imposed behavior that is “Argo‐like” and “RAFOS‐like” diffusivity estimates from both sets of synthetic particles agreed closely at the three dynamically very different test sites, the Kerguelen Island region, the Southeast Pacific Ocean, and the Scotia Sea, and support our approach. Observed cross‐stream diffusivities at 1000 m, calculated from Argo float trajectories, ranged between 300 and 2500 m2 s−1, with peaks corresponding to topographic features associated with the Scotia Sea, the Kerguelen Plateau, the Campbell Plateau, and the Southeast Pacific Ridge. These observational estimates agree with previous regional estimates from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) near the Drake Passage, and other estimates from natural tracers (helium), inverse modeling studies, and current meter measurements. These estimates are also compared to the suppressed eddy diffusivity in the presence of mean flows. The comparison suggests that away from regions of strong topographic steering suppression explains both the structure and magnitude of eddy diffusivity but that eddy diffusivities in the regions of topographic steering are greater than what would be theoretically expected and the ACC experiences localized enhanced cross‐stream mixing in these regions.
Intensification and poleward shift of subtropical western boundary currents in a warming climate
Authors: Yang Hu , Lohmann Gerrit , Wei Wei , Dima Mihai , Ionita Monica , Liu Jiping
Published: June 2016

A significant increase in sea surface temperature (SST) is observed over the midlatitude western boundary currents (WBCs) during the past century. However, the mechanism for this phenomenon remains poorly understood due to limited observations. In the present paper, several coupled parameters (i.e., sea surface temperature (SST), ocean surface heat fluxes, ocean water velocity, ocean surface winds and sea level pressure (SLP)) are analyzed to identify the dynamic changes of the WBCs. Three types of independent data sets are used, including reanalysis products, satellite‐blended observations. and climate model outputs from the fifth phase of the Climate Model Intercomparison Project (CMIP5). Based on these broad ranges of data, we find that the WBCs (except the Gulf Stream) are intensifying and shifting toward the poles as long‐term effects of global warming. An intensification and poleward shift of near‐surface ocean winds, attributed to positive annular mode‐like trends, are proposed to be the forcing of such dynamic changes. In contrast to the other WBCs, the Gulf Stream is expected to be weaker under global warming, which is most likely related to a weakening of the Atlantic Meridional Overturning Circulation (AMOC). However, we also notice that the natural variations of WBCs might conceal the long‐term effect of global warming in the available observational data sets, especially over the Northern Hemisphere. Therefore, long‐term observations or proxy data are necessary to further evaluate the dynamics of the WBCs.
Constraints on olivine‐rich rock types on the Moon as observed by Diviner and M3: Implications for the formation of the lunar crust
Authors: Arnold J. A. , Glotch T. D. , Lucey P. G. , Song E. , Thomas I. R. , Bowles N. E. , Greenhagen B. T.
Published: June 2016

We place upper limits on lunar olivine abundance using midinfrared (5–25 µm) data from the Lunar Reconnaissance Orbiter Diviner Lunar Radiometer Experiment (Diviner) along with effective emissivity spectra of mineral mixtures in a simulated lunar environment. Olivine‐bearing, pyroxene‐poor lithologies have been identified on the lunar surface with visible‐near‐infrared (VNIR) observations. Since the Kaguya Spectral Profiler (SP) VNIR survey of olivine‐rich regions is the most complete to date, we focus this work on exposures identified by that study. We first confirmed the locations with VNIR data from the Moon Mineralogy Mapper (M3) instrument. We then developed a Diviner olivine index from our laboratory data which, along with M3 and Lunar Reconnaissance Orbiter Camera wide‐angle camera data, was used to select the geographic area over which Diviner emissivity data were extracted. We calculate upper limits on olivine abundance for these areas using laboratory emissivity spectra of anorthite‐forsterite mixtures acquired under lunar‐like conditions. We find that these exposures have widely varying olivine content. In addition, after applying an albedo‐based space weathering correction to the Diviner data, we find that none of the areas are unambiguously consistent with concentrations of forsterite exceeding 90 wt %, in contrast to the higher abundance estimates derived from VNIR data.
Testing a land model in ecosystem functional space via a comparison of observed and modeled ecosystem flux responses to precipitation regimes and associated stresses in a Central U.S. forest
Authors: Gu Lianhong , Pallardy Stephen G. , Yang Bai , Hosman Kevin P. , Mao Jiafu , Ricciuto Daniel , Shi Xiaoying , Sun Ying
Published: June 2016

Testing complex land surface models has often proceeded by asking the question: does the model prediction agree with the observation? Such an approach has yet led to high‐performance terrestrial models that meet the challenges of climate and ecological studies. Here we test the Community Land Model (CLM) by asking the question: does the model behave like an ecosystem? We pursue its answer by testing CLM in the ecosystem functional space (EFS) at the Missouri Ozark AmeriFlux (MOFLUX) forest site in the Central U.S., focusing on carbon and water flux responses to precipitation regimes and associated stresses. In the observed EFS, precipitation regimes and associated water and heat stresses controlled seasonal and interannual variations of net ecosystem exchange (NEE) of CO2 and evapotranspiration in this deciduous forest ecosystem. Such controls were exerted more strongly by precipitation variability than by the total precipitation amount per se. A few simply constructed climate variability indices captured these controls, suggesting a high degree of potential predictability. While the interannual fluctuation in NEE was large, a net carbon sink was maintained even during an extreme drought year. Although CLM predicted seasonal and interanual variations in evapotranspiration reasonably well, its predictions of net carbon uptake were too small across the observed range of climate variability. Also, the model systematically underestimated the sensitivities of NEE and evapotranspiration to climate variability and overestimated the coupling strength between carbon and water fluxes. We suspect that the modeled and observed trajectories of ecosystem fluxes did not overlap in the EFS and the model did not behave like the ecosystem it attempted to simulate. A definitive conclusion will require comprehensive parameter and structural sensitivity tests in a rigorous mathematical framework. We suggest that future model improvements should focus on better representation and parameterization of process responses to environmental stresses and on more complete and robust representations of carbon‐specific processes so that adequate responses to climate variability and a proper degree of coupling between carbon and water exchanges are captured.
Cold ion demagnetization near the X‐line of magnetic reconnection
Authors: Toledo‐Redondo Sergio , André Mats , Khotyaintsev Yuri V. , Vaivads Andris , Walsh Andrew , Li Wenya , Graham Daniel B. , Lavraud Benoit , Masson Arnaud , Aunai Nicolas , Divin Andrey , Dargent Jeremy , Fuselier Stephen , Gershman Daniel J. , Dorelli John , Giles Barbara , Avanov Levon , Pollock Craig , Saito Yoshifumi , Moore Thomas E. , Coffey Victoria , Chandler Michael O. , Lindqvist Per‐Arne , Torbert Roy , Russell Christopher T.
Published: June 2016

Although the effects of magnetic reconnection in magnetospheres can be observed at planetary scales, reconnection is initiated at electron scales in a plasma. Surrounding the electron diffusion region, there is an Ion‐Decoupling Region (IDR) of the size of the ion length scales (inertial length and gyroradius). Reconnection at the Earth's magnetopause often includes cold magnetospheric (few tens of eV), hot magnetospheric (10 keV), and magnetosheath (1 keV) ions, with different gyroradius length scales. We report observations of a subregion inside the IDR of the size of the cold ion population gyroradius (∼15 km) where the cold ions are demagnetized and accelerated parallel to the Hall electric field. Outside the subregion, cold ions follow the E × B motion together with electrons, while hot ions are demagnetized. We observe a sharp cold ion density gradient separating the two regions, which we identify as the cold and hot IDRs.
Comparisons of mapped magnetic field lines with the source path of the 7 April 1995 type III solar radio burst
Authors: Li B. , Cairns Iver H. , Gosling J. T. , Malaspina D. M. , Neudegg D. , Steward G. , Lobzin V. V.
Published: June 2016

Ideally, the sources of type III solar radio bursts, which are produced mainly by flare‐accelerated electron beams, trace the magnetic field lines along which the beams propagate from the Sun to interplanetary space. A recently developed 2‐D approach for large‐scale mapping of magnetic field lines between the Sun and Earth in the solar equatorial plane is applied to the sources of the 7 April 1995 type III radio burst imaged by Ulysses and Wind. The approach uses near‐Earth solar wind data and a solar wind model with intrinsic nonradial magnetic field at the source surface of the solar wind. Quantitative agreement is found between the mapped field lines, the observed path of the radio source centroids, and the field configurations inferred from solar wind suprathermal electrons observed by Wind. Moreover, the mapped field lines are consistent with Wind not observing the in situ type III electron beam, Langmuir waves, and local radio emission for this type III event.
Surface layer temperature inversion in the Bay of Bengal: Main characteristics and related mechanisms
Authors: Thadathil Pankajakshan , Suresh I. , Gautham S. , Prasanna Kumar S. , Lengaigne Matthieu , Rao R. R. , Neetu S. , Hegde Akshay
Published: June 2016

Surface layer temperature inversion (SLTI), a warm layer sandwiched between surface and subsurface colder waters, has been reported to frequently occur in conjunction with barrier layers in the Bay of Bengal (BoB), with potentially commensurable impacts on climate and postmonsoon tropical cyclones. Lack of systematic measurements from the BoB in the past prevented a thorough investigation of the SLTI spatiotemporal variability, their formation mechanisms, and their contribution to the surface temperature variations. The present study benefits from the recent Research Moored Array for African‐Asian‐Australian Monsoon Analysis and Prediction (RAMA) buoys located in BoB along 90°E at 4°N, 8°N, 12°N, and 15°N over the 2006–2014 period. Analysis of data from these RAMA buoys indicates that SLTI forms after the summer monsoon and becomes fully developed during winter (December–February). SLTI exhibits a strong geographical dependency, with more frequent (80% times during winter) and intense inversions (amplitude, ΔT ∼ 0.7°C) occurring only in the northern BoB compared to central and southern Bay. SLTI also exhibits large interannual and intraseasonal variations, with intraseasonal amplitude significantly larger (ΔT ∼ 0.44°C) than the interannual amplitude (∼0.26°C). Heat budget analysis of the mixed layer reveals that the net surface heat loss is the most dominant process controlling the formation and maintenance of SLTI. However, there are instances of episodic advection of cold, low‐saline waters over warm‐saline waters leading to the formation of SLTI as in 2012–2013. Vertical processes contribute significantly to the mixed layer heat budget during winter, by warming the surface layer through entrainment and vertical diffusion.
Contributions of different tidal interactions to fortnightly variation in tidal duration asymmetry
Authors: Guo Wenyun , Song Dehai , Wang Xiao Hua , Ding Pingxing , Ge Jianzhong
Published: June 2016

The general framework for identifying tidal duration asymmetry proposed by Song et al. (2011) is extended to express fortnightly variability in duration asymmetry. The extended metrics are verified and studied using observed sea level data at 481 stations worldwide. The results reveal that fortnightly variability is universal and that duration asymmetry can be stronger during neap tide than during spring tide. The fortnightly variability in duration asymmetry is primarily induced by three types of tidal interactions: interactions within the principal tidal constituents, interactions between high‐frequency and principal tidal constituents, and interactions between long‐period and principal tidal constituents. Among these interactions, the first type is most important at most of the stations and is related to the form number F. The contributions of different interactions can be quantified using their frequencies, amplitudes and phases. Global patterns of the fortnightly variation are illustrated using TOPEX/Poseidon altimetry data. The findings show that remarkable fortnightly variation in the tidal duration asymmetry occurs in most open oceans and is significant around an amphidromic point. The metrics derived in this study can be used to examine any time‐varying characteristics in tidal asymmetry (not limited to duration asymmetry) by selecting a suitable frequency threshold.
Impacts of the East Asian Monsoon on springtime dust concentrations over China
Authors: Lou Sijia , Russell Lynn M. , Yang Yang , Xu Li , Lamjiri Maryam A. , DeFlorio Michael J. , Miller Arthur J. , Ghan Steven J. , Liu Ying , Singh Balwinder
Published: June 2016

We use 150 year preindustrial simulations of the Community Earth System Model to quantify the impacts of the East Asian Monsoon strength on interannual variations of springtime dust concentrations over China. The simulated interannual variations in March‐April‐May (MAM) dust column concentrations range between 20–40% and 10–60% over eastern and western China, respectively. The dust concentrations over eastern China correlate negatively with the East Asian Monsoon (EAM) index, which represents the strength of monsoon, with a regionally averaged correlation coefficient of −0.64. Relative to the strongest EAM years, MAM dust concentrations in the weakest EAM years are higher over China, with regional relative differences of 55.6%, 29.6%, and 13.9% in the run with emissions calculated interactively and of 33.8%, 10.3%, and 8.2% over eastern, central, and western China, respectively, in the run with prescribed emissions. Both interactive run and prescribed emission run show the similar pattern of climate change between the weakest and strongest EAM years. Strong anomalous northwesterly and westerly winds over the Gobi and Taklamakan deserts during the weakest EAM years result in larger transport fluxes, and thereby increase the dust concentrations over China. These differences in dust concentrations between the weakest and strongest EAM years (weakest‐strongest) lead to the change in the net radiative forcing by up to −8 and −3 W m−2 at the surface, compared to −2.4 and +1.2 W m−2 at the top of the atmosphere over eastern and western China, respectively.
The whole atmosphere response to changes in the Earth's magnetic field from 1900 to 2000: An example of “top‐down” vertical coupling
Authors: Cnossen Ingrid , Liu Hanli , Lu Hua
Published: June 2016

We study the effects of changes in the Earth's magnetic field between 1900 and 2000 on the whole atmosphere (0–500 km altitude), based on simulations with the Whole Atmosphere Community Climate Model eXtension. Magnetic field changes directly affect the temperature and wind in the upper atmosphere (> ~110 km) via Joule heating and the ion drag force. However, we also find significant responses in zonal mean temperature and zonal wind in the Southern Hemisphere (SH) middle‐ to high‐latitude troposphere, stratosphere, and mesosphere of up to ±2 K and ±2 m/s, as well as regionally significant changes in Northern Hemisphere (NH) polar surface temperatures of up to ±1.3 K, in December‐January‐February. In the SH, changes in gravity wave filtering in the thermosphere induce a change in the residual circulation that extends down into the upper mesosphere, where further changes in the mean wind climatology are generated, together with changes in local planetary wave generation and/or amplification and gravity wave filtering. This induces further changes to a residual circulation cell extending down into the troposphere. However, inaccuracies in the simulated SH upper mesospheric wind climatology probably mean that the simulated temperature and wind responses in the SH lower and middle atmosphere are also inaccurate. The NH middle atmosphere response is zonally asymmetric, consisting of a significant change in the positioning and shape of the upper stratospheric polar vortex, which is dynamically consistent with the surface temperature response. However, the downward coupling mechanism in the NH is generally less clear.
On the deterministic and stochastic use of hydrologic models
Authors: Farmer William H. , Vogel Richard M.
Published: June 2016

Environmental simulation models, such as precipitation‐runoff watershed models, are increasingly used in a deterministic manner for environmental and water resources design, planning, and management. In operational hydrology, simulated responses are now routinely used to plan, design, and manage a very wide class of water resource systems. However, all such models are calibrated to existing data sets and retain some residual error. This residual, typically unknown in practice, is often ignored, implicitly trusting simulated responses as if they are deterministic quantities. In general, ignoring the residuals will result in simulated responses with distributional properties that do not mimic those of the observed responses. This discrepancy has major implications for the operational use of environmental simulation models as is shown here. Both a simple linear model and a distributed‐parameter precipitation‐runoff model are used to document the expected bias in the distributional properties of simulated responses when the residuals are ignored. The systematic reintroduction of residuals into simulated responses in a manner that produces stochastic output is shown to improve the distributional properties of the simulated responses. Every effort should be made to understand the distributional behavior of simulation residuals and to use environmental simulation models in a stochastic manner.