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Sample records for puna meridional argentina

  1. Viajes comerciales de intercambio en el departamento de Antofagasta de la Sierra, Puna meridional argentina: pasado y presente.

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    García, Silvia P.

    2002-05-01

    Full Text Available Los viajes hacia valles interserranos a lomo de mula fueron una experiencia compartida por todos en esta región de la puna argentina, hasta hace veinte años. En este trabajo se relacionan los datos obtenidos a través de entrevistas a informantes en el departamento de Antofagasta de la Sierra, con los surgidos tras la consulta de las Actas del Registro Civil y se arriba a conclusiones respecto de los vínculos de parentesco que unieron a quienes comerciaban e intercambiaban mercaderías producidas en alturas diferentes. También se compara la situación de entonces con la actualidad. En la capital del departamento los viajes de intercambio han desaparecido casi en su totalidad, en cambio en otras poblaciones del mismo departamento se han modificado incluyendo en ellos a las mercaderías obtenidas por compra y utilizando la sal como principal elemento de canje.

  2. RECURSOS VEGETALES Y TECNOFACTURAS EN UN SITIO ARQUEOLÓGICO DE LA PUNA MERIDIONAL ARGENTINA, ÁREA CENTRO - SUR ANDINA

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    María F. Rodríguez

    2008-01-01

    Full Text Available El objetivo de esta investigación fue analizar el uso de los recursos vegetales para confeccionar tecnofacturas en el pasado prehistórico. Se estudiaron los artefactos recuperados en el sitio arqueológico Punta de la Peña 4, capas 0 - 4, datadas entre ca. 3900 - 500 años AP. El sitio está ubicado en las proximidades de la localidad de Antofagasta de la Sierra, Catamarca, Argentina (26° 11' 16'' S y 67° 20' 51.3'' O, a una altura de 3650 m s. m. Esta localidad pertenece a la Puna meridional y de acuerdo con las características ambientales, se integra a la Puna salada. Los objetivos específicos fueron identificar las especies vegetales utilizadas como materia prima y su área de procedencia, así como también evaluar el posible uso de cada uno de los artefactos hallados. Asimismo, se discutió la movilidad y los posibles intercambios socioeconómicos teniendo en cuenta los vegetales no locales utilizados. El análisis anatómico comparativo entre las especies actuales que crecen en el área de estudio y aquellas utilizadas en la confección de estas tecnofacturas permitió la identificación de las últimas, las cuales pertenecen a las familias Asteraceae, Cactaceae, Cyperaceae, Fabaceae, Juncaceae, Poaceae, Solanaceae y Typhaceae. Considerando las posibles áreas de procedencia de las especies arqueológicas se registró un menor grado de movilidad a grandes distancias durante el Holoceno tardío; en su lugar se instalan circuitos de movilidad pautada que obedecen a las actividades de pastoralismo que comienzan a desarrollarse.

  3. Diagnóstico socio-ambiental para un desarrollo sustentable de la Puna Meridional Argentina, Localidad de Antofagasta de la Sierra, Catamarca

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    Liliana M. Manzi

    2008-05-01

    Full Text Available Se presenta un diagnóstico socio-ambiental realizado en la comunidad de Antofagasta de la Sierra, Provincia de Catamarca, Argentina, siendo tomados en consideración las unidades sociales de producción, los rebaños, las pasturas disponibles y los patrones de uso y tenencia de la tierra. Se pretende identificar y evaluar la incidencia del actual uso del espacio sobre el medio natural y discutir las iniciativas oficiales de desarrollo económico para este sector de la Puna argentina.

  4. Procesos tafonómicos, subsistencia y uso del espacio: análisis de la arqueofauna de un sitio agropastoril de la Puna Meridional Argentina (Punta de la Peña 9, Antofagasta de la Sierra, Catamarca

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    Sara M. L. López Campeny

    2005-12-01

    Full Text Available Se presentan los resultados del análisis de un conjunto de restos óseos faunísticos recuperados en una estructura arquitectónica (E2 excavada en el sitio Punta de la Peña 9. Dicho sitio se localiza en los Sectores Intermedios (3600 m snm, en la microregión de Antofagasta de la Sierra (Catamarca, Puna Meridional Argentina. El análisis incluyó una evaluación de los efectos de los procesos de formación del registro, un abordaje del conjunto óseo desde una perspectiva económica y un análisis de la distribución espacial de los restos óseos en los niveles ocupacionales del recinto. El abordaje de estas tres dimensiones amplias del conjunto arqueofaunístico nos permitió aproximarnos al estudio de múltiples aspectos entre los que destacamos: la evaluación del efecto de los factores de formación del registro en la integridad del conjunto óseo; las modalidades de uso del espacio en la estructura analizada; ciertas características de las secuencias de ocupación de la misma; los sistemas de descarte o actividades de mantenimiento de los espacios de uso intensivo; el conjunto de actividades llevadas a cabo y los patrones vinculados con la explotación, selección de partes y consumo de fauna.The results of the analysis of an assemblage of faunal bone remains recovered from an architectural structure (E2 excavated in the site Punta de la Peña 9 are presented. The site is located in the Intermediate Sectors (3600 m. above-sea-level in the micro-region of Antofagasta de la Sierra (Catamarca, Southern Puna, Argentina. The analysis included an evaluation of the effects of the formation processes of the archaeological record, a study of the bones from an economic perspective, and an analysis of the spatial distribution of bones in the occupation levels of the enclosure. Examination of these three broad dimensions of this archaeofaunal assemblage enabled us to study multiple aspects of this site. Among such aspects the following are

  5. El sitio Bajo del Coypar II: Las evidencias más tempranas (CA. 1000 AP del proceso agropastoril en la Puna Meridional Argentina (Antofagasta de la Sierra, Catamarca

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    Silvina Vigliani

    2005-01-01

    Full Text Available El sitio Bajo del Coypar II (BC II es un conjunto de estructuras de pequeñas dimensiones ubicado sobre una saliente de la ladera de los cerros del Coypar, frente y alrededor del cual se distribuye una gran superficie de campos de cultivo prehispánicos, (Bajo del Coypar I de aproximadamente 1000 ha. En un trabajo anterior se postuló que este amplio sistema de producción agrícola se originó hacia el final del proceso regional tardío (ca. 1300 AP en asociación con el crecimiento del principal centro habitacional de la región, La Alumbrera (Olivera et.al, 1994 y que luego fue apropiado y ampliado por el Incario. En el presente trabajo se plantean tres objetivos generales: conocer el tipo de actividades que se realizaban en el conjunto de estructuras de BC II, establecer la asociación que había entre este conjunto de estructuras y el sistema de producción agrícola e identificar posibles cambios en el uso del espacio a lo largo del tiempo. En un principio se pensó que Bajo del Coypar II formaba parte de la ampliación del espacio productivo implementada por el Imperio Incaico. Las investigaciones llevadas a cabo en el mismo permitieron determinar que efectivamente hacia las etapas más tardías y en asociación con el Incario había una estrecha relación con el sector agrícola, evidenciado en una alta frecuencia de vasijas para el almacenaje y/o el procesamiento de sustancias secas. Sin embargo, también revelaron ocupaciones más tempranas vinculadas a grupos o unidades domésticas con un desarrollo creciente de las prácticas agrícolas. De este modo, la actividad agro-pastoril fue, en este sector de la Puna meridional, mucho más temprana de lo que pensábamos.

  6. Evapofacies del Salar Hombre Muerto, Puna argentina: distribucion y genesis

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    D. Vinante

    2006-06-01

    Full Text Available En el presente trabajo se identifican, describen y se muestra la distribución areal de las facies y evapofacies asociadas al ambiente evaporítico del Salar Hombre Muerto, ubicado en el borde oriental de la Puna Austral, en una zona con una amplia difusión de yacimientos de boratos. El salar puede ser dividido en dos subcuencas, la occidental y la oriental, ambas separadas por el islote central de Farallón Catal. La subcuenca oriental es boratífera, con bajo contenido en cloruros, mientras que la subcuenca occidental presenta tanto en superficie como en profundidad potentes acumulaciones de halita (hasta 900 m y es prácticamente estéril en boratos. Se plantean varias hipótesis sobre la génesis de la evapofacies boratífera, representada mineralógicamente por el borato ulexita. Esta es la evapofacies de interés económico y que se explota en el salar, donde además se extraen salmueras de litio.

  7. Estructuras agrarias comparadas: la Puna argentina y el sur boliviano a comienzos del siglo XX

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    Ana A. Teruel

    2005-01-01

    Full Text Available This article expects to be another contribution to the knowledge about the social-economic problems from the Argentine Puna, especifically to its agricultural structure, paying special attention to changes and permanences, concerning to property and land, key to economical and social power and fundamental axis of production relationship of this society. It focuses on the problematical fact of indian lands, making a comparison between the North of Argentina and the South of Bolivia, considering both political state systems about comunity lands and its effects in the agrarian structures in the begining of the XXth century.Este artículo tiene por propósito realizar un aporte más al conocimiento de la problemática socio-económica de la Puna argentina, específicamente a su estructura agraria, atendiendo los cambios y permanencias relativos a la propiedad y tenencia de la tierra, clave del poder económico y social y eje fundamental en las relaciones de producción de esta sociedad agraria. Se trata la cuestión en el marco de la problemática de las tierras indígenas, comparando la situación del Norte argentino con la del Sur boliviano, analizando las políticas de ambos Estados en torno a la tierra de las comunidades y sus efectos en las estructuras agrarias de comienzos del siglo XX.

  8. The ages and tectonic setting of the Faja Eruptiva de la Puna Oriental, Ordovician, NW Argentina

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    Bahlburg, Heinrich; Berndt, Jasper; Gerdes, Axel

    2016-07-01

    The Ordovician Faja Eruptiva de la Puna Oriental is a magmatic, predominantly intrusive belt in the Puna of northwestern Argentina with a N-S extension of ca. 400 km. Scarce isotope geochemical ages and biostratigraphic data on some of the folded Faja Eruptiva country rocks assign the magmatism either to the Lower and lower Middle Ordovician, or to the latest Ordovician. Interpretations of origin and tectonic framework of the Faja Eruptiva are controversial and vary between arc, back-arc and collisional-orogenic settings. We present high-resolution La-ICP-MS U-Pb age and Hf isotope data on zircons from 10 plutonic samples covering the magmatic belt along a length of 200 km in the northern Argentinian Puna. The xenocrystic and magmatic zircon age data have a wide spread between 2700 Ma and 440 Ma. Concordia and weighted mean age data document protracted magmatism in two phases between 480 and 460 Ma, and between 453 and 444 Ma, and constrain the time of the last intrusions at 444 ± 3 Ma and at 445 ± 2 Ma thus defining this last and main phase of intrusion at 444 Ma. εHf(t) values define a main vertical trend centered at 500 Ma with εHf(t) values between + 3 and - 16 indicating significant mixing of juvenile early Paleozoic melts with Paleoproterozoic crustal components. A second trend is formed by zircons with ages between 1.1 Ga and c. 500 Ma and predominantly positive εHf values between + 8 and - 3 and originates in juvenile mantle compositions between 1.6 and 1.1 Ga. The spread of the zircon and Hf data document that the Faja Eruptiva intrusives have experienced large-scale contamination by the hosting crustal basement. It follows that the basement of the Puna is formed either by the upper Proterozoic-lower Cambrian Puncoviscana Formation as an erosional product of the Proterozoic orogenic belts of SW Amazonia or that the Puna including its Puncoviscana basement is underlain by a crust shaped by these orogenies. The main intrusive event at 444 Ma has been

  9. Recent, slow normal and strike-slip faulting in the Pasto Ventura region of the southern Puna Plateau, NW Argentina

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    Zhou, Renjie; Schoenbohm, Lindsay M.; Cosca, Michael

    2013-01-01

    Recent normal and strike-slip faulting on the Puna Plateau of NW Argentina has been linked to lithospheric foundering, gravitational spreading, plate boundary forces and a decrease in crustal shortening from north to south. However, the timing, kinematics and rate of extension remain poorly constrained. We focus on the Pasto Ventura region (NW Argentina) located on the southern Puna Plateau and recent deformation (cinder cones show that the overall extension direction is subhorizontal, is oriented NE-SW to NNE-SSW, and occurs at a slow, time-integrated rate of 0.02 to 0.08 mm/yr since at least 0.8–0.5 Ma. A regional compilation from this study and existing data shows that recent extension across the Puna Plateau is subhorizontal but varies in azimuthal orientation dramatically. Data from the Pasto Ventura region are consistent with a number of models to explain normal and strike-slip faulting on the Puna Plateau, all of which likely influence the region. Some role for lower lithospheric foundering through dripping appears to be seen based on the regional extension directions and ages of mafic volcanism in the southern Puna Plateau.

  10. Las ignimbritas del complejo volcánico Coranzuli (Puna Argentina-Andes Centrales

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    Martí, J.

    1987-12-01

    Full Text Available The Coranzulí is a large Upper Miocene volcanic complex located on a NE-SW and NW-SE regional faults intersection, at 66º 15' W 23º S, in the Northwest of Argentina in Jujuy province. It corresponds to one of four large volcanic complexes which represent the end of Transversal Volcanic Chaines in La Puna Argentina in the Central Andes. The volcanic activity was characterized by at least four separate ignimbrite eruptions which produced four different ignimbrite sheets. These are well welded, very crystal-rich, lithie poor ignimbrites and have a moderate to high pumice content. The total volume of the Coranzuli ignimbrites exeededs 650 Km3. Preliminary data indicate that the eruption oeeurred from a homogeneous magmatic chamber without zoning. The emplacement characteristics of the ignimbrites and the lack of basal or interbedded plinian fall deposits suggest that the eruptions developed quickly to massive proportions.El Coranzuli es uno de los grandes complejos volcánicos que representan el remate final de las Cadenas Volcánicas Transversales de la Puna Argentina, en los Andes Centrales. Se trata de un complejo volcánico del Mioceno superior situado a los 66º 15' W 23º S en el NW de Argentina en la provincia de Jujuy, en la intersección entre dos fallas regionales de dirección NE-SW y NW-SE, respectivamente. La actividad eruptiva se caracterizó por la existencia de, al menos, cuatro erupciones ignimbríticas que produjeron cuatro diferentes mantos ignimbríticos. Se trata de ignimbritas bien soldadas, muy ricas en cristales, pobre en fragmentos líticos y que presentan un contenido en fragmentos pumíticos de moderado a alto. El volumen total que representan estas ignimbritas supera los 650 km3. Los datos preliminares indican que el magma juvenil deriva de una cámara magmática homogénea no zonada. Las características de emplazamiento de estas ignimbritas, así como la falta de depósitos plinianos de caída en la base o

  11. Structural control on geothermal circulation in the Tocomar geothermal volcanic area (Puna plateau, Argentina)

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    Giordano, Guido

    2016-04-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous thermal springs. This study presents new stratigraphic, structural, volcanological, geochemical and hydrogeological data on the geothermal field. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field.

  12. Late Quaternary stratigraphy, sedimentology, and geochemistry of an underfilled lake basin in the Puna (north-west Argentina)

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    McGlue, Michael M.; Cohen, Andrew S.; Ellis, Geoffrey S.; Kowler, Andrew L.

    2013-01-01

    Depositional models of ancient lakes in thin-skinned retroarc foreland basins rarely benefit from appropriate Quaternary analogues. To address this, we present new stratigraphic, sedimentological and geochemical analyses of four radiocarbon-dated sediment cores from the Pozuelos Basin (PB; northwest Argentina) that capture the evolution of this low-accommodation Puna basin over the past ca. 43 cal kyr. Strata from the PB are interpreted as accumulations of a highly variable, underfilled lake system represented by lake-plain/littoral, profundal, palustrine, saline lake and playa facies associations. The vertical stacking of facies is asymmetric, with transgressive and thin organic-rich highstand deposits underlying thicker, organic-poor regressive deposits. The major controls on depositional architecture and basin palaeogeography are tectonics and climate. Accommodation space was derived from piggyback basin-forming flexural subsidence and Miocene-Quaternary normal faulting associated with incorporation of the basin into the Andean hinterland. Sediment and water supply was modulated by variability in the South American summer monsoon, and perennial lake deposits correlate in time with several well-known late Pleistocene wet periods on the Altiplano/Puna plateau. Our results shed new light on lake expansion–contraction dynamics in the PB in particular and provide a deeper understanding of Puna basin lakes in general.

  13. Processing, validating, and comparing DEMs for geomorphic application on the Puna de Atacama Plateau, northwest Argentina

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    Purinton, Benjamin; Bookhagen, Bodo

    2016-04-01

    This study analyzes multiple topographic datasets derived from various remote-sensing methods from the Pocitos Basin of the central Puna Plateau in northwest Argentina at the border to Chile. Here, the arid climate and clear atmospheric conditions and lack of vegetation provide ideal conditions for remote sensing and Digital Elevation Model (DEM) comparison. We compare the following freely available DEMs: SRTM-X (spatial resolution of ~30 m), SRTM-C v4.1 (90 m), and ASTER GDEM2 (30 m). Additional DEMs for comparison are generated from optical and radar datasets acquired freely (ASTER Level 1B stereo pairs and Sentinal-1A radar), through research agreements (RapidEye Level 1B scenes, ALOS radar, and ENVISAT radar), and through commercial sources (TerraSAR-X / TanDEM-X radar). DEMs from ASTER (spatial resolution of 15 m) and RapidEye (~5-10 m) optical datasets are produced by standard photogrammetric techniques and have been post-processed for validation and alignment purposes. Because RapidEye scenes are captured at a low incidence angle (validated against over 400,000 differential GPS (dGPS) measurements gathered during four field campaigns in 2012 and 2014 to 2016. Of these points, more than 250,000 lie within the Pocitos Basin with average vertical and horizontal accuracies of 0.95 m and 0.69 m, respectively. Dataset accuracy is judged by the lowest standard deviations of elevation compared with the dGPS data and with the SRTM-X control DEM. Of particular interest in the field of quantitative geomorphology are topometrics (e.g., relief, channel steepness, and hillslope concavity) derived from the DEMs. The accuracy of these metrics is partly dependent on the overall DEM accuracy, but also on the accuracy of the depiction of the river network (a small areal fraction of the DEM). In addition, several topometrics depend on the first and second derivative of elevation (slope and curvature), which are affected by DEM accuracy and noise. In light of these issues

  14. Asociación Thysanoptera (Insecta-Vicia faba (Fabaceae en la Prepuna y Puna de Jujuy, Argentina Thysanoptera (Insecta-Vicia faba (Fabaceae association in Prepuna and Puna in Jujuy, Argentina

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    María Inés Zamar

    2012-03-01

    . occidentalis utilizan la planta en forma temporal y oportunista en Prepuna, mientras que la presencia de F. gemina en Puna es esporádica. Se amplía el número de especies de tisanópteros asociadas al cultivo de haba en ArgentinaThysanoptera (Insecta-Vicia faba (Fabaceae association in Prepuna and Puna in Jujuy, Argentina. The different phenological stages of Vicia faba provide food resources and substrates for the development of a significant diversity of insects. This study aimed to identify the complex of anthophyllous thrips, analyze the species population fluctuations, to obtain some bioecological aspects and the role they play in this association. The study and sampling was conducted during the flowering-fruiting bean crop stages in two phytogeographical regions of Jujuy: Prepuna (2 479m asl on a weekly basis, from October-December 1995-1996 and Puna (3 367m asl every two weeks, from December 2007-March 2008. Each sample consisted of 25 flowers taken at random; only at Prepuna a complementary sampling of three hits per plant (n=10 plants was conducted. Observations were made on oviposition sites, admission to the flower, pupation sites, feeding behavior and injuries caused. In Prepuna, the Thysanoptera complex consisted of Frankliniella australis, F. occidentalis, F. gemina, F. schultzei and Thrips tabaci; in Puna, the specific diversity was restricted to F. australis and F. gemina. Although the planting-harvest period in both areas did not match, the fluctuations in populations showed the same pattern: as flowering progressed, the number of thrips coincided with the availability of food resources. In both areas, F. australis was the dominant species and maintained successive populations; it layed eggs in flower buds, and larvae hatched when flowers opened; feeding larvae and adults brought about silvery stains with black spots. In Prepuna, F. australis went through the mobile immature stages on flowers, while quiescent stages were on the ground; in the Puna, all

  15. Teleseismic tomography of the southern Puna plateau in Argentina and adjacent regions

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    Bianchi, M.; Heit, B.; Jakovlev, A.; Yuan, X.; Kay, S. M.; Sandvol, E.; Alonso, R. N.; Coira, B.; Brown, L.; Kind, R.; Comte, D.

    2013-02-01

    We performed a teleseismic P wave tomography study using seismic events at both teleseismic and regional distances, recorded by a temporary seismic array in the Argentine Puna Plateau and adjacent regions. The tomographic images show the presence of a number of positive and negative anomalies in a depth range of 20-300 km beneath the array. The most prominent of these anomalies corresponds to a low-velocity body, located in the crust, most clearly seen in the center of the array (27°S, 67°W) between the Cerro Peinado volcano, the Cerro Blanco caldera and the Farallon Negro in the east. This anomaly (southern Puna Magmatic Body) extends from the northern most part of the array and follows the line with the highest density of stations towards the south where it becomes smaller. It is flanked by high velocities on the west and the east respectively. On the west, the high velocities might be related to the subducted Nazca plate. On the northeast the high velocity block coincides with the position of the Hombre Muerto basin in the crust and could be indicating an area of lithospheric delamination where we detected a high velocity block at 100 km depth on the eastern border of the Puna plateau, north of Galan. This block might be related to a delamination event in an area with a thick crust of Paleozoic metamorphic rocks at the border between Puna and Eastern Cordillera. In the center of the array the Southern Puna magmatic body is also flanked by high velocities but the most prominent region is located on the east and is interpreted as part of the Sierras Pampeanas lithosphere with high velocities. The position of the Sierras Pampeanas geological province is key in this area as it appears to limit the extension of the plateau towards the south.

  16. Nódulos opalinos en facies marginales del salar Olaroz (Puna Argentina

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    Alonso, R.

    1989-04-01

    Full Text Available This article reports the results of a petrological and geochemical study of silica nodules from Quaternary alluvial fallS of the Olaroz Salar. The nodules are mainly constituted by C-T opal, d. (101 spacing to 4,11 A, implying a high-disorder; this is commonly observed in opa! rocks formed in near surface environments, without burial and heating. The chemical composition of the nodules is anomalous when compared with other typical silica-rocks formed in arid continental closed basin, without any eruptive environments (for instance the Cuenca del Tajo in Spain. The siliceous nodules do not have the characteristics of the silcretes and are not associated to the evaporitic facies of the salar. Their genesis is probably related to contamination of groundwater of the alluvial fan with high-silica thermal water. The C-T opal would thus precipitate by either displacing tbe terrigenous host-rock or replacing previous ulexite nodules.Se realiza un estudio petrológico y geoquímico de los nódulos silíceos que se encuentran incluidos en sedimentos terrígenos cuaternarios de la Cuenca de Olaroz (La Puna, Argentina. Estos nódulos se localizan en abanicos aluviales que aparecen encajados, debido a los cambios en el nivel de base que se produce desde el Pleistoceno a la actualidad, durante la evolución de los cuerpos lacustres a salares. Un estudio mediante DRX revela que son rocas constituidas por ópalo C-T, con un espaciado (101 a 4,11 A, que implica un grado de desorden alto, típico de las rocas silíceas formadas en superficie y que no han sufrido enterramiento ni influencia térmica. Su composición química es anómala si se compara con rocas silíceas continentales formadas en ambiente endorreico y fuera de un marco volcánico (Mioceno de la Cuenca del Tajo. No poseyendo características de silcretas y no estando asociadas a la sedimentación evaporítica de los salares, se considera la influencia de aguas termales. La contaminación local y en

  17. Structural control on geothermal circulation in the Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Argentina)

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    Giordano, Guido; Pinton, Annamaria; Cianfarra, Paola; Baez, Walter; Chiodi, Agostina; Viramonte, José; Norini, Gianluca; Groppelli, Gianluca

    2013-01-01

    The reconstruction of the stratigraphical-structural framework and the hydrogeology of geothermal areas is fundamental for understanding the relationships between cap rocks, reservoir and circulation of geothermal fluids and for planning the exploitation of the field. The Cerro Tuzgle-Tocomar geothermal volcanic area (Puna plateau, Central Andes, NW Argentina) has a high geothermal potential. It is crossed by the active NW-SE trans-Andean tectonic lineament known as the Calama-Olacapato-Toro (COT) fault system, which favours a high secondary permeability testified by the presence of numerous springs. This study presents new stratigraphic and hydrogeological data on the geothermal field, together with the analysis from remote sensed image analysis of morphostructural evidences associated with the structural framework and active tectonics. Our data suggest that the main geothermal reservoir is located within or below the Pre-Palaeozoic-Ordovician basement units, characterised by unevenly distributed secondary permeability. The reservoir is recharged by infiltration in the ridges above 4500 m a.s.l., where basement rocks are in outcrop. Below 4500 m a.s.l., the reservoir is covered by the low permeable Miocene-Quaternary units that allow a poor circulation of shallow groundwater. Geothermal fluids upwell in areas with more intense fracturing, especially where main regional structures, particularly NW-SE COT-parallel lineaments, intersect with secondary structures, such as at the Tocomar field. Away from the main tectonic features, such as at the Cerro Tuzgle field, the less developed network of faults and fractures allows only a moderate upwelling of geothermal fluids and a mixing between hot and shallow cold waters. The integration of field-based and remote-sensing analyses at the Cerro Tuzgle-Tocomar area proved to be effective in approaching the prospection of remote geothermal fields, and in defining the conceptual model for geothermal circulation.

  18. Fluid geochemistry of a deep-seated geothermal resource in the Puna plateau (Jujuy Province, Argentina)

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    Peralta Arnold, Y.; Cabassi, J.; Tassi, F.; Caffe, P. J.; Vaselli, O.

    2017-05-01

    This study focused on the geochemical and isotopic features of thermal fluids discharged from five zones located in the high altitude Puna plateau (Jujuy Province between S 22°20‧-23°20‧ and W 66°-67°), i.e. Granada, Vilama, Pairique, Coranzulí and Olaroz. Partially mature waters with a Na+-Cl- composition were recognized in all the investigated zones, suggesting that a deep hydrothermal reservoir hosted within the Paleozoic crystalline basement represents the main hydrothermal fluid source. The hydrothermal reservoirs are mainly recharged by meteoric water, although based on the δ18O-H2O and δD-H2O values, some contribution of andesitic water cannot be completely ruled out. Regional S-oriented faulting systems, which generated a horst and graben tectonics, and NE-, NW- and WE-oriented transverse structures, likely act as preferentially uprising pathways for the deep-originated fluids, as also supported by the Rc/Ra values (up to 1.39) indicating the occurrence of significant amounts of mantle He (up to 16%). Carbon dioxide, the most abundant compound in the gas phase associated with the thermal waters, mostly originated from a crustal source, although the occurrence of CO2 from a mantle source, contaminated by organic-rich material due to the subduction process, is also possible. Relatively small and cold Na+-HCO3--type aquifers were produced by the interaction between meteoric water and Cretaceous, Palaeogene to Miocene sediments. Dissolution of evaporitic surficial deposits strongly affected the chemistry of the thermal springs in the peripheral zones of the study area. Geothermometry in the Na-K-Ca-Mg system suggested equilibrium temperatures up to 200 °C for the deep aquifer, whereas lower temperatures (from 105 to 155 °C) were inferred by applying the H2 geothermometer, likely due to re-equilibrium processes during the thermal fluid uprising within relatively shallow Na-HCO3 aquifers. The great depth of the geothermal resource (possibly > 5000 m

  19. Elastic stress interaction between faulting and volcanism in the Olacapato-San Antonio de Los Cobres area (Puna plateau, Argentina)

    Science.gov (United States)

    Bonali, F. L.; Corazzato, C.; Tibaldi, A.

    2012-06-01

    We describe the relationships between Plio-Quaternary tectonics, palaeoseismicity and volcanism along the NW-trending Calama-Olacapato-El Toro (COT) lineament that crosses the Andean chain and the Puna Plateau and continues within the eastern Cordillera at about 24° S. We studied in detail the area from the Chile-Argentina border to a few km east of the San Antonio del Los Cobres village. Satellite and field data revealed the presence of seven Quaternary NW-striking normal left-lateral fault segments in the southeastern part of the studied area and of a Plio-Quaternary N-S-striking graben structure in the northwestern part. The NW-striking Chorrillos fault (CF) segment shows the youngest motions, of late Pleistocene age, being marked by several fault scarps, sag ponds and offset Quaternary deposits and landforms. Offset lavas of 0.78 ± 0.1 Ma to 0.2 ± 0.08 Ma indicate fault kinematics characterised by a pitch angle of 20° to 27° SE, a total net displacement of 31 to 63.8 m, and a slip-rate of 0.16 to 0.08 mm/yr. This fault segment is 32 km long and terminates to the northwest near a set of ESE-dipping thrust faults affecting Tertiary strata, while to the southeast it terminates 10 km further from San Antonio. In the westernmost part of the examined area, in Chile at altitudes > 4000 m, recent N-S-striking normal fault scarps depict the 5-km-wide and 10-km-long graben structure. Locally, fault pitches indicate left-lateral normal kinematics. These faults affect deposits up to ignimbrites of Plio-Quaternary age. Scarp heights are from a few metres to 24 m. Despite that this area is located along the trace of the COT strike-slip fault system, which is reported as a continuous structure from Chile to Argentina in the literature, no evidence of NW-striking Plio-Quaternary strike-slip structures is present here. A series of numerical models were also developed in an elastic half-space with uniform isotropic elastic properties using the Coulomb 3.1 code. We studied

  20. New U-Pb ages in the Diablillos Intrusive Complex, Southern Puna, Argentina: A long magmatic event in the Paleozoic Arc, SW Gondwana

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Agustin; Hauser, Natalia [Universidade de Brasilia (UnB), DF (Brazil). Instituto de Geociencias. Lab. de Geocronologia; Becchio, Raul; Nieves, Alexis; Suzano, Nestor [Universidad Nacional de Salta (UNSa)-CONICET, Salta (Argentina)

    2015-07-01

    The Puna geological region comprises Salta, Jujuy and Catamarca provinces, northwestern Argentina. This 4000 meter above sea level high-plateau region lies between the Central Argentinian Andes. The Puna basement in the central Andes consists of Proterozoic–Paleozoic metamorphic rocks and granitoids. Diverse authors, proposed different models to explain the origin of the basement, where two orogenic events are recognized: the Pampean (Upper Precambrian–Lower Cambrian) and Famatinian (Upper Cambrian–Lower Silurian) (e.g. Ramos et al., 1986; Ramos, 1988; Loewy et al., 2004; for opposite points of view see Becchio et al., 1999; Bock et al., 2000; Buttner et al., 2005). Hence, Lucassen et al. (2000) proposed for the Central Andean basement, an evolution in a mobile belt, where the Pampean and Famatinian cycles are not distinct events but, they are one single, non-differentiable event from 600 to 400 Ma. The mobile belt culminated in low-P/ high-T metamorphism at approximately 525-500 Ma. Then, these were followed by a long-lasting high-thermal gradient regime in the mid-crust until Silurian times. Becchio et al., (2011) defined the Diablillos Intrusive Complex (CID, by its Spanish name), emplaced in the Inca Viejo Range. This range splits the Salares Ratones-Centenario with the Salar Diablillos (Fig.1). This Complex is located in the Eastern Magmatic Belt, Southern Puna, Argentina. Here we present new zircons U-Pb ages by LA-MC-ICPMS in the Diablillos Intrusive Complex, contributing to understanding the magmatic event in the lower Paleozoic arc, SW Gondwana. (author)

  1. Evapofacies del Salar Hombre Muerto, Puna argentina: distribucion y genesis Evapofacies associated with the Salar Hombre Muerto, Puna: Distribution and genesis

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    D. Vinante

    2006-06-01

    Full Text Available En el presente trabajo se identifican, describen y se muestra la distribución areal de las facies y evapofacies asociadas al ambiente evaporítico del Salar Hombre Muerto, ubicado en el borde oriental de la Puna Austral, en una zona con una amplia difusión de yacimientos de boratos. El salar puede ser dividido en dos subcuencas, la occidental y la oriental, ambas separadas por el islote central de Farallón Catal. La subcuenca oriental es boratífera, con bajo contenido en cloruros, mientras que la subcuenca occidental presenta tanto en superficie como en profundidad potentes acumulaciones de halita (hasta 900 m y es prácticamente estéril en boratos. Se plantean varias hipótesis sobre la génesis de la evapofacies boratífera, representada mineralógicamente por el borato ulexita. Esta es la evapofacies de interés económico y que se explota en el salar, donde además se extraen salmueras de litio.This paper identifies, describes and shows the areal distribution of facies and evapofacies associated with Salar Hombre Muerto, located in the eastern border of the Southern Puna, in an area with a wide diffusion of borates. The salar can be divided in two sub-basins, the western and the eastern, both separate for the central island of Farallón Catal. The eastern sub-basin is boratiferous, with low chlorides contained, while the western one shows a thick halite accumulation (up to 900 m in surface and in depth and it is practically sterile in borates. Several hypothesis on the genesis of the boratiferous evapofacies, minerallogically represented by the borate ulexite, are proposed. This evapofacies is the economic interest mined area, where lithium brines are also extracted.

  2. PRIMER REGISTRO PREHISPÁNICO DE OBSIDIANAS EN EL PIEDEMONTE MERIDIONAL DE LA PROVINCIA DE TUCUMÁN (ARGENTINA: ANÁLISIS TECNOLÓGICO Y DE PROCEDENCIA / First pre Hispanic record of obsidian in the southern foothill of the Tucuman province (Argentina: tech

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    Gabriel Eduardo Miguez

    2015-06-01

    Full Text Available En este trabajo se presentan los resultados del estudio realizado sobre restos de obsidiana, los cuales constituyen los primeros registrados en contextos arqueológicos de las selvas meridionales de la provincia de Tucumán. Estos materiales fueron recuperados en capas estratigráficas del primer milenio D.C. correspondientes al sitio Santa Rosa, el cual se ubica en la base de las laderas orientales de la Sierra del Aconquija (Tucumán, Argentina. Se realizó un análisis técnico-morfológico de los especímenes, en conjunto con un análisis geoquímico mediante fluorescencia de rayos X (FRX para determinar la procedencia geográfica de los materiales de obsidiana. Los resultados determinaron que la materia prima de la muestra, compuesta exclusivamente por desechos de talla, procede de la cantera de Ona-Las Cuevas, la cual se ubica a ca.270 km al noroeste del sitio Santa Rosa, en el norte de la provincia de Catamarca, en la Puna meridional argentina. La gran distancia sitio-cantera nos lleva a proponer que las comunidades prehispánicas de estas tierras bajas habrían participado de esferas estables de interacción con grupos de áreas muy distantes, propiciando la circulación e intercambio de obsidianas dentro de la porción meridional del NO de Argentina. Abstract In this paper we present the results of the study conducted on obsidian specimens, which constitutes the first record of this kind in archaeological contexts of the southern forests of the province of Tucumán are presented. These materials were recovered in stratigraphic layers of the first millennium AD of the Santa Rosa site, which is located at the base of the eastern slopes of the Sierra del Aconquija (Tucumán, Argentina. A techno-morphological analysis of specimens in conjunction with geochemic alanalysis using X-ray fluorescence (XRF was performed to determine the geographical provenance of obsidian archaeological materials. Results determined that the sample raw material

  3. The role of magma mixing in the evolution of the Early Paleozoic calc-alkaline granitoid suites. Eastern magmatic belt, Puna, NW Argentina

    Science.gov (United States)

    Suzaño, Néstor; Becchio, Raúl; Sola, Alfonso; Ortiz, Agustín; Nieves, Alexis; Quiroga, Mirta; Fuentes, Gabriela

    2017-07-01

    The outcrops of the Eastern magmatic belt in Puna, NW Argentina, offer an excellent field laboratory to study the interaction processes between magmas of contrasting composition in a plutonic environment. We evaluate the genesis of Cambrian-Ordovician intermediate to acid rocks from the Diablillos Intrusive Complex and the Cerro Bayo area, through detailed geological, petrographic, mineralogical, geochemical, and Nd isotopic analyses in combination with published data. These localities display a great variety of magmatic rocks from diorite/Qz-diorite to two-mica syenogranites with tonalite, granodiorite, monzogranite and Bt-Ttn-leucogranites as mixed products. Major, trace element and whole-rock Nd isotope modeling and petrological data, suggests that magma mixing between hydrous juvenile mantle- and crustal-derived magmas contributed significantly to the geochemical variation of these granites. The estimated proportion of mafic component 0.40-0.67 and 0.14-0.35 in the mixtures may produce the tonalite-granodiorites and monzogranites magmas. The mixing model excludes the predominant influence of fractional crystallization from a mafic magma and local assimilation-fractional-crystallization processes. Isotopic and geochemical comparison between the studied rocks and the magmatic belts in Puna and Tastil batholith suites reveals a marked resemblance. The data suggests that those rocks were probably generated by magma mixing and denotes a regionally and continuous process in a long-lasting (∼540-440 Ma) active continental margin. We propose that partial melting of the crust and magma mixing occurred in the lower crust and was possibly triggered by underplated and intraplated hydrous (4.37-5.91 wt% H2O) mafic magmas. The hybrid magmas were emplaced at shallow depth (∼8-9 km, 684-727 °C) and occasionally injected either by synplutonic-to late successive pulses of mafic magmas.

  4. Chironomidae (Diptera en cursos de agua de Puna y Chaco Serrano de Catamarca (Argentina: primeros registros y distribución de géneros y especies

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    Gretel N. RODRÍGUEZ GARAY

    2015-01-01

    Full Text Available La distribución en América del Sur (Region Neotropical de Stictocladius prati Saether & Cranston, Podonomus. regalis Brundin y P. setosus Brundin 1966 es ampliada a partir de primeros registros de la Argentina. Podonomus fastigians Brundin, y Allocladius quadrus Andersen et al. se citan por primera vez de Catamarca Se describe el morfotipo pupal de Barbadocladius sp. “Chaco” (cerca de B. andinus Cranston & Krosh. Se incorporan las variables ambientales de los cursos de agua donde se registraron las especies. Los ríos de Puna presentan aguas muy alcalinas, pH (8.12-8.8, alta conductividad y alto contenido en MO, mientras que el arroyo de Chaco Serrano es de aguas débilmente alcalinas, pH (7, baja conductividad y bajo contenido en materia orgánica (MO. Las especies Stictocladius prati, Allocladius quadrus, Podonomus fastigians, P. setosus y P. regalis estuvieron presentes en ríos de altura con aguas alcalinas y alta conductividad, mientras Barbadocladius sp. “Chaco” se registró en un arroyo de menor altura, con aguas de baja alcalinidad y conductividad.

  5. Continuidades e hiatos ocupacionales durante el holoceno medio en el borde oriental de la puna salada, Antofagasta de la Sierra, Argentina

    National Research Council Canada - National Science Library

    Pintar, Elizabeth

    2014-01-01

    ...) durante el Holoceno Medio, un periodo de aridez generalizada en toda la Puna. Esta cueva fue un espacio optimo donde grupos cazadores- recolectores realizaron actividades de subsistencia (caza y recoleccion...

  6. A geothermal resource in the Puna plateau (Jujuy Province, Argentina): New insights from the geochemistry of thermal fluid discharges

    Science.gov (United States)

    Peralta Arnold, Yesica; Cabassi, Jacopo; Tassi, Franco; Caffe, Pablo; Vaselli, Orlando

    2017-04-01

    Several hydrothermal mineralization and thermal fluid discharges are distributed in the high altitude Puna plateau at the eastern border of the Central Volcanic Zone of the Andes in the Jujuy Province, a region where volcanic explosive activity developed from Oligocene-Miocene to Neogene produced giant calderas and huge ignimbrite deposits. This study presents the geochemical and isotopic composition of thermal fluids discharged from Granada, Vilama, Pairique, Coranzulì and Olaroz zones, which are located between S 22°20'- 23°20' and W 66°- 67°. This aim is to provide insights into the physicochemical features of the deep fluid circulating system in order to have a preliminary indication about the geothermal potential in this area. The occurrence of partially mature Na+-Cl- waters suggests that a deep (>5,000 m b.g.l.) hydrothermal reservoir, hosted within the Paleozoic crystalline basement, represents the main fluid source. Regional tectonics, dominated by S-oriented faulting systems that produced a horst and graben tectonics, as well as NE-, NW- and WE-oriented transverse structures, favour the uprising of the deep-originated fluids, including a significant amount (up to 16%) of mantle He. The dry gas phase mainly consists of CO2 mostly produced from subducted C-bearing organic-rich material. The interaction between meteoric water and Cretaceous, Palaeogene to Miocene sediments at shallow depth gives rise to relatively cold Na+-HCO3-type aquifers. Dissolution of evaporitic surficial deposits (salares), produced by the arid climate of the region, strongly affects the chemistry of the thermal springs in the peripheral zones of the study area. Geothermometry in the Na-K-Ca-Mg system suggests equilibrium temperatures up to 200 °C for the deep aquifer, whereas the H2 geothermometer equilibrates at lower temperatures (from 105 to 155 °C), likely corresponding to those of the shallower aquifer. Although the great depth of the main fluid reservoir represents a

  7. Un universo de formas, colores y pinturas: Caracterización del estilo alfarero yavi de la puna nororiental de Jujuy A Universe Of Form, Color And Paintings: A Characterization Of The Yavi Pottery Style From The Eastern Puna Of Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    Florencia Ávila

    2008-12-01

    Full Text Available En el presente trabajo presentaremos una sistematización y análisis del estilo alfarero yavi de la Puna nororiental de Jujuy. Nuestro objetivo es brindar un marco de referencia de la variación morfológica, cromática y pictográfica que presenta este estilo. La línea de evidencia que emplearemos para llevar a cabo el análisis, será la documentación y registro de piezas cerámicas enteras correspondientes a esta entidad. Las mismas se encuentran distribuidas en diversos museos y colecciones de distintas instituciones y museos de Argentina. Como fin último, buscaremos establecer qué atributos se toman en cuenta para identificar a una pieza como yavi y cómo se ponen en juego en su conformación, para así evaluar la unidad perceptiva que caracteriza al estilo.In this paper the Yavi ceramic style from the Northeastern Puna of Jujuy, Argentina, is systematized and analyzed. The goal is to offer a characterization of the morphological, chromatic, and pictographic variation that this style presents. The study is based on the analysis of over two hundred whole vessels that belong to this style. These are distributed across various museums and collections in different parts of Argentina. The study aims to establish which attributes should be included to classify a vessel as Yavi and how these are combined in order to define the perceptive unity that characterizes the style.

  8. Sistema de asentamiento prehispánico en la sierra meridional de Chañi (Salta, Argentina

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    Christian Vitry

    2007-01-01

    Full Text Available El área de investigación se ubica en el sector meridional de la Sierra de Chañi, Provincia de Salta, República Argentina. La estructura espacial y distribucional de los sitios arqueológicos en el área de estudio y sistemas montañosos aledaños posee un gran potencial informativo. Estos atributos cualicuantitativos nos permiten estudiar la variabilidad y complejidad del sistema de asentamiento en la región. Nuestro abordaje parte desde las perspectivas de la evolución del paisaje cultural y el proceso de cambio geopolítico. El registro arqueológico presente en el área de estudio manifiesta una recurrencia con relación al sistema de asentamiento, para el cual proponemos un modelo hipotético de ocupación del espacio durante los períodos de Desarrollos Regionales e Inka. Durante estos períodos analizamos la interacción de las diferentes formas de poder y posibles situaciones emergentes de desigualdad social

  9. Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24°37'S, 67°03'W)

    Science.gov (United States)

    Strecker, Manfred; Bookhagen, Bodo; Freymark, Jessica; Pingel, Heiko; Alonso, Ricardo N.

    2015-04-01

    Similar to other Cenozoic orogenic plateaus, extensional tectonics associated with mafic volcanism typifies the Altiplano-Puna of the southern Central Andes, while the flanks of the plateau and adjacent foreland areas experience shortening. Extensional tectonism in the plateau region since the late Miocene has been explained with delamination of lithospheric mantle. However, new evidence for protracted basin-wide shortening in the Salar de Pocitos region in the south-central Puna documents that the kinematic changeover from shortening to extension is highly diachronous. In this study we assess the deformation and geomorphic history of the Salar de Pocitos region using DGPS surveys, CRN dating of deformed pediment surfaces, and U/Pb dating of volcanic ash horizons in deformed strata. With average elevations of about 3.7 km the Altiplano-Puna is a first-order morphotectonic province of the southern central Andes and constitutes the world's second largest orogenic plateau. With few exceptions the Andean plateau consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by reverse-fault bounded ranges, 5 to 6 km high. While there are many unifying plateau characteristics in the Altiplano (north) and Puna (south), including internal drainage, semi-arid to arid climate and associated deposition of evaporites, there are notable differences between both plateau sectors. In contrast to the vast Altiplano basin of Bolivia, the Argentine Puna comprises numerous, smaller and partly coalesced basins that reflect continued comparmentalization by the combined effects of tectonism and volcanic activity. The N-S oriented Salar de Pocitos basin is the vestige of a formerly contiguous sedimentary basin within the Puna interior. Unlike many other basins in this region it is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the eastern border is a reverse-faulted range front. To the north and south the

  10. Miocene to present-day shortening and intermontane basin formation in the Andean Puna Plateau, NW Argentina (24°30'S)

    Science.gov (United States)

    Strecker, M. R.; Bookhagen, B.; Alonso, R. N.; Pingel, H.; Freymark, J.

    2015-12-01

    With average elevations of about 3.7 km the Altiplano-Puna Plateau of the southern central Andes constitutes the world's second largest orogenic plateau. The plateau generally consists of internally drained, partly coalesced sedimentary basins bordered by reverse-fault bounded ranges, >5 km high. In the Puna, the Argentine sector of the plateau, active tectonism has been interpreted to be characterized by a low level of strike-slip and normal faulting associated with mafic volcanism. In contrast, the eastern plateau margins and the adjacent foreland record a higher level of seismicity and ongoing contraction. Despite ubiquitous Plio-Pleistocene normal faulting along the eastern plateau margins, our new observations record contraction in the plateau interior. Fanning of E-dipping Miocene sedimentary strata involved in the formation of an anticline in the Pocitos Basin of the central Puna interior indicates growth, which must have begun after 7 Ma; 1.5-m.y.-old lacustrine strata as well as tilted Pleistocene lacustrine shorelines associated with this structure indicate sustained uplift into the Quaternary. Corresponding observations along the eastern border of the Pocitos Basin show that <3.5-m.y.-old strata are involved in contractile deformation and basin compartmentalization. Shortening in the central Puna is compatible with Plio-Pleistocene shortening in the low-elevation Salar de Atacama farther west, and may indicate that low-elevation sectors of the plateau have not yet reached a critical elevation that is conducive to normal faulting as observed elsewhere. The onset of extensional deformation in the Puna is thus highly disparate in space and time. Coeval regional thrusting, strike-slip, and normal faulting do not support a structural and topographic setting that promotes wholesale extension and orogenic collapse of the plateau realm.

  11. A Middle Miocene (13.5-12 Ma) deformational event constrained by volcanism along the Puna-Eastern Cordillera border, NW Argentina

    Science.gov (United States)

    Aramayo, Alejandro; Guzmán, Silvina; Hongn, Fernando; del Papa, Cecilia; Montero-López, Carolina; Sudo, Masafumi

    2017-04-01

    The features of Middle Miocene deposits in the Puna-Eastern Cordillera transition (Valles Calchaquíes) indicate that Cenozoic deformation, sedimentation and volcanism follow a complex spatiotemporal relationship. The intense volcanic activity recorded in the eastern Puna border between 14 and 11.5 Ma coincides with the occurrence of one of the most important deformation events of the Neogene tectonic evolution in the region. Studies performed across the Puna-Eastern Cordillera transition show different relationships between volcanic deposits of ca. 13.5-12.1 Ma and the Oligocene-Miocene Angastaco Formation. In this paper we describe the ash-flow tuff deposits which are the first of this type found concordant in the sedimentary fill of Valles Calchaquíes. Several analyses performed on these pyroclastic deposits allow a correlation to be made with the Alto de Las Lagunas Ignimbrite (ca. 13.5 Ma) of the Pucarilla-Cerro Tipillas Volcanic Complex located in the Puna. Outcrops of the ca. 13.5 Ma pyroclastic deposits are recognised within the Puna and the Valle Calchaquí. However, in the southern prolongation of the Valle de Hualfín (Tiopampa-Pucarilla depression) that separates the Puna from the Valle Calchaquí at these latitudes, these deposits are partially eroded and buried, and thus their occurrence is recorded only by abundant volcanic clasts included in conglomerates of the Angastaco Formation. The sedimentation of the Angastaco Formation was aborted at ca. 12 Ma in the Tiopampa-Pucarilla depression by the Pucarilla Ignimbrite, which unconformably covers the synorogenic units. On the contrary, in the Valle Calchaquí the sedimentation of the Angastaco Formation continued until the Late Miocene. The different relationships between the Miocene Angastaco Formation and the ignimbrites with ages of ca. 13.5 and ca. 12 Ma reveal that in this short period ( 1.5 m.y.) a significant deformation event took place and resulted in marked palaeogeographic changes, as

  12. Diagnóstico de situación de la equinococosis quística en heces dispersas en las zonas de Quebrada y Puna, provincia de Jujuy, Argentina

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    Silvia Frison de Costas

    Full Text Available La equinococosis es una enfermedad parasitaria común en el ganado, causada por el cestode Echinococcus granulosus; el perro es su principal hospedador definitivo. La provincia de Jujuy es un área endémica, situada en el ángulo noroeste de la República Argentina. Las condiciones ecológicas restringidas de Quebrada y Puna hacen que la actividad más importante de la población sea la pecuaria formal pastoril y trashumante, especialmente dedicada a ovinos y camélidos. El perro adquiere en estas comunidades una doble función de compañía y como pastor. El objetivo del presente estudio fue realizar un diagnóstico de situación en las áreas de Quebrada y Puna, donde se sospecha que hay circulación de E. granulosus. Desde 2002 hasta 2012 se recolectaron 523 muestras de materia fecal de canino dispersas en el ambiente. Las prevalencias variaron desde un 2 % en Susques hasta un 27,7 % (la mayor de la provincia en Humahuaca. Tumbaya presentó una prevalencia del 21 % en 2007, llegó a 0 % en 2010, pero volvió a aumentar al 10,5 % en 2011. La disminución observada durante 2010 puede explicarse en el hecho de que las muestras se tomaron en localidades donde se había realizado educación sanitaria previamente. En el resto de las regiones estudiadas se observaron prevalencias entre 2 % y 19,4 %. Estos resultados sugieren que la falta de estrategias para el control de la equinococosis ha permitido la dispersión de la enfermedad.

  13. Desarrollo de un proyecto agrícola en la región marginal de la Patagonia Meridional Argentina. El caso de Gobernador Gregores

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    María Eugenia Cepparo de Grosso

    2012-02-01

    Full Text Available Santa Cruz, provincia ubicada en el extremo sur del territorio continental argentino, posee un ambiente fuertemente condicionado por la fragilidad de sus características naturales y una situación socioeconómica tradicionalmente orientada a la monoactividad ganadera en el área rural y a los servicios públicos en los centros urbanos. En ese marco, y durante la década de 1990, surgió una iniciativa apoyada por organismos del Estado y financiada por bancos provinciales para estimular un proyecto agrícola adaptado a las limitadas aptitudes agrícolas de la región. Un reducido número de agricultores, inquietos por generar actividades que diversificaran el tradicional modelo pastoril, experimentaron los dilemas de los comienzos y las crisis de un proyecto de estímulo económico en un territorio marginal. Este trabajo contribuye con una serie de reflexiones acerca de las motivaciones que justifican el estudio de pequeñas sociedades en áreas marginales; de la confrontación entre el marco conceptual de la marginalidad según los países centrales y los periféricos; y del accionar y el compromiso de los actores sociales motivados por una alternativa de desarrollo local en una localidad ubicada en el centro de la Patagonia Meridional Argentina.

  14. Genesis and Eruptive Dynamics of the Garnet-Bearing Rhyolites from the Ramadas Volcanic Centre (Altiplano-Puna Plateau, Central Andes, Argentina).

    Science.gov (United States)

    De Astis, G.; Baez, W.; Bardelli, L.; Becchio, R.; Giordano, G.; Lucci, F.; Rossetti, F.; Viramonte, J. G.

    2015-12-01

    Ramadas volcanic centre (6.6 Ma) is a monogenetic calderic depression, now largely obliterated, almost coeval with the Late Miocene outbreak of highly explosive silicic activity in the Altiplano-Puna plateau. Ramadas erupted a rather complex suite of garnet-bearing, rhyolitic pyroclastic rocks, dominated by a >35 km3 fall deposit and preceded by the emplacement of a lag breccia containing abundant metasedimentary lithics and garnet-tourmaline leucogranites. During the waning stage of the eruption, small volume phreatomagmatic deposits formed a small tuff-ring, followed by a lava coulée emplacement. Volcanological data together with textural features of typical tube pumice evidence a volatiles-rich, plinian eruption. Petrographic and textural studies on juveniles confirm the presence of euhedral garnet as dominant phase and identify micrometric metaigneous fragments (Qtz+Bt+Kfs+Mt+Tur). BSE imaging and microprobe analyses on glasses, garnets and accessory mineral phases (zircon and monazite) provide further data to understand the genesis and eruptive conditions of these atypical rhyolites, geochemically different from those outcropping in the same region. Garnets display a homogeneous, unzoned almandine-spessartine composition (Alm72-71Sps24-23Pyr0-1Grs4-3) and are contained in a glassy rhyolitic magma with peraluminous character, HREE depleted and relative LREE enriched. It's known that primary igneous garnets are rare and can only develop under restricted conditions. Additionally, the presence of Zr and Mnz is associated with both magmatic and high-T metamorphic processes. Although more data need to be collected, our study and preliminary modelling point to the occurrence of thermal metamorphism shifting to partial melting of Fe-MnO-rich metapelitic rocks (or even re-melting of older acid volcanics), with final extraction of volatiles-rich rhyolitic melts, able to produce a plinian eruption. Here, Alm-Sps garnet could represent the peritectic product of the

  15. Receiver function results from the PUDEL (PUna DELamination) Seismic Array in the Southern Puna plateau

    OpenAIRE

    Benjamin Heit; Xiaohui Yuan; Rainer Kind; Kay, S; E. Sandvol; Alonso, R; Coira, B.; Comte, D.

    2010-01-01

    A passive seismic array which operated between December 2007 and November 2010 has been deployed in the southern Puna plateau between 25°S to 28°S latitude and 65W to 70W longitude in Argentina and Chile to address fundamental questions on the processes that form, modify and destroy continental lithosphere and control lithospheric dynamics along Andean-type continental margins. This experiment consisted of 75 stations has been conducted by Argentine, Chilean, German and US scientists and was ...

  16. The origin of an unusual tuff ring of perlitic rhyolite pyroclasts: The last explosive phase of the Ramadas Volcanic Centre, Andean Puna, Salta, NW Argentina

    Science.gov (United States)

    Tait, M. A.; Cas, R. A. F.; Viramonte, J. G.

    2009-05-01

    A thick sequence of bedded pyroclastic deposits, comprised largely of crystal poor, partially flow-banded perlite fragments defines the remains of a tuff ring around the eastern margin of the Miocene Ramadas Volcanic Centre (RVC), Central Andes, NW Argentina. In numerous quarry exposures, planar bed-forms dominate, but low-angle cross-stratification, lensoidal truncations and lateral pinching and swelling of cm-dm scale bed-forms occur, consistent with pyroclastic surge as the dominant transport and depositional mechanism. Intercalated are mantling, very fine grained, well-sorted, mm-cm scale planar ash layers that represent deposition from pyroclastic fall out and are most likely the products of co-surge ash clouds. Also observed are thick m-scale, laterally continuous, poorly-sorted horizons that are interpreted as pyroclastic flow deposits. Grainsize variations within the > 70 m thick succession range from fine ash to coarse lapilli, with occasional large blocks reaching 20 cm. Clast vesicularities are typically very low. The sequence constitutes a rhyolitic tuff ring around the proximal margins of the RVC. Stratigraphic relationships indicate that the tuff ring was developed following cessation of the major plinian eruption phase of the RVC. A series of pyroclastic density currents and associated ash clouds is inferred to have resulted in the construction of the rhyolitic tuff ring, with deposition focussed on the eastern and southern margins of the central vent. The fine-grained nature of the deposits and low clast vesicularity are consistent with some degree of magma:water interaction during fragmentation. Pervasive perlitic fracturing of clasts found within the tuff deposits also indicates hydration and an extended, post-depositional hydration of the pyroclastic sequence, due to the influence of meteoric water, is likely to have occurred, with deposit permeability, clast specific surface and climate influential in facilitating additional textural

  17. Resultados del análisis arqueofaunístico de un basural, un recinto y un sector interrecinto del sitio Matancillas 2, Puna de Salta Archaeofaunal study of a dump, an enclosure, and an inter-enclosure sector in Matancillas 2 site, Puna of Salta (Argentina

    Directory of Open Access Journals (Sweden)

    Gabriel E. J. López

    2006-12-01

    Full Text Available Se analizan tres conjuntos arqueofaunísticos del sitio Matancillas 2 (Puna de Salta, provenientes de un basural, un recinto, y un sector interrecinto, con el objetivo de obtener información sobre el consumo de recursos faunísticos en esta población humana del Temprano (ca. 2000 AP. También se determinan sus grados de integridad, los cuales proporcionan información diferencial de cada conjunto. Las evidencias demuestran un rol principal del agente humano en la formación y modificación de los conjuntos, con claros indicadores de actividades vinculadas al consumo; esto especialmente en los especimenes de camélidos, absolutamente mayoritarios en las muestras. Asimismo, existiría un procesamiento integral de estos artiodáctilos, teniendo en cuenta la representación de casi todas sus partes esqueletarias. Por otra parte, la alta presencia de falanges y huesos del tarso, posiblemente se relacione a su bajísimo índice de fragmentación. Por último, se resalta que la diversidad taxonómica es muy baja, y los camélidos (tanto domesticados como silvestres fueron los recursos faunísticos principales para esta población del Temprano de la Puna.The present work analyzes three archaeofaunal assemblages from the Matancillas 2 site (Puna de Salta. They come from a dump, an enclosure, and an inter-enclosure sector. The objective is to obtain information about the consumption of faunal resources in the human population of the Early Period (ca. 2000 BP. Their degree of integrity was also determined, which gave differential information for each assemblage. The evidence shows the principal role of human agency in the formation and modification of the assemblages, which demonstrate with certainty activities related to consumption, especially in relation to camelid specimens that are the majority in the samples. These artiodactyls were fully processed, as almost every skeletal part was found; the elevated presence of phalanx and tarsus bones is

  18. ZOOARQUEOLOGÍA Y TAFONOMÍA DEL PERÍODO TARDÍO-INCA EN PEÑAS COLORADAS, ANTOFAGASTA DE LA SIERRA (PUNA DE CATAMARCA, ARGENTINA/Zooarchaeology and taphonomy of the Late Period-INCA in Peñas Coloradas, Antofagasta de la Sierra (Puna of Catamarca, Argentina

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    Jorge Guillermo Ortiz

    2012-11-01

    Full Text Available Se presenta el análisis integrado del conjunto arqueofaunístico, constituido por vertebrados e invertebrados, del sitio Peñas Coloradas 3-cumbre (PC3-c, Antofagasta de la Sierra (Catamarca, Argentina. El sitio se localiza en la cumbre de un farallón de ignimbrita y está conformado por estructuras arquitectónicas asignadas a momentos Tardíos-Incas, algunas de las cuales han sido reutilizadas hasta principios del siglo XX. Con la finalidad de complementar los datos y reconstruir la historia tafonómica de los conjuntos faunísticos, se estudió el contexto sedimentario mediante métodos físico-químicos (textura; pH; determinación de albúmina, P y MO. Los materiales analizados brindaron datos sobre algunas de las actividades realizadas en las estructuras, el consumo de animales, temporalidad, estacionalidad de las ocupaciones, y sobre los procesos diagenéticos actuantes. La integración contextual de los datos materiales analizados y del emplazamiento del sitio y sus estructuras, nos permite inferir prácticas sociales diferenciadas entre las estructuras con cubierta y sin cubierta. Las primeras, se vinculan a depósitos de alimentos y manufacturas, mientras que las segundas se asocian con  prácticas residenciales, procesamiento y consumo de alimentos. Abstract In this paper, an integrated analysis of archaeofaunal data consisting of vertebrates and invertebrates of the Peñas Coloradas 3-summit (PC3-c, Antofagasta de la Sierra (Catamarca, Argentina is conducted. The site is located at the top of an ignimbrite hill and is composed of architectural structures attributed to Late Inca times, some of which had been re-used until the early 20th century. In order to complement the data and reconstruct the taphonomic history of the faunal assemblages, we studied the sedimentary context by physicochemical methods (texture, pH, determination of albumin, P and MO. The material tested has provided data on some of the activities in the structures

  19. La construcción del patrimonio arqueológico en una comunidad de la puna de Jujuy, Argentina en tiempos de globalización La construcción del patrimonio arqueológico en una comunidad de la puna de Jujuy, Argentina en tiempos de globalización

    Directory of Open Access Journals (Sweden)

    Mónica Montenegro

    2009-12-01

    Full Text Available We share some thoughts on the building of the archaeological patrimony at an Altiplano community in northwestern Argentina.The tourist development programs that are being implemented in our province in recent years have given way to changes in the traditional way of life of the local communities. Some processes of patrimony activation have been emphasized which put into value the local resources within a global context.This dynamics is also shown in the educational community, who from certain pedagogic processes, it is actively inserted in the construction of the local patrimony. We value their representations on this process and reflexion on the archaeology, education, and community relationships.Compartimos reflexiones acerca de la construcción del patrimonio arqueológico, en una comunidad altiplánica del Noroeste Argentino (NOA.Los programas de desarrollo turístico que han venido implementándose en nuestra provincia en el transcurso de los últimos años, han motivado cambios en el modo tradicional de vida de las comunidades locales. Se han enfatizado ciertos procesos de activación patrimonial que valorizan los recursos locales en un contexto globalizado.Esta dinámica también se manifiesta en la comunidad educativa que, a partir de ciertos procesos pedagógicos, participa activamente de la construcción del patrimonio local. Rescatamos sus representaciones acerca de este proceso y reflexionamos sobre la relación entre arqueología, educación y comunidad.

  20. Argentina

    OpenAIRE

    Nogues, Julio J.

    2005-01-01

    After decades of being a marginal player in the GATT trade negotiations, Argentina decided to participate actively in the Uruguay Round. This chapter measures the imbalance between the concessions given and received and concludes that the value of the first are far more important than the second. I discusss the economic consequence of this imbalance, and the prospects that the outcome of the Doha Round can be more balanced outcome for Argentina.

  1. Cacao 3 (Cc 3, Arte rupestre del formativo temprano en Antofagasta de la Sierra, Catamarca, Argentina

    Directory of Open Access Journals (Sweden)

    Alvaro Rodrigo Martel

    2004-01-01

    Full Text Available En el presente trabajo hemos abordado el estudio de la producción del arte rupestre del sitio Cacao 3 –Cc3- (Antofagasta de la Sierra, Catamarca con relación a las prácticas socioculturales de grupos agropastoriles del periodo Formativo Temprano en la Puna meridional argentina, haciendo hincapié en el emplazamiento del sitio y su asociación contextual con las demás evidencias arqueológicas conocidas para el área de estudio y estableciendo las relaciones entre las manifestaciones rupestres de Cc3 con las de otros sitios, a nivel micro y macrorregional, a través de indicadores estilísticos

  2. Seismicity and average velocities beneath the Argentine Puna Plateau

    Science.gov (United States)

    Schurr, B.; Asch, G.; Rietbrock, A.; Kind, R.; Pardo, M.; Heit, B.; Monfret, T.

    A network of 60 seismographs was deployed across the Andes at ∼23.5°S. The array was centered in the backarc, atop the Puna high plateau in NW Argentina. P and S arrival times of 426 intermediate depth earthquakes were inverted for 1-D velocity structure and hypocentral coordinates. Average velocities and υp/υs in the crust are low. Average mantle velocities are high but difficult to interpret because of the presence of a fast velocity slab at depth. Although the hypocenters sharply define a 35° dipping Benioff zone, seismicity in the slab is not continuous. The spatial clustering of earthquakes is thought to reflect inherited heterogeneties of the subducted oceanic lithosphere. Additionally, 57 crustal earthquakes were located. Seismicity concentrates in the fold and thrust belt of the foreland and Eastern Cordillera, and along and south of the El Toro-Olacapato-Calama Lineament (TOCL). Focal mechanisms of two earthquakes at this structure exhibit left lateral strike-slip mechanisms similar to the suggested kinematics of the TOCL. We believe that the Puna north of the TOCL behaves like a rigid block with little internal deformation, whereas the area south of the TOCL is weaker and currently deforming.

  3. Argentina

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    This report presents a brief overview of the socio-economic, energy and environmental context in which climate change mitigation actions in Argentina shall be inserted. To that end, the dynamic of the Argentine economic development, its influence on the energy system and environmental impacts is summarised. From the environmental standpoint, emphasis shall only be made on the impact of economic development patterns and energy policies on GHG emission. (au) 73 refs.

  4. Argentina

    Directory of Open Access Journals (Sweden)

    Karina M. Michetti

    2007-01-01

    Full Text Available Draparnaldia mutabilis posee un talo compuesto por un sistema rizoidal postrado reducido y un sistema erguido que muestra una marcada diferenciación entre filamentos axiales y laterales, estos últimos agrupados en fascículos densos, altamente ramificados. La reproducción asexual ocurre por medio de zoósporas que poseen un patrón de germinación erguido. El registro de esta especie constituye la primera cita cierta para la República Argentina. Se presenta además, una clave con las especies mejor definidas.

  5. Argentina.

    Science.gov (United States)

    1993-02-01

    Background notes on Argentina provide a profile of the geography, selected demographic features, government and economic conditions. Descriptive text includes a discussion of the people, their history and political conditions, the government and officials, the state of the economy, their defense, foreign relations, and relations with the US. The 1992 estimated population was about 33 million of whom 97% are European (mostly Spanish and Italian). Religions represented are Roman Catholic (92%), Protestant (2%), Jewish (2%), and other (4%). Adult literacy is 95%. 36% are engaged in industry and commerce, 20% in services, 19% in agriculture, 6% in transport and communications, and 19% other. Per capita gross domestic product was $4,500. There are only 50,000 native Indians remaining in peripheral provinces. The population enjoys a high standard of living and a low growth rate. The country was shaped by dominant forces: modern agricultural techniques and the integration of the country into the world economy. Foreign investment aided the economic revolution. Conservative and radical rule has swung the country back and forth politically since 1916. Colonel Juan Domingo Peron led a successful military coup in 1943 and was elected in 1946. Policies were instituted to give a greater voice to the working class, and with the influences of his wife, women's groups. In 1955, he was ousted by the military, which failed to revive the economy and quiet increasing terrorism. After a number of difficult elections, Peron was reinstated as president in 1973. Extremists on the left and right threatened public order; the military as a consequence imprisoned persons indefinitely. Peron's wife succeeded him after his death, but was removed from office in the military coup of 1976. Basic human rights were violated during this period. By 1983, a fair election was held and support increased for a democratic system. In 1989, Carlos Saul Menem, a Peronist candidate, won and established

  6. Argentina

    Directory of Open Access Journals (Sweden)

    G. Benedetti

    2007-01-01

    Full Text Available El presente trabajo tiene como objetivo realizar un diagnóstico ambiental de un sector de la ciudad de Bahía Blanca, Argentina basado en el arbolado urbano de alineación. El arbolado constituye un componente fundamental de los paisajes artifi ciales ya que contribuye al aumento del confort y al mejoramiento de la calidad del medio. En este sentido, actúa como un factor moderador de las condiciones climáticas, la contaminación y la salud de la población. El municipio de la ciudad de Bahía Blanca tiene como proyecto la realización de inventarios del arbolado en los distintos barrios, para lograr optimizar la relación entre la cantidad de ejemplares arbóreos y la densidad poblacional. Es importante considerar la variedad de ejemplares en función del uso del suelo y de las características ambientales de cada sector. Por lo tanto, este trabajo presenta un diseño metodológico para la elaboración del plano verde de la ciudad.

  7. Argentina

    Directory of Open Access Journals (Sweden)

    Hernan Galperin

    2004-01-01

    Full Text Available En este trabajo se analizan las bases sobre las que se está desarrollando el proceso de transición hacia la TV digital en Brasil y Argentina, y se discuten las posibilidades que la transición presenta para replantear la estructura de mercado y el modelo de regulación de la TV abierta en los países del Mercosur. La principal hipótesis es que la TV digital abre una oportunidad única para reformar el actual modelo de radiodifusión basado en la concesión de un número reducido de licencias a operadores de tipo generalista. Al multiplicar la capacidad de transmisión y facilitar el desarrollo de servicios interactivos tanto de entretenimiento como educativos y de información, la transición a la TV digital se ofrece como instrumento de política pública para alcanzar objetivos clave en materia de comunicación, como el pluralismo, la apertura del mercado y el achicamiento de la llamada brecha digital.

  8. The uncertain future of Puna.

    Science.gov (United States)

    Madina, M

    1997-01-01

    Each week, the Asociacion Pro-Bienestar de la Familia Ecuadoriana (APROFE), the Ecuadorian family planning association, sends a boat carrying a physician, a psychologist, and a nurse to provide basic and reproductive health care to approximately 4000 inhabitants of isolated fishing villages in Puna where housing on six islands consists of wooden shacks. One island has a church and a school but no priest or teacher. The island women have an average of five children each and cannot recall their children's ages or birth dates. The UN Population Fund (UNFPA) supported the training of island midwives that has led to a dramatic improvement in infant mortality and morbidity rates. The islands must import their drinking water, and the inadequate supply and poor hygiene lead to illnesses that are hard to overcome. During an outbreak of cholera, the team visited every house to advise the residents to boil their water. The team son realized that the people were drinking boiling water to kill the germs. The settlements offer no communal activities beyond talking or, for the men, drinking together. The APROFE team has supervised the building of the first latrines in the communities and has organized a community Public Health Committee to mobilize the population to engage in community development. The APROFE team's efforts were supported from 1992-95 by the Dutch government and from 1995-96 by the UNFPA. With UNFPA funding nearing an end, APROFE is attempting to secure additional funding to continue to provide this population with the help they so desperately need.

  9. A seroepidemiological survey of HTLV-I/II carriers in the Puna Jujeña.

    Science.gov (United States)

    Dipierri, J E; Tajima, K; Cartier Robirosa, L; Sonoda, S

    1999-01-01

    Human T-cell leukemia virus type I (HTLV-I) carriers are clustered in limited groups in the world. One of these groups is the Andean native population of South America. As part of an international collaborative study devoted to explore the clustering of HTVL-I carriers in different countries, the aim of this paper was to evaluate the seroprevalence of HTLV-I/II virus in the native population of Puna Argentina in Jujuy. Blood samples of individuals of three populations of Puna Jujeña (Susques, Rinconada, Cochinoca) were screened with particle agglutination (PA), immunofluorescence (IF) and western immunoblotting analysis (WB) tests. Two out 86 (2.32%) individuals examined in the Puna Jujeña showed positive results for HTLV-I antibodies. It is concluded that the Province of Jujuy, in particular its less miscegenated highest altitude areas, constitute the northern and southern Andean natural geographical clustering of HTLV-I. This distribution is probably linked both to a history of prehistoric human dispersal in the Andes and to high mother- to-child transmission of the virus under close conditions of each group.

  10. Quaternary tectonic movements in the Argentine Puna, 24/sup 0/ to 27/sup 0/ s latitude

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, M.R.; Alonso, R.; Rivelli, F.; Mon, R.

    1985-01-01

    The Puna of NW Argentina, one of the highest plateaus in the world, is the southern continuation of the Andean Altiplano geomorphic province of Peru and Bolivia. The region is not seismically active and reports of neotectonic movements are scarce. However, the areas of Salar de los Pastos Grandes, Salar del Hombre Muerto and Sierra Calalaste clearly have experienced Quaternary tectonic movements. At Salar de los Pastos Grandes, early Pleistocene lake sediments are offset by reverse faulting. At Salar del Hombre Muerto, Quaternary pyroclastic and debris-flow deposits are unconformable over sediments 5.86 m.y. old that were folded during the Pliocene-Pleistocene Diaguita deformation. Within the Quaternary sediments two separate deformational phases with reverse faulting and shallow thrusting are recognized. The timing of movement is well defined since the deformed strata are covered by a basalt flow 0.75 m.y. old. The flow in turn is affected by normal faulting. Similar normal faults associated with basalt flows were found at Sierra Calalaste. These observations are in accord with pronounced extensional movements and basaltic volcanism at the Calama-Olacapato-Toro Lineament (0.2 m.y. old flows) and might document the Quaternary transition from a compressive to an extensional tectonic regime in the southern Puna.

  11. Exploration of Possible Astroblemes in the Argentine Puna

    Science.gov (United States)

    Acevedo, R. D.; Alonso, R.; Rocca, M.; Klajnik, K.; Tálamo, E.

    2014-09-01

    Potential three new astrobleme sites have been detected by remote sensors and checked in situ in Argentine Puna: an elevated plateau that it has remained stable and invariable across long geological periods.

  12. Producción y uso de ornamentos en las tierras bajas de Sudamérica: el caso de las poblaciones humanas prehispánicas del extremo meridional de la cuenca del Plata (Argentina

    Directory of Open Access Journals (Sweden)

    Acosta, A.A., Buc, N., Davrieux, M.N.

    2015-01-01

    Full Text Available En este trabajo se analizan los conjuntos ornamentales generados por las poblaciones humanas prehispánicas que ocuparon el extremo meridional de la cuenca del Plata. Se describen las piezas recuperadas en diversos sitios arqueológicos teniendo en cuenta las materias primas empleadas, sus mecanismos de obtención y otros aspectos relacionados con la manufactura. Posteriormente se evalúa y discute su potencial uso como medios de transmisión de información. Para ello se consideran diferentes factores vinculados con los sistemas de intercambio y la extensión de las redes sociales en el marco del crecimiento demográfico y del grado de complejidad social que alcanzaron dichas poblaciones durante la fase final del Holoceno tardío.

  13. Prácticas productivas y tradiciones tecnológicas: la manufactura cerámica prehispánica tardía y colonial en la cuenca sur de Pozuelos y el área de Santa Catalina, Puna de Jujuy,Argentina

    OpenAIRE

    Pérez Pieroni, María Josefina

    2015-01-01

    Con el objetivo de contribuir a la comprensión de la organización de la producción de la cerámica en las sociedades puneñas de la provincia de Jujuy, en este trabajo intentamos caracterizar las secuencias de procedimientos técnicos empleados en la elaboración de las piezas cerámicas en dos áreas de la puna jujeña, la cuenca sur de Pozuelos y el área de Santa Catalina, para el período prehispánico tardío y momentos coloniales. Asimismo, nos planteamos objetivos más particulares consistentes en...

  14. The Structure of Arizaro, Salta, Argentina: A New Simple Type Meteorite Impact Site?

    Science.gov (United States)

    Acevedo, R. D.; Rocca, M.; Alonso, R.; Rabassa, J.; Ponce, J. F.; Klajnik, K.

    2012-09-01

    A possible new impact crater had been found in Puna, Argentina: the structure of Arizaro (24º 55" 45.30” S, 67º 27" 09.64” W), located at 3,650 m.a.s.l. This structure is probably a new young simple-type impact crater on Tertiary-Quaternary sedimentary deposits.

  15. Peatlands of the Peruvian Puna ecoregion: types, characteristics and disturbance

    Directory of Open Access Journals (Sweden)

    F. Salvador

    2014-05-01

    Full Text Available Peatlands represent one of the most important water resources in the Puna grassland ecoregion, but this fact is not yet widely recognised. Puna peatlands also provide key environmental services such as increasing the regional biodiversity of the Andean Altiplano plateau and contributing to the wellbeing of high-altitude human populations by providing grazing land and cooking fuel. We conducted a study in the Peruvian Puna ecoregion to describe the current condition of peatlands in terms of their vegetation, physical and chemical characteristics and disturbance status. Our results suggest that peat thickness, organic matter and degree of humification are good indicators for identifying peatlands in the Puna ecoregion. In general, the peatland sites that we sampled were dominated by mixtures of cushion and acaulescent rosette forming plants such as Distichia muscoides Nees & Meyen and Plantago tubulosa Decne. These Distichia and Plantago peatland sites were characterised by a mean surface water pH of 6.3, corrected electrical conductivity (K corr. in the range 300–1814 μS cm-1 and presented the following mean exchangeable cation values: Ca2+ 48 mg L-1, Mg2+ 9.6 mg L-1, Na+ 8.2 mg L-1 and K+ 2.1 mg L-1. The most common causes of disturbance we encountered were grazing, peat extraction and roads. Disturbance was most severe in mining sites, where peatlands are especially vulnerable because they are not under legal protection.

  16. Geothermal research at the Puna Facility. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B.

    1986-04-01

    This report consists of a summary of the experiments performed to date at the Puna Geothermal Research Facility on silica in the geothermal fluid from the HGP-A well. Also presented are some results of investigations in commercial applications of the precipitated silica. (ACR)

  17. Sites for Gamma-ray Astronomy in Argentina

    CERN Document Server

    Rovero, A C; Allekotte, I; Bertou, X; Colombo, E; Etchegoyen, A; García, B; Garcia-Lambas, D; Levato, H; Medina, M C; Muriel, H; Recabarren, P

    2008-01-01

    We have searched for possible sites in Argentina for the installation of large air Cherenkov telescope arrays and water Cherenkov systems. At present seven candidates are identified at altitudes from 2500 to 4500 m. The highest sites are located at the Northwest of the country, in La Puna. Sites at 2500 and 3100 m are located in the West at El Leoncito Observatory, with excellent infrastructure. A description of these candidate sites is presented with emphasis on infrastructure and climatology.

  18. Primera aproximación a la manufactura cerámica en la localidad arqueológica de Río Herrana (cuenca sur de la laguna de Pozuelos, puna de Jujuy An initial approach to ceramic manufacture at Río Herrana archaeological sites, south Pozuelos basin, Puna of Jujuy

    Directory of Open Access Journals (Sweden)

    María Josefina Pérez Pieroni

    2012-07-01

    of the puna of Jujuy, such as Casabindo and Yavi. This article represents an initial contribution both to the study of this kind of material in an area archaeologically little known and to the understanding of ceramic manufacture in the puna, for which there are few technological studies in spite of the relevance they have in the rest of Northwest Argentina.

  19. Meridional Considerations of the Centrifugal Compressor Development

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    C. Xu

    2012-01-01

    Full Text Available Centrifugal compressor developments are interested in using optimization procedures that enable compressor high efficiency and wide operating ranges. Recently, high pressure ratio and efficiency of the centrifugal compressors require impeller design to pay attention to both the blade angle distribution and the meridional profile. The geometry of the blades and the meridional profile are very important contributions of compressor performance and structure reliability. This paper presents some recent studies of meridional impacts of the compressor. Studies indicated that the meridional profiles of the impeller impact the overall compressor efficiency and pressure ratio at the same rotational speed. Proper meridional profiles can improve the compressor efficiency and increase the overall pressure ratio at the same blade back curvature.

  20. Herencia materna en poblaciones de Puna y Valle Calchaqui - Salta

    Directory of Open Access Journals (Sweden)

    Albeza, María V.

    2005-01-01

    Full Text Available Las poblaciones de la Puna y el Valle Calchaquí han sido estudiadas, tanto desde la perspectiva demográfica como de marcadores genéticos clásicos y nucleares. En este trabajo se analizan las secuencias de la región hipervariable I del mtDNA, en muestras de 100 individuos de diferentes localidades. La zona comprendida entre las posiciones 15997-16400 según la secuencia Anderson (región hipervariable I-HVRI fue secuenciada. El motivo RFLP- 7025 AluI fue adicionalmente analizado en las muestras para determinar su inclusión dentro del haplogrupo H. Las muestras que resultaron no-H fueron asignadas a distintos haplogrupos. Se han detectado un total de 34 haplotipos distintos definidos por 50 posiciones variables de los que una muy baja proporción (13,1 % resultaron haplotipos únicos. Sólo 4 de los 34 haplotipos son compartidos entre la población de la Puna y la de los Valles.

  1. X-ray diffraction and Raman spectroscopy study of white decorations on tricolored ceramics from Northwestern Argentina

    Science.gov (United States)

    Freire, E.; Acevedo, V.; Halac, E. B.; Polla, G.; López, M.; Reinoso, M.

    2016-03-01

    White virgules, commas, and dot designs on tricolored ceramics are sporadically found in different archaeological sites located in Northwestern Argentina area, as Puna and Quebrada de Humahuaca. This decorating style has been reported in several articles, but few previous archaeometric studies have been carried out on the pigment composition. Fragments from Puna and Quebrada archaeological sites, belonging to Regional Development Period (900-1430 AD), were analyzed by X-ray diffraction and Raman spectroscopy in order to characterize the pigments employed. Red and black pigments are based on iron and manganese oxides, as it has been extensively reported for the NW Argentina area. White pigments from white virgules, comma, and dot designs have shown different composition. Hydroxyapatite was found in samples from Doncellas site (North Puna region), and calcium and calcium-magnesium containing compounds, as vaterite and dolomite, along with titanium containing compounds were detected on samples from Abralaite (Central Puna region) and Gasoducto (Quebrada de Humahuaca region). It has been concluded that pigment composition is not characteristic of a unique region.

  2. Thermal and geodynamic contributions to the elevation of the Altiplano-Puna plateau

    Science.gov (United States)

    Prezzi, Claudia; Iglesia Llanos, María Paula; Götze, Hans-Jürgen; Schmidt, Sabine

    2014-12-01

    The most remarkable feature of the Central Andes is the Altiplano-Puna plateau. This plateau is characterized by 3.5 km average elevation, approximately 70 km crustal thickness and very high heat flow. The upper mantle structure changes along strike below the plateau. The upper mantle below the Puna becomes hotter, and the lithosphere becomes thinner and weaker. These features suggest that thermal isostasy could play a role in the compensation of the Altiplano-Puna. Thermal isostasy is the geodynamic process whereby regional variations in the lithospheric thermal regime cause changes in elevation. Elevation changes result from variations in rock density in response to thermal expansion. The aim of this study is to estimate the thermal and geodynamic contributions to the elevation. While the thermal component of the Altiplano elevation would be of 1 km, the thermal contribution to the southern Puna elevation would be of 1.5 km. However, in the case of the southern Puna a portion of the actual topography (∼20%) cannot be explained considering only compositional and thermal effects, suggesting additional geodynamical support. The obtained results suggest that the thermal state of the lithosphere would play a significant role in the elevation of the Central Andes, and may be responsible of some of the geological differences displayed by the Altiplano and the Puna.

  3. Estacionalidad de las muertes en la puna de Atacama

    Directory of Open Access Journals (Sweden)

    Bejarano, Ignacio

    2001-01-01

    Full Text Available En distintas culturas y geografías la mortalidad se distribuye de acuerdo a un patrón estacional variable según las poblaciones. El objetivo de este trabajo fue analizar la estacionalidad de las muertes en un medio ambiente extremo como lo es la Puna de Atacama (PA. Los datos de defunciones (1890-1950 corresponden a dos localidades de la PA: Susques y San Pedro de Atacama. En el análisis se consideraron, por sexo, tres grupos de edad: a prerreproductiva (0-15 años (PRE, reproductiva (16-44 años (REP y postreproductiva (<45 años (POS. Se calculo el coeficiente de estacionalidad de Henry y para identificar estadísticamente variaciones estacionales se aplicó una prueba de homogeneidad. Se utilizó la prueba de Edwards para detectar ciclos armónicos en la distribución de muertes. Independientemente de la edad y el sexo se observó un patron estacional diferencial significativo que responde a un modelo de variación armónica simple, los coeficientes de Henry mas altos se presentaron en verano e invierno. Cuando se analiza la estacionalidad por grupo de edad y sexo el patrón previamente descripto se mantiene sólo en las edades REP y POS y en el sexo masculino. Este estudio proporciona un indicio del comportamiento de la estacionalidad de las muertes en la Puna de Atacama. Sin embargo no difiere del observado en poblaciones contemporáneas de países desarrollados, por lo que se concluye que el patrón observado no sería consecuencia directa de las condiciones climáticas, culturales, etc. de este ambiente extremo.

  4. Meridional transport in the Venusian atmosphere

    Science.gov (United States)

    Widemann, Thomas; Mota Machado, Pedro; Peralta, Javier; Marcq, Emmanuel; Helbert, Joern; Smrekar, Suzanne

    2016-10-01

    Atmospheric superrotation on Venus and to a lesser extent, on Titan, is thought to be maintained by opposing transfers of angular momentum between the mean meridional circulation and large-scale planetary waves. The details of this transfer depend on the presence of wave-generating dynamical instabilities and on the strength and direction of the meridional flow. Observational constraints have been gathered over the course of the Venus Express mission. The upper cloud exhibits global meridional motions which are consistent with the upper branch of a Hadley cell circulation (Sánchez-Lavega et al., 2008 ; Hueso et al., 2012). Peralta et al. (2012) determined the meridional structure for the amplitude of the diurnal tide affecting the meridional component of the wind, while VMC cloud-tracked features allowed to detect a diurnal component peaking in the early afternoon (Khatuntsev et al., 2013).New measurements of the meridional flow were simultaneously gathered by VEx/VIRTIS-M and CFHT/ESPaDOnS from the ground with a significant temporal and spatial overlap in April 2014. A symmetrical, poleward meridional Hadley flow is evidenced at cloud top in both hemispheres peaking at v = 22.5 ± 15.5 ms-1 at 9-10am near 40°N-S with a sharp drop poleward of 50° (Machado et al., submitted).The lower cloud meridional motions are less organized with some cloud features moving with intense northwards and southwards motions up to v = ±15 m s-1 but, on average, with almost null global meridional motions at all latitudes. Due to the unfavourable viewing geometry and poor UV contrast of polar clouds, only a fraction of the total wind measurements have been reported for the polar regions. Existing data indicate a circumpolar circulation close to solid-body rotation. The VEM instrument on board VERITAS (Smrekar et al., 2016 ; Helbert et al., 2016) will allow for a comprehensive study of lower cloud climatology spanning at least one Venusian year. Three filter bands of VEM at 1.195, 1

  5. Meridional circulation in the Sun and stars

    CERN Document Server

    Kitchatinov, L L

    2016-01-01

    Mean-field hydrodynamics advanced to clear explanations for the origin and properties of the global meridional flow in stellar convection zones. Qualitative arguments and analysis of basic equations both show that the meridional circulation is driven by non-conservative centrifugal and buoyancy forces and results from a slight disbalance between these two drivers. The deviations from the thermal wind balance are relatively large near the boundaries of convection zones. Accordingly, the meridional flow attains its largest velocities in the boundary layers and decreases inside the convection zone. This picture, however, is neither supported nor dismissed by the conflicting results of recent helioseismic soundings or 3D numerical experiments. The relevant physics of the differential temperature and its possible relation to the solar oblateness are briefly discussed.

  6. Subsurface Meridional Circulation in the Active Belts

    CERN Document Server

    Hernandez, I Gonzalez; Hill, F; Howe, R; Komm, R

    2008-01-01

    Temporal variations of the subsurface meridional flow with the solar cycle have been reported by several authors. The measurements are typically averaged over periods of time during which surface magnetic activity existed in the regions were the velocities are calculated. The present work examines the possible contamination of these measurements due to the extra velocity fields associated with active regions plus the uncertainties in the data obtained where strong magnetic fields are present. We perform a systematic analysis of more than five years of GONG data and compare meridional flows obtained by ring-diagram analysis before and after removing the areas of strong magnetic field. The overall trend of increased amplitude of the meridional flow towards solar minimum remains after removal of large areas associated with surface activity. We also find residual circulation toward the active belts that persist even after the removal of the surface magnetic activity, suggesting the existence of a global pattern o...

  7. Gravity modelling of the Ramadas Caldera (Argentinean Puna, central Andes)

    Energy Technology Data Exchange (ETDEWEB)

    Casas, A. [Barcelona Univ. (Spain). Facultad de Geologia; Hernandez, E.; Marti, J. [Consejo Superior de Investigaciones Cientificas, Barcelona (Spain). Inst. de Ciencias de la Terra Jaume Almera; Petrinovic, I. [Universidad Nacional de Salta (Argentina)

    1995-12-31

    In order to identify and characterize the event area of abundant Upper Miocene proximal rhyolitic pyroclastic deposits and extrusive domes which concentrate in the Ramadas area, near Sant`Antonio de los Cobres (Salta) at the Puna Altiplano (Central Andes), a detailed gravity survey has been carried out. Regional Bouguer gravity data were augmented with new 173 gravity observations measured sufficiently close-spaced to resolve the short wavelength produced by the structure of interest. Besides, the geophysical survey was done in conjunction with geologic and geochemical studies which were critically important to our interpretation. After the separation of the regional trend, the residual anomaly map displays a circular gravity low reaching-80 m Gal centered over scarce outcrops of rhyolitic and pyroclastic. This gravity low is interpreted as produced by block subsidence along ring fractures during eruption and/or deflation of the chamber. As the accumulation of thick, low density rock types in the zone of collapse is responsible of the prominent negative gravity anomalies, them has been used to estimated the thickness of caldera infill. (author). 8 refs., 4 figs

  8. Subdivisión poblacional en la Puna

    Directory of Open Access Journals (Sweden)

    Acreche, Noemí

    2001-01-01

    Full Text Available La definición de los límites poblacionales en nuestra especie es generalmente arbitraria. En el caso de la unidad geoestructural que conocemos como Puna, la población, por razones geográficas y socio económicas, se encuentra parcialmente aislada. Sin embargo, la relación entre los habitantes de las diferentes localidades, medida como coeficientes de migración, requiere mayores consideraciones, por lo que se estudió la variabilidad genotípica para cinco loci de grupos sanguíneos (ABO, Cc, Ee, MN, Ss y uno de HLA (DRB1. Se determinaron los índices de fijación de Wright FIS, FST y FIT y se realizó análisis jerárquico con otras poblaciones del noroeste. Se encontró alta correlación gamética y baja diferenciación entre subpoblaciones.

  9. New Early Paleozoic Paleomagnetic Poles From NW Argentina: a Reappraisal of Tectonic Models

    Science.gov (United States)

    Spagnuolo, C. M.; Rapalini, A. E.; Astini, R. A.

    2007-05-01

    A paleomagnetic study carried out on Early Ordovician volcanic units in the Famatina Ranges of NW Argentina yielded a pre-tectonic paleomagnetic pole at 32.7°S, 4.3°E, (5.6°/ 8.6°, N=14 sites) that is consistent with four previous Early Ordovician poles from the Famatina - Eastern Puna Eruptive Belt of NW Argentina. However, these five poles are rotated around 50° clockwise respect to the coeval reference pole of Gondwana. Our new results seem to confirm previous models of this belt as a paraauthocthonous rotated terrane on the southwestern margin of Gondwana. However, a recent paleomagnetic pole from the Late Cambrian Mesón Group, at the Eastern Cordillera of NW Argentina, corresponding to the Gondwana foreland (4.5°S, 359.0°E, dp=5.5°, dm=8.8°, n=26 samples) and preliminary paleopoles obtained from the same unit and the latest Cambrian - Early Ordovician Santa Victoria Group at other three localities in the same region, also indicate an anomalous pole position rotated some 40° clockwise respect to the reference pole for Gondwana. These results suggest that the postulated model of a rotated terrane for the Famatina-Eastern Puna belt must be reconsidered. Different alternative scenarios including the possibility of an Early Paleozoic displacement of the whole basement of the Eastern Sierras Pampeanas of Argentina ("Pampia") will be explored.

  10. Catálogo de hongos gasteroides (Basidiomycota de Catamarca, Argentina Catalogue of gasteroid fungi (Basidiomycota from Catamarca, Argentina

    Directory of Open Access Journals (Sweden)

    María Marta Dios

    2011-06-01

    Full Text Available Se realiza un listado de los hongos gasteroides de la provincia de Catamarca (Argentina basado en la bibliografía hasta abril de 2010. En total aparecen citadas 43 especies distribuidas en 2 órdenes, 4 familias y 13 géneros. El número de especies catalogadas es relativamente baja pero este número probablemente se incremente cuando se estudien las zonas aún no muestreadas como son las regiones fitogeográfícas de la Puna y las Yungas.A compiled check list of gasteroid fungi of Catamarca Province (Argentina was made. It was based on literature records, available until April 2010. There were 43 species of fungi distributed in 2 orders, 4 families and 13 genera. The number of species recorded in this area was relatively poor but it is likely to increase with the study of unexplored areas not yet surveyed as the phytogeographical regions of the Puna and Yungas.

  11. Native Hawaiian Ethnographic Study for the Hawaii Geothermal Project Proposed for Puna and Southeast Maui

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, J.K; Minerbi, L. [Cultural Advocacy Network for Developing Options (CANDO) (United States); Kanahele, P.; Kelly, M.; Barney-Campbell, N.; Saulsbury [Oak Ridge National Lab., TN (United States); Trettin, L.D. [Tennessee Univ., Knoxville, TN (United States)

    1996-05-01

    This report makes available and archives the background scientific data and related information collected for an ethnographic study of selected areas on the islands of Hawaii and Maui. The task was undertaken during preparation of an environmental impact statement for Phases 3 and 4 of the Hawaii Geothermal Project (HGP) as defined by the state of Hawaii in its April 1989 proposal to Congress. Since the state of Hawaii is no longer pursuing or planning to pursue the HGP, DOE considers the project to be terminated. Information is included on the ethnohistory of Puna and southeast Maui; ethnographic fieldwork comparing Puna and southeast Maui; and Pele beliefs, customs, and practices.

  12. Sombrero uplift above the Altiplano-Puna Magma Body: evidence of a ballooning mid-crustal diapir.

    Science.gov (United States)

    Fialko, Yuri; Pearse, Jill

    2012-10-12

    The Altiplano-Puna ultralow-velocity zone in the central Andes, South America, is the largest active magma body in Earth's continental crust. Space geodetic observations reported an uplift in the Altiplano-Puna proper at a rate of ~10 mm/year; however, the nature of the inferred inflation source has been uncertain. We present data showing that the uplift has persisted at a nearly constant rate over the past two decades, and is surrounded by a broad zone of subsidence. We show that the ongoing uplift and peripheral subsidence may result from a large mid-crustal diapir fed by partial melt from the Altiplano-Puna Magma Body.

  13. The Puna Vegetation of Moquegua, South Peru: Chasmophytes, grasslands and Puya raimondii stands

    NARCIS (Netherlands)

    Montesinos-Tubée, D.B.; Cleef, A.M.; Sýkora, K.V.

    2015-01-01

    The phytosociology and ecology of puna vegetation in twelve localities at an altitude of 3750-4500 m in northern Moquegua (south Peru) have been studied. The study area has a pluviseasonal climate with summer rainfall. Using TWINSPAN, Detrended Correspondence Analysis and Farthest Neighbor Clusterin

  14. The Puna vegetation of Moquegua, South Peru: Chasmophytes, grasslands and Puya raimondii stands

    NARCIS (Netherlands)

    Montesinos, D.B.; Cleef, Antoine; Sykora, K.V.

    2015-01-01

    Abstract: The phytosociology and ecology of puna vegetation in twelve localities at an altitude of 3750–4500 m
    in northern Moquegua (south Peru) have been studied. The study area has a pluviseasonal climate with summer
    rainfall. Using TWINSPAN, Detrended Correspondence Analysis and Farthest

  15. Optimization of Meridional Flow Channel Design of Pump Impeller

    OpenAIRE

    Miyauchi Sunao; Horiguchi Hironori; Fukutomi Jun-ichirou; Takahashi Akihiro

    2004-01-01

    The meridional flow channel design of a pump impeller affects its performance. However, since so many design parameters exist, a new design method is proposed in which a meridional and blade-to-blade flow channel is designed by the parallel use of the circulation distribution provided by the designer. Thus, an optimization method was used to design an axis-symmetrical meridional flow channel from the circulation distribution. In addition, the inverse design method proposed by Zangeneh et al. ...

  16. Currents, Geostrophic, Aviso, 0.25 degrees, Global, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Aviso Meridional Geostrophic Current is inferred from Sea Surface Height Deviation, climatological dynamic height, and basic fluid mechanics.

  17. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna Sedimentological study of Carboniferous and Permian deposits on the western edge of the Puna

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.The study of Carboniferous - Permian deposits exposed in the south-west of Salar del Rincón, on the western edge of

  18. Interbasin transport of the meridional overturning circulation

    Science.gov (United States)

    Jones, C. S.; Cessi, P.

    2016-02-01

    The meridional overturning circulation (MOC) is important in setting high latitude oceanographic conditions in both the northern and southern hemispheres: in particular, it transports heat northward in the Atlantic. In this work, the MOC is studied in a domain of simplified geometry comprising two basins connected by a circumpolar channel in the southernmost region. Flow is forced at the surface by longitude-independent wind-stress, freshwater flux and fast temperature relaxation to a prescribed profile. The only asymmetry between the two basins is that one is twice as wide as the other. Two states are compared, one with sinking in the wide basin and one with sinking in the narrow basin. In both cases, sinking is compensated by upwelling everywhere else, including the passive basin. Despite the greater area of the wide basin, the residual overturning transport is found to be the same, regardless of the location of sinking. However, the interbasin transport is larger when sinking occurs in the narrow basin. The interbasin transport is geostrophically balanced, and maintained by a difference in the depth of the thermocline at the eastern boundaries of each basin. Gnanadesikan's (1999) model for the upper branch of the MOC is extended to include two basins connected by a re-entrant channel, and is used to illustrate the basic properties of the solution in this geometry: the layer containing the intermediate water is shallower in the active basin than it is in the passive basin, and this difference geostrophically balances an interbasin-exchange flow from the passive to the active basin. This exchange flow is larger when sinking occurs in the narrow basin, while the net residual overturning is approximately the same regardless of the sinking location. A visualization of the horizontal structure of the upper branch of the MOC shows that both the gyres and the meridional flow are important in determining the flow field in the upper layer.

  19. Plant community variation across a puna landscape in the Chilean Andes Variación en la comunidad vegetal de un paisaje de puna en los Andes chilenos

    Directory of Open Access Journals (Sweden)

    JOHN G LAMBRINOS

    2006-06-01

    Full Text Available We describe patterns of plant species and growth form abundance in the puna vegetation of Parque Nacional Lauca, Chile. At more than 4,300 m, the extreme habitat of the study site supported relatively few species. These few species, however, represented a diverse array of growth forms that were organized with respect to distinct environmental gradients. Both species richness and growth form diversity increased with the degree of habitat rockiness and on more xeric north and east facing slopes. These xeric, rocky sites supported the greatest overall abundance of cushion forms. Less rocky sites with more soil development supported a greater abundance of tussock grass and shrub forms. Congeneric species occupied distinct microhabitats and were often markedly divergent in growth form. These patterns suggest that water and thermal stress are critical forces shaping functional form as well as community organization in the high Andean punaDescribimos los patrones de abundancia de las especies vegetales y las formas de vida en la vegetación de puna en el Parque Nacional Lauca, Chile. A una altitud que excede los 4.300 m de altitud, el hábitat extremo de nuestro sitio de estudio presenta relativamente pocas especies. Dichas especies, sin embargo, representan un arreglo diverso de formas de vida organizadas con respecto a distintos gradientes ambientales. Tanto la riqueza de especies como el hábito de crecimiento aumentaron en los suelos más rocosos y en las pendientes expuestas al norte y al este, cuya vegetación es más xerófila. Dichos sitios presentaron la mayor abundancia en formas de cojines. Los sitios menos rocosos con un suelo más desarrollado presentaron una mayor abundancia de pastos y arbustos. Distintos microhábitats fueron ocupados por especies congénericas que con frecuencia divergieron en su hábito de crecimiento. Los patrones observados sugieren que el agua y el estrés térmico son fuerzas críticas que moldean la forma

  20. Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body

    Science.gov (United States)

    Perkins, Jonathan P.; Ward, Kevin M.; de Silva, Shanaka L.; Zandt, George; Beck, Susan L.; Finnegan, Noah J.

    2016-10-01

    The Altiplano-Puna Magma Body (APMB) in the Central Andes is the largest imaged magma reservoir on Earth, and is located within the second highest orogenic plateau on Earth, the Altiplano-Puna. Although the APMB is a first-order geologic feature similar to the Sierra Nevada batholith, its role in the surface uplift history of the Central Andes remains uncertain. Here we show that a long-wavelength topographic dome overlies the seismically measured extent of the APMB, and gravity data suggest that the uplift is isostatically compensated. Isostatic modelling of the magmatic contribution to dome growth yields melt volumes comparable to those estimated from tomography, and suggests that the APMB growth rate exceeds the peak Cretaceous magmatic flare-up in the Sierran batholith. Our analysis reveals that magmatic addition may provide a contribution to surface uplift on par with lithospheric removal, and illustrates that surface topography may help constrain the magnitude of pluton-scale melt production.

  1. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

    OpenAIRE

    Alberto,M.R.; Zampini,I.C.; Isla, M. I.

    2009-01-01

    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts sh...

  2. Colonization of native Andean grasses by arbuscular mycorrhizal fungi in Puna: a matter of altitude, host photosynthetic pathway and host life cycles.

    Science.gov (United States)

    Lugo, Mónica A; Negritto, María A; Jofré, Mariana; Anton, Ana; Galetto, Leonardo

    2012-08-01

    The relationships of altitude, host life cycle (annual or perennial) and photosynthetic pathway (C(3) or C(4) ) with arbuscular mycorrhiza (AM) root colonization were analysed in 35 species of Andean grasses. The study area is located in north-western Argentina along altitudinal sites within the Puna biogeographical region. Twenty-one sites from 3320 to 4314 m were sampled. Thirty-five grasses were collected, and the AM root colonization was quantified. We used multivariate analyses to test emerging patterns in these species by considering the plant traits and variables of AM colonization. Pearson's correlations were carried out to evaluate the specific relationships between some variables. Most grasses were associated with AM, but the colonization percentages were low in both C(3) and C(4) grasses. Nevertheless, the AM root colonization clearly decreased as the altitude increased. This distinctive pattern among different species was also observed between some of the populations of the same species sampled throughout the sites. An inverse relationship between altitude and AM colonization was found in this Southern Hemisphere Andean system. The effect of altitude on AM colonization seems to be more related to the grasses' photosynthetic pathway than to life cycles. This study represents the first report for this biogeographical region.

  3. Argentina; Argentine

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-04-01

    This economical study summarizes the energy situation of Argentina: energy institutions and policy, energy companies (oil, electricity, gas, coal), energy supplies (resources, power production, petroleum, natural gas), prices and tariffs, consumption, economical stakes and perspectives (investments, agreements, projects). Energy data for the 1971-1999 period are summarized in graphs and tables. (J.S.)

  4. Rafaela, Argentina

    OpenAIRE

    2004-01-01

    Brinda información acerca de la provincia de Rafaela, Argentina. Da a conocer el planeamiento estratégico de Rafaela, los temas a resolver con el sector privado, así como las acciones para abordar la relación público-privada.

  5. Meridional Transport in the Atmospheres of Earth and Mars

    CERN Document Server

    Soto, Alejandro

    2015-01-01

    As we continue to discover terrestrial exoplanets, many with orbital and planetary characteristics drastically different from anything encountered in our solar system, we are likely to encounter 'exotic' atmospheric transport processes. As an example, we show an analysis of meridional transport from simulations Mars. These simulations provide insight into the differences in meridional transport between Earth and Mars, particularly through the role of a condensation flow. The differences between Earth and Mars are a reminder that there may be a wide variety of meridional transport processes at work across the range of observed terrestrial planets.

  6. Argentina: spotlight.

    Science.gov (United States)

    Patriquin, W

    1987-10-01

    In 1987 Argentina had a population of 31.5 million, with an annual rate of increase of 1.6%. The total fertility rate was 3.3, and the birth rate was 24/1000 population. Mortality stood at 8/1000 population, and the infant mortality rate was 35.3/1000 live births. Life expectancy at birth is 70 years. 84% of the population lives in Argentina's urban areas. Current government policies call for regional development to maintain and increase population in rural areas and control growth in urban centers. 90% of the population is of European descent, largely as a result of high rates of immigration during the 1880s-1930s from countries such as Spain and Italy. In 1985 the gross national product per capita was US$2130. Argentina is rich in resources and almost self-sufficient in terms of basic foodstuffs, power supply, and advanced communication networks. On the other hand, political conflicts and economic crises have hindered the realization of both human and natural resource potential. 80% of the value of export products is the amount due in interest on foreign debts.

  7. Reinterpretation of the Ordovician rotations in NW Argentina and Northern Chile: a consequence of the Precordillera collision?

    Science.gov (United States)

    Spagnuolo, Cecilia M.; Rapalini, Augusto E.; Astini, Ricardo A.

    2011-04-01

    Early Paleozoic paleomagnetic data from NW Argentina and Northern Chile have shown large systematic rotations within two domains: one composed of the Western Puna that yields very large (up to 80°) counter-clockwise rotations, and the other formed by the Famatina Ranges and the Eastern Puna that shows (~40°) clockwise rotations around vertical axes. In several locations, lack of significant rotations in younger rocks constrains this kinematic pattern to have occurred during the Paleozoic. Previous tectonic models have explained these rotations as indicative of rigid-body rotations of large para-autochthonous crustal blocks or terranes. A different but simple tectonic model that accounts for this pattern is presented in which rotations are associated to crustal shortening and tectonic escape due to the collision of the allochthonous terrane of Precordillera in the Late Ordovician. This collision should have generated dextral shear zones in the back arc region of the convergent SW Gondwana margin, where systematic domino-like clockwise rotations of small crustal blocks accommodate crustal shortening. The Western Puna block, bordering the Precordillera terrane to the north, might have rotated counterclockwise as an independent microplate due to tectonic escape processes, in a fashion similar to the present-day relationship between the Anatolia block and the Arabian microplate.

  8. On the meridional structure of the equatorial mixed layer

    OpenAIRE

    Mueller, P; Ross, M.

    1987-01-01

    The authors compare three two-dimensional models of the meridional structure of the mixed layer near the equator: a 1 1/2-layer linear reduced gravity model and two bulk mixed layer models, one with meridional advection and one with an atmospheric feedback. The reduced gravity model is a purely dynamic model; the two bulk mixed layer models include the thermodynamic processes of mixing and heating. The differences between the models become most pronounced when their response to changes in the...

  9. Transformaciones y conflictos socioambientales en la jach´a puna del sur peruano

    OpenAIRE

    Varas Castrillo, Maria Nilda; Universidad Pablo de Olavide, Sevilla, España.

    2015-01-01

    Se estudian las transformaciones y los conflictos socioambientales en la jach ´a puna, en el sur peruano. Los resultados muestran cambios institucionales y ecosistémicos que se aceleraron hace cinco décadas por la intervención del Estado y la incursión de las empresas mineras transnacionales, las cuales utilizan intensivamente el agua, lo que ha provocado que los territorios y las relaciones humanas se complejicen y reconfiguren creando situaciones que podrían tener graves consecuencias para ...

  10. en Argentina

    Directory of Open Access Journals (Sweden)

    Patricia Davolos

    2005-01-01

    Full Text Available Hacia finales de la década pasada comienza a cobrar dinamismo la protesta social en Argentina como respuesta a la crisis resultante de las políticas neoliberales que dominaron la escena nacional en los noventa. En ese contexto, grupos de trabajadores ocupan empresas en riesgo de cerrar sus puertas, organizándose para operarlas en forma autogestionaria. Aquí se estudian las características del mercado de trabajo, así como las tradiciones y los recursos que permitieron a los trabajadores llevar adelante este tipo de acciones, delineando distintas trayectorias que otorgaron inteligibilidad al fenómeno analizado.

  11. Meridional Circulation in Solar and Stellar Convection Zones

    CERN Document Server

    Featherstone, Nicholas A

    2015-01-01

    We present a series of 3-D nonlinear simulations of solar-like convection, carried out using the Anelastic Spherical Harmonic (ASH) code, that are designed to isolate those processes that drive and shape meridional circulations within stellar convection zones. These simulations have been constructed so as to span the transition between solar-like differential rotation (fast equator/slow poles) and ``anti-solar' differential rotation (slow equator/fast poles). Solar-like states of differential rotation, arising when convection is rotationally constrained, are characterized by a very different convective Reynolds stress than anti-solar regimes, wherein convection only weakly senses the Coriolis force. We find that the angular momentum transport by convective Reynolds stress plays a central role in establishing the meridional flow profiles in these simulations. We find that the transition from single-celled to multi-celled meridional circulation profiles in strong and weak regimes of rotational constraint is lin...

  12. Patagonia Argentina

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    A.J. Acuña

    2008-01-01

    Full Text Available La zona central de la Patagonia, Argentina, se encuentra sometida a explotación petrolera y sus suelos se caracterizan por ser deficientes en nitrógeno. Esto causaría un efecto negativo en los procesos de atenuación natural que se desarrollan en los suelos contaminados con hidrocarburos. El objeto de este estudio fue determinar cual es el efecto de la deficiencia de nitrógeno sobre la biodegradación de los hidrocarburos en un suelo de la Patagonia, Argentina. Se trabajó con tres microcosmos a los que se les realizó tratamientos diferentes. En uno se monitoreo la atenuación natural del sistema, en otro la fertilización con nitrógeno (N, fósforo (P y potasio (K, y en el último la fertilización con P y K. Durante el seguimiento se determinaron mineralización y medición de hidrocarburos, y se realizaron recuentos bacterianos y determinación de nitrato, nitrito y amonio. Los resultados indican que es posible la biodegradación de hidrocarburos en el suelo deficiente de nitrógeno de la Patagonia estudiado en tiempos mas prolongados que en aquellos que se realiza una fertilización con nitrógeno. El nitrógeno necesario para el proceso sería obtenido por los microorganismos del suelo por fijación biológica.

  13. Geochemistry of the hydrothermal systems in the Jujuy Province, Argentina, and relationship with the regional geology

    Science.gov (United States)

    Peralta Arnold, Yesica; Cabassi, Jacopo; Tassi, Franco; Caffe, Pablo; Vaselli, Orlando

    2016-04-01

    The western sector of the Jujuy province (22°-24° S), Argentina, basically consisting of the Puna region (from 3,500 to 4,700 m a.s.l.) that borders the Central Volcanic Zone (CVZ), is characterized by sub-meridional ridges that alternate with elongated basins and by extremely voluminous intermediate and silicic ignimbrite deposits, the latter being related to late miocenic and pliocenic calderas and central volcanic edifices. In this region, several hydrothermal discharges with outlet temperatures up to 62°C occur. Among them, the Coranzulí and Pairique thermal emissions show a spatial relationship with miocenic volcanic complexes, whereas other thermal manifestations (Queñual, Orosmayo, Pirquitas, Arizutar, Cono Panizo and Rachaite) are clearly controlled by the local structural setting. Most of these thermal waters have relatively high total dissolved solids (TDS up to 46,500 mg/L), an alkaline-chloride composition and significant concentrations of B, NH4 and SiO2, i.e. they show the typical geochemical features of geothermal brine. Exceptions are the Coranzulí, Orosmayo and Rachaite springs, mainly fed by a shallow Na(Ca)-bicarbonate aquifer. The eastern sector of the province consists of the Eastern Cordillera, composed of a proterozoic basement constituted by the sedimentary sequences of the Puncoviscana Fm, and the Subandean Range, which shows wide east-vergence anticlines whose detachment levels are Silurian-Devonian shales. Both regions are separated by a major thrust that rises the Proterozoic and Eopaleozoic sequences over the Subandean System. The thermal waters in the Eastern Cordillera, namely Termas de Reyes, are characterized by alkaline-sulfate composition, temperature of ≈50°C and neutral pH. In contrast, in the Subandean Ranges, which is separated from the Eastern Cordillera by a thrust rising Proterozoic and Eopaleozoic sequences over the Subandean System, the Aguas Calientes springs are characterized by low temperature (from 21°C to

  14. PRIMEROS ESTUDIOS SOBRE MANUFACTURA CERÁMICA DE CONTEXTOS COLONIALES DEL SUR DE POZUELOS (PUNA DE JUJUY, ARGENTINA

    Directory of Open Access Journals (Sweden)

    Angiorama Carlos

    2012-12-01

    Full Text Available The results of the first studies on ceramic materials from three colonial contexts of south Pozuelos are presented here. These studies were undertaken from a technological perspective. Macroscopic and sub macroscopic observations on attributes related to the production sequence were made, including pastes attributes, morphology and surface characteristics. The results, when compared to previous analysis of prehispanic materials,allowed identifying several continuities in the production of prehispanic and colonial pottery, as well as some discontinuities. The prevalence of the continuities in the analyzed pottery allows stating that the material culture from the studied colonial contexts had not gone through great changes since prehispanic times.

  15. Sarcophagidae (Diptera de importancia forense en la puna de Catamarca, Argentina: la ovoviviparidad como ventaja en condiciones de extrema aridez

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    Fernando H. ABALLAY

    2011-01-01

    Full Text Available A pesar de ser fauna necrófaga y de estar presentes en cadáveres humanos, los Sarcophagidae no suelen utilizarse en estudios forenses debido a la dificultad en su identificación y la poca información sobre su biología. En este trabajo, se identificaron las especies de Sarcophagidae asociadas a cadáveres y se estudió su relación con los estados de descomposición. Se analizaron las preferencias por los sustratos cadavéricos (cerdo y llama y las condiciones microambientales (sol y sombra en un ambiente de altura (3.600 msnm, durante la primavera. Se utilizaron dos cadáveres de cerdo dispuestos al sol y a la sombra y un cadáver de llama dispuesto al sol. Se colectaron 597 individuos pertenecientes a cinco especies de Sarcophagidae: M. antofagastensis Mulieri, Mariluis & Aballay (n=347, M. quimaliensis (Lopes (n=117, M. rusca (Hall (n=32, M. penai (Lopes (n=5 y M. aulacophyto Pape (n=96. Tanto M. antofagastensis, como M. quimaliensis fueron las únicas especies con colonización efectiva y representaron el 78% del total de adultos colectados. Microcerella antofagastensis fue la colonizadora primaria. Ambas especies respondieron de forma similar ante las condiciones microambientales y prefirieron el cadáver de cerdo. Se discute la importancia de M. antofagastensis y M. quimaliensis, como especies indicadoras y las posibles ventajas de la ovoviviparidad frente a otras especies ovíparas, en condiciones de extrema aridez.

  16. Migraciones en la puna: su relación con el uso de los recursos naturales del departamento Los Andes Migraciones en la puna: su relación con el uso de los recursos naturales del departamento Los Andes

    Directory of Open Access Journals (Sweden)

    Francisco R. Barbarán

    2009-12-01

    Full Text Available From an historic and demographic perspective, as well as the use of natural resources, we analyzed the relationship between human migrations and the economic activities of Los Andes Department, West of the Salta Province, in NW Argentina. Using the residual method, we calculated migratory balances between Argentinean population censuses carried out in 1947,1960, 1970, 1980 and 2001. The migratory balances were negative for all the periods studied. When the train started to run through Ramal C-14, the workers who built it have to find jobs somewhere else. At the same time, the railway made easier for the natives, to find better economicopportunities out of the Puna. The close of mine La Casualidad by the end of the 70’s, the low creation of jobs by the remaining mining operations, focused in to hire qualified technicians no available in Los Andes and the privatization of the railway in early 90’s, were important factors of emigration. Despite of cattle rising as the main economic activity in rural areas, it is practiced without any technology of management. The overgrazing caused for that reason, has reduced almost to the half the quantity of sheep by inhabitant between 1947 and 2001. That is why the local people have to press more on the wildlife, trading illegally with vicuña (Vicugna vicugna fiber. Despite of a touristic development plan, a law promoting sheep rising and a census of vicuña population carried out by the provincial government, these recent actions should be part of a development project of regional scale, oriented to the sustainable use of the natural resources of Los Andes Department. That project would create jobs and discourage emigration.Desde una perspectiva histórica, demográfica y del uso de los recursos naturales, analizamos la relación existente entre las migraciones humanas y las actividades económicas en el departamento Los Andes, ubicado al W de la provincia de Salta, en el Noroeste Argentino. Usando el m

  17. El registro biológico humano de la costa meridional de Santa Cruz

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    Suby, Jorge A.

    2009-01-01

    Full Text Available La costa patagónica constituye un sector de riesgo para el registro arqueológico, asociado a factores naturales y antrópicos. Al mismo tiempo, la conservación de las colecciones bioarqueológicas, destacándose la pérdida de restos óseos e información asociada por escasez de recursos, desconocimiento o falta de atención especializada, representa escenarios de riesgo para el registro. Una de las áreas para las cuales no se dispone hasta el momento de información bioarqueológica es la región que comprende la costa meridional de la provincia de Santa Cruz. Considerando esta ausencia de información, el objetivo de este trabajo es presentar y discutir los primeros resultados sobre restos óseos humanos hallados en la región costera próxima a la desembocadura del Río Santa Cruz (Santa Cruz, Argentina. Los estudios incluyen el análisis de las situaciones de hallazgo y riesgo de los restos recuperados en acciones de rescate, el reconocimiento y puesta en valor de materiales depositados en el Museo Regional "Carlos Borgialli" (Puerto Santa Cruz, Santa Cruz, Argentina y estudios paleopatológicos. Al mismo tiempo se informan y analizan resultados cronológicos e isotópicos. Los resultados brindan evidencias claras de la ocupación de la región costera al menos durante los últimos 2000 años, consumo de recursos predominantemente terrestres y un estilo de vida que favorece el desarrollo de lesiones articulares, con escasos indicios de estrés sistémico que coinciden con los resultados reportados para la región continental del estrecho de Magallanes.

  18. PRIMEROS AVANCES EN LA CARACTERIZACIÓN GEOQUÍMICA DE VULCANITAS DE AFLORAMIENTOS DE ANTOFAGASTA DE LA SIERRA (PROV. DE CATAMARCA, ARGENTINA / First advances in the geochemical characteristics of volcanic outcrops of Antofagasta de la Sierra (Catamarca

    Directory of Open Access Journals (Sweden)

    Alejandra M. Elías

    2013-07-01

    Full Text Available En distintos sectores de la microrregión de Antofagasta de la Sierra (Provincia de Catamarca, Puna Meridional Argentina se registran afloramientos de vulcanitas (rocas volcánicas con proporciones de vidrio menores a 80%, sensu Aschero et al. 2002/2004 macroscópicamente muy similares. Con el objetivo de diferenciarlas y aportar, de esta forma, a su identificación en el registro arqueológico, se aplicaron diversos métodos y técnicas sobre muestras de estas rocas procedentes de los distintos afloramientos. En esta instancia, se exponen los resultados obtenidos a partir de caracterización geoquímica por medio de Fluorescencia de Rayos X de Energía Dispersiva. Las vulcanitas procedentes de los diferentes afloramientos tienden a presentar disímiles concentraciones de ciertos elementos. Estos resultados son prometedores y estimulan a continuar investigando la aplicación de métodos geoquímicos en la diferenciación y determinación de la procedencia de estas rocas volcánicas. Cabe destacar que en el Noroeste Argentino los métodos geoquímicos fueron exclusivamente aplicados sobre una roca volcánica específica, la obsidiana, y aún no habían sido utilizados en otras rocas volcánicas anisótropas, con superficies, texturas y estructuras más irregulares. Abstract   In different sectors of the Antofagasta de la Sierra micro-region (Catamarca Province, Southern Argentine Pune outcrops of macroscopically very similar vulcanites (volcanic rocks with ratios of glass below 80%, sensu Aschero et al. 2002/2004 have been recorded. In order to differentiate between these and contribute to their identification in the archaeological record, various methods and techniques were applied to samples of these rocks. In this instance, the initial results obtained from geochemical characterization, through Energy Dispersive X-ray Fluorescence, are presented. The vulcanites from different outcrops tend to show different concentrations for some elements

  19. Transient Characteristics of Residual Meridional Circulation during Stratospheric Sudden Warming

    Institute of Scientific and Technical Information of China (English)

    DENG Shumei; CHEN Yuejuan; HUANG Yong; LUO Tao; BI Yun

    2011-01-01

    The residual meridional circulation derived from the transformed Eulerian-mean thermodynamic equation and continuity equation can be separated into two parts, the slowly varying diabatic circulation and the transient circulation, as demonstrated by others. We calculated and composite-analyzed the transient and diabatic circulation for 14 stratospheric sudden warming (SSW) events from 1979-2002 by using the daily ECMWF reanalysis data. Specifically, the transient residual meridional circulation was calculated both with and without inclusion of the eddy heat transport term in the transformed Eulerian-mean thermodynamic equation to investigate the importance of the eddy heat transport term. The results showed that calculations of transient residual meridional circulation present rapid variations during SSWs, with or without inclusion of the eddy heat transport term. Although the patterns of transient residual meridional circulation with the eddy heat transport term were similar to that without the eddy heat transport term during SSW, the magnitudes in the upper stratosphere and high-latitude regions differed. As for the diabatic circulation, its daily variations were small during SSW events, and its patterns were in agreement with its monthly average.

  20. Transient Characteristics of Residual Meridional Circulation during Stratospheric Sudden Warming

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The residual meridional circulation derived from the transformed Eulerian-mean thermodynamic equation and continuity equation can be separated into two parts,the slowly varying diabatic circulation and the transient circulation,as demonstrated by others.We calculated and composite-analyzed the transient and diabatic circulation for 14 stratospheric sudden warming(SSW) events from 1979-2002 by using the daily ECMWF reanalysis data.Specifically,the transient residual meridional circulation was calculated both with and without inclusion of the eddy heat transport term in the transformed Eulerian-mean thermodynamic equation to investigate the importance of the eddy heat transport term.The results showed that calculations of transient residual meridional circulation present rapid variations during SSWs,with or without inclusion of the eddy heat transport term.Although the patterns of transient residual meridional circulation with the eddy heat transport term were similar to that without the eddy heat transport term during SSW,the magnitudes in the upper stratosphere and high-latitude regions differed.As for the diabatic circulation,its daily variations were small during SSW events,and its patterns were in agreement with its monthly average.

  1. Mean meridional currents in the central and eastern equatorial Atlantic

    Science.gov (United States)

    Perez, Renellys C.; Hormann, Verena; Lumpkin, Rick; Brandt, Peter; Johns, William E.; Hernandez, Fabrice; Schmid, Claudia; Bourlès, Bernard

    2014-12-01

    Ship-based acoustic Doppler current profiler (ADCP) velocity measurements collected by several major field programs in the tropical Atlantic are averaged and combined with estimates of the mean near-surface velocity derived from drifters and Argo float surface drifts (ADCP+D) to describe the mean cross-equatorial and vertical structure of the meridional currents along 23°W and 10°W. Data from moored ADCPs and fixed-depth current meters, a satellite-derived velocity product, and a global ocean reanalysis were additionally used to evaluate the mean ADCP+D meridional velocity. The dominant circulation features in the long-term mean ADCP+D meridional velocity in the upper 100 m are the tropical cells (TCs) located approximately between 5°S and 5°N, with near-surface poleward flow and subsurface equatorward flow that is stronger and shallower in the northern cell compared to the southern cell. The thickness of the surface limb of the TCs decreases and the northern cell is found to shift further south of the equator from the central to eastern tropical Atlantic. Analysis of two-season means estimated from the ship-based ADCP, near-surface drift, and moored velocity data, as well as the simulated fields, indicates that the maximum poleward velocity in the surface limb of the TCs intensifies during December-May along 23°W largely due to seasonal compensation between the geostrophic and ageostrophic (or wind-driven) components of the meridional velocity, whereas the maximum equatorward flow in the subsurface limb of the northern cell intensifies during June-November along both 23°W and 10°W due to the seasonality of the geostrophic meridional velocity.

  2. A Preliminary Report on the Early History and Archaeology of Kahauale'A, Puna, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Tommy

    1982-04-14

    The following is a report on the findings of a documentary literature search on the ahupuaa of Kahauale'a in the Puna District of the island of Hawaii. Attention is given to the entirety of the ahupuaa, though the emphasis is on the mauka portions from about 1,500 to 3,800-feet elevation, or roughly three miles inland to the northern terminus of the ahupuaa, just below Kilauea. The report was commissioned by The Estate of James Campbell for purposes of ascertaining what the extent of early Hawaiian activities and/or habitation occurred in the mauka regions of Kahauale'a--specifically to see if proposed geothermal drilling activities in these areas would disturb any archaeological sites.

  3. Soil organic matter dynamics at the paramo and puna highlands in the Andean mountains

    Science.gov (United States)

    Ángeles Muñoz, M.; Faz, Ángel; Mermut, Ahmet R.; Zornoza, Raúl

    2014-05-01

    Mountains and uplands represent the most diverse and fragile ecosystems in the world, cover about 20% of the terrestrial surface and are distributed across all continents and major ecoregions. The Andean Plateau is the main mountain range of the American continent and one of the largest in the world with more than 7,500 km. The soil organic matter is a corner stone in the fertility management of the Andean agriculture as well as in the erosion control. However, its role is still much unknown in these ecosystems. Moreover, the influence of current global climatic change on soil organic C reservoirs and dynamics is still not clearly understood. The aim of this work was to review the soil C dynamics and the implication of the soil organic matter in the fertility management, erosion control, conservation of biodiversity and global climate change to improve the knowledge on the mountain Andean highlands. Climate, landscape, soil C pools, biomass and management were studied. In general, the Andean climate is affected by three main factors: ocean currents, winds and orography characterized by an abrupt topography. The entire Andean belt is segmented into the Northern, Central and Southern Andes. Northern Andes are called paramo and are characterized by humid climate while Central and Southern Andes dryer zones are called puna. Most of the region is tectonically and volcanically active. Sedimentary rocks predominated in the paramo while sedimentary, igneous and metamorphic ones prevailed in the puna. The most common soils were Andosols, Regosols, Umbrisols and Histosols. The cold and wet climate and the low atmospheric pressure favored organic matter accumulation in the soil. The accumulation of organic matter is further enhanced by the formation of organomineral complexes strongly resistant to the microbial breakdown mainly in the paramo. High organic C contents were observed in the paramo (10%) oppositely to the low contents found in the dryer puna (1%). The C/N ratio

  4. Sediment aggradation and erosional dynamics of intermontane basins in NW Argentina

    Science.gov (United States)

    Bookhagen, Bodo; Castino, Fabiana; Purinton, Ben; Strecker, Manfred

    2017-04-01

    The NW Argentine Andes constitute the Andean Plateau (Altiplano-Puna), the second-largest orogenic plateau on Earth, an internally drained highland with a mean elevation of 4.0 ± 0.5 km (±2 sigma). The Puna is flanked by the externally drained Eastern Cordillera thrust belt and the adjacent broken foreland that are connected to the Atlantic Ocean. These mountain ranges lie in the south-central Andes and are characterized by steep topographic and climatic gradients: The first windward topographic rise east of the Puna forms a significant orographic barrier resulting in high orographic rainfall causing some of the wettest places on Earth. In contrast, the higher-elevation areas of the windward flanks become progressively drier westward, until arid conditions are attained in the central Puna. During the Quaternary the south-central Andes have repeatedly experienced significant paleoclimatic changes associated with deeper penetration of moisture into the orogen, and thus an orogenward shift of the climate gradient. This mechanism has resulted in large variations in erosion dynamics and sediment transfer toward the foreland, resulting in thick valley fills and multiple terrace levels. At much shorter timescales, climate variability during the Holocene has caused similar, yet less pronounced hydrologic trends and associated sedimentation- and erosion processes. Here, we use a time series of Digital Elevation Models (DEMs) to reconstruct land-level changes in the intramontane basins in NW Argentina. We generated the DEMs and height measurements based on stereo airphotos from the 1980s, ASTER satellite imagery, ICESat and dGPS measurements during the past decade, and several TerraSAR-X and TanDEM-X CoSSC pairs starting in 2013. Our data show a strong signal of fluvial sediment aggradation during the past 30 years, in places up to 0.5m per decade, which explains the regionally observed, modern sediment accumulation in basins that has caused major infrastructural problems

  5. Micromamiferos andinos holocenicos del sitio arqueologico Inca Cueva 5, Ju Juy, Argentina: tafonomia, zoogeografia y reconstruccion paleoambiental

    Directory of Open Access Journals (Sweden)

    Ortiz, P. E.

    2002-08-01

    Full Text Available A micromammal archaeological sequence (2120 f 120 to 780 f 100 years BP from Inca Cueva 5 site (23" 05' S - 65" 27' W; 3700 m.a.s.l., Jujuy Province, Argentina was studied. The following mammalian taxa were recorded: Order Didelphimorphia, Family Didelphidae, Thylamys cf. T. pallidior; Order Rodentia, Family Muridae, Akodon cf. A. albiventer, Andinomys edax, Auliscomys sublimis, Calomys lepidus, Neotomys ebriosus, Phyllotis sp.; Family Caviidae, Cavia cf. C. tschudii, Galea musteloides; Family Abrocomidae, Abrocoma cinerea; Family Chinchillidae, Lagidium viscacia; Family Octodontidae, Octodontomys gliroides. The taphonomy indicates that the sequence is an owl pellet accumulation inside the cave. The general landscape corresponds to the oriental border of the Puna steppe, with scattered shrub and low brush vegetation. Near the site there are small tree groups of Polylepis australis as well as small streams covered with grass and ciperaceous vegetation known as «vegas». Al1 the recorded taxa at Inca Cueva 5 exist today in Puna and Prepuna environments from Jujuy and Salta Provinces and southem Bolivia, excepting Cavia cf. C. tschudii. The modem records of this species in northem Argentina and southern Bolivia come from localities with high montane bunchgrass prairies and forests of the humid Yungas phytogeographical region. The presence of this species in the sequence suggests wetter climatic conditions on this region when the archaeological site was originated. Later drier conditions, caused probably by anthropic influence in the last 500 years, produced the retraction of Cavia tschudii to the moist eastern side of the Andes and its disappeareance of the Puna areas.El sitio arqueológico Inca Cueva 5 se encuentra en la provincia de Jujuy, Argentina, en el borde oriental de la región de la Puna (23" 05' S - 65" 27' W; 3700 m s n m y está fechado entre 2120 f 120 y 780 f 100 años radiocarbónicos AP. El estudio de una pequeña muestra de

  6. Panamericanismo y arbitraje en conflictos de límites: la participación de Estados Unidos en la definición de la frontera argentino-chilena en la Puna de Atacama (1899

    Directory of Open Access Journals (Sweden)

    Perla Zusman

    2014-01-01

    Full Text Available Hacia finales del siglo XIX , el proyecto panamericanista implicó una serie de estrategias políticas, económicas y culturales destinadas a aumentar la influencia de Estados Unidos en Latinoamérica. En ese contexto, los países del Cono Sur comenzaron a aceptar el arbitraje de presidentes o delegados norteamericanos en los conflictos de límites territoriales. Este trabajo analiza la participación del país del norte en el diferendo de Argentina y Chile por la Puna de Atacama (1899. A través de esta aproximación se busca, en primer lugar, identificar las contribuciones de Estados Unidos en la elección de criterios para la negociación del límite y, en segundo lugar, explorar los vínculos de su arbitraje con el alcance del panamericanismo en la región.

  7. Panamericanismo y arbitraje en conflictos de límites: la participación de Estados Unidos en la definición de la frontera argentino-chilena en la Puna de Atacama (1899

    Directory of Open Access Journals (Sweden)

    Perla Zusman

    2014-05-01

    Full Text Available Hacia finales del siglo XIX, el proyecto panamericanista implicó una serie de estrategias políticas, económicas y culturales destinadas a aumentar la influencia de Estados Unidos en Latinoamérica. En ese contexto, los países del Cono Sur comenzaron a aceptar el arbitraje de presidentes o delegados norteamericanos en los conflictos de límites territoriales. Este trabajo analiza la participación del país del norte en el diferendo de Argentina y Chile por la Puna de Atacama (1899. A través de esta aproximación se busca, en primer lugar, identificar las contribuciones de Estados Unidos en la elección de criterios para la negociación del límite y, en segundo lugar, explorar los vínculos de su arbitraje con el alcance del panamericanismo en la región.

  8. Alleviating alpha quenching by solar wind and meridional flow

    CERN Document Server

    Mitra, Dhrubaditya; Tavakol, Reza; Brandenburg, Axel

    2010-01-01

    We study the ability of magnetic helicity expulsion to alleviate catastrophic $\\alpha$-quenching in mean field dynamos in two--dimensional spherical wedge domains. Motivated by the physical state of the outer regions of the Sun, we consider $\\alpha^2\\Omega$ mean field models with a dynamical $\\alpha$ quenching. We include two mechanisms which have the potential to facilitate helicity expulsion, namely advection by a mean flow (``solar wind'') and meridional circulation. We find that a wind alone can prevent catastrophic quenching, with the field saturating at finite amplitude. In certain parameter ranges, the presence of a large-scale meridional circulation can reinforce this alleviation. However, the saturated field strengths are typically below the equipartition field strength. We discuss possible mechanisms that might increase the saturated field.

  9. Alleviating α quenching by solar wind and meridional flows

    Science.gov (United States)

    Mitra, D.; Moss, D.; Tavakol, R.; Brandenburg, A.

    2011-02-01

    Aims: We study the ability of magnetic helicity expulsion to alleviate catastrophic α-quenching in mean field dynamos in two-dimensional spherical wedge domains. Methods: Motivated by the physical state of the outer regions of the Sun, we consider α^2Ω mean field models with a dynamical α quenching. We include two mechanisms which have the potential to facilitate helicity expulsion, namely advection by a mean flow ("solar wind") and meridional circulation. Results: We find that a wind alone can prevent catastrophic quenching, with the field saturating at finite amplitude. In certain parameter ranges, the presence of a large-scale meridional circulation can reinforce this alleviation. However, the saturated field strengths are typically below the equipartition field strength. We discuss possible mechanisms that might increase the saturated field.

  10. Atlantic Meridional Overturning Circulation slowdown cooled the subtropical ocean.

    Science.gov (United States)

    Cunningham, Stuart A; Roberts, Christopher D; Frajka-Williams, Eleanor; Johns, William E; Hobbs, Will; Palmer, Matthew D; Rayner, Darren; Smeed, David A; McCarthy, Gerard

    2013-12-16

    [1] Observations show that the upper 2 km of the subtropical North Atlantic Ocean cooled throughout 2010 and remained cold until at least December 2011. We show that these cold anomalies are partly driven by anomalous air-sea exchange during the cold winters of 2009/2010 and 2010/2011 and, more surprisingly, by extreme interannual variability in the ocean's northward heat transport at 26.5°N. This cooling driven by the ocean's meridional heat transport affects deeper layers isolated from the atmosphere on annual timescales and water that is entrained into the winter mixed layer thus lowering winter sea surface temperatures. Here we connect, for the first time, variability in the northward heat transport carried by the Atlantic Meridional Overturning Circulation to widespread sustained cooling of the subtropical North Atlantic, challenging the prevailing view that the ocean plays a passive role in the coupled ocean-atmosphere system on monthly-to-seasonal timescales.

  11. Kinematic solar dynamo models with a deep meridional flow

    Science.gov (United States)

    Guerrero, G. A.; Muñoz, J. D.

    2004-05-01

    We develop two different solar dynamo models to verify the hypothesis that a deep meridional flow can restrict the appearance of sunspots below 45°, proposed recently by Nandy & Choudhuri. In the first one, a single polytropic approximation for the density profile was taken, for both radiative and convective zones. In the second one, that of Pinzon & Calvo-Mozo, two polytropes were used to distinguish between both zones. The magnetic buoyancy mechanism proposed by Dikpati & Charbonneau was chosen in both models. We have in fact obtained that a deep meridional flow pushes the maxima of toroidal magnetic field towards the solar equator, but, in contrast to Nandy & Choudhuri, a second zone of maximal fields remains at the poles. The second model, although closely resembling the solar standard model of Bahcall et al., gives solar cycles three times longer than observed.

  12. Kinematic solar dynamo models with a deep meridional flow

    CERN Document Server

    Guerrero, G A

    2004-01-01

    We develop two different solar dynamo models to verify the hypothesis that a deep meridional flow can restrict the apperance of sunspots below 45 degrees, proposed by Nandy & Choudhuri (2002). In the first one, a single polytropic approximation for the density profile was taken, for both radiative and convective zones. In the second one, two polytropes were used to distinguish between both zones Pinzon & Calvo-Mozo (2001). The magnetic buoyancy mechanism proposed by Dikpati & Charbonneau (1999) was chosen in both models. We, actually, have obtained that a deep meridional flow pushes the maxima of toroidal magnetic field toward the solar equator, but in contrast to Nandy & Choudhuri (2002) a second zone of maximal fields remains at the poles. The second model, although closely resembling the solar standard model of Bahcall, Pinsonneault & Wasserbug (1995); Bahcall, Pinsonneault & Basu (2001), gives solar cyles three times longer than observed.

  13. The mean meridional circulation and midlatitude ozone buildup

    Directory of Open Access Journals (Sweden)

    G. Nikulin

    2005-06-01

    Full Text Available The development of wintertime ozone buildup over the Northern Hemisphere (NH midlatitudes and its connection with the mean meridional circulation in the stratosphere are examined statistically on a monthly basis from October to March (1980–2002. The ozone buildup begins locally in October with positive ozone tendencies over the North Pacific, which spread eastward and westward in November and finally cover all midlatitudes in December. During October–January a longitudinal distribution of the ozone tendencies mirrors a structure of quasi-stationary planetary waves in the lower stratosphere and has less similarity with this structure in February–March when chemistry begins to play a more important role. From November to March, zonal mean ozone tendencies (50°–60° N show strong correlation (|r|=0.7 with different parameters used as proxies of the mean meridional circulation, namely: eddy heat flux, the vertical residual velocity (diabatically-derived and temperature tendency. The correlation patterns between ozone tendency and the vertical residual velocity or temperature tendency are more homogeneous from month to month than ones for eddy heat flux. A partial exception is December when correlation is strong only for the vertical residual velocity. In October zonal mean ozone tendencies have no coupling with the proxies. However, positive tendencies averaged over the North Pacific correlate well, with all of them suggesting that intensification of northward ozone transport starts locally over the Pacific already in October. We show that the NH midlatitude ozone buildup has stable statistical relation with the mean meridional circulation in all months from October to March and half of the interannual variability in monthly ozone tendencies can be explained by applying different proxies of the mean meridional circulation.

  14. Receiver function images from the Moho and the slab beneath the Altiplano and Puna plateaus in the Central Andes

    Science.gov (United States)

    Wölbern, I.; Heit, B.; Yuan, X.; Asch, G.; Kind, R.; Viramonte, J.; Tawackoli, S.; Wilke, H.

    2009-04-01

    Teleseismic data recorded during one and a half years are investigated with the receiver function technique to determine the crustal and upper-mantle structures underneath the highly elevated Altiplano and Puna plateaus in the central Andes. A series of converting interfaces are determined along two profiles at 21°S and 25.5°S, respectively, with a station spacing of approximately 10 km. The data provide the highest resolution gained from a passive project in this area, so far. The oceanic Nazca plate is detected down to 120 km beneath the Altiplano whereas beneath the Puna, the slab can unexpectedly be traced down to 200 km depth at longer periods. A shallow crustal low-velocity zone is determined beneath both plateaus exhibiting segmentation. In the case of the Altiplano, the segments present vertical offsets and are separated by inclined interfaces, which coincide with major fault systems at the surface. An average depth to Moho of about 70 km is determined for the Altiplano plateau. A strong negative velocity anomaly located directly below the Moho along with local crustal thinning is interpreted beneath the volcanic arc of the Altiplano plateau between 67°W and 68.5°W. A deep section of the Puna profile reveals thinning of the mantle transition zone. Although poorly resolved, the detected anomaly may suggest the presence of a mantle plume, which may constitute the origin of the anomalous temperatures at the depth of the upper-mantle discontinuities.

  15. Diatomeas (Bacillariophyceae de Ambientes Acuáticos de Altura de la Provincia de Catamarca, Argentina II Diatoms (Bacillariophyceae from high altitude aquatic environments of Catamarca Province in Argentina. II

    Directory of Open Access Journals (Sweden)

    Nora I. Maidana

    2006-07-01

    Full Text Available En esta contribución al conocimiento de las diatomeas de humedales de altura, se analizaron 14 muestras pertenecientes a distintos cuerpos de agua de la Provincia de Catamarca (Argentina, entre los 2420 y 4240 m s. n. m. Se identificaron 208 taxones infragenéricos de los cuales 90 son nuevas citas para la Provincia de Catamarca. Se mencionan por primera vez para Argentina los géneros: Frankophila y Microcostatus y las especies: Achnanthes thermalis var. rumrichorum Lange-Bertalot; Amphora mira Krasske; Brachysira atacamae Hustedt; Frankophila similioides Lange-Bertalot & Rumrich; Gomphonema punae Lange-Bertalot & Rumrich; Haloroundia speciosa Diaz & Maidana; Luticola mollis Lange-Bertalot& Rumrich; Mastogloia atacamae Hustedt; Microcostatus andinus Lange-Bertalot & Rumrich; Navicula atacamana Patrick; Navicula parinacota Rumrich & Lange-Bertalot; Planothidium chilense (Hustedt Lange-Bertalot; Staurosira pseudoconstruens (Marciniak Lange-Bertalot; Surirella chilensis var constricta Hustedt y Surirella wetzellii Hustedt. Además se propone una nueva combinación: Ulnaria ulna var. constricta.In this research focusing the diatoms of high topographic wetlands, 14 samples of different freshwater bodies (between 2,420 and 4,240 m a. s. l. were studied. Two hundred and eight infrageneric taxa were identified, 90 of them are new records for the Catamarca province. The genera: Frankophila and Microcostatus and the species Achnanthes thermalis var. rumrichorum Lange-Bertalot; Amphora mira Krasske; Brachysira atacamae Hustedt; Frankophila similioides Lange-Bertalot & Rumrich; Gomphonema punae Lange-Bertalot & Rumrich; Haloroundia speciosa Diaz & Maidana; Luticola mollis Lange-Bertalot & Rumrich; Mastogloia atacamae Hustedt; Microcostatus andinus Lange-Bertalot& Rumrich; Navicula atacamana Patrick; Navicula parinacota Rumrich & Lange-Bertalot; Planothidium chilense (Hustedt Lange-Bertalot; Staurosira pseudoconstruens (Marciniak Lange-Bertalot; Surirella

  16. Response To And Lessons Learned From Two Back-To-Back Disasters At Kilauea Volcano, Puna District, Hawaii

    Science.gov (United States)

    Gregg, C. E.; Houghton, B. F.; Kim, K.

    2015-12-01

    The Puna District, Hawaii, is exposed to many natural hazards, including those associated with volcanic eruptions and tropical storms, but for decades Puna has also been the fastest growing District in the state due to its affordable real estate. In 2014, populated areas were affected by back-to-back hurricane and volcanic eruption crises. Both events were declared Presidential Disasters and tested response and recovery systems of many of Puna's 49, 000 residents, government services and businesses. This paper summarizes individual and organizational response to the two crises: the relatively rapid onset Tropical Storm Iselle, which made landfall in Puna on August 5 and the slow onset June 27 lava flow. The latter took some 2 months to advance to the edge of developed areas, prompting widespread community reaction. While the lava flows no longer pose an immediate threat to development because they are repaving remote, near-source and upflow areas, the lava could again advance into developed areas over similar time scales as in 2014. Puna is mostly a rural setting with many narrow, privately owned dirt roads. Some residents have no municipal electricity and water; they use solar and gasoline generators and rain catchment systems. High winds and collapse of exotic Albizia trees during Iselle isolated many residents, but people self-organized through social media to respond and recover. Social media and community meetings dominated information sharing during the lava crisis. Major expenses were incurred in response to the lava crisis, primarily through upgraded alternate roads that provide redundancy and construction of temporary school buildings linked to evacuation and relocation of students. Experiences during Iselle primed residents to rapidly self-organize and address the impending inundation by slow moving lava flows which advanced in uncertain directions at rates of 0-450 m/day. People's demand for constant and near-real time information from authorities placed

  17. A cluster of human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis in Jujuy, Argentina.

    Science.gov (United States)

    Biglione, Mirna M; Pizarro, Manuel; Puca, Alberto; Salomón, Horacio E; Berría, Maria I

    2003-04-01

    Compared with other regions in Argentina, greater human T-cell lymphotropic virus type I (HTLV-I) seroprevalence has been reported in Jujuy Province, where it reaches 2.32% in the general population, so that a search for HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) cases deserved to be carried out. Accordingly, a clinically diagnosed and serologically confirmed cluster of cases in 1 man and 10 women, including 2 sisters, is described here. Most patients (9/11) were born in Cochinoca Department, located in an Andes highland area called Puna Jujeña, situated at more that 3400 m above sea level. No history of risk factors was disclosed, except for a single transfusion in 1 patient. In contrast to the Andean region of Bolivia, where high HTLV-I seroprevalence is in part attributable to Japanese immigrants, the Jujuy population mainly consists of aborigines, mestizos, and European descendants. Therefore, the long-term presence of virus in Jujuy natives may be taken for granted. Considering the HAM/TSP cluster described here plus previously reported isolated cases in neighboring Salta Province, we speculate that the Puna Jujeña region and regions in that vicinity would be a microepidemic focus of disease. To determine the role of possible pathogenic cofactors such as geographic, ethnic, genetic, and cultural features, further pertinent surveys are required in subtropical northwestern Argentina.

  18. Archaeology in the Kilauea East Rift Zone: Part 2, A preliminary sample survey, Kapoho, Kamaili and Kilauea geothermal subzones, Puna District, Hawaii island

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, M.T.K.; Burtchard, G.C. [International Archaeological Research Inst., Inc., Honolulu, HI (United States)

    1995-05-01

    This report describes a preliminary sample inventory and offers an initial evaluation of settlement and land-use patterns for the Geothermal Resources Subzones (GRS) area, located in Puna District on the island of Hawaii. The report is the second of a two part project dealing with archaeology of the Puna GRS area -- or more generally, the Kilauea East Rift Zone. In the first phase of the project, a long-term land-use model and inventory research design was developed for the GRS area and Puna District generally. That report is available under separate cover as Archaeology in the Kilauea East Rift Zone, Part I: Land-Use Model and Research Design. The present report gives results of a limited cultural resource survey built on research design recommendations. It offers a preliminary evaluation of modeled land-use expectations and offers recommendations for continuing research into Puna`s rich cultural heritage. The present survey was conducted under the auspices of the United States Department of Energy, and subcontracted to International Archaeological Research Institute, Inc. (IARII) by Martin Marietta Energy Systems, Inc. The purpose of the archaeological work is to contribute toward the preparation of an environmental impact statement by identifying cultural materials which could be impacted through completion of the proposed Hawaii Geothermal Project.

  19. Estudios sedimentológicos en los depósitos carboníferos y pérmicos del borde occidental de la puna

    Directory of Open Access Journals (Sweden)

    Claudia Inés Galli

    2010-03-01

    Full Text Available Se realizó el estudio de los depósitos carboníferos y pérmicos expuestos al sudoeste del Salar del Rincón, en el borde occidental de la Puna argentina; éstos comprenden a las capas rojas continentales de la Formación Cerro Oscuro (Carbonífero Superior y a las calizas marinas de la Formación Arizaro (Pérmico Inferior. La columna estratigráfica analizada consta de 480 m de rocas clásticas y carbonáticas, con niveles volcaniclásticos intercalados. Los depósitos integran una estructura sinclinal de rumbo NNO, que se hunde hacia el NO. Los depósitos carbonífero-pérmicos fueron relevados en ambos flancos del sinclinal. En base a las características estratigráficas y sedimentológicas analizadas en las Formaciones Cerro Oscuro y Arizaro, se brindan nuevas interpretaciones paleoambientales: i. La secuencia grano y estratodecreciente que documenta la Formación Cerro Oscuro comprende, de base a techo, flujos de detritos acumulados en un sistema de abanico aluvial y tres ciclos o secuencias positivas, correspondientes a un sistema fluvial gravoso a arenoso tipo braided. ii. En las secciones analizadas, la relación entre las Formaciones Cerro Oscuro y Arizaro es una paraconformidad. iii. La Formación Arizaro comprende tres ciclos desarrollados en paleoambientes de plataforma marina silicoclástico - carbonática. Se describen características mineralógicas y petrográficas de las facies reconocidas y se incorpora un análisis de proveniencia, que sugiere la existencia de diferentes áreas de aporte. Se analiza la transgresión que documenta la Formación Arizaro y se la vincula con el evento de inundación global que provocaron los fenómenos de deglaciación ocurridos durante el Artinskiano-Kunguriano. Se discute la injerencia de procesos tectónicos y volcánicos que habrían afectado la cuenca durante su evolución.

  20. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

    Directory of Open Access Journals (Sweden)

    M.R. Alberto

    2009-09-01

    Full Text Available We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida that grow in the Argentine Puna (3800 m above sea level and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL, mainly flavones and flavonols (0.1-0.8 mg/mL. The extracts showed hydrogen donating ability (DPPH and ABTS and reactive oxygen species scavenging activity (O2●-, OH-, H2O2. The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2 was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  1. Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna.

    Science.gov (United States)

    Alberto, M R; Zampini, I C; Isla, M I

    2009-09-01

    We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 microg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 microM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

  2. Medical revolution in Argentina.

    Science.gov (United States)

    Ballarin, V L; Isoardi, R A

    2010-01-01

    The paper discusses the major Argentineans contributors, medical physicists and scientists, in medical imaging and the development of medical imaging in Argentina. The following are presented: history of medical imaging in Argentina: the pioneers; medical imaging and medical revolution; nuclear medicine imaging; ultrasound imaging; and mathematics, physics, and electronics in medical image research: a multidisciplinary endeavor.

  3. Argentina Welcomes Chinese Enterprises

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ On July 13,China-Argentina Entrepreneur Luncheon Meeting was held in Beijing.Cristina Fernandez de Kirchner,President of Argentina,Hui Liangyu,Vice Prime Minister of China and Wan Jifei,President of CCPIT attended the meeting.

  4. Instability of Meridional Axial System in f(R) Gravity

    CERN Document Server

    Sharif, M

    2015-01-01

    We analyze dynamical instability of non-static reflection axial stellar structure by taking into account generalized Euler's equation in metric $f(R)$ gravity. Such an equation is obtained by contracting Bianchi identities of usual anisotropic and effective stress-energy tensors, which after using radial perturbation technique gives modified collapse equation. In the realm of $R+\\epsilon R^n$ gravity model, we investigate instability constraints at Newtonian and post-Newtonian approximations. We find that instability of meridional axial self-gravitating system depends upon static profile of structure coefficients while $f(R)$ extra curvature terms induce stability to the evolving celestial body.

  5. The Meridional Flux of Sensible Heat over the Northern Hemisphere

    OpenAIRE

    White, Robert M.

    2011-01-01

    The meridional eddy flux of sensible heat is examined by means of finite difference integration methods from northern hemisphere charts for the winter 1945-46. The eddy sensible heat flux is shown to occur principally in the lowest layers of the atmosphere and to decrease with elevation. The magnitude of the eddy sensible heat transports are compared with the total poleward energy flux required by the radiation balance, and are shown to comprise a very large fraction of this flux.DOI: 10.1111...

  6. Sedimentary record of regional deformation and dynamics of the thick-skinned southern Puna Plateau, central Andes (26-27°S)

    Science.gov (United States)

    Zhou, Renjie; Schoenbohm, Lindsay M.; Sobel, Edward R.; Carrapa, Barbara; Davis, Donald W.

    2016-01-01

    The Puna Plateau, adjacent Eastern Cordillera and the Sierras Pampeanas of the central Andes are largely characterized by thick-skinned, basement-involved deformation. The Puna Plateau hosts ∼N-S trending bedrock ranges bounded by deep-seated reverse faults and sedimentary basins. We contribute to the understanding of thick-skinned dynamics in the Puna Plateau by constraining regional kinematics of the poorly understood southern Puna Plateau through a multidisciplinary approach. On the southeastern plateau, sandstone modal composition and detrital zircon U-Pb and apatite fission-track data from Cenozoic strata indicate basin accumulation during the late Eocene to early Oligocene (∼38-28 Ma). Provenance analysis reveals the existence of a regional-scale basin covering the southern Puna Plateau during late Eocene to early Oligocene time (∼38-28 Ma) that was sourced from both the western plateau and the eastern plateau margin and had a depocenter located to the west. Petrographic and detrital zircon U-Pb data reveal erosion of proximal western and eastern sources after ∼12 Ma, in mid-late Miocene time. This indicates that the regional basin was compartmentalized into small-scale depocenters by the growth of basement-cored ranges continuing into the late Miocene (∼12-8 Ma). We suggest that the Cenozoic history of the southern Puna Plateau records the formation of a regional basin that was possibly driven by lithospheric flexure during the late Eocene to early Oligocene, before the growth of distributed basement-cored ranges starting as early as the late Oligocene.

  7. Los testimonios de Marte en la Meseta Meridional

    Directory of Open Access Journals (Sweden)

    Julián Hurtado Aguña

    2001-01-01

    Full Text Available Marte, fue una de las más importantes divinidades romanas presentes en Híspanla. Dentro de la Meseta meridional sus testimonios aparecen en algunas localidades de la provincia de Madrid, como Alcalá de Henares, Talamanca del Jarama o Collado Villalba, estando ausentes en otras partes de esta región. Especialmente importante es la presencia de inscripciones dedicadas a Marte en la ciudad romana de Complutum (Alcalá de Henares, donde sus dedicantes pudieran pertenecer en algún caso al grupo social de los libertos.One oí the most important román divinities in Híspanla was Mars. His testimonies in the Meridional Plateau are in some villages of Madrid's province, as Alcalá de Henares, Talamanca del Jarama or Collado Villalba, and they are not in other places of this reglan. Specially important is ttie presence of inscriptions to Mars in ttie román town of Complutum (Alcalá de Henares, wtiere his devotes could belong to the social freedmans group.

  8. Radial Transport and Meridional Circulation in Accretion Disks

    Science.gov (United States)

    Philippov, Alexander A.; Rafikov, Roman R.

    2017-03-01

    Radial transport of particles, elements and fluid driven by internal stresses in three-dimensional (3D) astrophysical accretion disks is an important phenomenon, potentially relevant for the outward dust transport in protoplanetary disks, origin of the refractory particles in comets, isotopic equilibration in the Earth–Moon system, etc. To gain better insight into these processes, we explore the dependence of meridional circulation in 3D disks with shear viscosity on their thermal stratification, and demonstrate a strong effect of the latter on the radial flow. Previous locally isothermal studies have normally found a pattern of the radial outflow near the midplane, switching to inflow higher up. Here we show, both analytically and numerically, that a flow that is inward at all altitudes is possible in disks with entropy and temperature steeply increasing with height. Such thermodynamic conditions may be typical in the optically thin, viscously heated accretion disks. Disks in which these conditions do not hold should feature radial outflow near the midplane, as long as their internal stress is provided by the shear viscosity. Our results can also be used for designing hydrodynamical disk simulations with a prescribed pattern of the meridional circulation.

  9. CARACTERIZACIÓN FÍSIOGRÁFICA DE LA PUNA DE SAJAMA, CORDILLERA OCCIDENTAL DE LOS ANDES (BOLIVIA

    Directory of Open Access Journals (Sweden)

    Fernando Javier Santa Cecilia Mateos

    2015-01-01

    Full Text Available Este artículo aproxima a la realidad física de la cordillera Occidental de los Andes. Un espacio geográfico donde los caracteres geológicos relacionados con el vulcanismo adquieren una relevancia especial en la configuración del paisaje andino. Los nevados y llanuras intermedias o altiplanos, son los dos elementos que constituyen la imagen de la puna andina, un territorio situado por encima de los 4.000 metros, ámbito intermedio entre los valles húmedos o yungas y las más altas cumbres de los Andes. A la singularidad volcánica habría que añadir la relacionada con el modelado glaciar, los aspectos hidrográficos y la biogeografia en esta área. El artículo toma como ejemplo de estudio la puna de Sajama en eldepartamento de Oruro, en la frontera boliviano-chilena.Abstract. This article approaches the physical reality of the Western Cordillera of the Andes. A geographical space where characters related geological volcanism are of particular importance in shaping the landscape Andean. The intermediate plains or mountains and plateaus, are the two elements that make up the image of the Andean puna, an area located above 4,000 meters, the middle ground between Yungas wet valley and the highest peaks of the Andes. A volcanic uniqueness should add that related to glacier modeling, hydrographic aspects and biogeography in this area. The article uses the example of the highlands of Sajama study in thedepartment of Oruro in Bolivian-Chilean border.

  10. Using earthquake clusters to identify fracture zones at Puna geothermal field, Hawaii

    Science.gov (United States)

    Lucas, A.; Shalev, E.; Malin, P.; Kenedi, C. L.

    2010-12-01

    The actively producing Puna geothermal system (PGS) is located on the Kilauea East Rift Zone (ERZ), which extends out from the active Kilauea volcano on Hawaii. In the Puna area the rift trend is identified as NE-SW from surface expressions of normal faulting with a corresponding strike; at PGS the surface expression offsets in a left step, but no rift perpendicular faulting is observed. An eight station borehole seismic network has been installed in the area of the geothermal system. Since June 2006, a total of 6162 earthquakes have been located close to or inside the geothermal system. The spread of earthquake locations follows the rift trend, but down rift to the NE of PGS almost no earthquakes are observed. Most earthquakes located within the PGS range between 2-3 km depth. Up rift to the SW of PGS the number of events decreases and the depth range increases to 3-4 km. All initial locations used Hypoinverse71 and showed no trends other than the dominant rift parallel. Double difference relocation of all earthquakes, using both catalog and cross-correlation, identified one large cluster but could not conclusively identify trends within the cluster. A large number of earthquake waveforms showed identifiable shear wave splitting. For five stations out of the six where shear wave splitting was observed, the dominant polarization direction was rift parallel. Two of the five stations also showed a smaller rift perpendicular signal. The sixth station (located close to the area of the rift offset) displayed a N-S polarization, approximately halfway between rift parallel and perpendicular. The shear wave splitting time delays indicate that fracture density is higher at the PGS compared to the surrounding ERZ. Correlation co-efficient clustering with independent P and S wave windows was used to identify clusters based on similar earthquake waveforms. In total, 40 localized clusters containing ten or more events were identified. The largest cluster was located in the

  11. Giant magmatic water reservoir beneath Uturuncu volcano and Altiplano-Puna region (Central Andes)

    Science.gov (United States)

    Laumonier, Mickael; Gaillard, Fabrice; Muir, Duncan; Blundy, Jon; Unsworth, Martyn

    2016-04-01

    Volcanism at continental arcs is the surface manifestation of long-lived crustal magmatic processes whereby mantle-derived hydrous basalt magma differentiates to more silica-rich magmas by a combination of crystallization and crustal melting. What erupts is just a fraction of the total volume of magma produced by these processes; the unerupted, plutonic residues solidify and are inaccessible to direct study until millions of years of uplift and erosion bring them to the surface. In contrast, geophysical surveys, using electromagnetic and seismic waves, can provide real-time images of subduction zone magmatic systems. Several such studies have revealed that arc volcanoes are underlain by large partially molten regions at depths of >10 km, the largest known example being the Altiplano-Puna magma body (APMB) in central Andes. Interpreting such geophysical images in terms of amount, composition and distribution of partial melts is limited by our lack of knowledge of the physical properties of silicate melts at elevated pressures and temperatures. Here we present high-pressure, in situ experimental data showing that the electrical conductivity of andesitic melts is primarily controlled by their dissolved water contents. Linking our new measurements to petrological constraints from andesites erupted on the Altiplano, we show that the APMB is composed of 10-20% of an andesitic melt containing 8-10 wt% dissolved water. This implies that the APMB is a giant water anomaly in the global subduction system, with a total mass of dissolved magmatic water about half of the water contained within the Adriatic Sea. In addition to the controls on the physical properties of the melts, the abundance of dissolved water governs the structural levels of magma ponding, equivalent to the depth of water saturation, where degassing and crystallisation promote partial melting and weakening of the upper crust. Unexpectedly, very high concentrations of water in andesite magmas shall impede their

  12. Constraints for recently discovered ignimbrites in the Altiplano-Puna Volcanic Complex (APVC), northern Chile

    Science.gov (United States)

    Layana, S.; Aguilera, F.

    2014-12-01

    One of most voluminous ignimbrite provinces in the world (>30.000 km3) is located in the Central Andean Volcanic Zone (CAVZ), which has been continuously active since Upper Oligocene. Altiplano-Puna Volcanic Complex (APVC), located between 21 and 24ºS, is a volcano-tectonic province constituted by diverse caldera complexes and ignimbrite deposits (Upper Miocene - Lower Pleistocene) that covers an area ~50.000 km2. In this work, we present data from three new ignimbrites discovered in a portion of APVC (22°-22,4°S), with the objective to establish its origin and provenance. Were identified 3 new ignimbrites: 1) Cabana ignimbrite (>7.5 Ma), constituted by 3 pyroclastic flow and 1 pyroclastic surge units of crystal-glass rich dacitic tuffs, 80 m maximum thick, 0.18 km3 volume and 0.14 km3 DRE; 2) Inacaliri ignimbrite (7.5 Ma) constituted by two members, corresponding to glassy dacitic (basal member) and basaltic andesites (upper member) tuffs, the total thick reach up 20 m, 0.003 km3 volume and 0.002 km3 DRE; 3) Tolar ignimbrite (>1.3 Ma), constituted by a single pyroclastic flow and a basal fall glassy dacitic deposits, 50 m maximum thick, 0.04 km3 volume and 0.03 km3 DRE. Cabana ignimbrite seems to have been originated from a single caldera complex, whose cannot be recognized in the field. Inacaliri ignimbrite could be related to initial phases of building of Inacaliri and Apacheta-Aguilucho volcanic complexes, or originated to a buried caldera located below both volcanic complexes. Finally, Tolar ignimbrite corresponds to initial building stage of Toconce volcano, located 2 km at NE from these deposits.

  13. Surveys of arthropod and gastropod diversity in the geothermal resource subzones, Puna, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.E.; Burgett, J.; Bruegmann, M.

    1995-04-01

    The invertebrate surveys reported here were carried out as part of ecological studies funded by the Department of Energy in support of their environmental impact statement (EIS) for the Hawaii Geothermal Project. Currently, preparation of the EIS has been suspended, and all supporting information is being archived and made available to the public. The invertebrate surveys reported here assessed diversity and abundance of the arthropod and gastropod fauna in forested habitat and lava tubes in or near the three geothermal resource subzones. Recommendations for conservation of these organisms are given in this report. Surveys were conducted along three 100-m transect lines at each of the six forested locations. Malaise traps, baited pitfall traps, yellow pan traps, baited sponge lures, and visual examination of vegetation were used to assess invertebrate diversity along each transect line. Three of these locations were adjacent to roads, and three were adjacent to lava flows. Two of these lava-forest locations (Keauohana Forest Reserve and Pu`u O`o) were relatively remote from direct human impacts. The third location (Southeast Kula) was near a low-density residential area. Two lava tubes were surveyed. The forest over one of these tubes (Keokea tube) had recently been burned away. This tube was used to assess the effects of loss of forest habitat on the subterranean fauna. An undisturbed tube (Pahoa tube) was used as a control. Recommendations offered in this report direct geothermal development away from areas of high endemic diversity and abundance, and toward areas where natural Hawaiian biotic communities have already been greatly disturbed. These disturbed areas are mainly found in the lower half of the Kamaili (middle) geothermal subzone and throughout most of the Kapoho (lower) geothermal subzone. These recommendation may also generally apply to other development projects in the Puna District.

  14. Light transmission for polymer fibers using skew and meridional rays

    Science.gov (United States)

    Tekelioglu, Murat

    This dissertation is concerned with the development of a light transmission model for polymer optical fibers having application in hybrid solar lighting (HSL) systems. Conceptually, the HSL system consists of a solar collector/receiver that focuses concentrated visible solar light onto a polymer optical fiber (up to 10-m-long) that transports the solar light to an interior space. For this study, the polymer optical fiber is a large-core (0.2-40 mm diameter) plastic optical fiber (POF) comprised of various lengths of straight and bent sections. Although there has been extensive research on the transmission of monochromatic light through optical fibers for the communications industry, there are relatively few publications for visible light transmission through POFs. These publications were critically reviewed in this research. It is shown that the light transmission can be described with either skew or meridional rays. For each ray type, the HSL system light transmission was determined as a function of fiber geometrical properties (core and cladding radii, bend radius, bend angle, and fiber length) and optical properties (core and clad refractive indices, absorption and scattering coefficients, core-clad rms roughness height, and core-clad interface defects loss coefficient). To do this, first, models were developed for separate straight and bent sections for multiple skew and meridional rays. Second, the straight and bent models were combined into a FORTRAN simulation program for an arbitrary fiber with a combination of arbitrary straight and bent sections. The input condition of the rays (arrangement of rays, incident angle, and intensity profile) is user-defined. Third, the simulation results were experimentally validated using two different POFs, twelve configurations of straight and bent fiber subsystems, and two ray types. These experimental comparisons show that the transmission model using meridional rays is slightly better than that with the skew rays. But

  15. Instability of meridional axial system in f(R) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Sharif, M.; Yousaf, Z. [University of the Punjab, Department of Mathematics, Lahore (Pakistan)

    2015-05-15

    We analyze the dynamical instability of a non-static reflection axial stellar structure by taking into account the generalized Euler equation in metric f(R) gravity. Such an equation is obtained by contracting the Bianchi identities of the usual anisotropic and effective stress-energy tensors, which after using a radial perturbation technique gives a modified collapse equation. In the realm of the R + εR{sup n} gravity model, we investigate instability constraints at Newtonian and post-Newtonian approximations. We find that the instability of a meridional axial self-gravitating system depends upon the static profile of the structure coefficients, while f(R) extra curvature terms induce the stability of the evolving celestial body. (orig.)

  16. Meridional Winds derived from ionosonde measurements: comparison of different models

    Science.gov (United States)

    Katamzi, Zama; Bosco Habarulema, John; Aruliah, Anasuya

    2016-07-01

    Thermospheric meridional winds are derived from ionospheric F2 region peak parameters (i.e. F2 maximum density, NmF2, and F2 peak height, hmF2) obtained using South African ionosonde for solar maximum (2001 and 2014) and solar minimum (2009). The study uses several different techniques and models to investigate the climatology behaviour of the winds in order to understand wind variability over South Africa. Detailed solar cycle, seasonal and diurnal trends will help establish how the winds influence ionospheric behaviour at this latitude. Comparisons of ionosonde derived neutral winds with empirical and numerical models such as the Coupled Middle Atmosphere Thermosphere Model (CMAT2) and Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) are important to understand the validity of theoretical and empirical models.

  17. Pulling the Meridional Overturning Circulation From the South DESC0005100

    Energy Technology Data Exchange (ETDEWEB)

    Cessi, Paola [Univ. of California, San Diego, CA (United States); Wolfe, Christopher L. [Scripps Inst. of Oceanography, San Diego, CA (United States)

    2015-11-25

    This project concerned the Atlantic Meridional Overturning Circulation (AMOC), its stability, variability and sensitivity to atmospheric forcing, both mechanical (wind-stress) and thermodynamical (heat and freshwater surface fluxes). The focus of the study is the interhemispheric cell in the largely adiabatic regime, where the flow is characterized by a descending branch in the high latitudes of the North Atlantic and the upwelling branch in the Antarctic Circumpolar Current (ACC) region of the Southern Ocean. These two end points are connected by shared isopycnals along which the flow takes place. The approach is to systematically study the amplitude and frequency of the AMOC’s response to localized buoyancy with an ocean-only model in both coarse and high-resolution configurations, analyzed with innovative diagnostics, focused on the “residual overturning circulation” (ROC), which is the proper measure of the transport of heat and other tracers.

  18. An analytical framework for understanding tropical Meridional Modes

    CERN Document Server

    Martinez-Villalobos, Cristian

    2016-01-01

    A theoretical framework is developed for understanding the transient growth and propagation characteristics of thermodynamically coupled, meridional mode-like structures in the tropics. The model consists of a Gill-Matsuno type steady atmosphere under the longwave approximation coupled via a wind-evaporation-sea surface temperature (WES) feedback to a "slab" ocean model. When projected onto basis functions for the atmosphere the system simplifies to a non-normal set of equations that describes the evolution of individual sea surface temperature (SST) modes, with clean separation between symmetric and anti-symmetric modes. The following major findings result from analysis of the system: (i) a transient growth process exists whereby specific SST modes propagate toward lower order modes at the expense of the higher-order modes; (ii) the same dynamical mechanisms govern the evolution of symmetric and anti-symmetric SST modes except for the lowest-order wave number, where for symmetric structures the atmospheric K...

  19. The Atlantic Meridional Overturning Circulation and Abrupt Climate Change

    Science.gov (United States)

    Lynch-Stieglitz, Jean

    2017-01-01

    Abrupt changes in climate have occurred in many locations around the globe over the last glacial cycle, with pronounced temperature swings on timescales of decades or less in the North Atlantic. The global pattern of these changes suggests that they reflect variability in the Atlantic meridional overturning circulation (AMOC). This review examines the evidence from ocean sediments for ocean circulation change over these abrupt events. The evidence for changes in the strength and structure of the AMOC associated with the Younger Dryas and many of the Heinrich events is strong. Although it has been difficult to directly document changes in the AMOC over the relatively short Dansgaard-Oeschger events, there is recent evidence supporting AMOC changes over most of these oscillations as well. The lack of direct evidence for circulation changes over the shortest events leaves open the possibility of other driving mechanisms for millennial-scale climate variability.

  20. Introduction to: Atlantic Meridional Overturning Circulation(AMOC)

    Science.gov (United States)

    Hakkinen, Sirpa; Carton, James A.

    2011-01-01

    A striking conclusion of the Intergovernmental Panel on Climate Change 2007 report is the crucial role that the Atlantic Meridional Overturning Circulation (AMOC) may play in anthropogenic climate change. However, these IPCC coupled climate simulations show a broad range of uncertainty in the magnitude and timing of AMOC transport change ranging from none to nearly complete collapse within the 21st century. The potential consequences of large changes in the characteristics of AMOC have motivated the creation in the United States of an interagency program and implementation plan to develop monitoring and prediction capabilities for the AMOC This program parallels the development of substantial monitoring efforts by European, South American and African countries -- notably the UK Rapid and Rapid-Watch programs. The papers contained in this volume are derived from presentations at the First U.S. Atlantic Meridional Overturning Circulation (AMOC) Meeting held 4 - 6 May, 2009 to review the US implementation plan and its coordination with other monitoring activities. The Atlantic Meridional Overturning Circulation consists of multiple components illustrated in an attached figure. Water enters the South Atlantic at upper and intermediate depths through both western and eastern routes (where eddy transport is especially important) and is transported northward across the equator, where it recirculates within the northern subtropical and subpolar gyres. The northern end is defined by the sinking regions of the Nordic Seas and the Labrador Sea where the waters that eventually form the upper and lower branches of North Atlantic Deep Water are conditioned. High surface salinities, the result of high net evaporation in the tropics and subtropics (including the Mediterranean Sea), and presence of regions of the Arctic Ocean that remain ice-free even in winter allow for the rapid cooling and thus densification of surface water. This dense surface water becomes the source of deep

  1. Astronomy in Argentina

    CERN Document Server

    Muriel, Hernán

    2013-01-01

    This article analyses the current state of Astronomy in Argentina and describes its origins. We briefly describe the institutions where astronomical research takes place, the observational facilities available, the training of staff and professionals, and the role of the institutions in scientific promotion. We also discuss the outreach of Astronomy towards the general public, as well as amateur activities. The article ends with an analysis of the future prospects of astronomy in Argentina.

  2. North Pacific Meridional Mode over the Common Era

    Science.gov (United States)

    Sanchez, S. C.; Charles, C. D.; Amaya, D. J.; Miller, A. J.

    2016-12-01

    The Pacific Meridional Mode (PMM) has been increasingly recognized as an influential mode of variability for channeling extratropical anomalies to the equatorial ocean-atmosphere system. The PMM has been identified as an important precursor for ENSO, a source of much decadal power in the tropical Pacific, and is potentially intensifying. It is still unknown why the Pacific Meridional Mode might be intensifying; most arguments center around the changing mean state associated with anthropogenic global warming. There are a number of processes by which the background state could influence the PMM: altering the location of trade winds, the characteristics of stochastic forcing, the sensitivity of latent heat flux to surface wind anomalies, the wind response to SST anomalies, or changing the Intertropical Convergence Zone (ITCZ) structure. Recent work has found that the PMM is particularly sensitive to ITCZ shifts in intensity and location (using a simple linear coupled model, [Martinez-Villalobos and Vimont 2016]). Over the last millennium the ITCZ has experienced epochs of notable latitudinal shifts to balance the cross equatorial energy transport. Here we investigate how the strength of the PMM may have varied with these shifts in the ITCZ over the Common Era using the CESM-Last Millennium Ensemble (LME). We assess the strength of the PMM pathway by the degree of air-sea coupling and the amplitude of tropical decadal variability. We expect the ITCZ location and the degree of air-sea coupling (WES feedback) to play a critical role in determining the effectiveness and intensity of the PMM pathway. We verify our inferences in the LME with coral paleoproxy records from the central tropical Pacific. Chiefly we target records from the Line Islands (spanning 1°N to 6°N) to infer variations in the location of the ITCZ and the amplitude of decadal variability. This work enables us to discuss the idea of an intensifying PMM in a more historical context.

  3. The Cerro Bitiche Andesitic Field: petrological diversity and implications for magmatic evolution of mafic volcanic centers from the northern Puna

    Science.gov (United States)

    Maro, Guadalupe; Caffe, Pablo J.

    2016-07-01

    The Cerro Bitiche Andesitic Field (CBAF) is one of the two largest mafic volcanic fields in northern Puna (22-24° S) and is spatially and temporally associated with ignimbrites erupted from some central Andean Altiplano-Puna Volcanic Complex calderas. The CBAF comprises seven scoria cones and widespread high-K calcalkaline lava flows that cover an area of 200 km2. Although all erupted rocks have a relatively narrow chemical range (56-62 % SiO2, 3-6 % MgO), there is a broad diversity of mineral compositions and textures. The least evolved lavas (˜58-61 % SiO2) are high-Mg andesites with scarce (andesites (˜62 wt% SiO2), on the other hand, are porphyritic rocks with plagioclase + orthopyroxene + biotite and ubiquitous phenocryst disequilibrium textures. These magmas were likely stored in crustal reservoirs, where they experienced convection caused by mafic magma underplating, magma mixing, and/or assimilation. Trace element and mineral compositions of CBAF lavas provide evidence for complex evolution of distinct magma batches.

  4. Meridional Circulation From Differential Rotation in an Adiabatically Stratified Solar/Stellar Convection Zone

    CERN Document Server

    Dikpati, Mausumi

    2013-01-01

    Meridional circulation in stellar convection zones is not generally well observed, but may be critical for MHD dynamos. Coriolis forces from differential rotation (DR) play a large role in determining what the meridional circulation is. Here we consider whether a stellar DR that is constant on cylinders concentric with the rotation axis can drive a meridional circulation.Conventional wisdom says that it can not. Using two related forms of governing equations that respectively estimate the longitudinal components of the curl of meridional mass flux and the vorticity, we show that such DR will drive a meridional flow. This is because to satisfy anelastic mass conservation, non-spherically symmetric pressure contours must be present for all DRs, not just ones that depart from constancy on cylinders concentric with the rotation axis. Therefore the fluid is always baroclinic if DR is present, because, in anelastic systems, the perturbation pressure must satisfy a Poisson type equation, as well as an equation of st...

  5. Munroa argentina, a Grass of the South American Transition Zone, Survived the Andean Uplift, Aridification and Glaciations of the Quaternary

    Science.gov (United States)

    Amarilla, Leonardo D.; Anton, Ana M.; Chiapella, Jorge O.; Manifesto, María M.; Angulo, Diego F.; Sosa, Victoria

    2015-01-01

    The South American Transition Zone (SATZ) is a biogeographic area in which not only orogeny (Andes uplift) and climate events (aridification) since the mid-Miocene, but also Quaternary glaciation cycles had an important impact on the evolutionary history of the local flora. To study this effect, we selected Munroa argentina, an annual grass distributed in the biogeographic provinces of Puna, Prepuna and Monte. We collected 152 individuals from 20 localities throughout the species’ range, ran genetic and demographic analyses, and applied ecological niche modeling. Phylogenetic and population genetic analyses based on cpDNA and AFLP data identified three phylogroups that correspond to the previously identified subregions within the SATZ. Molecular dating suggests that M. argentina has inhabited the SATZ since approximately 3.4 (4.2–1.2) Ma and paleomodels predict suitable climate in these areas during the Interglacial period and the Last Glacial Maximum. We conclude that the current distribution of M. argentina resulted from the fragmentation of its once continuous range and that climate oscillations promoted ecological differences that favored isolation by creating habitat discontinuity. PMID:26110533

  6. Melt production constrained by the topographic signature of the Altiplano-Puna Magma Body

    Science.gov (United States)

    Perkins, J. P.; Ward, K. M.; de Silva, S. L.; Zandt, G.; Beck, S. L.; Finnegan, N. J.

    2015-12-01

    The Altiplano-Puna Magma Body (APMB) is a ~200 km diameter, ~10 km thick elliptical zone of low seismic shear velocity interpreted as partial melt within the mid crust of the Central Andes (Ward et al., 2014). It is thought to be the crustal magmatic source for a flare-up of large-volume ignimbrites since 10 Ma (e.g. de Silva et al., 1989), and recent rapid uplift events such as those at Uturuncu volcano appear to be associated with magmatism from the APMB at depth (e.g., Fialko and Pearse, 2011). Hence, the APMB is a first-order geologic feature on par with the Sierra Nevada batholith in CA. Here we use the topographic signature of the low-density APMB in order to quantitatively constrain the melt production necessary to generate a magmatic zone of this size. A long-wavelength, ~1 km high topographic dome spatially coincides with the seismically measured extent of the APMB. The peak of the long wavelength dome acts as a regional drainage divide, and exposed basement rock elevations show that doming is a structural feature and does not reflect solely the accumulation of volcanic deposits on the plateau. Additionally, the minimal free-air gravity anomaly above the APMB and the dome's length scale suggest that the uplift is isostatically compensated. Based on a buried load isostatic model (e.g., Forsyth, 1985), the dome above the APMB implies that 5.6-5.8 km of crustal thickening occurred during the emplacement of the magma body. Our estimate compares well with calculations of crustal addition using magma chamber volume and a standard melt mixing model (Ward et al., 2014), and suggests that the magma production rate for the APMB may be within the range of 70-117 km3/km/yr, similar to rates of the Late Cretaceous magmatic episode in the Sierra Nevada Batholith (e.g., Ducea, 2001). Surface topography may therefore be able to provide quantitative constraints on the magnitude of pluton-scale melt fluxes.

  7. The drama of Puna: For and against the Hawai'i geothermal project

    Science.gov (United States)

    Keyser, William Henry

    The geothermal project was conceived in the context of the international oil business and the economic growth of Hawai'i. From the point of view of the State, the geothermal project is necessary because imported petroleum provides Hawai'i with 911/2 percent of its total energy. That petroleum consists of 140,000 b/d of crude (1990) and it comes from Alaska, Indonesia and a few other suppliers. However, the Alaskan North Slope is beginning to run dry and the Southeast Asian suppliers of crude will be exporting less petroleum as time goes on. Increasingly, Hawai'i will become dependent on "unstable Middle Eastern" suppliers of crude. From this worry about the Middle East, the State seeks indigenous energy to reduce its dependence on petroleum and to support economic growth. Hence, the geothermal project was born after the 1973 oil embargo. The major source of geothermal energy is the Kilauea Volcano on the Big Island. Kilauea is characterized by the Kilauea caldera and a crack in the Island which extends easterly from the caldera to Cape Kumukahi in Puna and southwest to Pahala in Ka'u. The eastern part of the crack is approximately 55 kilometers long and 5 kilometers wide. The geothermal plants will sit on this crack. While the State has promoted the geothermal project with the argument of reducing "dependence" on imported petroleum, it hardly mentions its goal of economic growth. The opponents have resisted the project on the grounds of protecting Pele and Hawaiian gathering rights, protecting the rain forest, and stopping the pollution in the geothermal steam. What the opponents do not mention is their support for economic growth. The opposition to the project suggests a new environmental politics is forming in Hawai'i. Is this true? The dissertation will show that the participants in this drama are involved in a strange dance where each side avoids any recognition of their fundamental agreement on economic growth. Hence the creation of a new environmental

  8. Helosis (Balanophoraceae en Argentina Helosis (Balanophoraceae in Argentina

    Directory of Open Access Journals (Sweden)

    José Luis Fontana

    2006-07-01

    Full Text Available Se cita por primera vez para Argentina Helosis cayennensis (Swartz Sprengel var. cayennensis en base a colecciones hechas por los autores en la Isla argentina de Apipé Grande, Ituzaingó, provincia de Corrientes. Se describe e ilustra la especie, el desarrollo de la planta y su estado de conservación. Esta cita de Helosis corresponde a un género nuevo para la flora argentina.Helosis cayennensis var. cayennensis is reported for the first time for Argentina. The species is described and ilustrated. Developement and ecology are also given. Helosis is also a new generic record for Argentina.

  9. The Meridional Mode in an Idealized Aquaplanet Model: Dependence on the Mean State

    Science.gov (United States)

    Zhang, H.; Clement, A. C.; Medeiros, B.

    2016-12-01

    The meridional mode provides a source of predictability for the tropical climate variability and change on seasonal and longer time scales by transporting extratropical climate signals into the tropics. Previous research shows that the tropical imprint of the meridional mode is constrained by the interhemispheric asymmetry of the tropical mean climate state. In this study the constraint of the zonal asymmetry is investigated in an AGCM thermodynamically coupled with an aquaplanet slab ocean model. The strategy is to modify the zonal asymmetry of the mean climate state and examine the response of the meridional mode. Presented here are two simulations of different zonal asymmetries in the mean state. In the zonally symmetric case, the meridional mode operates throughout the subtropics but only becomes evident after removing a dominant global-scale eastward-propagating mode. In the zonally asymmetric case, the meridional mode operates only in regions where trade winds converge onto the equator and has an enlarged spatial scale due to the modified mean climate including cold sea surface and weak trade winds. In both simulations, the tropical imprint of the meridional mode is constrained by the north-south seasonal migration of the intertropical convergence zone. These results suggest that the meridional mode does not require the zonal asymmetry of the mean state but is intrinsic to the subtropical ocean-atmosphere coupled system with its characteristics subject to the mean climate state. The implication is that the internal climate variability needs to be assessed in the context of the mean climate state.

  10. Estratigrafía y centros eruptivos de la region de Pairique, Puna jujeña Stratigraphy and eruptive centers of the Pairique region, Puna Jujeña

    Directory of Open Access Journals (Sweden)

    P.J. Caffe

    2007-06-01

    Full Text Available La región de Pairique en la Puna jujeña, hospeda un importante registro volcánico de edad miocena superior entre ~11,5 a ~6,6 Ma, que incluye unidades tanto piroclásticas como lávicas. Una estructura anular en el sector central de la zona de estudio fue interpretada previamente como la caldera de colapso más antigua relacionada al volcanismo cenozoico en la región del complejo volcánico Altiplano-Puna (APVC. En este trabajo se analiza la estratigrafía de la región de Pairique, en función de distinguir los productos de origen caldérico de aquéllos provenientes de otros centros. A partir de las propiedades litológicas y de las distribuciones geográfica y cronoestratigráfica, sugerimos que sólo algunas de las unidades volcánicas reconocidas se vinculan con la estructura anular de Pairique. Asimismo, no hay evidencia estratigráfica suficiente para modelar un colapso caldérico a lo largo de la misma. Consecuentemente, Pairique se redefine como un complejo volcánico, es decir un centro que experimentó volcanismo persistente durante un lapso de tiempo importante (>11.5 a ~10.3 Ma. Su modelo eruptivo deberá ser elaborado a la luz de nuevos datos estructurales y volcanológicos. En esta contribución también se reconocen otras tres zonas de procedencia para algunas unidades antes consideradas como provenientes de Pairique: volcán compuesto Nevado Torona-San Pedro, complejo volcánico Lina y complejo dómico Pairique Grande. Al igual que en el "arco interno" peruano-boliviano, el volcanismo en Pairique ha tenido características composicionales peculiares, donde coexistieron unidades andesíticas a dacíticas de tendencia calcoalcalina y volcanitas félsicas de afinidad peraluminosa (con cordierita o granate magmáticos.The Pairique region of northern Puna hosts an Upper Miocene volcanic record erupted from ~11.5 to ~6.6 Ma, which includes pyroclastic as well as lava units. A ring structure, which appears in the central zone of

  11. Numerical simulation of the sensitivity of the Pacific subtropical-tropical meridional cell to global warming

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tianjun; YU Yongqiang; LIU Hailong; LI Wei; YU Rucong

    2006-01-01

    Sensitivity of the Pacific subtropical-tropical meridional cell to global warming is examined by using a global ocean-atmosphere coupled model developed at LASG/IAP. Results indicate that associated with the increasing of atmospheric carbon dioxide, the most prominent signals of global warming locate at high latitudes, and the change of middle and low latitudes, in particular the surface wind, is relatively weak, which leads to a weak response of the Pacific subtropical-tropical meridional cell. At the time of atmospheric carbon dioxide doubling, the change of the meridional cell strength is smaller than the amplitude of natural variability.

  12. A multimodel comparison of centennial Atlantic meridional overturning circulation variability

    Energy Technology Data Exchange (ETDEWEB)

    Menary, Matthew B.; Vellinga, Michael; Palmer, Matthew D. [Met Office Hadley Centre, Exeter, Devon (United Kingdom); Park, Wonsun; Latif, Mojib [IFM-GEOMAR, Leibniz-Institut fuer Meereswissenschaften, Kiel (Germany); Lohmann, Katja; Jungclaus, Johann H. [Max Planck Inst Meteorol, Hamburg (Germany)

    2012-06-15

    A mechanism contributing to centennial variability of the Atlantic Meridional Overturning Circulation (AMOC) is tested with multi-millennial control simulations of several coupled general circulation models (CGCMs). These are a substantially extended integration of the 3rd Hadley Centre Coupled Climate Model (HadCM3), the Kiel Climate Model (KCM), and the Max Plank Institute Earth System Model (MPI-ESM). Significant AMOC variability on time scales of around 100 years is simulated in these models. The centennial mechanism links changes in the strength of the AMOC with oceanic salinities and surface temperatures, and atmospheric phenomena such as the Intertropical Convergence Zone (ITCZ). 2 of the 3 models reproduce all aspects of the mechanism, with the third (MPI-ESM) reproducing most of them. A comparison with a high resolution paleo-proxy for Sea Surface Temperatures (SSTs) north of Iceland over the last 4,000 years, also linked to the ITCZ, suggests that elements of this mechanism may also be detectable in the real world. (orig.)

  13. A multimodel comparison of centennial Atlantic meridional overturning circulation variability

    Science.gov (United States)

    Menary, Matthew B.; Park, Wonsun; Lohmann, Katja; Vellinga, Michael; Palmer, Matthew D.; Latif, Mojib; Jungclaus, Johann H.

    2012-06-01

    A mechanism contributing to centennial variability of the Atlantic Meridional Overturning Circulation (AMOC) is tested with multi-millennial control simulations of several coupled general circulation models (CGCMs). These are a substantially extended integration of the 3rd Hadley Centre Coupled Climate Model (HadCM3), the Kiel Climate Model (KCM), and the Max Plank Institute Earth System Model (MPI-ESM). Significant AMOC variability on time scales of around 100 years is simulated in these models. The centennial mechanism links changes in the strength of the AMOC with oceanic salinities and surface temperatures, and atmospheric phenomena such as the Intertropical Convergence Zone (ITCZ). 2 of the 3 models reproduce all aspects of the mechanism, with the third (MPI-ESM) reproducing most of them. A comparison with a high resolution paleo-proxy for Sea Surface Temperatures (SSTs) north of Iceland over the last 4,000 years, also linked to the ITCZ, suggests that elements of this mechanism may also be detectable in the real world.

  14. Meridional equatorial electrojet current in the American sector

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available Huancayo is the only equatorial electrojet station where the daytime increase of horizontal geomagnetic field (H is associated with a simultaneous increase of eastward geomagnetic field (Y. It is shown that during the counter electrojet period when ∆H is negative, ∆Y also becomes negative. Thus, the diurnal variation of ∆Y at equatorial latitudes is suggested to be a constituent part of the equatorial electrojet current system. Solar flares are known to increase the H field at an equatorial station during normal electrojet conditions (nej. At Huancayo, situated north of the magnetic equator, the solar flare effect, during nej, consists of positive impulses in H and Y and negative impulse in Z field. During counter electrojet periods (cej, a solar flare produces a negative impulse in H and Y and a positive impulse in Z at Huancayo. It is concluded that both the zonal and meridional components of the equatorial electrojet in American longitudes, as in Indian longitudes, flows in the same, E region of the ionosphere.

    Key words. Geomagnetism and paleomagnetism (dynamo theories · Ionosphere (equatorial ionosphere; ionosphere disturbances

  15. Diagnosing Meridional Meandering of the Antarctic Circumpolar Current

    Science.gov (United States)

    Gille, S. T.; Shao, A.

    2008-12-01

    Long-term warming trends in the Southern Ocean appear consistent with a multi-decadal scale poleward migration of the Antarctic Circumpolar Current (ACC), possibly linked to a long-term shift in the Southern Annular Mode. Since historic in situ hydrographic data are sparse, definitive assessments of the actual trends and mechanisms governing them have proved difficult. Satellite data offer some promise for evaluating the meridional migrations of the ACC. However, studies carried out using microwave sea surface temperature (SST) data as well as satellite altimetry have sometimes reached differing conclusions. In part these differences may stem from the variety of definitions used to locate the frontal jets that define the ACC, which have been based on absolute sea surface height, gradients in sea surface height, or gradients in SST. In addition alternate statistical measures, such as the variance and skewness of sea surface height, have been proposed as means to identify the position of the ACC. This study represents an effort to identify consistent and robust definitions of the ACC jets from satellite altimeter data and to make use of these to investigate the physical processes governing ACC variability.

  16. Relevamiento serológico de anticuerpos contra enfermedades virales de interés sanitario en llamas (Lama glama de la provincia de Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    Elena S Barbieri

    Full Text Available Las poblaciones de llamas de Argentina se concentran principalmente en la provincia de Jujuy; su explotación representa un importante recurso económico de las comunidades altoandinas. El objetivo de este trabajo fue evaluar la seroprevalencia de anticuerpos contra algunos agentes virales asociados a enfermedades de impacto productivo en rodeos de llamas de Jujuy. Se analizaron 349 sueros de llamas adultas de 6 departamentos de la puna jujeña ubicados por encima de los 3300 msnm. Se obtuvo una prevalencia del 100 % para rotavirus grupo A y del 70 % para el virus parainfluenza-3 bovino, mientras que no se detectaron reactores para herpesvirus bovino 1, virus de la diarrea viral bovina, influenza A humana (H1N1 e influenza equina (H3N8. Los resultados obtenidos confirman la amplia distribución de rotavirus y virus parainfluenza y la baja susceptibilidad a herpesvirus y pestivirus en las tropas de llamas de la puna jujeña.

  17. InSAR Observations Of Crustal Deformation Mechanics In The Interior Of The Puna Plateau Of The Southern Central Andes

    Science.gov (United States)

    Eckelmann, Felix; Motagh, Mahdi; Bokhagen, Bodo; Strecker, Manfred

    2013-12-01

    Crustal deformation evidences in the orogenic interior of the Southern Central Andes at different time scales are observed by applying ENVISAT InSAR time series from 2005 - 2009 and differential GPS data taken in the study area of the palaeo-lake Salar de Pocitos (24.5°S, 67°W, 3650 m asl). Ongoing shortening in the region from the Tertiary to the present-day is indicated by an uplift of Quaternary palaeo-lake terraces of about 4 to 5m within the last 44ka as well as by the growth of an anticline in Tertiary sediments and the reactivation of the reverse-fault bounded Sierra de Macón, both with uplift rates of 2 - 5mm/a. In summary, this study emphasizes the diachronous and spatially disparate character of the tectonic regime at the Puna Plateau.

  18. The Calama-Olacapato-El Toro fault system in the Puna Plateau, Central Andes: Geodynamic implications and stratovolcanoes emplacement

    Science.gov (United States)

    Norini, Gianluca; Baez, Walter; Becchio, Raul; Viramonte, Jose; Giordano, Guido; Arnosio, Marcelo; Pinton, Annamaria; Groppelli, Gianluca

    2013-11-01

    The structural evolution of the Puna Plateau is characterized by the activity of both orogen-parallel and orogen-oblique faults. Understanding the possible relationship between these two structural styles, their geodynamic implications and the influence on the migration of magmas is important to get insights into the tectonic and magmatic evolution of the Central Andes. In this study, we present a structural analysis of the orogen-oblique Calama-Olacapato-El Toro fault system and the surrounding orogen-parallel thrust faults in the central-eastern Puna Plateau. Morphostructural analysis and field mapping reveal the geometry, kinematics and dynamics of the tectonic features in the studied area. We propose a three-dimensional geometrical reconstruction of the main fault planes showing their attitude and intersections at depth. The study indicates that the crust underwent simultaneous deformation along both the vertical transcurrent Calama-Olacapato-El Toro fault system and the low-angle thrust faults, and that the back-arc portion of the Calama-Olacapato-El Toro fault system developed as a transfer zone among the main N-striking thrusts. Our model considers that both orogen-parallel and orogen-oblique fault systems should be regarded as parts of the same tectonic system, accommodating crustal shortening of a thickened crust. The study suggests that the tectonic control on the magma and fluid circulation in the crust is mainly related to the geometry of the fault planes and the orientation of the stress field, with a previously unrecognized important role played by the orogen-parallel thrust faults on the emplacement of the stratovolcanoes.

  19. Volcanismo máfico terciario de la Puna jujeña, los Cerros Negros de Jama.

    Directory of Open Access Journals (Sweden)

    Caffe, Pablo, J.

    2011-12-01

    Full Text Available Tertiary mafic volcanism of the Jujuy Puna, the Cerros Negros de Jama. The Cerros Negros de Jama (23°29’ S – 66°56’ W monogenetic volcanoes belong to a group of eruptive centers that are representative of the most mafic magmatism in the northern Puna during the Cenozoic. They comprise scoria cones and associated lava flows erupted during coeval strombolian and effusive volcanic activity.Aphyric to microporphyritic skeletal textures and microphenocryst assemblages dominated by olivine and/or orthopyroxene suggest inexistent or short residence times in supracrustal magma chambers, as well as magma temperatures higher than 1000º C and near to water saturation conditions. The frequent occurrence of magmatic quartz xenocrysts with different degrees of reaction suggests assimilation of silicic magmas/igneous rocks under variable P-T conditions. A combination of large ascent rates and strong turbulence, together with an overheating of the magmas would have been crucial for this in-route contamination process.The Jama volcanic rocks are basaltic andesites and andesites to trachyandesites which belong to the high-K calcalkaline series. The observed geochemical signature is typical of continental arc magmas, showing negative anomalies of Nb, Ta and P, La/Ta > 30 and Ba/Nb > 25. Two main groups of rocks with different evolution patterns can be distinguished from major and trace element diagrams. Different concentrations of some elements at intermediate degrees of evolution point to variable degrees of incompatibility for them, which in turn may have been caused by magma evolution at different depths from the same or different primary magmas.

  20. Wind Stress, METOP ASCAT, 0.25 degrees, Global, Near Real Time, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

  1. Wind Diffusivity Current, METOP ASCAT, 0.25 degrees, Global, Near Real Time, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  2. Currents, HF Radio-derived, Monterey Bay, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  3. Currents, HF Radio-derived, Monterey Bay, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  4. Currents, HF Radio-derived, Ano Nuevo, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  5. Currents, HF Radio-derived, SF Bay Outlet, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  6. Currents, HF Radio-derived, SF Bay, 33 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 33 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  7. Currents, HF Radio-derived, Bodega Bay, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  8. Currents, HF Radio-derived, Ano Nuevo, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  9. Currents, HF Radio-derived, Ano Nuevo, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  10. Wind Stress, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

  11. THE ROLE OF MERIDIONAL WIND STRESS IN THE TROPICAL UNSTABLE AIR-SEA INTERACTION

    Institute of Scientific and Technical Information of China (English)

    房佳蓓; 杨修群

    2003-01-01

    With a simple tropical coupled ocean-atmosphere model, this paper presents an analysis aiming to understand the relative role of the meridional and zonal wind stresses in the tropical unstable air-sea interaction. The roles of thezonal wind stress, the meridional wind stress and the both are considered respectively into the coupled system. It is demonstrated that the meridional component of the wind stress does not lead to any instability under the local thermal balance assumption, but it does lead to a weak instability under the sea surface temperature advection assumption. Unstable air-sea interaction is dominated by the zonal component of the wind stress, suggesting that ignoring the meridional wind stress is approximately feasible in studying the tropical unstable air-sea interaction.

  12. Wind Stress, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

  13. Currents, HF Radio-derived, Monterey Bay, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  14. Currents, HF Radio-derived, SF Bay Outlet, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  15. Currents, HF Radio-derived, Bodega Bay, 25 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  16. Currents, HF Radio-derived, SF Bay Outlet, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  17. Albert Einstein visits Argentina

    CERN Document Server

    Gangui, A; Gangui, Alejandro; Ortiz, Eduardo L.

    2005-01-01

    This is a detailed, day by day, account of Albert Einstein's activities, both social and scientific, during his 30-day stay in Argentina in 1925, including his lectures on relativity at the various local universities and his visit to the National Academy of Sciences, as follows from his personal Diary of the trip to South-America and other contemporary documents.

  18. Argentina : una literatura urbana

    Directory of Open Access Journals (Sweden)

    Hugo Dolgopol

    1979-04-01

    Full Text Available Gran parte del trayecto histórico de la literatura argentina está signado por la influencia de la ciudad. Esta ciudad es, fundamentalmente, Buenos Aires, la megalópolis nacida a orillas del Plata, frente mismo a Montevideo, otra urbe que mucho tiene que ver con el desarrollo más reciente de la literatura uruguaya.

  19. A lab in Argentina

    Science.gov (United States)

    2016-06-01

    Mauricio Erben, a researcher at the National University of La Plata and the National Scientific and Technical Research Council, talks to Nature Chemistry about his experience of research in Argentina, and how it is inherently linked to the country's political climate.

  20. Mathematics Education in Argentina

    Science.gov (United States)

    Varsavsky, Cristina; Anaya, Marta

    2009-01-01

    This article gives an overview of the state of mathematics education in Argentina across all levels, in the regional and world contexts. Statistics are drawn from Mercosur and UNESCO data bases, World Education Indicators and various national time-series government reports. Mathematics results in national testing programmes, Programme for…

  1. Mathematics Education in Argentina

    Science.gov (United States)

    Varsavsky, Cristina; Anaya, Marta

    2009-01-01

    This article gives an overview of the state of mathematics education in Argentina across all levels, in the regional and world contexts. Statistics are drawn from Mercosur and UNESCO data bases, World Education Indicators and various national time-series government reports. Mathematics results in national testing programmes, Programme for…

  2. Inversions for Deep Solar Meridional Flow Using Spherical Born Kernels

    Science.gov (United States)

    Böning, Vincent G. A.; Roth, Markus; Jackiewicz, Jason; Kholikov, Shukur

    2017-08-01

    The solar meridional flow is a crucial ingredient in modern dynamo theory. Seismic estimates of this flow have, however, been contradictory in deeper layers below about 0.9 {R}⊙ . Results from time-distance helioseismology have so far been obtained using the ray approximation. Here, we perform inversions using the Born approximation. The initial result is similar to the result previously obtained by Jackiewicz et al. using ray kernels while using the same set of GONG data and the SOLA inversion technique. However, we show that the assumption of uncorrelated measurements used in earlier studies may lead to inversion errors being underestimated by a factor of about 2-4. In a second step, refined inversions are performed using the full covariance matrix and a regularization for cross-talk. As the results are found to depend on the threshold used in the singular value decomposition, they were obtained for a medium threshold ({10}-7{--}{10}-5, about 50% of the values used) and a threshold lower by a factor of 10 (about 70% of the values used). The result obtained with the medium threshold is again similar to the original, with less latitudinal variation. However, using the lower threshold, the inverted flow in the southern hemisphere shows two or three cells stacked radially depending on the associated radial flows. Both the single-cell and the multi-cell profiles are consistent with the measured travel times. All our results confirm a shallow return flow at about 0.9 {R}⊙ .

  3. The Effect of Transient Eddy on Interannual Meridional Displacement of Summer East Asian Subtropical Jet

    Institute of Scientific and Technical Information of China (English)

    XIANG Yang; YANG Xiuqun

    2012-01-01

    Using ERA-40 reanalysis daily data for the period 1958-2002.this study investigated the effect of transient eddy (TE) on the interannual meridional displacement of summer East Asian subtropical jet (EASJ)by conducting a detailed dynamical diagnosis.The summer EASJ axis features a significant interannual coherent meridional displacement.Associated with such a meridional displacement,the TE vorticity forcing anomalies are characterized by a meridional dipole pattern asymmetric about the climatological EASJ axis.The TE vorticity forcing anomalies yield barotropic zonal wind tendencies with a phase meridionally leading the zonal wind anomalies,suggesting that they act to reinforce further meridional displacement of the EASJ and favor a positive feedback in the TE and time-mean flow interaction.However,The TE thermal forcing anomalies induce baroclinic zonal wind tendencies that reduce the vertical shear of zonal wind and atmospheric baroclinicity and eventually suppress the TE activity,favoring a negative feedback in the TE and time-mean flow interaction.Although the two types of TE forcing tend to have opposite feedback roles,the TE vorticity forcing appears to be dominant in the TE effect on the time-mean flow.

  4. The effect of transient eddy on interannual meridional displacement of summer East Asian subtropical jet

    Science.gov (United States)

    Xiang, Yang; Yang, Xiuqun

    2012-05-01

    Using ERA-40 reanalysis daily data for the period 1958-2002, this study investigated the effect of transient eddy (TE) on the interannual meridional displacement of summer East Asian subtropical jet (EASJ) by conducting a detailed dynamical diagnosis. The summer EASJ axis features a significant interannual coherent meridional displacement. Associated with such a meridional displacement, the TE vorticity forcing anomalies are characterized by a meridional dipole pattern asymmetric about the climatological EASJ axis. The TE vorticity forcing anomalies yield barotropic zonal wind tendencies with a phase meridionally leading the zonal wind anomalies, suggesting that they act to reinforce further meridional displacement of the EASJ and favor a positive feedback in the TE and time-mean flow interaction. However, The TE thermal forcing anomalies induce baroclinic zonal wind tendencies that reduce the vertical shear of zonal wind and atmospheric baroclinicity and eventually suppress the TE activity, favoring a negative feedback in the TE and time-mean flow interaction. Although the two types of TE forcing tend to have opposite feedback roles, the TE vorticity forcing appears to be dominant in the TE effect on the time-mean flow.

  5. The momentum constraints on the shallow meridional circulation associated with the marine ITCZ

    Science.gov (United States)

    Dixit, Vishal; Srinivasan, J.

    2016-11-01

    Recent studies have shown that the shallow meridional circulation (SMC) coexists with the deep circulation in the marine ITCZ. The SMC has been assumed to be forced by strong meridional gradients of Sea Surface Temperature (SST) which affect the atmosphere under hydrostatic balance. In this paper, we present a new viewpoint that the shallow meridional circulation is a part of circulation that forms when the marine ITCZ is located away from the equator. To support this view, we have used reanalysis data over east Pacific ocean to show that the shallow meridional circulation is absent when the ITCZ is located near the equator while it is strong to the south of the ITCZ when the ITCZ is located away from the equator. To further support this view, we have conducted idealized aquaplanet experiments by shifting SST maximum polewards to simulate the observed contrast in the meridional circulation associated with near equatorial and off-equatorial ITCZ. The detailed momentum budget of the flow above the boundary layer shows that, to the south of an off-equatorial ITCZ, the dominant balance between the Coriolis force and the advection of relative vorticity by the mean flow leads to cancellation of the planetary rotational effects. As a result, the net rotational effects experienced by the diverging flow above the boundary layer are negligible and a shallow meridional flow along the pressure gradients is generated. This dominant balance does not occur in the aquaplanet GCM when the ITCZ forms near the equator.

  6. La divergencia genética entre poblaciones del Área Andina Centro Meridional evaluada mediante rasgos no métricos del cráneo

    Directory of Open Access Journals (Sweden)

    Cocilovo, José Alberto

    2009-01-01

    Full Text Available Durante más de 10.000 años el Area Andina Centro Meridional proporcionó un escenario ideal para el desarrollo de distintas poblaciones y entidades culturales, interactuando a través de una amplia red de intercambio y distribución de productos. A pesar de este nivel de interacción, la información métrica disponible (Bolivia, Norte de Chile y Noroeste Argentino, reveló un fuerte proceso de divergencia genética (FST = 0.195 entre subregiones (Varela et al., 2008. Esta evidencia es contrastada en el presente trabajo a partir del análisis de una muestra integrada por 1416 individuos de ambos sexos, cubriendo un intervalo de 4.500 años. Se emplearon 12 atributos (rasgos no métricos del cráneo registrados como presencia-ausencia. Las diferencias entre subáreas fueron evaluadas mediante la estadística MMDS y D2 de Mahalanobis calculada a partir de componentes principales. Ambas matrices de distancias fenotípicas presentaron una alta correlación, destacando una significativa diferenciación a nivel regional. La mayor distancia se registra entre el Noroeste Argentino y el Norte de Chile, ocupando Bolivia una posición equidistante entre ambas regiones. Dentro de cada región las muestras están más relacionadas entre si ((Cochabamba, (Puna, Quebrada, Valliserrana y Pampa Grande, (Arica, Pisagua, Norte Semiárido. Hay mayor vinculación entre Cochabamba y el Noroeste Argentino y mayor divergencia entre los grupos de Chile. Se confi rma un modelo de poblamiento a partir de la subdivisión de una población ancestral en dos ramas que ocuparon: una el Norte de Chile y otra el Noroeste Argentino. En cada una de ellas el proceso dispersivo originó varias líneas que se diferenciaron gradualmente hacia el sur, durante la exploración de nuevos ambientes cuya conquista y colonización garantizó la subsistencia de la población.

  7. Atlantic Meridional Overturning Circulation response to idealized external forcing

    Energy Technology Data Exchange (ETDEWEB)

    Park, W.; Latif, M. [Leibniz-Institut fuer Meereswissenschaften an der Universitaet Kiel, Kiel (Germany)

    2012-10-15

    The response of the Atlantic Meridional Overturning Circulation (AMOC) to idealized external (solar) forcing is studied in terms of the internal (unforced) AMOC modes with the Kiel Climate Model (KCM), a coupled atmosphere-ocean-sea ice general circulation model. The statistical investigation of KCM's internal AMOC variability obtained from a multi-millennial control run yields three distinct modes: a multi-decadal mode with a period of about 60 years, a quasi-centennial mode with a period of about 100 years and a multi-centennial mode with a period of about 300-400 years. Most variance is explained by the multi-centennial mode, and the least by the quasi-centennial mode. The solar constant varies sinusoidally with two different periods (100 and 60 years) in forced runs with KCM. The AMOC response to the external forcing is rather complex and nonlinear. It involves strong changes in the frequency structure of the variability. While the control run depicts multi-timescale behavior, the AMOC variability in the experiment with 100 year forcing period is channeled into a relatively narrow band centered near the forcing period. It is the quasi-centennial AMOC mode with a period of just under 100 years which is excited, although it is heavily damped in the control run. Thus, the quasi-centennial mode retains its period which does not correspond exactly to the forcing period. Surprisingly, the quasi-centennial mode is also most strongly excited when the forcing period is set to 60 years, the period of the multi-decadal mode which is rather prominent in the control run. It is largely the spatial structure of the forcing rather than its period that determines which of the three internal AMOC modes is excited. The results suggest that we need to understand the full modal structure of the internal AMOC variability in order to understand the circulation's response to external forcing. This could be a challenge for climate models: we cannot necessarily expect that the

  8. Argentina: A Country Study

    Science.gov (United States)

    1983-05-17

    Forundizi stayed in office until March 29, 1962. Skillfully, Frondizi managed partially to revive the economy and set the country on the road toward... Frondizi could not win the support of all sections of the population for a concentrated effort of austerity to save Argentina’s economy from the chaos it...make sacrifices. Frondizi came to grief when the reinstated Peronist Party won control of several provinces and increased its membership in congress in

  9. Regional Seismology in Argentina

    Science.gov (United States)

    1981-05-11

    Historia (Pananerican Institute of Geography and History, sponsored by the Organization of American States: Revista Geoffsica (Geophysical Journal). B...South America and the Recurrence Relation of Earthquakes. Revista Geofisica del Instituto Panamericano do Geograffa • Historia (IPGH), No. 4, June, 155...Underground Explosion, 8-18 September, Oslo, Norway. Universidad Nacional do San Juan, 1979. Informs del Simposio Bi- nacional Argentina-Estados Unidos sobre

  10. The SOUTHERN PUNA Seismic Experiment: Shape of the Subducting Nazca Plate, Areas of Concentrated Mantle and Crustal Earthquakes, and Crustal Focal Mechanisms

    Science.gov (United States)

    Mulcahy, P.; Chen, C.; Kay, S. M.; Brown, L. D.; Alvarado, P. M.; Sandvol, E. A.; Heit, B.; Yuan, X.

    2010-12-01

    The SOUTHERN PUNA Seismic Experiment in the Central Andes between 25° - 28°S and 70° - 65°W recorded data in a 74-instrument array from Dec 07 to Nov 09 with the purpose of evaluating the structure and seismic character of the mantle and crust at the southern end of the Puna-Antiplano Plateau. Hypocenter locations for local and regional mantle earthquakes from 16 months of continuous recording confirm the persistence of the backarc teleseismic Antofalla Gap in intermediate depth mantle seismicity between 25.5° and 27.5°S consistent with the interpretation of a hot mantle wedge under this region. The best located Wadati Benioff Zone events agree with the subducting Nazca Plate contours of Cahill and Isacks (1992) north of 27°S, but show a more abrupt southward shallowing of contours in agreement with the Anderson et al. (2007) contours outlining the projected path of the already subducted Juan Fernandez Ridge. Another prominent feature in the data is the concentration of hypocenters in the Pipanaco nest to the south of the Antofalla Gap between 27° and 29°S. New PUNA results together with available HCMT solutions indicate NW oriented normal and strike-slip faulting in three general clusters within this nest at ~130km, 150km and 180km depth. Hypocenter locations and fault solutions for the Pipanaco Nest suggest flexure associated with steepening of the subducting slab consistent with the revised Wadati Benioff Zone contours. In an area of little to no crustal seismicity in global catalogs over the same time period, hundreds of well-located crustal earthquakes at depths less than 15km were recorded by the PUNA array. Among these earthquakes are three distinct clusters near relatively young volcanic centers. One cluster defines a nest northeast of the < 1 Ma Cerro Blanco caldera. The other two clusters are characterized by large quantities of earthquakes within 24-36 hours (swarms) near the Cerro Galan caldera that last erupted at ~2 Ma and near a ~1 Ma or

  11. Survey of Lava Tubes in the Former Puna Forest Reserve and on Adjacent State of Hawaii Lands

    Energy Technology Data Exchange (ETDEWEB)

    McEldowney, H.; Stone, F.D.

    1991-10-01

    This study was initiated after members of the Puna community brought to the attention of the Historic Preservation Office that major lava tube systems extended from the Pahoa area into at least portions of the former Puna Forest Reserve. They were concerned that planned geothermal exploration and development could damage these lava tubes which they said contained extensive evidence of past Hawaiian use including fortifications, shrines, platforms and burials. Geothermal development is currently being planned by Campbell Estate and True Geothermal Energy Company in the southern portion of the former Reserve which has been designated by the State of Hawaii as one of the three Geothermal Sub-Zones in Puna. To demonstrate these claims, two staff members of the Historic Sites Section were shown examples in a lava tube makai of the Campbell Estate boundary. After reviewing the archaeological and historical reports commissioned for geothermal exploration, it was agreed that if these lava tubes did extend inland and continued to contain archaeological sites or burials then the potential of significant sub-surface sites had not been adequately addressed in the Historic Sites Section review process. Most reports acknowledged the possibility of lava tubes in the area and that they could contain burials, but no tube systems were ever identified or explored during any of the field surveys. These surveys primarily assessed the presence or absence of cultural properties that occur on the surface or as deposits within the soil layer. With the assistance of the Division of Water Resource Management (DWRM), the Historic Sites Section agreed to conduct this survey because those community members who came forward requested that this information be handled by a neutral party. They asked that documentation occur in such a manner that it could be kept as confidential as possible while still providing enough information to protect any sites from damage. The survey had three major aims

  12. de la sociedad argentina

    Directory of Open Access Journals (Sweden)

    Diego Galeano

    2007-01-01

    Full Text Available Este artículo trata sobre un período de la historia argentina en el cual la "mirada médica", a través de un grupo de prestigiosos intelectuales, se convirtió en una clave de interpretación de la sociedad argentina. El análisis gira en torno a la obra de uno de los médicos higienistas más influyentes, José María Ramos Mejía, deteniéndose especialmente en su libro más famoso: Las multitudes argentinas (1899. La hipótesis principal que recorre el texto es la siguiente: la medicalización de la sociedad, acentuada luego de las epidemias de cólera y fiebre amarilla de mediados del siglo XIX, ofreció a las elites públicas la posibilidad de construir dominios legítimos de intervención estatal. Intromisiones del Estado en la vida privada que, además de ser algo resistidas por la población, entraban en tensión con los principios teóricos del liberalismo que los propios miembros de la elite defendían.

  13. Poder y relaciones sociales en curatos de indios. El curato de Cochinoca en el siglo XVIII (Puna de Jujuy-Argentina

    Directory of Open Access Journals (Sweden)

    Normando Cruz, Enrique

    2006-06-01

    Full Text Available The exercise of the religious power in rural pastorates of mainly native population, was developed in the Andean districts of the viceroyalty of the River of the Silver by the «you cure doctrineros». This work puts in consideration the conjecture that the exercise of the power of them you cure doctrineros develops from an «agreement of colonial expropriation» among he himself, the native authorities and the parishioners of the pastorate. Confronting it a specific identification of the participants of the agreement is carried out: native authorities, priests doctrineros, you help religious and grocers; and the origin is described and development of those of traditions institutionalized» fruit of such agreement: brotherhoods and bonuses.El ejercicio del poder religioso en curatos rurales de población mayoritariamente indígena, fue desarrollado en los distritos andinos del virreinato del Río de la Plata por los «curas doctrineros». Este trabajo pone en consideración la conjetura de que el ejercicio del poder de los curas doctrineros se desarrolla a partir de un entre él mismo, las autoridades indígenas y los feligreses del curato. Para confrontarla se realiza una específica identificación de los partícipes del acuerdo: autoridades indígenas, curas doctrineros, auxiliares religiosos y encomenderos; y se describe el origen y desarrollo de las «tradiciones institucionalizadas» fruto de tal acuerdo: cofradías y obvenciones.

  14. Prevalence and determinants of the dual burden of malnutrition at the household level in Puna and Quebrada of Humahuaca, Jujuy, Argentina.

    Science.gov (United States)

    Bassete, M N; Romaguera, D; Giménez, M A; Lobo, M O; Samman, N C

    2014-02-01

    El objetivo del presente estudio fue identificar los hogares en los que coexisten el sobrepeso y bajo peso (doble carga de malnutrición) y explorar los factores que podrían contribuir a la doble carga de malnutrición en los hogares de esta población. Después de aplicar los criterios de exclusión, se incluyeron 136 hogares. Las madres fueron clasificadas como de peso normal o con sobrepeso/ obesidad basado en puntos de corte del índice de masa corporal (IMC), los niños y adolescentes fueron clasificados según z–score de la talla para la edad, si tenían o no retraso en el crecimiento (Stunted). Los hogares con una madre obesa y niños o adolescentes con retraso en el crecimiento fueron clasificados como hogares de doble carga. La prevalencia de hogares con doble carga fue del 12 %. En comparación con los otros hogares, en los hogares con doble carga de malnutrición habitan un mayor número de personas en la casa, y el nivel de educación del jefe de familia fue menor. Las personas que viven en hogares de doble carga mostraron ingestas de energía global más bajas y eran más propensos a tener una ingesta insuficiente de calcio y hierro. Una de las principales causas de la doble carga de malnutrición observada en esta comunidad podría ser la transición nutricional. Los resultados presentados aquí indican la necesidad de considerar a los programas que se centran en un solo tipo de problema nutricional y que en realidad podrían exacerbar el otro.

  15. ESTIMATING THE DEEP SOLAR MERIDIONAL CIRCULATION USING MAGNETIC OBSERVATIONS AND A DYNAMO MODEL: A VARIATIONAL APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Ching Pui; Jouve, Laurène; Brun, Allan Sacha [Laboratoire AIM Paris-Saclay, CEA/IRFU Université Paris-Diderot CNRS/INSU, F-91191 Gif-Sur-Yvette (France); Fournier, Alexandre [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot UMR 7154 CNRS, F-75005 Paris (France); Talagrand, Olivier [Laboratoire de météorologie dynamique, UMR 8539, Ecole Normale Supérieure, Paris Cedex 05 (France)

    2015-12-01

    We show how magnetic observations of the Sun can be used in conjunction with an axisymmetric flux-transport solar dynamo model in order to estimate the large-scale meridional circulation throughout the convection zone. Our innovative approach rests on variational data assimilation, whereby the distance between predictions and observations (measured by an objective function) is iteratively minimized by means of an optimization algorithm seeking the meridional flow that best accounts for the data. The minimization is performed using a quasi-Newton technique, which requires knowledge of the sensitivity of the objective function to the meridional flow. That sensitivity is efficiently computed via the integration of the adjoint flux-transport dynamo model. Closed-loop (also known as twin) experiments using synthetic data demonstrate the validity and accuracy of this technique for a variety of meridional flow configurations, ranging from unicellular and equatorially symmetric to multicellular and equatorially asymmetric. In this well-controlled synthetic context, we perform a systematic study of the behavior of our variational approach under different observational configurations by varying their spatial density, temporal density, and noise level, as well as the width of the assimilation window. We find that the method is remarkably robust, leading in most cases to a recovery of the true meridional flow to within better than 1%. These encouraging results are a first step toward using this technique to (i) better constrain the physical processes occurring inside the Sun and (ii) better predict solar activity on decadal timescales.

  16. Estratigrafía y centros eruptivos de la region de Pairique, Puna jujeña

    Directory of Open Access Journals (Sweden)

    P.J. Caffe

    2007-06-01

    Full Text Available La región de Pairique en la Puna jujeña, hospeda un importante registro volcánico de edad miocena superior entre ~11,5 a ~6,6 Ma, que incluye unidades tanto piroclásticas como lávicas. Una estructura anular en el sector central de la zona de estudio fue interpretada previamente como la caldera de colapso más antigua relacionada al volcanismo cenozoico en la región del complejo volcánico Altiplano-Puna (APVC. En este trabajo se analiza la estratigrafía de la región de Pairique, en función de distinguir los productos de origen caldérico de aquéllos provenientes de otros centros. A partir de las propiedades litológicas y de las distribuciones geográfica y cronoestratigráfica, sugerimos que sólo algunas de las unidades volcánicas reconocidas se vinculan con la estructura anular de Pairique. Asimismo, no hay evidencia estratigráfica suficiente para modelar un colapso caldérico a lo largo de la misma. Consecuentemente, Pairique se redefine como un complejo volcánico, es decir un centro que experimentó volcanismo persistente durante un lapso de tiempo importante (>11.5 a ~10.3 Ma. Su modelo eruptivo deberá ser elaborado a la luz de nuevos datos estructurales y volcanológicos. En esta contribución también se reconocen otras tres zonas de procedencia para algunas unidades antes consideradas como provenientes de Pairique: volcán compuesto Nevado Torona-San Pedro, complejo volcánico Lina y complejo dómico Pairique Grande. Al igual que en el "arco interno" peruano-boliviano, el volcanismo en Pairique ha tenido características composicionales peculiares, donde coexistieron unidades andesíticas a dacíticas de tendencia calcoalcalina y volcanitas félsicas de afinidad peraluminosa (con cordierita o granate magmáticos.

  17. Surface changes in the North Atlantic meridional overturning circulation during the last millennium

    DEFF Research Database (Denmark)

    Wanamaker, A.D.; Butler, P.G.; Scourse, J.D.

    2012-01-01

    the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation......Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance...... of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning...

  18. A Note on the Role of Meridional Wind Stress Anomalies and Heat Flux in ENSO Simulations

    Institute of Scientific and Technical Information of China (English)

    ZHU Jieshun; SUN Zhaobo; ZHOU Guangqing

    2007-01-01

    Four comparative experiments and some supplementary experiments were conducted to examine the role of meridional wind stress anomalies and heat flux variability in ENSO simulations by using a highresolution Ocean General Circulation Model (OGCM). The results indicate that changes in the direction and magnitude of meridional wind stress anomalies have little influence on ENSO simulations until meridional wind stress anomalies are unrealistically enlarged by a factor of 5.0. However, evidence of an impact on ENSO simulations due to heat flux variability was found. The simulated Ni(n)o-3 index without the effect of heat flux anomalies tended to be around 1.0° lower than the observed, as well as the control run, during the peak months of ENSO events.

  19. MERIDIONAL TILT OF THE STELLAR VELOCITY ELLIPSOID DURING BAR BUCKLING INSTABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Kanak [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Pfenniger, Daniel [Geneva Observatory, University of Geneva, CH-1290 Sauverny (Switzerland); Taam, Ronald E., E-mail: saha@mpe.mpg.de [Institute of Astronomy and Astrophysics, Academia Sinica-TIARA, Taiwan (China)

    2013-02-20

    The structure and evolution of the stellar velocity ellipsoid play an important role in shaping galaxies undergoing bar-driven secular evolution and the eventual formation of a boxy/peanut bulge such as is present in the Milky Way. Using collisionless N-body simulations, we show that during the formation of such a boxy/peanut bulge, the meridional shear stress of stars, which can be measured by the meridional tilt of the velocity ellipsoid, reaches a characteristic peak in its time evolution. It is shown that the onset of a bar buckling instability is closely connected to the maximum meridional tilt of the stellar velocity ellipsoid. Our findings bring a new insight to this complex gravitational instability of the bar which complements the buckling instability studies based on orbital models. We briefly discuss the observed diagnostics of the stellar velocity ellipsoid during such a phenomenon.

  20. The impact of meridional circulation on stellar butterfly diagrams and polar caps

    CERN Document Server

    Holzwarth, V R; MacKay, D H

    2006-01-01

    Observations of rapidly rotating solar-like stars show a significant mixture of opposite-polarity magnetic fields within their polar regions. To explain these observations, models describing the surface transport of magnetic flux demand the presence of fast meridional flows. Here, we link sub-surface and surface magnetic flux transport simulations to investigate (i) the impact of meridional circulations with peak velocities of <125m/s on the latitudinal eruption pattern of magnetic flux tubes and (ii) the influence of the resulting butterfly diagrams on polar magnetic field properties. Prior to their eruption, magnetic flux tubes with low field strengths and initial cross sections below about 300km experience an enhanced poleward deflection through meridional flows. In particular flux tubes which originate between low and intermediate latitudes within the convective overshoot region are strongly affected. This latitude-dependent poleward deflection of erupting magnetic flux renders the wings of stellar but...

  1. Multi-spatial variability modes of the Atlantic Meridional Overturning Circulation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tianjun

    2003-01-01

    The multi-spatial variability modes of the Atlantic Meridional Overturning Circulation (MOC) are identified in the natural coupled simulation of two climate models, the MOC either oscillates at decadal scales with strong cross- equatorial flow or fluctuates locally at interannual scales with weaker cross-equatorial flow. Former studies mainly emphasize the paleo-environmental and paleo-climatic impacts of the meridional overturning states transition; this analysis indicates the existence of the multi-spatial variability modes of the MOC at interannual to decadal scales. Further analysis indicates that the conventionally used MOC index, which is defined as the maximum zonal mean meridional stream-function of the North Atlantic, cannot properly describe the multi-spatial variability characteristics of the MOC.

  2. Surface changes in the North Atlantic meridional overturning circulation during the last millennium

    DEFF Research Database (Denmark)

    Wanamaker, A.D.; Butler, P.G.; Scourse, J.D.

    2012-01-01

    the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation......Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance...... of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning...

  3. Surface changes in the North Atlantic meridional overturning circulation during the last millennium.

    Science.gov (United States)

    Wanamaker, Alan D; Butler, Paul G; Scourse, James D; Heinemeier, Jan; Eiríksson, Jón; Knudsen, Karen Luise; Richardson, Christopher A

    2012-06-12

    Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation dynamics likely amplified the relatively warm conditions during the Medieval Climate Anomaly and the relatively cool conditions during the Little Ice Age within the North Atlantic sector.

  4. Double-Cell Type Solar Meridional Circulation Based on Mean-Field Hydrodynamic Model

    CERN Document Server

    Bekki, Yuto

    2016-01-01

    The main object of the paper is to present the condition of the non-diffusive part of the Reynolds stress for driving the double-cell structure of the solar meridional circulation, which has been revealed by recent helioseismic observations. By conducting a set of mean-field hydrodynamic simulations, we confirm for the first time that the double-cell meridional circulation can be achieved along with the solar-like differential rotation when the Reynolds stress transports the angular momentum upward in the lower part and downward in the upper part of the convection zone. It is concluded that, in a stationary state, the accumulated angular momentum via the Reynolds stress in the middle layer is advected to both the upper and lower parts of the convection zone by each of the two meridional circulation cells, respectively.

  5. Escleroplastia meridional: A propósito de un caso en 1999 Meridional scleroplasty: With regard to a case in 1999

    Directory of Open Access Journals (Sweden)

    Enrique J. Machado Fernández

    2000-06-01

    Full Text Available En este artículo se presenta un caso reciente de rechazo al aloplante utilizado para escleroplastia meridional. Se refieren las características del cuadro clínico presentado y su tratamiento. Además, se expresan consideraciones basadas en datos estadísticos y hallazgos anatomopatológicos que fundamentan la suspensión de la práctica de esta técnica en el Centro de Microcirugía Ocular.In present paper, authors present a recent case of rejection to allograft used to meridional scleroplasty. Festures of clinical picture and its treatment are related. Furthermore, we express statistical data based on considerations and anatomic-pathologic findings supporting suspension of practice of this technique in Center of Microsurgery of Eye.

  6. The Sun's Meridional Flow and Its Role in Magnetic Flux Transport and the Sunspot Cycle

    Science.gov (United States)

    Hathaway, D. H.; Upton, L.

    2014-12-01

    The Sun's meridional flow can be measured with a variety of measurement techniques including, but not limited to: direct Doppler, magnetic feature tracking, velocity feature tracking, time-distance helioseismology, and ring-diagram analysis. Direct Doppler gives information on the flow in the photosphere while the other measurement techniques provide information about the flow at some depth or range of depths in the Sun's convection zone. These various measurement methods now provide a converging (but not yet fully converged) picture of the meridional flow as a function of latitude, depth, and time. This converging picture has a flow which is poleward from the equator all the way to pole in the near surface layers, has an equatorward return flow beginning at a depth of about 50 Mm, and has another poleward branch deeper in the convection zone. The poleward flow in the near surface layers varies systematically in strength and latitudinal structure with the phase of the sunspot cycle and from one cycle to the next. This near surface meridional flow is observed to play a significant role in the poleward transport of the magnetic flux that emerges at the surface in the form of bipolar active regions. Variations in the strength and structure of the meridional flow introduce variations in the strength of the Sun's polar fields, which in turn introduce variations in the size of subsequent sunspot cycles. The polar fields at the end of cycle 23 (2008-2009) were much weaker than the polar fields at the end of the previous cycles. This led to the production of the weakest sunspot cycle in 100 years - cycle 24. Surprisingly, we find that the variations we observed in the meridional flow during cycle 23 led to stronger polar fields than would have been produced otherwise. This suggests that variations in the meridional flow can be one mechanism for modulating the sizes of sunspot cycles - helping to keep them from getting too big or too small.

  7. Improvements in launchings and recipients of PIG in Malha de Gasodutos Nordeste Meridional; Melhorias nos lancamentos e recebedores de PIG da Malha de Gasodutos Nordeste Meridional

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, Jairo A.C.; Lemos, Francisco A.C.; Lima, Artur W.R. de S. [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    This paper describes the study that resulted in the preparation of a project for improvement of launchers and receivers of PIG in facilities maintained and operated by PETROBRAS S.A. (TRANSPETRO) in the Malha de Gasodutos Nordeste Meridional (Malha NEM). The improvements are part of the component in cleaner production system and reduce the risks of accidents and the costs of hazardous waste management.

  8. Unveiling Current Guanaco Distribution in Chile Based upon Niche Structure of Phylogeographic Lineages: Andean Puna to Subpolar Forests

    Science.gov (United States)

    González, Benito A.; Samaniego, Horacio; Marín, Juan Carlos; Estades, Cristián F.

    2013-01-01

    Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distribution of the recently resolved phylogeography of guanaco (Lama guanicoe) lineages on the western slope of the southern Andes. Using a maximum entropy framework, field data, and information on climate, topography, human density, and vegetation cover, we identify differences between the two subspecies (L.g.cacsilensis, L.g.guanicoe) and their intermediate-hybrid lineage, that most likely determine the distribution of this species. While aridity seems to be a major factor influencing the distribution at the species-level (annual precipitation Chile, producing discrepancies when comparing range distribution at the species-level (81,756 km2) with lineages-level (65,321 km2). The subspecies-specific description of niche structure is provided here based upon detailed spatial distribution of the lineages of guanacos in Chile. Such description provides a scientific tool to further develop large scale plans for habitat conservation and preservation of intraspecific genetic variability for this far ranging South American camelid, which inhabits a diversity of ecoregion types from Andean puna to subpolar forests. PMID:24265726

  9. Angular momentum fluxes caused by Lambda-effect and meridional circulation structure of the Sun

    CERN Document Server

    Pipin, V V

    2016-01-01

    Using mean-field hydrodynamic models of the solar angular momentum balance we show that the non-monotonic latitudinal dependence of the radial angular momentum fluxes caused by Lambda-effect can affect the number of the meridional circulation cells stacking in radial direction in the solar convection zone. In particular, our results show the possibility of a complicated triple-cell meridional circulation structure. This pattern consists of two large counterclockwise circulation cells (the N-hemisphere) and a smaller clockwise cell located at low latitudes at the bottom of the convection zone.

  10. Meridional overturning circulation: stability and ocean feedbacks in a box model

    CERN Document Server

    Cimatoribus, Andrea A; Dijkstra, Henk A

    2012-01-01

    A box model of the inter-hemispheric Atlantic meridional overturning circulation is developed, including a variable pycnocline depth for the tropical and subtropical regions. The circulation is forced by winds over a periodic channel in the south and by freshwater forcing at the surface. The model is aimed at investigating the ocean feedbacks related to perturbations in freshwater forcing from the atmosphere, and to changes in freshwater transport in the ocean. These feedbacks are closely connected with the stability properties of the meridional overturning circulation, in particular in response to freshwater perturbations.

  11. República Argentina

    OpenAIRE

    Centro de Estudios Sudamericanos

    2008-01-01

    El sistema de gobierno en la Argentina adopta la forma representativa, republicana y federal (Constitución Nacional, art. 1º).Por su extensión -que corresponden al Continente Americano; al Continente Antártico (incluyendo las Islas Orcadas del Sur) y las islas australes (Georgias del Sur y Sandwich del Sur)- ocupa el cuarto lugar entre los países americanos (después de Canadá, Estados Unidos de América y la República Federativa del Brasil) y el séptimo a nivel mundial. Con una población de má...

  12. República Argentina

    OpenAIRE

    Centro de Estudios Sudamericanos (CENSUD)

    2008-01-01

    El sistema de gobierno en la Argentina adopta la forma representativa, republicana y federal (Constitución Nacional, art. 1º).Por su extensión -que corresponden al Continente Americano; al Continente Antártico (incluyendo las Islas Orcadas del Sur) y las islas australes (Georgias del Sur y Sandwich del Sur)- ocupa el cuarto lugar entre los países americanos (después de Canadá, Estados Unidos de América y la República Federativa del Brasil) y el séptimo a nivel mundial. Con una población de má...

  13. Pre-Andean Rotations in NW Argentina: a Clue to a Possible Tectonic Model?

    Science.gov (United States)

    Spagnuolo, C. M.; Rapalini, A. E.; Astini, R. A.

    2008-05-01

    In the early Paleozoic western South America underwent a complex tectonic history that includes a more or less continuous active margin that witnessed the accretion and displacement of several terranes. In particular, many models have been proposed to account for the geologic evolution of the northwestern region of Argentina in the Lower Paleozoic, which range from a wholly ensialic evolution to the accretion of exotic and/or para- autochthonous terranes. During the last three years a systematic paleomagnetic study on Lower Paleozoic sedimentary and volcanic rocks from NW Argentina have yielded a Late Cambrian paleomagnetic pole for the Eastern Cordillera (23° S 65° W, Campanario Fm.), an Early to Middle Ordovician pole for the Famatina volcanic arc (28° S 68° W, Cerro Morado and Los Molles Fms.) and a Permian one in the same locality. A clockwise rotation around 35° is found for both Lower Paleozoic units, while the Permian one is coincident with the apparent polar wander path of Gondwana. The Early Paleozoic results are virtually identical to others found several years ago in the Eastern Puna magmatic belt and in the same Famatina System. On the other hand, a counter-clockwise rotation has been reported for Early Paleozoic rocks exposed at different localities of the Antofalla block. Those results are reviewed together with the structural and geological information of the region in order to evaluate the feasibility of different tectonic models such as i) the opening and closure of a back-arc basin, ii) the collision or displacement of a para-autochthonous terrane, or iii) the development of systematic block rotations associated to oblique subduction or scape tectonics.

  14. Volcanismo oligoceno superior - mioceno inferior en la sierra de Pirurayo, Puna jujeña: estratigrafía y mecanismos eruptivos Upper Oligocene - Lower Miocene volcanism in the mountain range of Pirurayo, northern Puna: stratigraphy and eruptive mechanisms

    Directory of Open Access Journals (Sweden)

    M. M. Soler

    2002-06-01

    Full Text Available Resumen El Complejo Volcánico Pirurayo (CVP aflora en la sierra homónima, aproximadamente entre los 65°54' y 65°50' de longitud oeste y los 22°25' y 22°17' de latitud sur, en el ámbito de la Puna jujeña. Se encuentra intercalado en la Formación Moreta, una secuencia sedimentaria continental integrada por areniscas y conglomerados rojos y morados. El CVP ocupa su sección intermedia, con un espesor máximo en el sector norte que supera los 640 m y que disminuye bruscamente hacia el sur. Representa un sistema volcánico compuesto, de composición andesítico_dacítica, desarrollado en el marco de una cuenca continental de régimen fluvial, emplazado durante el Oligoceno superior - Mioceno inferior, según sistemas de fracturación submeridianos. Dicho complejo mostró en sus comienzos participación de fenómenos netamente explosivos y de carácter magmático, los que produjeron depósitos de volúmenes reducidos principalmente de oleadas piroclásticas y en menor proporción de ignimbritas. Posteriormente los mecanismos eruptivos cambiaron, caracterizándose por la alternancia entre emisiones lávicas y desarrollo de domos, acompañados por frecuentes colapsos de los mismos, depositándose intercalados mantos de lavas con bancos de flujos de bloques y cenizas y escasos y delgados depósitos de caída. El área de proveniencia de dichos depósitos se encontraba en el sector NNO del complejo y la boca de emisión de los mismos pudo ser única o haberse tratado de un volcán compuesto, de bocas múltiples.The Pirurayo Volcanic Complex (PVC crops out in the Pirurayo Range, approximately between 65º54' - 65º50' W, and 22º25' - 22º17' S, in the northern Puna region. The complex belongs to the Moreta Formation, a continental sedimentary sequence integrated by red and purple sandstones and conglomerates. The PVC occupies the middle section of the Moreta Formation, reaching a thickness of 640 m in the north, whereas to the south it diminishes

  15. Hedeoma mandonianum (Lamiaceae en Argentina Hedeoma mandonianum (Lamiaceae in Argentina

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Slanis

    2005-12-01

    Full Text Available En el presente trabajo se confirma la presencia de H. mandonianum Wedd. en el Noroeste de Argentina, la cual había sido citada previamente para los Andes de Perú y Bolivia. Se presenta una clave para diferenciar las especies argentinas de Hedeoma como así también descripción, ilustraciones, usos, distribución geográfica y observaciones ecológicas de la especie aquí tratada.In this paper the presence of H. mandonianum Wedd. from Northwestern Argentina is confirmed. This species has been previously cited for the Andes of Peru and Bolivia. A description, illustrations, uses, geographical distribution and ecological observations of the treated species are presented herein, together a key to identify the species of the genus Hedeoma in Argentina.

  16. Meridional overturning circulation: stability and ocean feedbacks in a box model

    NARCIS (Netherlands)

    Cimatoribus, A.A.; Drijfhout, S.S.; Dijkstra, H.A.

    2014-01-01

    A box model of the inter-hemispheric Atlantic meridional overturning circulation is developed, including a variable pycnocline depth for the tropical and subtropical regions. The circulation is forced by winds over a periodic channel in the south and by freshwater forcing at the surface. The model

  17. Interdecadal North-Atlantic meridional overturning circulation variability in EC-EARTH

    NARCIS (Netherlands)

    Wouters, B.; Drijfhout, D.; Hazeleger, W.

    2012-01-01

    The Atlantic meridional overturning circulation (AMOC) in a 600 years pre-industrial run of the newly developed EC-EARTH model features marked interdecadal variability with a dominant time-scale of 50–60 years. An oscillation of approximately 2 Sverdrup (1 Sv = 106 m3 s-1) is identified, which manif

  18. Sensitivity of the Meridional Overturning Circulation to the Pattern of the Surface Density Flux

    Science.gov (United States)

    2010-09-01

    a better prognosis of anthropogenic climate change . Figure 1. Classical representation of the global thermohaline circulation and oceanic...modeling efforts and long-term strategy related to climate change . 15. NUMBER OF PAGES 105 14. SUBJECT TERMS Meridional Overturning Circulation ... Thermohaline Circulation , Thermocline, Residual-Mean Theory, Air-Sea Fluxes, Surface Density Flux , Mixed-Layer Density, Water-mass Transformation

  19. Micropaleontological evidence for increased meridional heat transport in the North Atlantic Ocean during the pliocene

    Science.gov (United States)

    Dowsett, H.J.; Cronin, T. M.; Poore, R.Z.; Thompson, R.S.; Whatley, R.C.; Wood, A.M.

    1992-01-01

    The Middle Pliocene (???3 million years ago) has been identified as the last time the Earth was significantly warmer than it was during the Last Interglacial and Holocene. A quantitative micropaleontological paleotemperature transect from equator to high latitudes in the North Atlantic indicates that Middle Pliocene warmth involved increased meridional oceanic heat transport.

  20. Effect of meridional wind on gap-leaping western boundary current

    Science.gov (United States)

    Wang, Zheng; Yuan, Dongliang; Hou, Yijun

    2010-03-01

    Using a 1.5-layer reduced-gravity nonlinear shallow-water equation model, we studied the effect of the meridional wind on the western boundary currents (WBC) at critical states with hysteresis courses. The results of the simulation indicate that the WBC is prone to penetrating into the gap under northerly winds, and its path is more difficult to alter due to the larger interval between the two critical transition curves ( C 1 P and C 1 L). For southerly winds, the WBC is prone to leaping across the gap, and its path is easier to alter due to the smaller interval between the two critical transition curves. The simulation results also indicate that the meridional winds over the southern region of the gap are the dominant factor determining the formation of the WBC. The dynamic mechanism influencing the transport of WBC near the gap is both Ekman transport and the blocking of Ekman transport. Ekman transport induced by northerly winds may reduce the transport of the WBC, causing the β-effect to dominate the meridional advection (promoting the penetration). Southerly winds, however, may enhance the transport of the WBC, causing the meridional advection to dominate the β-effect (promoting the leaping state). These results explain some structural features of the Kuroshio at the Luzon Strait.

  1. MERIDIONAL CIRCULATION DYNAMICS FROM 3D MAGNETOHYDRODYNAMIC GLOBAL SIMULATIONS OF SOLAR CONVECTION

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Dário [CENTRA, Instituto Superior Tecnico, Universidade de Lisboa, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); Charbonneau, Paul [Départment de Physique, Université de Montréal, C.P. 6128, Centre-ville, Montréal, QC H3C 3J7 (Canada); Miesch, Mark, E-mail: dariopassos@ist.utl.pt [High Altitude Observatory, NCAR, Boulder CO 80301-2252 (United States)

    2015-02-10

    The form of solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. However, a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic techniques is challenging. In this work, we use results from three-dimensional global simulations of solar convection to infer the dynamical behavior of the established meridional circulation. We make a direct comparison between the meridional circulation that arises in these simulations and the latest observations. Based on our results, we argue that there should be an equatorward flow at the base of the convection zone at mid-latitudes, below the current maximum depth helioseismic measures can probe (0.75 R{sub ⊙}). We also provide physical arguments to justify this behavior. The simulations indicate that the meridional circulation undergoes substantial changes in morphology as the magnetic cycle unfolds. We close by discussing the importance of these dynamical changes for current methods of observation which involve long averaging periods of helioseismic data. Also noteworthy is the fact that these topological changes indicate a rich interaction between magnetic fields and plasma flows, which challenges the ubiquitous kinematic approach used in the vast majority of mean field dynamo simulations.

  2. The Shallow Meridional Overturning Circulation in the Northern Indian Ocean and Its Interannual Variability

    Institute of Scientific and Technical Information of China (English)

    HU Ruijin; LIU Qinyu; WANG Qi; J. Stuart GODFREY; MENG Xiangfeng

    2005-01-01

    The shallow meridional overturning circulation (upper 1000 m) in the northern Indian Ocean and its interannual variability are studied, based on a global ocean circulation model (MOM2) with an integration of 10 years (1987-1996). It is shown that the shallow meridional overturning circulation has a prominent seasonal reversal characteristic. In winter, the flow is northward in the upper layer and returns southward at great depth. In summer, the deep northward inflow upwells north of the equator and returns southward in the Ekman layer. In the annual mean, the northward inflow returns through two branches: one is a southward flow in the Ekman layer, the other is a flow that sinks near 10°N and returns southward between 500 m and 1000 m. There is significant interannual variability in the shallow meridional overturning circulation, with a stronger (weaker) one in 1989 (1991) and with a period of about four years. The interannual variability of the shallow meridional overturning circulation is intimately related to that of the surface wind stress. Several indices are proposed to describe the anomaly of this circulation associated with the cross-equatorial part.

  3. Is a deep one-cell meridional circulation essential for the flux transport Solar Dynamo?

    CERN Document Server

    Hazra, Gopal; Choudhuri, Arnab Rai

    2014-01-01

    The solar activity cycle is successfully modeled by the flux transport dynamo, in which the meridional circulation of the Sun plays an important role. Most of the kinematic dynamo simulations assume a one-cell structure of the meridional circulation within the convection zone, with the equatorward return flow at its bottom. In view of the recent claims that the return flow occurs at a much shallower depth, we explore whether a meridional circulation with such a shallow return flow can still retain the attractive features of the flux transport dynamo (such as proper butterfly diagram, proper phase relation between the toroidal and poloidal fields). We consider additional cells of the meridional circulation below the shallow return flow---both the case of multiple cells radially stacked above one another and the case of more complicated cell patterns. As long as there is an equatorward flow in low latitudes at the bottom of the convection zone, we find that the solar behavior is approximately reproduced. Howeve...

  4. High Andean butterflies from southern Peru, I. Dry puna Satyrinae, with the description of two new taxa and three new records from Peru (Lepidoptera: Nymphalidae

    Directory of Open Access Journals (Sweden)

    José Alfredo Cerdeña

    2014-12-01

    Full Text Available This is the first part of a series of contributions to the knowledge of the high Andean butterfly fauna in southern Peru. In this work the butterfly species of the subfamily Satyrinae present in the dry puna of Peru are reviewed. A new species, Pampasatyrus gorkyi sp. nov. and a new subspecies Argyrophorus lamna cuzcoensis ssp. nov. are described from the department Cusco, Peru. Three species are recorded for the first time for Peru, Argyrophorus gustavi Staudinger, Faunula euripides (Weymer and Faunula eleates (Weymer previously reported from Chile and Bolivia. Ecological and biogeographical data are provided.

  5. Estrategias campesinas de reproducción social. El caso de las Tierras Altas Jujeñas, Argentina

    Directory of Open Access Journals (Sweden)

    Cowan Ros, Carlos

    2008-08-01

    Full Text Available This article analyzes peasantry persistence in a context of deepening of the capitalist relations of production, as given by the diffusion of neoliberal policies in periphery countries. The case study focuses on crisis and recreation of peasant’s social reproduction strategies in the Puna and Quebrada de Humahuaca, Argentina. The article analyzes the new economic strategies of peasantry, focusing on its logics of accumulation and conversion of capitals. Results suggests that the productive conversion was oriented towards strengthening typical peasant activities such as farming and handicraft production —whereas the main followed mechanism against decapitalisation was the accumulation of social capital for its further conversion in other types of capitals. Nevertheless, the implementation of these strategies has been conditioned by structural and social factors that make difficult the consolidation of a commercial agriculture in peasant systems in these regions.

    Este artículo analiza la persistencia del campesinado en un contexto de profundización de las relaciones capitalistas de producción, que se caracteriza por la difusión de las políticas neoliberales en los países periféricos. El caso empírico estudiado es la crisis y la reconversión de las estrategias de reproducción social de los campesinos de la Puna y de la Quebrada de Humahuaca, Argentina. El artículo analiza las nuevas estrategias económicas campesinas, centrándose en las lógicas de acumulación y conversión de capitales. Se propone que la reconversión productiva se ha orientado hacia el fortalecimiento de las actividades típicamente campesinas —agropecuarias y artesanales— y que, frente a la descapitalización, el principal mecanismo seguido fue la acumulación de capital social para su posterior conversión en otros tipos de capitales. Sin embargo, la implementación de estas estrategias ha sido condicionada por factores estructurales y sociales que

  6. Interconverting the matrix and principal-meridional representations of dioptric power and reduced vergence.

    Science.gov (United States)

    Harris, W F

    2000-11-01

    Converting the traditional representation of power as sphere, cylinder and axis to the dioptric power matrix F is usually performed by means of Long's equations and the reverse process by means of Keating's equations. It is sometimes useful to be able to convert directly between the matrix and power expressed in terms of principal powers F1 and F2 along corresponding principal meridians at angles a1 and a2. The equations for interconverting F and the principal-meridional representation expressed as F1(a1)F2 are presented here. Equivalent equations allow direct interconversion of the reduced vergence matrix L and the principal-meridional representation of vergence L1(a1)L2. Vergence becomes infinite at line and point focuses. Similarly effective power and back- and front-vertex power are infinite for some systems. Nevertheless it is possible unambiguously to represent infinite vergence and vertex power in principal-meridional form. However, information is usually lost in these infinite cases when the principal-meridional representation is converted to the matrix representation, and the former is not recoverable from the latter. As a consequence the matrix representation is usually unsatisfactory for vergences and vertex powers that are infinite. On the other hand, the principal-meridional representation of vergence and power is always satisfactory. If one adopts the position that effective powers and vertex powers are really vergences rather than powers then one concludes that the matrix provides a satisfactory representation for powers of thin systems in general but not for vergences. Implied by a vergence at a point is an interval of Sturm. The equations for characterizing the interval from the reduced vergence are presented.

  7. Unveiling current Guanaco distribution in chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests.

    Science.gov (United States)

    González, Benito A; Samaniego, Horacio; Marín, Juan Carlos; Estades, Cristián F

    2013-01-01

    Niche description and differentiation at broad geographic scales have been recent major topics in ecology and evolution. Describing the environmental niche structure of sister taxa with known evolutionary trajectories stands out as a useful exercise in understanding niche requirements. Here we model the environmental niche structure and distribution of the recently resolved phylogeography of guanaco (Lama guanicoe) lineages on the western slope of the southern Andes. Using a maximum entropy framework, field data, and information on climate, topography, human density, and vegetation cover, we identify differences between the two subspecies (L.g.cacsilensis, L.g.guanicoe) and their intermediate-hybrid lineage, that most likely determine the distribution of this species. While aridity seems to be a major factor influencing the distribution at the species-level (annual precipitation overlap: I (Similarity Index) = 0.06 and D (Schoener's Similarity Index) = 0.01; and higher levels when comparing Northern and Southern subspecies with hybrids lineage ( I = 0.32-0.10 and D = 0.12-0.03, respectively). This suggests that important ecological and/or evolutionary processes are shaping the niche of guanacos in Chile, producing discrepancies when comparing range distribution at the species-level (81,756 km(2)) with lineages-level (65,321 km(2)). The subspecies-specific description of niche structure is provided here based upon detailed spatial distribution of the lineages of guanacos in Chile. Such description provides a scientific tool to further develop large scale plans for habitat conservation and preservation of intraspecific genetic variability for this far ranging South American camelid, which inhabits a diversity of ecoregion types from Andean puna to subpolar forests.

  8. Groundwater chemistry in the vicinity of the Puna Geothermal Venture Power Plant, Hawai‘i, after two decades of production

    Science.gov (United States)

    Evans, W.C.; Bergfeld, D.; Sutton, A.J.; Lee, R.C.; Lorenson, T.D.

    2015-01-01

    We report chemical data for selected shallow wells and coastal springs that were sampled in 2014 to determine whether geothermal power production in the Puna area over the past two decades has affected the characteristics of regional groundwater. The samples were analyzed for major and minor chemical species, trace metals of environmental concern, stable isotopes of water, and two organic compounds (pentane and isopropanol) that are injected into the deep geothermal reservoir at the power plant. Isopropanol was not detected in any of the groundwaters; confirmed detection of pentane was restricted to one monitoring well near the power plant at a low concentration not indicative of source. Thus, neither organic compound linked geothermal operations to groundwater contamination, though chemical stability and transport velocity questions exist for both tracers. Based on our chemical analysis of geothermal fluid at the power plant and on many similar results from commercially analyzed samples, we could not show that geothermal constituents in the groundwaters we sampled came from the commercially developed reservoir. Our data are consistent with a long-held view that heat moves by conduction from the geothermal reservoir into shallow groundwaters through a zone of low permeability rock that blocks passage of geothermal water. The data do not rule out all impacts of geothermal production on groundwater. Removal of heat during production, for example, may be responsible for minor changes that have occurred in some groundwater over time, such as the decline in temperature of one monitoring well near the power plant. Such indirect impacts are much harder to assess, but point out the need for an ongoing groundwater monitoring program that should include the coastal springs down-gradient from the power plant.

  9. DERECHO AMBIENTAL EN ARGENTINA

    Directory of Open Access Journals (Sweden)

    Silvia Nonna

    2014-05-01

    Full Text Available El objetivo de la presente publicación es brindar un panorama general, introductorio y actualizado del derecho ambiental argentino. Entendiendo que el derecho ambiental es un signo de nuestra era y que por la dinamicidad de la cuestión ambiental requiere de permanente actualización regulatoria. La autora desarrolla en forma objetiva su postura en relación con la necesidad de hacer sostenible al derecho ambiental. Para luego analizar brevemente la situación actual del derecho vigente en Argentina, haciendo un rápido y resumido recorrido desde la última reforma de la Constitución Nacional hasta la consideración especial de cada una de las nuevas normas de presupuestos mínimos de protección ambiental.

  10. gobierno dividido en Argentina

    Directory of Open Access Journals (Sweden)

    María Elisa Alonso García

    2008-01-01

    Full Text Available Este artículo es una reflexión sobre el gobierno dividido en Argentina, y un análisis sobre las consecuencias negativas que tiene el binomio presidencialismo –multipartidismo para la gobernabilidad y el desarrollo institucional del país. El estudio del caso argentino permite comprobar que el gobierno en minoría no constituye un obstáculo para el desarrollo institucional, y que los problemas que de él se derivan, como el bloqueo legislativo y el conflicto institucional pueden solventarse, evitando la crisis. En este sentido, se analiza el papel jugado por los partidos provinciales, que han sido determinantes para evitar los problemas vinculados con el gobierno dividido

  11. nueva realidad de Argentina

    Directory of Open Access Journals (Sweden)

    Roberto Miranda

    2011-01-01

    Full Text Available Una de las características de la política latinoamericana de los últimos tiempos ha sido la tensión entre integración y fragmentación. En este contexto hubo una reproducción de situaciones conocidas. Pero también se procesaron cambios importantes. Uno de éstos estuvo relacionado con la irrupción de los liderazgos regionales, de naturaleza y envergadura diversa. Encontramos una puja muy particular entre el liderazgo de Venezuela en un proyecto alternativo y la respuesta geopolítica de Estados Unidos a través de Colombia. La realidad de los liderazgos impactó notoriamente a Argentina. Fue evidente que a partir de la crisis de 2001 perdió capacidad de influencia en la región.

  12. Metropolization in Argentina

    OpenAIRE

    Dagnino Pastore, José María; Canavese, Paula

    1996-01-01

    A partir de la regla de "orden-magnitud" el trabajo formula el concepto de "metropolización" (Smger) y explicita su relación con el índice de urbanización usual. Rastrea la evolución de la metropolización en Argentina a través de sus ocho censos, tanto para el conjunto de todos los centros urbanos como para tres subconjuntos: grandes, medianos y pequeños. El trabajo presenta después la idea de economías de "concentración geográfica" de las actividades (Lösch), explorando su relación -bajo sup...

  13. Argentina, ¿trabaja?

    OpenAIRE

    De Sena, Angélica; Chahbenderian, Florencia

    2012-01-01

    En la última década en la Argentina se implementaron una serie de políticas sociales denominadas socio-productivas, socio-laboral y socio-económicas con el objeto de mejorar la situación de desempleo o precariedad laboral de la población. Las mismas pueden considerarse un modo de compensación de los efectos de exclusión del régimen de producción y acumulación vigente. En este contexto en el año 2009 nace el Plan “Ingreso Social con Trabajo” desde el Ministerio de Desarrollo Social, que declar...

  14. Soft rocks in Argentina

    Institute of Scientific and Technical Information of China (English)

    Giambastiani; Mauricio

    2014-01-01

    Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification (consolidation, cemen-tation, new formed minerals), chemical sedimentary rocks and metamorphic rocks formed by minerals with Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the latter. They also include any type of rock that suffered alteration processes (hydrothermal or weathering). In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties (UCS, deformability) to physical index (porosity, density, etc.) has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text (Chihuído dam, N. Kirchner dam, J. Cepernic Dam, etc.) and others such as International Tunnel in the Province of Mendoza (Corredor Bioceánico), which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improv-ing techniques will result in benefits to the better understanding of the geomechanics of weak rocks.

  15. Lithium- and boron-bearing brines in the Central Andes: exploring hydrofacies on the eastern Puna plateau between 23° and 23°30'S

    Science.gov (United States)

    Steinmetz, R. L. López

    2016-04-01

    Internally drained basins of the Andean Plateau are lithium- and boron-bearing systems. The exploration of ionic facies and parental links in a playa lake located in the eastern Puna (23°-23°30'S) was assessed by hydrochemical determinations of residual brines, feed waters and solutions from weathered rocks. Residual brines have been characterized by the Cl- (SO4 =)/Na+ (K+) ratio. Residual brines from the playa lake contain up to 450 mg/l of boron and up to 125 mg/l of lithium, and the Las Burras River supplies the most concentrated boron (20 mg/l) and lithium (3.75 mg/l) inflows of the basin. The hydro-geochemical assessment allowed for the identification of three simultaneous sources of boron: (1) inflow originating from granitic areas of the Aguilar and Tusaquillas ranges; (2) weathering of the Ordovician basement; and (3) boron-rich water from the Las Burras River. Most of the lithium input of the basin is likely generated by present geothermal sources rather than by weathering and leaching of ignimbrites and plutonic rocks. However, XRD analyses of playa lake sediments revealed the presence of lithian micas of clastic origin, including taeniolite and eucriptite. This study is the first to document these rare Li-micas from the Puna basin. Thus, both residual brines and lithian micas contribute to the total Li content in the studied hydrologic system.

  16. Lithium- and boron-bearing brines in the Central Andes: exploring hydrofacies on the eastern Puna plateau between 23° and 23°30'S

    Science.gov (United States)

    Steinmetz, R. L. López

    2017-01-01

    Internally drained basins of the Andean Plateau are lithium- and boron-bearing systems. The exploration of ionic facies and parental links in a playa lake located in the eastern Puna (23°-23°30'S) was assessed by hydrochemical determinations of residual brines, feed waters and solutions from weathered rocks. Residual brines have been characterized by the Cl- (SO4 =)/Na+ (K+) ratio. Residual brines from the playa lake contain up to 450 mg/l of boron and up to 125 mg/l of lithium, and the Las Burras River supplies the most concentrated boron (20 mg/l) and lithium (3.75 mg/l) inflows of the basin. The hydro-geochemical assessment allowed for the identification of three simultaneous sources of boron: (1) inflow originating from granitic areas of the Aguilar and Tusaquillas ranges; (2) weathering of the Ordovician basement; and (3) boron-rich water from the Las Burras River. Most of the lithium input of the basin is likely generated by present geothermal sources rather than by weathering and leaching of ignimbrites and plutonic rocks. However, XRD analyses of playa lake sediments revealed the presence of lithian micas of clastic origin, including taeniolite and eucriptite. This study is the first to document these rare Li-micas from the Puna basin. Thus, both residual brines and lithian micas contribute to the total Li content in the studied hydrologic system.

  17. Titan's meridional wind profile and Huygens' orientation and swing inferred from the geometry of DISR imaging

    Science.gov (United States)

    Karkoschka, Erich

    2016-05-01

    The altitude and zonal motion of the Huygens probe descending through Titan's atmosphere was determined early under the assumption of no meridional motion (Bird et al. [2005]. Nature 438, 800-802). By comparing images taken during the descent, Karkoschka et al. (Karkoschka et al. [2007]. Planet. Space Sci. 55, 1895-1935) determined the meridional motion of Huygens, which was generally much smaller than its zonal motion. Here, we present a comprehensive geometrical analysis of all images taken during the descent that is four times more accurate than the previous study. The result is a meridional wind profile across Titan's troposphere with northward winds by up to 0.4 m/s with an average of 0.1 m/s above 1 km altitude, and southward winds below, peaking at 0.9 m/s near 0.4 km altitude. The imaging data extend down to 0.22 km altitude, although additional information came from the horizontal impact speed near 0.8 m/s southward (Schröder et al. [2012]. Planet. Space Sci. 73, 327-340). There is a region between 5 and 8 km altitude with no significant meridional wind. In the stratosphere, the average meridional wind was 1.2 ± 1.5 m/s northward, and zero meridional motion is possible down to 15 km altitude. We present the difference between the zonal speeds of Huygens and the wind that was ignored in previous publications and amounts to up to 7 m/s. We determined the three rotational angles of Huygens for the times of each exposure that showed surface features. During 26 exposures, the swing speed of Huygens was fast enough to smear images. Inferred swing speeds were up to 20°/s during the calm phase of the descent, consistent with up to 40°/s swings reported before during the rough phase. The improved geometric calibration of images allowed identification of many features also seen in Cassini radar images. This comparison yields the location of the Huygens LandingSite as 192.34 ± 02° West and 10.47 ± 0.02° South.

  18. Structure of the Rangel alkaline complex (Salta, NW Argentina)

    Science.gov (United States)

    Vegas, Nestor; Hongn, Fernando; María Tubía, José; Menegatti, Nilda; Aranguren, Aitor; Rodriguez-Méndez, Lidia

    2017-04-01

    The alcaline complex of the Sierra de Rangel is a Cretaceous granitoid emplaced in the Puna Region, at the province of Salta (NW Argentina). This granitoid spreads over 9 km2 and is elongated following a NE-SW trend. The Rangel complex intrudes Quaternary sediments of the Salinas Grandes salt flat towards the east and Ordovician quartzites and metapelites to the west. There are three main facies in the Rangel granitoid: the easternmost part of the intrusion is composed by sienites that crop out in three hills isolated into the salt flat; the central part of the stock made of alkaline granites and quartz-sienites; and the westernmost side composed by alkaline granites. The available rubidium-strontium ages point out two magmatic pulses: 134±1,6Ma for the granites and quartz-sienites and the sienites of the central and eastern part and 122±1,5 Ma for the alkaline granites of the western border. The most common structure in the host quartzites and metapelites is N55oE-trending schistosity that dips around 60o to the SE. This schistosity is parallel to the axial surface of asymmetric folds with axes plunging to the east. The sharp western contact of the Rangel complex with the host rocks display a N30oE strike and dips around 40o to the SE. This contact is parallel to the intra-magmatic contact between the western and central facies and to the NE-SW elongation of the granitoid. The study of the magnetic fabrics carried on 52 sites of the Rangel complex outline the presence of two sets of tabular intrusions: a main group of overlapping NE-trending sheets that dip to the SE; and a minor group roughly perpendicular to the previous one. The integration of the magnetic fabrics results and the structural data suggest that the former set of intrusions are feeder dykes of the NE-trending sheeted intrusions. Moreover, the radiometric data suggest that the oldest pulse corresponds to the upper part of the granitoid. This fact would imply that the emplacement was controlled by

  19. OSTEOMETRÍA DE VICUGNA VICUGNA MOLINA, 1782 EN EL PLEISTOCENO FINAL DE PATAGONIA MERIDIONAL CHILENA: IMPLICANCIAS PALEOECOLÓGICAS Y BIOGEOGRÁFICAS / Osteometry of Vicugna vicugna Molina, 1782 in the late Pleistocene of southern chilean Patagonia

    Directory of Open Access Journals (Sweden)

    Rafael Labarca Encina

    2009-12-01

    Full Text Available  Se presenta un análisis osteométrico uni y multivariado con los materiales fósiles -principalmente huesos cortos y falanges- de Vicugna sp. del yacimiento Cueva Lago Sofía 4 (13500 – 11000 AP, ubicado en la provincia de Última Esperanza (Región de Magallanes, Chile. Los resultados indican que los elementos analizados poseen un tamaño compatible con los registrados para Vicugna vicugna, no superando en ningún caso a los especímenes conocidos para Vicugna gracilis del Pleistoceno de la región Pampeana. Esto confirma la información morfológica y de ADN antiguo que indicaba la presencia de Vicugna vicugna en la Patagonia meridional chilena. Se discuten los resultados en términos taxonómicos, biogeográficos y paleoecológicos sugiriendo que la presencia de este taxón fuera de su rango actual de distribución se debió a las condiciones ambientales compartidas entre la Puna y Patagonia austral durante la transición Pleistoceno-Holoceno. La extinción de V. vicugna se habría debido al impacto de los cambios climáticos ocurridos al inicio del Holoceno producto de su dieta pastadora y etología no migratoria y territorial, a lo que se habría sumado una caza por parte de depredadores humanos y no humanos.Palabras clave: género Vicugna, osteometría, Pleistoceno, Patagonia AbstractThis contribution presents the results of single and multi-variable osteometric analyses performed on a sample of short bones and phalanxes assigned to Vicugna sp. from Lago Sofía Cave 4 site (13500 – 11000 BP, Región de Magallanes, Chile. The elements analyzed show a similar size to the reference collections for Vicugna vicugna, and do not exceed the metrics for the pampean pleistocenic specimens of Vicugna gracilis. This confirms the morphological and ancient DNA data that indicated the presence of vicuña in southern Chilean Patagonia. The taxonomic, biogeographic and palaeoecologic discussion of these results, suggests that the presence of this

  20. Remote influence of Interdecadal Pacific Oscillation on the South Atlantic meridional overturning circulation variability

    Science.gov (United States)

    Lopez, Hosmay; Dong, Shenfu; Lee, Sang-Ki; Campos, Edmo

    2016-08-01

    This study explores potential factors that may influence decadal variability of the South Atlantic meridional overturning circulation (SAMOC) by using observational data as well as surface-forced ocean model runs and a fully coupled climate model run. Here we show that SAMOC is strongly correlated with the leading mode of sea surface height (SSH) variability in the South Atlantic Ocean, which displays a meridional dipole between north and south of 20°S. A significant portion ( 45%) of the South Atlantic SSH dipole variability is remotely modulated by the Interdecadal Pacific Oscillation (IPO). Further analysis shows that anomalous tropical Pacific convection associated with the IPO forces robust stationary Rossby wave patterns, modulating the wind stress curl over the South Atlantic Ocean. A positive (negative) phase IPO increases (decreases) the westerlies over the South Atlantic, which increases (decreases) the strength of the subtropical gyre in the South Atlantic and thus the SAMOC.

  1. Angular momentum fluxes caused by Λ -effect and meridional circulation structure of the Sun

    Science.gov (United States)

    Pipin, Valery V.; Kosovichev, Alexander G.

    2016-10-01

    Using mean-field hydrodynamic models of the solar angular momentum balance we show that the non-monotonic latitudinal dependence of the radial angular momentum fluxes caused by Λ -effect can affect the number of the meridional circulation cells stacking in the radial direction in the solar convection zone. In particular, our results show the possibility of a complicated triple-cell meridional circulation structure. This pattern consists of two large counterclockwise circulation cells (the N-hemisphere) and a smaller clockwise cell located at low latitudes at the bottom of the convection zone. Similar triple-cell circulation patterns were previously earlier found in a number of 3D global simulations models. The effect is demonstrated for the first time using the mean-field parametrization of the Λ -effect.

  2. A Simple Model of the Warm-water Branch of Meridional Overturning

    Science.gov (United States)

    Samelson, R. M.

    2008-12-01

    A reduced-gravity model is presented of the warm-water branch of the mid-depth meridional overturning circulation in a rectangular basin with a circumpolar connection. The model describes the balance between production of warm water by Ekman advection across the circumpolar current, dissipation of water water by eddy fluxes southward across the current, and the net production or dissipation of warm water by diabatic processes north of the current. Analytical solutions are obtained for weak friction and diabatic forcing. The results emphasize the role of the eastern boundary condition in setting the thermocline structure north of the current, and the nonlinear interactions between wind forcing, eddy fluxes, and diabatic mixing, which together control the structure and amplitude of the model meridional overturning circulation.

  3. Three-dimensional simulation of equatorial spread-F with meridional wind effects

    Directory of Open Access Journals (Sweden)

    J. Krall

    2009-05-01

    Full Text Available The NRL SAMI3 three-dimensional simulation code is used to examine the effect of meridional winds on the growth and suppression of equatorial spread F (ESF. The simulation geometry conforms to a dipole field geometry with field-line apex heights from 200 to 1600 km at the equator, but extends over only 4 degrees in longitude. The full SAMI3 ionosphere equations are included, providing ion dynamics both along and across the field. The potential is solved in two dimensions in the equatorial plane under a field-line equipotential approximation. By selectively including terms in the potential equation, the reduced growth predicted by Maruyama (1988 and the stabilization predicted by Zalesak and Huba (1991 are separately realized. We find that ESF is stabilized by a sufficiently large constant meridional wind (60 m/s in our example.

  4. Meridional Flow in the Solar Convection Zone II: Helioseismic Inversions of GONG Data

    CERN Document Server

    Jackiewicz, J; Kholikov, S

    2015-01-01

    Meridional flow is thought to play a very important role in the dynamics of the solar convection zone; however, because of its relatively small amplitude, precisely measuring it poses a significant challenge. Here we present a complete time-distance helioseismic analysis of about two years of ground-based GONG Doppler data to retrieve the meridional circulation profile for modest latitudes, in an attempt to corroborate results from other studies. We use an empirical correction to the travel times due to an unknown center-to-limb systematic effect. The helioseismic inversion procedure is first tested and reasonably validated on artificial data from a large-scale numerical simulation, followed by a test to broadly recover the solar differential rotation found from global seismology. From GONG data, we measure poleward photospheric flows at all latitudes with properties that are comparable with earlier studies, and a shallow equatorward flow about $65$\\,Mm beneath the surface, in agreement with recent findings f...

  5. Coccocypselum pulchellum (Rubiaceae, nuevo registro para Argentina

    Directory of Open Access Journals (Sweden)

    Elsa L. Cabral

    2007-01-01

    Full Text Available Se cita Coccocypselum pulchellum por primera vez para Argentina, en Predio Guaraní, Misiones. Esta es la tercera especie de Coccocypselum registrada para la flora de Argentina junto con C. hasslerianum y C. lanceolatum. Se incluyen descripciones, ilustraciones y una clave para reconocer las tres especies argentinas de Coccocypselum.

  6. Meridional Circulation Cells Observed In The Upper Troposphere Over Suriname During The Monsoon Period

    Science.gov (United States)

    Fortuin, P.; Kelder, H.

    Since September 1999, weekly balloon sondes are released at tropical Paramaribo sta- tion (5.8N 55.2W), located at the northern coast of South America. The station lies approximately in the middle of the annual migration range of the ITCZ, and therefore experiences either a northeast or a southeast trade wind regime (ITCZ respectively to the south, north). The wet season corresponds with the period of northeasterly trade winds (December-July) and is normally interrupted by a short dry period (February- March) when the ITCZ lies farthest to the south. During this monsoon period a sys- tematic return flow to higher latitudes can be detected, centered around 12 km (200 hPa), which seems to constitute the upper branch of the Hadley cell. However, this upper branch of the Hadley cell seems to be flanked above and below by southward flow. On closer inspection, these meridional sub-cells persist in a domain of negative potential vorticity, brought about by the horizontal gradient in zonal wind near the Equator as the northern subtropical jet reaches its southern-most point. As predicted by Stevens (1982), this inertially unstable domain responds with vertically sctacked meridional flow cells, in order to restore a minimum horizontal shear in zonal wind near the Equator. These meridional cells continuously exhibit alternating periods of growth and decay, on a time-scale consistent with inertial instability. Their meridional extent is from the Equator to approcimately 10-12 degrees North, such that Paramaribo (at 5.8N) witnesses approximately the maximal merinional wind velocity near the cen- ter of these cells. Due to their persistent recurring nature in the monsoon period, they leave a signature on the water vapor distribution in the upper troposphere, which shows a dry layer sandwithced between wetter layers - with a spatial distribution similar to the sub-cellular flow.

  7. Interannual Meridional Displacement of the East Asian Upper-tropospheric Jet Stream in Summer

    Institute of Scientific and Technical Information of China (English)

    LIN Zhongda; LU Riyu

    2005-01-01

    On the interannual timescale, the meridional displacement of the East Asian upper-tropospheric jet stream (EAJS) is significantly associated with the rainfall anomalies in East Asia in summer. In this study, using the data from the National Centers for Environmental Prediction-Department of Energy (NCEP/DOE) reanalysis-2 from 1979 to 2002, the authors investigate the interannual variations of the EAJS's meridional displacement in summer and their associations with the variations of the South Asian high (SAH) and the western North Pacific subtropical high (WNPSH), which are dominant circulation features in the upper and lower troposhere, respectively. The result from an EOF analysis shows that the meridional displacement is the most remarkable feature of the interannual variations of the EAJS in each month of summer and in summer as a whole. A composite analysis indicates that the summer (June-JulyAugust, JJA) EAJS index, which is intended to depict the interannual meridional displacement of the EAJS, is not appropriate because the anomalies of the zonal wind at 200 hPa (U200) in July and August only, rather than in June, significantly contribute to the summer EAJS index. Thus, the index for each month in summer is defined according to the location of the EAJS core in each month. Composite analyses based on the monthly indexes show that corresponding to the monthly equatorward displacement of the EAJS, the South Asian high (SAH) extends southeastward clearly in July and August, and the western North Pacific subtropical high (WNPSH) withdraws southward in June and August.

  8. Probing Magnetic Fields Near the Base of the Convection Zone with Meridional Flows

    Science.gov (United States)

    CHOU, DEAN-YI

    2017-08-01

    We study the solar-cycle variations of the meridional flows near the base of the convection zone to probe the solar-cycle variations of magnetic fields. Using SOHO/MDI data, we measure the acoustic travel-time difference on the meridional plane for different latitudes and different travel distances over 15 years, including two minima and one maximum. The measured travel-time differences averaged over two minima are similar, but significantlydifferent from that at the maximum. The measured travel-time difference is inverted to obtain the meridional flow at the minimum and maximum. The flow at the minimum has a two-cell pattern in the convection zone: poleward flow in the upper layer (above 0.86R), equator-ward flow in the mid-layer (0.74-0.86R), and poleward flow again in the lower layer (below 0.74R). The two-cell pattern is changed to a more complicated pattern at the maximum. The active latitudes appear to play a key role in the changes.

  9. Causes and impacts of changes in the stratospheric meridional circulation in a chemistry-climate model

    Energy Technology Data Exchange (ETDEWEB)

    Garny, Hella

    2011-05-13

    The stratospheric meridional circulation is projected to be subject to changes due to enhanced greenhouse-gas concentrations in the atmosphere. This study aims to diagnose and explain long-term changes in the stratospheric meridional circulation using the chemistry-climate model E39CA. The diagnosed strengthening of the circulation is found to be driven by increases in tropical sea surface temperatures which lead to a strengthening and upward shift of the subtropical jets. This enables enhanced vertical propagation of large scale waves into the lower stratosphere, and therefore stronger local wave forcing of the meridional circulation in the tropical lower stratosphere. The impact of changes in transport on the ozone layer is analysed using a newly developed method that allows the separation of the effects of transport and chemistry changes on ozone. It is found that future changes of mean stratospheric ozone concentrations are largely determined by changes in chemistry, while changes in transport of ozone play a minor role. (orig.)

  10. Agrobiodiversity of cactus pear (Opuntia, Cactaceae in the Meridional Highlands Plateau of Mexico

    Directory of Open Access Journals (Sweden)

    Juan Antonio Reyes-Agüero

    2011-08-01

    Full Text Available Mexico is characterized by a remarkable richness of Opuntia, mostly at the Meridional Highlands Plateau; it is also here where the greatest richness of Opuntia variants occurs. Most of these variants have been maintained in homegardens; however, the gathering process which originated these homegardens has been disrupted over the past decades, as a result of social change and the destruction of large wild nopaleras. If the variants still surviving in homegardens are lost, these will be hard to recover, that is, the millenary cultural heritage from the human groups that populated the Mexican Meridional Highland Plateau will be lost forever. This situation motivated the preparation of a catalogue that records the diversity of wild and cultivated Opuntia variants living in the meridional Highlands Plateau. To this end, 379 samples were obtained in 29 localities, between 1998 and 2003. The information was processed through Twinspan. All specimens were identified and preserved in herbaria. Botanical keys and descriptions were elaborated. The catalogue includes information on 126 variants comprising 18 species. There were species with only one variant (Opuntia atropes, O. cochinera, O. jaliscana, O. leucotricha, O. rzedowskii and O. velutina, two (O. durangensis, O. lindheimeri, O. phaeacantha and O. robusta, five (O. joconostle and O. lasiacantha, seven (O. chavena, 12 (O. hyptiacantha and O. streptacantha, 15 (O. ficus-indica, 22 (O. albicarpa, and up to 34 (O. megacantha. Additionally, 267 common cactus pear names were related to those variants.

  11. Mechanisms of Interannual Variations of the Meridional Overturning Circulation of the North Atlantic Ocean

    Science.gov (United States)

    Cabanes, Cecile; Lee, Tong; Fu, Lee-Lueng

    2008-01-01

    The authors investigate the nature of the interannual variability of the meridional overturning circulation (MOC) of the North Atlantic Ocean using an Estimating the Circulation and Climate of the Ocean (ECCO) assimilation product for the period of 1993-2003. The time series of the first empirical orthogonal function of the MOC is found to be correlated with the North Atlantic Oscillation (NAO) index, while the associated circulation anomalies correspond to cells extending over the full ocean depth. Model sensitivity experiments suggest that the wind is responsible for most of this interannual variability, at least south of 40(deg)N. A dynamical decomposition of the meridional streamfunction allows a further look into the mechanisms. In particular, the contributions associated with 1) the Ekman flow and its depth-independent compensation, 2) the vertical shear flow, and 3) the barotropic gyre flowing over zonally varying topography are examined. Ekman processes are found to dominate the shorter time scales (1.5-3 yr), while for longer time scales (3-10 yr) the MOC variations associated with vertical shear flow are of greater importance. The latter is primarily caused by heaving of the pycnocline in the western subtropics associated with the stronger wind forcing. Finally, how these changes in the MOC affect the meridional heat transport (MHT) is examined. It is found that overall, Ekman processes explain a larger part of interannual variability (3-10 yr) for MHT (57%) than for the MOC (33%).

  12. A Simple Model Study of Bjerknes Compensation in Meridional Heat Transports under Global Warming

    Science.gov (United States)

    Yang, Qianzi; Zhao, Yingying; Yang, Haijun

    2017-04-01

    The Bjerknes Compensation (BJC) under global warming is studied in a coupled box model. This study suggests that BJC could be valid during the transient period of climate change in response to global warming. The theoretical BJC is derived. The OHT change can be decomposed into two components, one is related to the vertical stratification and the other is related to the strength of meridional overturning (MOC) circulation. The AHT change depends on meridional temperature gradient. Therefore, whether the BJC would happen depends largely on the relative magnitudes between vertical and meridional temperature gradients. During the transient period of global warming, the ocean vertical temperature gradient is enhanced while the AMOC strength does not change too much. The OHT is thus enhanced. At the same time, the surface poleward temperature gradient is weakened due to the polar amplification, so the AHT is reduced, compensating the enhanced OHT. The BJC is valid even the global energy is not conserved during the transient stage. In the equilibrium stage of global warming, the OHT is weakened because both the vertical stratification and the MOC are weakened. The AHT change is in-phase with the OHT change, so the BJC fails.

  13. Meridional Flow in the Solar Convection Zone I: Measurements from GONG Data

    CERN Document Server

    Kholikov, Shukur; Jackiewicz, Jason

    2014-01-01

    Large-scale plasma flows in the Sun's convection zone likely play a major role in solar dynamics on decadal timescales. In particular, quantifying meridional motions is a critical ingredient for understanding the solar cycle and the transport of magnetic flux. Because the signal of such features can be quite small in deep solar layers and be buried in systematics or noise, the true meridional velocity profile has remained elusive. We perform time-distance helioseismology measurements on several years worth of GONG Doppler data. A spherical harmonic decomposition technique is applied to a subset of acoustic modes to measure travel-time differences to try to obtain signatures of meridional flows throughout the solar convection zone. Center-to-limb systematics are taken into account in an intuitive, yet ad hoc manner. Travel-time differences near the surface that are consistent with a poleward flow in each hemisphere and are similar to previous work are measured. Additionally, measurements in deep layers near th...

  14. Unveiling current Guanaco distribution in chile based upon niche structure of phylogeographic lineages: Andean puna to subpolar forests.

    Directory of Open Access Journals (Sweden)

    Benito A González

    provides a scientific tool to further develop large scale plans for habitat conservation and preservation of intraspecific genetic variability for this far ranging South American camelid, which inhabits a diversity of ecoregion types from Andean puna to subpolar forests.

  15. Late Pleistocene pluton formation during the waning stages of the Altiplano-Puna ignimbrite flare-up

    Science.gov (United States)

    Tierney, C. R.; Schmitt, A. K.; Lovera, O. M.; de Silva, S. L.

    2015-12-01

    The latest phase of volcanism during the late Mio- to Pleistocene ignimbrite flare-up in the Altiplano-Puna Volcanic Complex consists of a series of late Pleistocene lava domes (Chao, Chillahuita, Chanka, Chascon-Runtu Jarita, and Tocopuri) which are distributed over a roughly elliptical area of ~2,000 km2. With a collective volume of ~40 km3, these represent a waning of magmatic activity from the peak of the flare-up. Zircon chronochemistry and zircon age spectra were modeled using a finite-difference thermal- and mass-balance model for open-system magma evolution (recharge-assimilation-fractional crystallization; RAFC) where zircon crystallization is treated in accord with experimentally calibrated zircon saturation. Zircon rims and interiors were dated (U-Th, U-Pb) for a total of 252 crystals distributed equally over the domes, with a ~50% subset also analyzed for trace elements. The domes share remarkably consistent zircon crystallization histories: the youngest zircon rim ages (ca. 83 to 104 ka) are near the 40Ar/39Ar eruption ages (ca. 87 to 120 ka; sanidine and biotite), but a significant population of rim ages predates eruption, often ranging to secular equilibrium. U-Pb interior ages of crystals with secular equilibrium rim ages date to ca. 2.0 Ma, and a single core of Chascon to 3.5 Ma. Ti-in-zircon, backed by indirectly T-dependent compositional parameters, show that zircon crystallized at steady-state in a magma reservoir with essentially insignificant (<10-4 °C/a) secular cooling. Most zircon rims postdate peak flare-up, but nevertheless record a protracted and continuous crystallization history. To match the record of zircon production, time-integrated recharge rates of ~1 ×10-3 km3/a are required. At lower rates, older zircon ages are predicted for the dominant zircon rim age population than observed. At higher rates zircon would crystallize late, resulting in a lack of antecrysts. Intermediate recharge rates that best match the data call for at

  16. Investigating sources of ignimbrites in the Altiplano-Puna Volcanic Complex using U-Pb dating of zircons

    Science.gov (United States)

    Kern, J. M.; de Silva, S. L.; Schmitt, A. K.

    2011-12-01

    Large silicic volcanic fields (LSVFs) are thought to represent the surface expression of upper crustal batholith emplacement, with the spatiotemporal distribution of the vents and eruptions representing the development of the system. The Altiplano-Puna Volcanic Complex (APVC) in the Central Andes is a LSVF active from 11-1 Ma that erupted over 13,000 km3 of magma from large, multicyclic caldera centers and smaller ignimbrite shields during 3 distinct pulses of volcanism at 8.4, 5.5, and 4.0 Ma. Links to the magmatic system beneath are being pursued through U-Pb zircon dating of APVC ignimbrites. Initial results comprise 61 238U/206Pb zircon ages of mostly marginal crystal domains from five APVC ignimbrites-the 0.98 ± 0.03 Ma Purico, 3.96 ± 0.08 Ma Atana, 4.0 ± 0.9 Ma Toconao, 4.09 ± 0.02 Ma Puripicar, and 8.33 ± 0.06 Ma Sifon ignimbrites-dated by high-resolution secondary ionization mass spectrometry (SIMS). Each zircon analyzed was less than 350 μm in length and cathodoluminescence images reveal zonations within individual zircons, though significant core-rim age differences are rare. The ~1 Ma Purico ignimbrite displays multiple zircon age populations significantly predating the 40Ar/39Ar eruption age, but younger than ages from the nearby large-volume Atana ignimbrite erupted from La Pacana caldera. Some peaks do, however, coincide with later resurgent activity within La Pacana as expressed by the 2.7 Ma Cerro Bola dome. Zircon ages in the Atana ignimbrite are indistinguishable from its eruption, while those from the 4.0 Ma Toconao ignimbrite-the volatile-rich cap of the Atana magma chamber-contains three populations of xenocrystic zircons from the Proterozoic-Ordivician, ~13 Ma, and ~9 Ma. The ~9 Ma zircons correlate with K-Ar ages from an underlying ignimbrite, whereas the 13 Ma xenocrysts likely have a plutonic source. The Purico ignimbrite thus provides direct evidence of zircon inheritance from previous eruption cycles, while the Toconao records a

  17. Nuevas evidencias geofísicas de la existencia de una caldera cubierta en laguna Pozuelos: Puna norte

    Directory of Open Access Journals (Sweden)

    Claudia B Prezzi

    2010-03-01

    Full Text Available En el extremo sur de la cuenca de laguna de Pozuelos aflora el complejo volcánico Pan de Azúcar. El mismo está integrado por varios centros eruptivos de composición dacítica y morfología dómica que poseen una edad de ~12 Ma. Interpretaciones previas de líneas sísmicas y un relevamiento magnetométrico detallado indicaron la presencia de cuerpos intrusivos no aflorantes. La determinación de la existencia de nuevos cuerpos intrusivos no aflorantes en la zona resulta de interés debido a que: 1 estos complejos volcánicos dacíticos están estrechamente asociados con mineralización de interés económico (forman parte del cinturón estañífero boliviano; y 2 la existencia de una caldera antigua (~ 12 Ma de grandes dimensiones, ahogada bajo la cubierta sedimentaria que rellena la depresión de Pozuelos, ha sido propuesta por distintos autores. Los complejos dómicos representarían las fases magmáticas finales de dicho sistema magmático caldérico. Con la finalidad de determinar la existencia de dicho sistema caldérico y/o de otros cuerpos intrusivos no aflorantes se llevaron a cabo nuevos relevamientos magnetométricos y gravimétricos terrestres detallados. El mapa magnetométrico obtenido presenta conspicuas anomalías positivas y negativas que dominan el sector sur de la cuenca, probablemente asociadas con la presencia de los domos dacíticos aflorantes. La anomalía residual de Bouguer presenta un patrón semicircular, mostrando sólo valores positivos. La curvatura de las señales magnetométricas y gravimétricas fue analizada y se utilizó la deconvolución de Euler para estimar las profundidades a las fuentes causantes de las anomalías detectadas. Los resultados obtenidos hasta el momento apoyan la hipótesis de la existencia de una gran caldera soterrada en la cuenca de Laguna Pozuelos. La identificación de un gran sistema caldérico mioceno medio contribuirá a una mejor comprensión de la evolución magmática de la Puna

  18. Nuevas evidencias geofísicas de la existencia de una caldera cubierta en laguna Pozuelos: Puna norte New geophysical evidences of the presence of a buried caldera in Laguna Pozuelos: Northern Puna

    Directory of Open Access Journals (Sweden)

    Claudia B Prezzi

    2010-03-01

    Full Text Available En el extremo sur de la cuenca de laguna de Pozuelos aflora el complejo volcánico Pan de Azúcar. El mismo está integrado por varios centros eruptivos de composición dacítica y morfología dómica que poseen una edad de ~12 Ma. Interpretaciones previas de líneas sísmicas y un relevamiento magnetométrico detallado indicaron la presencia de cuerpos intrusivos no aflorantes. La determinación de la existencia de nuevos cuerpos intrusivos no aflorantes en la zona resulta de interés debido a que: 1 estos complejos volcánicos dacíticos están estrechamente asociados con mineralización de interés económico (forman parte del cinturón estañífero boliviano; y 2 la existencia de una caldera antigua (~ 12 Ma de grandes dimensiones, ahogada bajo la cubierta sedimentaria que rellena la depresión de Pozuelos, ha sido propuesta por distintos autores. Los complejos dómicos representarían las fases magmáticas finales de dicho sistema magmático caldérico. Con la finalidad de determinar la existencia de dicho sistema caldérico y/o de otros cuerpos intrusivos no aflorantes se llevaron a cabo nuevos relevamientos magnetométricos y gravimétricos terrestres detallados. El mapa magnetométrico obtenido presenta conspicuas anomalías positivas y negativas que dominan el sector sur de la cuenca, probablemente asociadas con la presencia de los domos dacíticos aflorantes. La anomalía residual de Bouguer presenta un patrón semicircular, mostrando sólo valores positivos. La curvatura de las señales magnetométricas y gravimétricas fue analizada y se utilizó la deconvolución de Euler para estimar las profundidades a las fuentes causantes de las anomalías detectadas. Los resultados obtenidos hasta el momento apoyan la hipótesis de la existencia de una gran caldera soterrada en la cuenca de Laguna Pozuelos. La identificación de un gran sistema caldérico mioceno medio contribuirá a una mejor comprensión de la evolución magmática de la Puna

  19. Wind Diffusivity Current, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  20. Wind Diffusivity Current, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Meridional

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality Ekman current (in zonal, meridional, and modulus sets) and Ekman upwelling data. This data begins with wind velocity...

  1. del Estero, Argentina

    Directory of Open Access Journals (Sweden)

    Josefa Delgado

    2007-01-01

    Full Text Available Esta investigación, desde una perspectiva holística, buscó conocer en las familias de niños que asisten a los comedores comunitarios en un barrio capitalino de Santiago del Estero, Argentina, la red de apoyo que utilizan y los recursos que obtienen para poder resolver sus necesidades cotidianas. Es un estudio cuanticualitativo. Los datos fueron recolectados por encuestas parcialmente estructuradas y entrevistas en profundidad. El análisis de los datos se basó en identificación de frecuencias absolutas y relativas. Para los datos cualitativos se usó el referencial fenomenológico heideggeriano. Los resultados indican que 48% de las familias tienen 4 a 5 elementos en la red de apoyo; 91% buscan alimentos, 84% salud y el 73% trabajo; esta reducida red les genera importantes dificultades al momento de satisfacer sus necesidades básicas. La falta de trabajo y baja escolaridad son los principales condicionantes de su aislamiento social.

  2. Hungry China Shops in Argentina

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Chinese investment is flooding into Argentina as the Asian giant expands its global commodity hunt from the raw materials used in industry to the foodstuffs needed to feed its 1.3 billion citizens. China's investment in Latin America hit USI15.6 billion during the 12-month period through the end of May, nearly three times greater than the year-ago period, consulting firm Deloitte said in a report.Of that amount, Brazil received about 60% and Argentina close to 40%.

  3. Tick paralysis cases in Argentina

    Directory of Open Access Journals (Sweden)

    Carlos Remondegui

    2012-08-01

    Full Text Available Tick paralysis (TP occurs worldwide and is caused by a neurotoxin secreted by engorged female ticks that affects the peripheral and central nervous system. The clinical manifestations range from mild or nonspecific symptoms to manifestations similar to Guillain-Barré syndrome, bulbar involvement, and death in 10% of the patients. The diagnosis of TP is clinical. To our knowledge, there are no formal reports of TP in humans in South America, although clusters of TP among hunting dogs in Argentina have been identified recently. In this paper, clinical features of two cases of TP occurring during 1994 in Jujuy Province, Argentina, are described.

  4. New Elemental and Isotopic Data From Mafic Lavas on the Puna Plateau and Re-Examining the Geochemical Signature of Convective Lithospheric Removal in the Central Andes

    Science.gov (United States)

    Murray, K. E.; Ducea, M. N.; Reiners, P. W.

    2009-12-01

    Foundering or delamination of the lower lithosphere into the convecting mantle is required by mass balance in convergent orogens such as the central Andes. In the central Andean volcanic zone (CVZ), late Miocene to Recent mafic lavas erupted on the Puna plateau are small volume fissure flows and cinder cones classically cited as evidence of convective lithospheric removal, in concert with a suite of observations including high surface elevation (>4000m) and anomalously thin lithosphere relative to other parts of the CVZ. Mafic lavas provide the best available geochemical window into the recent history of the upper mantle in this and other regions. However, an increasing number of elemental and isotopic data suggest that these melts are less distinct from the neighboring arc magmatism than originally predicted. This observation weakens the hypothesis that there is a distinct geochemical fingerprint for so-called delamination magmatism, while advancing our understanding of the size of delaminating bodies and the timescales over which they detach from the lithosphere and interact with the mantle wedge. In this contribution, we present elemental and radiogenic isotopic data from 20 newly sampled mafic lavas from the Puna plateau (24.5°S to 27°S). Preliminary major element analyses show that the Puna lavas are high-K to shoshonitic in composition, in broad agreement with other mafic lavas sampled though out the region. Several sampled flows contain xenotliths of granitoid composition, which likely represent the crustal end member that contributed to the more evolved lavas. Along with major, trace and rare earth element analyses, we will present 87Sr/86Sr and 143Nd/144Nd data to further characterize source regions of these melts. In sum, these data will allow us to (1) expand the spatial coverage of this dataset in the central Andes, (2) contribute to the effort to parse contributions from the subcontinental lithosphere, asthenosphere, subduction-related fluids, and

  5. Tandil, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    María L. Bakker

    2006-01-01

    Full Text Available Se coleccionaron hojas maduras de ejemplares adultos de Populus alba, Populus deltoides, Robinia pseudoacacia, Ulmus pumila y Fraxinus americana del Campus Universitario, Tandil, Buenos Aires, Argentina (37° 19’S, 59° 08’O en febrero de 2004. La cera cuticular fue extraída, purificada, y el contenido y proporción relativa de n-alcanos de número impar de carbonos (C23C35 fue cuantificado mediante cromatografía gas-líquido capilar. La concentración total de n-alcanos (mg/kg MS fue P. alba (6935 > Robinia (1571 > P. deltoides (1379 > Ulmus (880 > Fraxinus (467. Los n-alcanos más abundantes en todas las especies fueron C27 y C29 que constituyeron entre 10 y 51% y entre 35 y 76% del total respectivamente, excepto en Fraxinus donde los más abundantes fueron C29 y C31 que constituyeron el 31 y 49% del total respectivamente. P. alba y P. deltoides difirieron no solo en la concentración total de n-alcanos sino también en la proporción relativa de C27 y C29, siendo C29 el n-alcano más abundante en la segunda especie (76% igual que en Robinia (75%. La presencia de nalcanos de número par de carbonos no fue detectable o resultó muy baja en general en todas las especies, con excepción de C26, C28 y C30, este último se destacó particularmente en Fraxinus.

  6. Determination of the UV solar risk in Argentina with high-resolution maps calculated using TOMS ozone climatology

    Science.gov (United States)

    Piacentini, Rubén D.; Cede, Alexander; Luccini, Eduardo; Stengel, Fernando

    2004-01-01

    The connection between ultraviolet (UV) radiation and various skin diseases is well known. In this work, we present the computer program "UVARG", developed in order to prevent the risk of getting sunburn for persons exposed to solar UV radiation in Argentina, a country that extends from low (tropical) to high southern hemisphere latitudes. The software calculates the so-called "erythemal irradiance", i.e., the spectral irradiance weighted by the McKinlay and Diffey action spectrum for erythema and integrated in wavelength. The erythemal irradiance depends mainly on the following geophysical parameters: solar elevation, total ozone column, surface altitude, surface albedo, total aerosol optical depth and Sun-Earth distance. Minor corrections are due to the variability in the vertical ozone, aerosol, pressure, humidity and temperature profiles and the extraterrestrial spectral solar UV irradiance. Key parameter in the software is a total ozone column climatology incorporating monthly averages, standard deviations and tendencies for the particular geographical situation of Argentina that was obtained from TOMS/NASA satellite data from 1978 to 2000. Different skin types are considered in order to determine the sunburn risk at any time of the day and any day of the year, with and without sunscreen protection. We present examples of the software for three different regions: the high altitude tropical Puna of Atacama desert in the North-West, Tierra del Fuego in the South when the ozone hole event overpasses and low summertime ozone conditions over Buenos Aires, the largest populated city in the country. In particular, we analyzed the maximum time for persons having different skin types during representative days of the year (southern hemisphere equinoxes and solstices). This work was made possible by the collaboration between the Argentine Skin Cancer Foundation, the Institute of Physics Rosario (CONICET-National University of Rosario, Argentina) and the Institute of

  7. Surveys of the distribution of seabirds found in the vicinity of proposed geothermal project subzones in the District of Puna, Hawaii. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M.; Ritchotte, G.; Viggiano, A.; Dwyer, J.; Nielsen, B.; Jacobi, J.D. [Fish and Wildlife Service, Hawaii National Park, HI (United States). Hawaii Research Station

    1994-08-01

    In 1993, the US Fish and Wildlife Service (USFWS) entered into an interagency agreement with the Department of Energy (DOE) to conduct specific biological surveys to identify potential impacts of the proposed geothermal development on the natural resources of the East Rift Zone. This report presents information from published literature information and new field data on seabird populations on the island of Hawaii. These data are analyzed with regard to potential impacts of geothermal development on seabird populations in this area. Fifteen species of seabirds, waterbirds, and shorebirds are documented or suspected of being found using habitats within or immediately adjacent to the three geothermal subzones located in the Puna district on the island of Hawai`i. Of these species, two are on the federal Endangered Species List, three are on the State of Hawaii Endangered Species List, and all 15 are protected by the federal Migratory Bird Act.

  8. Surveys of distribution and abundance of the Hawaiian hawk within the vicinity of proposed geothermal project subzones in the District of Puna, Hawaii. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M.; Ritchotte, G.; Viggiano, A.; Dwyer, J.; Nielsen, B.; Jacobi, J.D. [Fish and Wildlife Service, Hawaii National Park, HI (United States). Hawaii Research Station

    1994-08-01

    In 1993, the US Fish and Wildlife Service (USFWS) entered an interagency agreement with the Department of Energy (DOE) to conduct specific biological surveys to identify potential impacts of proposed geothermal development on the biota of the east rift zone of Kilauea volcano in the Puna district on the island of Hawaii. This report presents data on the distribution, habitat use, and density of the Hawaiian hawk or `Io (Buteo solitarius). Data were collected by the USFWS to assess the potential impacts of geothermal development on `Io populations on the island of Hawaii. These impacts include degradation of potential nesting habitat and increased disturbance due to construction and operation activities. Data from these surveys were analyzed as part of an island wide population assessment conducted by the Western Foundation of Vertebrate Zoology at the request of the USFWS.

  9. Sessea regnellii (Solanaceae en Argentina

    Directory of Open Access Journals (Sweden)

    Héctor A. Keller

    2006-01-01

    Full Text Available Se cita por primera vez a Sessea regnelli para la flora argentina. Se presenta una descripción de la especie sobre la base de los ejemplares examinados, como así también ilustraciones y observaciones ecológicas.

  10. NREL technical assistance to Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Lilienthal, P. [National Renewable Energy Lab., Golden, CO (United States)

    1997-12-01

    This paper describes assistance to Argentina from the National Renewable Energy Laboratory which has touched on four programs: tariff analysis for rural concessions programs; wind/diesel hybrid retrofits in Patagonia; small hybrid systems designs for rural schools; an assessment of wind resources. The paper expands briefly on the first two points.

  11. Archaeology in the Kilauea East Rift Zone: Part 1, Land-use model and research design, Kapoho, Kamaili and Kilauea Geothermal Subzones, Puna District, Hawaii Island

    Energy Technology Data Exchange (ETDEWEB)

    Burtchard, G.C.; Moblo, P. [International Archaeological Research Inst., Inc., Honolulu, HI (United States)

    1994-07-01

    The Puna Geothermal Resource Subzones (GRS) project area encompasses approximately 22,000 acres centered on the Kilauea East Rift Zone in Puna District, Hawaii Island. The area is divided into three subzones proposed for geothermal power development -- Kilauea Middle East Rift, Kamaili and Kapoho GRS. Throughout the time of human occupation, eruptive episodes along the rift have maintained a dynamic landscape. Periodic volcanic events, for example, have changed the coastline configuration, altered patterns of agriculturally suitable sediments, and created an assortment of periodically active, periodically quiescent, volcanic hazards. Because of the active character of the rift zone, then, the area`s occupants have always been obliged to organize their use of the landscape to accommodate a dynamic mosaic of lava flow types and ages. While the specific configuration of settlements and agricultural areas necessarily changed in response to volcanic events, it is possible to anticipate general patterns in the manner in which populations used the landscape through time. This research design offers a model that predicts the spatial results of long-term land-use patterns and relates them to the character of the archaeological record of that use. In essence, the environmental/land-use model developed here predicts that highest population levels, and hence the greatest abundance and complexity of identifiable prehistoric remains, tended to cluster near the coast at places that maximized access to productive fisheries and agricultural soils. With the possible exception of a few inland settlements, the density of archaeological remains expected to decrease with distance from the coastline. The pattern is generally supported in the regions existing ethnohistoric and archaeological record.

  12. Surnames, geographic altitude, and digital dermatoglyphics in a male population from the province of Jujuy (Argentina).

    Science.gov (United States)

    Dipierri, José E; Gutiérrez-Redomero, Esperanza; Alonso-Rodríguez, Concepción; Alfaro, Emma; Demarchi, Dario; Rivaldería, Noemí

    2014-06-01

    The possible association between finger dermatoglyphic patterns and altitude and surname distribution was analyzed in a sample of adult males from the province of Jujuy, Argentina. We also investigated the biological affinity of this population with other South American natives and admixed populations. Fingerprints were obtained from 996 healthy men, aged 18-20 years, from the highlands (HL: 2500m, Puna and Quebrada) and lowlands (LL: Valle and Selvas). Surnames were classified into native/autochthonous (A) or foreign (F), resulting in three surname classes: FF, when both paternal and maternal surnames were of foreign origin; FA, when one surname was foreign and the other was native; and AA, when both surnames were native. Frequencies of finger dermatoglyphic patterns - arches (A), radial loops (RL), ulnar loops (UL), and whorls (W) - were determined for each digit in relation to geographic location, altitude, and surname origin, resulting in the following categories: HL-FF, HL-FA, HL-AA, LL-FF, LL-FA, and LL-AA. The statistical analyses showed that UL and RL were more common in individuals of HL origin, whereas W and A were more frequent in the LL males (pdermatoglyphic patterns and surname origin when geographic altitude was considered. In the HL group, UL was associated with AA and FA; in the LL group, the presence of A was associated with FF and FA. The distribution of dermatoglyphic patterns shows that the population of Jujuy belongs to the Andean gene pool and that it has undergone differential levels of admixture related to altitude.

  13. An observations and model-based analysis of meridional transports in the South Atlantic

    Science.gov (United States)

    Majumder, Sudip; Schmid, Claudia; Halliwell, George

    2016-08-01

    A three-dimensional velocity field constructed from Argo observations and sea surface heights (called Argo and SSH, hereinafter) is used to estimate meridional overturning volume transport and meridional heat transport (MHT) across 20°S, 25°S, 30°S, and 35°S for the years 2000-2014 in the South Atlantic. Volume transport in the upper branch of Meridional Overturning Circulation (MOC) and MHT from the observations are consistent with the previous observations, but are higher than the estimates derived from three data assimilative ocean models, at some of the latitudes. Both the observations and models show strong correlations between the strength of MOC and MHT at all the latitudes. The corresponding change in MHT for 1 Sv change of MOC strength, in the observations, increases from 0.046 PW in 25°S, 30°S, and 35°S to 0.056 PW across 20°S. A comparison of model-based transports at 35°S at the boundaries and in the interior with those from Argo and SSH shows significant differences between them with respect to the contributions in the three segments of the section. In addition, the contributions also vary greatly between the different models. An analysis of the seasonality of MOC in the models and in the observations reveals that MOC anomalies in the models mostly show strong annual cycles at all the latitudes, whereas those derived from Argo and SSH exhibit annual cycles at three latitudes (35°S, 30°S, and to a lesser extent at 25°S) and a semiannual cycle at 20°S.

  14. Bjerknes Compensation in Meridional Heat Transport under Freshwater Forcing and the Role of Climate Feedback

    Science.gov (United States)

    Wen, Qin

    2017-04-01

    Using a coupled Earth climate model, freshwater experiments are performed to study the Bjerknes compensation (BJC) between meridional atmosphere heat transport (AHT) and meridional ocean heat transport (OHT). Freshwater hosing in the North Atlantic weakens the Atlantic meridional overturning circulation (AMOC) and thus reduces the northward OHT in the Atlantic significantly, leading to a cooling (warming) in surface layer in the Northern (Southern) Hemisphere. This results in an enhanced Hadley Cell and northward AHT. Meanwhile, the OHT in the Indo-Pacific is increased in response to the Hadley Cell change, partially offsetting the reduced OHT in the Atlantic. Two compensations occur here: compensation between the AHT and the Atlantic OHT, and that between the Indo-Pacific OHT and the Atlantic OHT. The AHT change compensates the OHT change very well in the extratropics, while the former overcompensates the latter in the tropics due to the Indo-Pacific change. The BJC can be understood from the viewpoint of large-scale circulation change. However, the intrinsic mechanism of BJC is related to the climate feedback of Earth system. Our coupled model experiments confirm that the occurrence of BJC is an intrinsic requirement of local energy balance, and local climate feedback determines the extent of BJC, consistent with previous theoretical results. Even during the transient period of climate change in the model, the BJC is well established when the ocean heat storage is slowly varying and its change is weaker than the net heat flux changes at the ocean surface and the top of the atmosphere. The BJC can be deduced from the local climate feedback. Under the freshwater forcing, the overcompensation in the tropics (undercompensation in the extratropics) is mainly caused by the positive longwave feedback related to cloud (negative longwave feedback related to surface temperature change). Different dominant feedbacks determine different BJC scenarios in different regions

  15. Support of Publication Costs, Atlantic Meridional Overturning Circulation Special Issue of Deep Sea Research II Journal

    Energy Technology Data Exchange (ETDEWEB)

    Amy Honchar

    2012-11-12

    The contribution of funds from DOE supported publication costs of a special issue of Deep Sea Research arising from presentations at the First U.S. Atlantic Meridional Overturning Circulation (AMOC) Meeting held 4-6 May, 2009 to review the US implementation plan and its coordination with other monitoring activities. The special issue includes a total of 16 papers, including publications from three DOE-supported investigators (ie Sevellec, F., and A.V. Fedorov; Hu et. al., and Wan et. al.,). The special issue addresses DOE interests in understanding and simulation/modeling of abrupt climate change.

  16. Inferring the zonal distribution of measured changes in the meridional overturning circulation

    Directory of Open Access Journals (Sweden)

    A. de Boer

    2006-10-01

    Full Text Available Recently, hydrographic measurements have been used to argue that the meridional overturning circulation at 25° N has decreased by 30% over the last 50 years. Here, we show that the most likely interpretation consistent with this approach (i.e., with the dynamic method together with a level-of-no-motion assumption and Ekman dynamics, is that any decrease in strength of the deep western boundary current must have been compensated, not by a basin-wide increase in upper layer southward flow, but by changes in the nonlinear region, immediately outside of the Florida Straits.

  17. Effect of meridional wind on gap-leaping western boundary current

    Institute of Scientific and Technical Information of China (English)

    王铮; 袁东亮; 侯一筠

    2010-01-01

    Using a 1.5-layer reduced-gravity nonlinear shallow-water equation model, we studied the effect of the meridional wind on the western boundary currents (WBC) at critical states with hysteresis courses. The results of the simulation indicate that the WBC is prone to penetrating into the gap under northerly winds, and its path is more difficult to alter due to the larger interval between the two critical transition curves (C1P and C1L). For southerly winds, the WBC is prone to leaping across the gap, and its ...

  18. Magnetic collimation of meridional-self-similar general relativistic MHD flows

    Science.gov (United States)

    Globus, Noemie; Sauty, Christophe; Cayatte, Véronique; Celnikier, Ludwik M.

    2014-06-01

    We present a model for the spine of relativistic Magnetohydrodynamics outflows in the Kerr geometry. Meridional self-similarity is invoked to derive semianalytical solutions close to the polar axis. The study of the energy conservation along a particular field line gives a simple criterion for the collimation of jets. Such parameter have already been derived in the classical case by Sauty et al. 1999 and also extended to the Schwarzschild metric by Meliani et al. 2006. We generalize the same study to the Kerr metric. We show that the rotation of the black hole increases the magnetic self-confinement.

  19. Magnetic collimation of meridional-self-similar general relativistic MHD flows

    CERN Document Server

    Globus, Noemie; Cayatte, Véronique; Celnikier, Ludwik M

    2014-01-01

    We present a model for the spine of relativistic MHD outflows in the Kerr geometry. Meridional self-similarity is invoked to derive semi-analytical solutions close to the polar axis. The study of the energy conservation along a particular field line gives a simple criterion for the collimation of jets. Such parameter have already been derived in the classical case by Sauty et al. 1999 and also extended to the Schwarzschild metric by Meliani et al. 2006. We generalize the same study to the Kerr metric. We show that the rotation of the black hole increases the magnetic self-confinement.

  20. Plaadid / Toomas Puna

    Index Scriptorium Estoniae

    Puna, Toomas, 1975-

    2007-01-01

    Uutest heliplaatidest Electronic "Get the message", U2 "U2: 18 singles", Jamiroquai "High Times", Sugababes "Overloaded", Staind "1996-2006 The Singles", Crowded House "Farewelll to the world", "Rock romantika"

  1. Plaadid / Toomas Puna

    Index Scriptorium Estoniae

    Puna, Toomas, 1975-

    2007-01-01

    Uutest heliplaatidest Armand Van Helden "Ghettoblaster", Queens of the Stone Age "ERA Vulgaris", Tuberkuloited "Mis sa teed", Zeb "Stop the Earth, I Want to Get Off", Frankie Valentine "The World of What", Ryan Adams "Easy Tiger", Bob Sinclar "Soundz of Freedom"

  2. Plaadid / Toomas Puna

    Index Scriptorium Estoniae

    Puna, Toomas, 1975-

    2007-01-01

    Uutest heliplaatidest Electronic "Get the message", U2 "U2: 18 singles", Jamiroquai "High Times", Sugababes "Overloaded", Staind "1996-2006 The Singles", Crowded House "Farewelll to the world", "Rock romantika"

  3. Plaadid / Toomas Puna

    Index Scriptorium Estoniae

    Puna, Toomas, 1975-

    2007-01-01

    Uutest heliplaatidest Armand Van Helden "Ghettoblaster", Queens of the Stone Age "ERA Vulgaris", Tuberkuloited "Mis sa teed", Zeb "Stop the Earth, I Want to Get Off", Frankie Valentine "The World of What", Ryan Adams "Easy Tiger", Bob Sinclar "Soundz of Freedom"

  4. Area Handbook Series: Argentina: A Country Study

    Science.gov (United States)

    1985-08-01

    processes of change. Socioeconomic statistical information has been systematically published by Argentina’s Instituto Nacional de Estadisticas y Censos in...Nacional de Estadisticas y Censos Estima- 353 Argentina: A Country Study clones y proyecdones de poblaciion, 1950-2025. Buenos Aires: 1982...Aires: Institute Nacional de Estadistica y Censos, 1983. Argentina. Ministerio de Educaciön. Departamento de Estadis- tica. Estadisticas de la

  5. Anaglyph: Patagonia, Argentina

    Science.gov (United States)

    2000-01-01

    This view of northern Patagonia, near El Cain, Argentina shows complexly eroded volcanic terrain, with basalt mesas, sinkholes, landslide debris, playas, and relatively few integrated drainage channels. Surrounding this site (but also extending far to the east) is a broad plateau capped by basalt, the Meseta de Somuncura. Here, near the western edge of the plateau, erosion has broken through the basalt cap in a variety of ways. On the mesas, water-filled sinkholes (lower left) are most likely the result of the collapse of old lava tubes. Along the edges of the mesas (several locations) the basalt seems to be sliding away from the plateau in a series of slices. Water erosion by overland flow is also evident, particularly in canyons where vegetation blankets the drainage channels (bright patterns, bottom of image). However, overland water flow does not extend very far at any location. This entire site drains to local playas, some of which are seen here (dark lakes with bright shores). While the water can reach the playas and then evaporate, what becomes of the eroded rock debris? Wind might excavate some of the finer eroded debris, but the fate of much of the missing bedrock remains mysterious.This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to

  6. Stereo Pair: Patagonia, Argentina

    Science.gov (United States)

    2000-01-01

    This view of northern Patagonia, near El Cain, Argentina shows complexly eroded volcanic terrain, with basalt mesas, sinkholes, landslide debris, playas, and relatively few integrated drainage channels. Surrounding this site (but also extending far to the east) is a broad plateau capped by basalt, the Meseta de Somuncura. Here, near the western edge of the plateau, erosion has broken through the basalt cap in a variety of ways. On the mesas, water-filled sinkholes (lower left) are most likely the result of the collapse of old lava tubes. Along the edges of the mesas (several locations) the basalt seems to be sliding away from the plateau in a series of slices. Water erosion by overland flow is also evident, particularly in canyons where vegetation blankets the drainage channels (green patterns, bottom of image). However, overland water flow does not extend very far at any location. This entire site drains to local playas, some of which are seen here (blue). While the water can reach the playas and then evaporate, what becomes of the eroded rock debris? Wind might excavate some of the finer eroded debris, but the fate of much of the missing bedrock remains mysterious.This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar Topography Mission, combined with an enhanced Landsat 7 satellite color image. The topography data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7

  7. On the role of meridional flows in flux transport dynamo models

    CERN Document Server

    Jouve, L

    2007-01-01

    The Sun is a magnetic star whose magnetism and cyclic activity is linked to the existence of an internal dynamo. We aim to understand the establishment of the solar magnetic 22-yr cycle, its associated butterfly diagram and field parity selection through numerical simulations of the solar global dynamo. Inspired by recent observations and 3D simulations that both exhibit multicellular flows in the solar convection zone, we seek to characterise the influence of various profiles of circulation on the behaviour of solar mean-field dynamo models. We are using 2-D mean field flux transport Babcock-Leighton numerical models in which we test several types of meridional flows: 1 large single cell, 2 cells in radius and 4 cells per hemisphere. We confirm that adding cells in latitude tends to speed up the dynamo cycle whereas adding cells in radius more than triples the period. We find that the cycle period in the four cells model is less sensitive to the flow speed than in the other simpler meridional circulation pro...

  8. Meridional motions and Reynolds stress from SDO/AIA coronal bright points data

    CERN Document Server

    Sudar, Davor; Skokić, Ivica; Beljan, Ivana Poljančić; Brajša, Roman

    2016-01-01

    Context. It is possible to detect and track coronal bright points (CBPs) in SDO/AIA images. Combination of high resolution and high cadence provides a wealth of data that can be used to determine velocity flows on the solar surface with very high accuracy. Aims. We derived a very accurate solar rotation profile and investigated meridional flows, torsional oscillations and horizontal Reynolds stress based on $\\approx$6 months of SDO/AIA data. Methods. We used a segmentation algorithm to detect CBPs in SDO/AIA images. We also used invariance of the solar rotation profile with central meridian distance (CMD) to determine the height of CBPs in 19.3 nm channel. Results. Best fit solar rotation profile is given by $\\omega(b)=(14.4060\\pm0.0051 + (-1.662\\pm0.050)\\sin^{2}b + (-2.742\\pm0.081)\\sin^{4}b)${\\degr} day$^{-1}$. Height of CBPs in SDO/AIA 19.3 nm channel was found to be $\\approx$6500 km. Meridional motion is predominantly poleward for all latitudes, while solar velocity residuals show signs of torsional oscill...

  9. On th meridional surface profile of the Gulf Stream at 55 deg W

    Science.gov (United States)

    Hallock, Zachariah R.; Teague, William J.

    1995-01-01

    Nine-month records from nine inverted echo sounders (IESs) are analyzed to describe the mean baroclinic Gulf Stream at 55 deg W. IES acoustic travel times are converted to thermocline depth which is optimally interpolated. Kinematic and dynamic parameters (Gulf Stream meridional position, velocity, and vorticity) are calculated. Primary Gulf Stream variabiltiy is attributed to meandering and and changes in direction. A mean, stream-coordinate (relative to Gulf Stream instantaneous position and direction) meridional profile is derived and compared with results presented by other investigators. The mean velocity is estimated at 0.84 m/s directed 14 deg to the right eastward, and the thermocline (12 c) drops 657 m (north to south), corresponding to a baroclinic rise of the surface of 0.87 m. The effect of Gulf Stream curvature on temporal mean profiles is found to be unimportant and of minimal importance overall. The derived, downstream current profile is well represented by a Gaussian function and is about 190 km wide where it crosses zero. Surface baroclinic transport is estimated to be 8.5 x 10(exp 4) sq m/s, and maximum shear (flanking the maximum) is 1.2 x 10(exp -5). Results compare well with other in situ observational results from the same time period. On the other hand, analyses (by others) of concurrent satellite altimetry (Geosat) suggest a considerable narrower, more intense mean Gulf Stream.

  10. Verification of the helioseismic Fourier-Legendre analysis for meridional flow measurements

    CERN Document Server

    Roth, Markus; Hartlep, Thomas

    2016-01-01

    Measuring the Sun's internal meridional flow is one of the key issues of helioseismology. Using the Fourier-Legendre analysis is a technique for addressing this problem. We validate this technique with the help of artificial helioseismic data. The analysed data set was obtained by numerically simulating the effect of the meridional flow on the seismic wave field in the full volume of the Sun. In this way, a 51.2-hour long time series was generated. The resulting surface velocity field is then analyzed in various settings: Two $360^\\circ \\times 90^\\circ$ halfspheres, two $120^\\circ \\times 60^\\circ$ patches on the front and farside of the Sun (North and South, respectively) and two $120^\\circ \\times 60^\\circ$ patches on the northern and southern frontside only. We compare two possible measurement setups: observations from Earth and from an additional spacecraft on the solar farside, and observations from Earth only, in which case the full information of the global solar oscillation wave field was available. We ...

  11. Intensification of the meridional temperature gradient in the Great Barrier Reef following the Last Glacial Maximum.

    Science.gov (United States)

    Felis, Thomas; McGregor, Helen V; Linsley, Braddock K; Tudhope, Alexander W; Gagan, Michael K; Suzuki, Atsushi; Inoue, Mayuri; Thomas, Alexander L; Esat, Tezer M; Thompson, William G; Tiwari, Manish; Potts, Donald C; Mudelsee, Manfred; Yokoyama, Yusuke; Webster, Jody M

    2014-06-17

    Tropical south-western Pacific temperatures are of vital importance to the Great Barrier Reef (GBR), but the role of sea surface temperatures (SSTs) in the growth of the GBR since the Last Glacial Maximum remains largely unknown. Here we present records of Sr/Ca and δ(18)O for Last Glacial Maximum and deglacial corals that show a considerably steeper meridional SST gradient than the present day in the central GBR. We find a 1-2 °C larger temperature decrease between 17° and 20°S about 20,000 to 13,000 years ago. The result is best explained by the northward expansion of cooler subtropical waters due to a weakening of the South Pacific gyre and East Australian Current. Our findings indicate that the GBR experienced substantial meridional temperature change during the last deglaciation, and serve to explain anomalous deglacial drying of northeastern Australia. Overall, the GBR developed through significant SST change and may be more resilient than previously thought.

  12. Meridional lenticular astigmatism associated with bilateral concurrent uveal metastases in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Priluck JC

    2012-11-01

    Full Text Available Joshua C Priluck, Sandeep Grover, KV ChalamDepartment of Ophthalmology, University of Florida College of Medicine, Jacksonville, FL, USAPurpose: To demonstrate a case illustrating meridional lenticular astigmatism as a result of renal cell carcinoma uveal metastases.Methods: Case report with images.Results: Clinical findings and diagnostic testing of a patient with acquired meridional lenticular astigmatism are described. The refraction revealed best-corrected visual acuity of 20/20–1 OD (−2.50 + 0.25 × 090 and 20/50 OS (−8.25 + 3.25 × 075. Bilateral concurrent renal cell carcinoma metastases to the choroid and ciliary body are demonstrated by utilizing ultrasonography, ultrawidefield fluorescein angiography, and unique spectral-domain optical coherence tomography.Conclusions: Metastatic disease should be included in the differential of acquired astigmatism. Spectral-domain optical coherence tomography, ultrawidefield fluorescein angiography, and ultrasonography have roles in delineating choroidal metastases.Keywords: astigmatism, metastasis, optical coherence tomography, renal cell carcinoma

  13. Control of pre-Cenozoic extensional heterogeneities on the kinematics of Cenozoic shortening: Northwestern Argentina

    Science.gov (United States)

    Pearson, D. M.; Kapp, P. A.; Reiners, P. W.; Gehrels, G. E.

    2012-12-01

    Results from regional-scale mapping and structural analysis, (U-Th)/He and U-Pb age dating of apatite and zircon, and a regional balanced cross section allow us to build upon the pre-existing geological framework for the retroarc of northwestern Argentina. Coupled with previous work in the region, our results suggest that the style, distribution, and kinematics of shortening in the Eastern Cordillera and Santa Bárbara tectonomorphic provinces of the thrust belt at this latitude (24-25°S) were strongly influenced by the architecture of a Mesozoic rift system. In contrast to the thin-skinned Subandean fold-thrust belt of southern Bolivia where structures are primarily W-dipping and propagated progressively eastward through time, reverse faults in northwestern Argentina are more variably oriented, steeply E-dipping, locally inverted structures that propagated in an overall eastward direction in a much more sporadic manner. The first major eastward propagation event at this latitude occurred at ~40 Ma and is expressed as Eocene (U-Th)/He apatite and zircon ages coincident with the western arm of the Cretaceous Salta rift system. Other workers also documented angular unconformities of this age in the western and eastern arms of the rift system. Up until ~10 Ma, deformation and exhumation were restricted to the western margin of the Cretaceous rift in the western Eastern Cordillera and eastern margin of the Puna plateau. This was followed by an ~75 km jump in the location of the thrust front toward the east to bypass the central portion of a horst block of the Cretaceous rift system, followed by subsequent initiation of new E-dipping reverse faults in a subsystem that propagated toward the west into this pre-existing structural high. During Pliocene time, deformation again migrated >100 km eastward to a Cretaceous syn-rift depocenter in the Santa Bárbara Ranges and was likely followed by additional westward propagation to the current location of deformation with the

  14. Pediatric intensive care in Argentina.

    Science.gov (United States)

    Schnitzler, E J

    1993-09-01

    8.2% of the gross domestic product is spent annually on health care in Argentina, a country of 32 million people. There is 1 medical doctor of every 147,000 beds in a total 3180 hospitals. The infant mortality rate in Argentina is 24.5/1000 live births which is high compared to developed countries. Perinatal causes and congenital anomalies are the main cause of death after the neonatal period, and accidents, cardiac disease, and respiratory tract infections are the main causes of death among children over age 1 year. Argentina has approximately 35 pediatric intensive care units (ICU), but 154 of 244 beds are within or near the capital. Only 2 hospitals have pediatric intensive care fellowship programs, so full time dedicated staff is rare. 250 registered pediatricians dedicated to intensive care are in the Argentine Pediatric Society and the nurse/bed ratio is 1:2-1:3. Moreover, the country has neither postanesthesia recuperation units, burn units, chronic ventilation units, nor approved home assistance programs, and intermediate care is not clearly standardized. These inadequacies have led to a shortage of beds and the caring for of critically ill children in general pediatric or emergency wards in hospitals which lack adequate equipment; patients are often discharged inappropriately to clear bed space. Even so, prehospital and emergency room care tends to be provided without the necessary coordination with the pediatric ICU, and structural conditions regarding electrical self-sufficiency, air conditioning, and circulation are met in only few units. Despite the existence of these adverse conditions for the care of critically ill children, a pediatric organ transplant program developed since 1987 has demonstrated 70% to 100% survival rates for 16l orthotopic liver and 9 heart transplants, respectively. Alternatives to improving intensive care in Argentina include optimizing the response of emergency and critical care delivery systems, categorizing hospitals and

  15. Thunderstorms, Andean Mountains Ridgeline, Argentina

    Science.gov (United States)

    1993-01-01

    In this scenic view of thunderstorms skirting the eastern ridgeline of the Andeas Mountains in northern Argentina (approximate coordinates 28.0S, 57.0W), the confluence of the Rio Salado and Rio Saladillo where they merge with the Rio Parana can be seen in sunglint. Thunderstorms along the eastern Andes are typical at this time of year (Southern Hemisphere summer) with anvils moving to the east from the core of the storm.

  16. Argentina em El siglo XXI.

    Directory of Open Access Journals (Sweden)

    Silvia Fernández Soto

    2013-01-01

    Full Text Available This present article has as its main focus the reconfiguration of the development matrix acting in Argentina, as a result of the deepening crisis and the social conflicts from 2001-02. Identifies the presence of inflexions and continuities in this moment of hegemonic recomposition, which some authors call of "post neo-liberal neo-developmentalist phase", fruit of the correlations of forces resulting in the general movement of the society. Therefore, addresses, in first place, the neo- liberal reaction in the mark of the capitalist crisis and the logic configuration of the accumulation in a flexible standard. In second place it analyzes the context of crisis from the beginning of the 21st century, highlighting the inflexions and continuities with the neo-liberalism and characterizing the behavior of the main socioeconomic indicators. In third place , discusses the reactions to neo-liberalism and the neo-developmentalist recomposition observed in Argentina as well in some national experiences in the latin american region, identifying continuities and ruptures. For last , taking as reference this context, it analyzes the orientation of the social policies after the 2001 crisis, putting in discussion the state action and its politics with the projects of society that are in dispute in Argentina nowadays.

  17. Relation between the meridional distribution of potential vorticity and the Lagrangian mean circulation in the troposphere

    Science.gov (United States)

    Satoh, Masaki; Damtp

    1999-10-01

    The meridional distribution of potential vorticity (PV) in the troposphere is examined in terms of the Lagrangian transport by using an idealistic general circulation model. A zonally uniform forcing and uniform boundary conditions are applied to the model to particularly examine the PV structure in the mid-latitudes and the subtropics. Trajectories of air parcels released from each grid point of the model and Lagrangian changes in PV are calculated for a period of 60days. Values of PV of each parcel are changing along the Lagrangian motions due to the diabatic effect, the frictional effect and the mixing effect which has smaller scales than those resolvable in the model. Both diabatic and frictional effects are dominant in the lower layers, and the mixing effect is larger in the other regions. It is found that the zonal mean PV changes have different characteristics between the "Underworld" in which isentropes intersect the ground and the "Middleworld" in which isentropes are above the ground and intersect the tropopause. In the Underworld, the zonal mean PV changes are determined by the equatorial flow in the lower layers. In particular, the PV changes are negative in the lower layers of the low- and the mid-latitudes. (The sign of PV tendency is for the northern hemisphere. The southern hemispheric tendency is opposite as in the followings.) This negative tendency is due to the diabatic effect near the surface. In the Middleworld, there remain positive and negative tendency regions, which are resulted from the isentropic mixing. In general, if a parcel moves poleward in the mid-latitudes, the value of PV increases, whereas the value of PV decreases if a parcel moves equatorward. The sign of the Lagrangian mean change in PV corresponds to whether the Lagrangian mean motions cross the PV contours equatorward or poleward in the meridional plane. In particular, the contour of no change in PV has a similar shape to that of meridional distribution of PV in the mid

  18. A new Batillipedidae (Tardigrada, Arthrotardigrada) from Argentina.

    Science.gov (United States)

    Menechella, Agustín G; Bulnes, Verónica N; Cazzaniga, Néstor J

    2015-10-16

    A new species of marine tardigrade, Batillipes acuticauda sp. n., has been found in midlittoral sand sediments collected at Monte Hermoso beach (Buenos Aires province, Argentina). The new species differs from all other members of Batillipedidae by its combination of caudal apparatus, lateral processes and toe patterns. It is the first description of an arthrotardigrade from Argentina.

  19. Mida õpetab Argentina finantskriis? / Karsten Staehr

    Index Scriptorium Estoniae

    Staehr, Karsten, 1962-

    2002-01-01

    Norra majandusanalüütik kirjeldab Argentina majanduspoliitikat, analüüsib tehtud vigu ning hoiatab avatud majandusega Eestit võimalike tulevaste välisshokkide eest. Diagramm: SKP kasv ja üleüldine riigieelarve tasakaal 1991-2001 Argentinas

  20. Mida õpetab Argentina finantskriis? / Karsten Staehr

    Index Scriptorium Estoniae

    Staehr, Karsten, 1962-

    2002-01-01

    Norra majandusanalüütik kirjeldab Argentina majanduspoliitikat, analüüsib tehtud vigu ning hoiatab avatud majandusega Eestit võimalike tulevaste välisshokkide eest. Diagramm: SKP kasv ja üleüldine riigieelarve tasakaal 1991-2001 Argentinas

  1. English in Argentina: A Sociolinguistic Profile.

    Science.gov (United States)

    Nielsen, Paul Maersk

    2003-01-01

    Provides insight into the dimensions and dynamics of English in Argentina by drawing a sociolinguistic profile of this language in a South American setting. Begins with an overview of the languages and cultures represented in Argentina and the historical presence, contact, and availability of English from the eighteenth century on. (VWL)

  2. The Stenopodainae (Hemiptera, Heteroptera) of Argentina

    Science.gov (United States)

    Diez, Fernando; Coscarón, María del Carmen

    2014-01-01

    Abstract In Argentina, 10 genera and 33 species of Stenopodainae (Hemiptera: Reduviidae) have been recorded. Diagnoses of the genera, subgenera and species are given, and an illustrated key to genera is provided. Six species are new records for Argentina and an additional seven species represent new records for provinces. PMID:25493054

  3. Meridional trapping and zonal propagation of inertial waves in a rotating fluid shell

    CERN Document Server

    Rabitti, Anna

    2014-01-01

    Inertial waves propagate in homogeneous rotating fluids, and constitute a challenging and simplified case study for the broader class of inertio-gravity waves, present in all geophysical and astrophysical media, and responsible for energetically costly processes as diapycnal and angular momentum mixing. However, a complete analytical description and understanding of internal waves in arbitrarily shaped enclosed domains, such as the ocean, or a planet liquid core, is still missing. In this work, the inviscid, linear inertial wave field is investigated by means of three dimensional ray tracing in spherical shell domains, having in mind possible oceanographic applications. Rays are here classically interpreted as representative of energy paths. But in contrast with previous studies, they are now launched with a non-zero initial zonal component allowing for a more realistic, localized forcing, and the development of azimuthal inhomogeneities. We find that meridional planes generally act in the shell geometry as a...

  4. Reduced interdecadal variability of Atlantic Meridional Overturning Circulation under global warming.

    Science.gov (United States)

    Cheng, Jun; Liu, Zhengyu; Zhang, Shaoqing; Liu, Wei; Dong, Lina; Liu, Peng; Li, Hongli

    2016-03-22

    Interdecadal variability of the Atlantic Meridional Overturning Circulation (AMOC-IV) plays an important role in climate variation and has significant societal impacts. Past climate reconstruction indicates that AMOC-IV has likely undergone significant changes. Despite some previous studies, responses of AMOC-IV to global warming remain unclear, in particular regarding its amplitude and time scale. In this study, we analyze the responses of AMOC-IV under various scenarios of future global warming in multiple models and find that AMOC-IV becomes weaker and shorter with enhanced global warming. From the present climate condition to the strongest future warming scenario, on average, the major period of AMOC-IV is shortened from ∼50 y to ∼20 y, and the amplitude is reduced by ∼60%. These reductions in period and amplitude of AMOC-IV are suggested to be associated with increased oceanic stratification under global warming and, in turn, the speedup of oceanic baroclinic Rossby waves.

  5. A reconstructed South Atlantic Meridional Overturning Circulation time series since 1870

    Science.gov (United States)

    Lopez, Hosmay; Goni, Gustavo; Dong, Shenfu

    2017-04-01

    This study reconstructs a century-long South Atlantic Meridional Overturning Circulation (SAMOC) index. The reconstruction is possible due to its covariability with sea surface temperature (SST). A singular value decomposition (SVD) method is applied to the correlation matrix of SST and SAMOC. The SVD is performed on the trained period (1993 to present) for which Expendable Bathythermographs and satellite altimetry observations are available. The joint modes obtained are used in the reconstruction of a monthly SAMOC time series from 1870 to present. The reconstructed index is highly correlated to the observational based SAMOC time series during the trained period and provides a long historical estimate. It is shown that the Interdecadal Pacific Oscillation (IPO) is the leading mode of SAMOC-SST covariability, explaining 85% with the Atlantic Niño accounting for less than 10%. The reconstruction shows that SAMOC has recently shifted to an anomalous positive period, consistent with a recent positive shift of the IPO.

  6. OCEAN CIRCULATION. Observing the Atlantic Meridional Overturning Circulation yields a decade of inevitable surprises.

    Science.gov (United States)

    Srokosz, M A; Bryden, H L

    2015-06-19

    The importance of the Atlantic Meridional Overturning Circulation (AMOC) heat transport for climate is well acknowledged. Climate models predict that the AMOC will slow down under global warming, with substantial impacts, but measurements of ocean circulation have been inadequate to evaluate these predictions. Observations over the past decade have changed that situation, providing a detailed picture of variations in the AMOC. These observations reveal a surprising degree of AMOC variability in terms of the intraannual range, the amplitude and phase of the seasonal cycle, the interannual changes in strength affecting the ocean heat content, and the decline of the AMOC over the decade, both of the latter two exceeding the variations seen in climate models. Copyright © 2015, American Association for the Advancement of Science.

  7. Effects of Southern Hemisphere Wind Changes on the Meridional Overturning Circulation in Ocean Models.

    Science.gov (United States)

    Gent, Peter R

    2016-01-01

    Observations show that the Southern Hemisphere zonal wind stress maximum has increased significantly over the past 30 years. Eddy-resolving ocean models show that the resulting increase in the Southern Ocean mean flow meridional overturning circulation (MOC) is partially compensated by an increase in the eddy MOC. This effect can be reproduced in the non-eddy-resolving ocean component of a climate model, providing the eddy parameterization coefficient is variable and not a constant. If the coefficient is a constant, then the Southern Ocean mean MOC change is balanced by an unrealistically large change in the Atlantic Ocean MOC. Southern Ocean eddy compensation means that Southern Hemisphere winds cannot be the dominant mechanism driving midlatitude North Atlantic MOC variability.

  8. There is no real evidence for a diminishing trend of the Atlantic meridional overturning circulation

    Directory of Open Access Journals (Sweden)

    A. Parker

    2016-01-01

    Full Text Available The Atlantic Meridional Overturning Circulation (AMOC is part of the great ocean “conveyor belt” that circulates heat around the globe. Since the early 2000s, ocean sensors have started to monitor the AMOC, but the measurements are still far from accurate and the time window does not permit the separation of short term variability from a longer term trend. Other works have claimed that global warming is slowing down the AMOC, based on models and proxies of temperatures. Some other observations demonstrate a stable circulation of the oceans. By using tide gauge data complementing recent satellite and ocean sensor observations, the stability of the AMOC is shown to go back to 1860. It is concluded that no available information has the due accuracy and time coverage to show a clear trend outside the inter-annual and multi-decadal variability in the direction of increasing or decreasing strength over the last decades.

  9. Magnetic Cycles and Meridional Circulation in Global Models of Solar Convection

    CERN Document Server

    Miesch, Mark S; Browning, Matthew K; Brun, Allan Sacha; Toomre, Juri

    2010-01-01

    We review recent insights into the dynamics of the solar convection zone obtained from global numerical simulations, focusing on two recent developments in particular. The first is quasi-cyclic magnetic activity in a long-duration dynamo simulation. Although mean fields comprise only a few percent of the total magnetic energy they exhibit remarkable order, with multiple polarity reversals and systematic variability on time scales of 6-15 years. The second development concerns the maintenance of the meridional circulation. Recent high-resolution simulations have captured the subtle nonlinear dynamical balances with more fidelity than previous, more laminar models, yielding more coherent circulation patterns. These patterns are dominated by a single cell in each hemisphere, with poleward and equatorward flow in the upper and lower convection zone respectively. We briefly address the implications of and future of these modeling efforts.

  10. Reduced Interdecadal Variability of Atlantic Meridional Overturning Circulation under Global Warming

    Science.gov (United States)

    Liu, Z.; Cheng, J.; Zhang, S.; Liu, W.; Dong, L.; Liu, P.; Li, H.

    2016-12-01

    Interdecadal variability of the Atlantic Meridional Overturning Circulation (AMOC-IV) plays an important role in climate variation and has significant societal impacts. Past climate reconstruction indicates that AMOC-IV has likely undergone significant changes. In spite of some previous studies, responses of AMOC-IV to global warming remain unclear, in particular regarding its amplitude and time scale. In this study, we analyze the responses of AMOC-IV under various scenarios of future global warming in multiple models and find that AMOC-IV becomes weaker and shorter with enhanced global warming. From the present climate condition to the strongest future warming scenario, on average the major period of AMOC-IV is shortened from 50 to 20 years and the amplitude is reduced by 60%. These reductions in period and amplitude of AMOC-IV are suggested to be associated with increased oceanic stratification under global warming and, in turn, the speed-up of oceanic baroclinic Rossby waves.

  11. The meridional variation of the eddy heat fluxes by baroclinic waves and their parameterization

    Science.gov (United States)

    Stone, P. H.

    1974-01-01

    The meridional and vertical eddy fluxes of sensible heat produced by small-amplitude growing baroclinic waves are calculated using solutions to the two-level model with horizontal shear in the mean flow. The results show that the fluxes are primarily dependent on the local baroclinicity, i.e., the local value of the isentropic slopes in the mean state. Where the slope exceeds the critical value, the transports are poleward and upward; where the slope is less than the critical value, the transports are equatorward and downward. These results are used to improve an earlier parameterization of the tropospheric eddy fluxes of sensible heat based on Eady's model. Comparisons with observations show that the improved parameterization reproduces the observed magnitude and sign of the eddy fluxes and their vertical variations and seasonal changes, but the maximum in the poleward flux is too near the equator.

  12. The concentration of the large-scale solar magnetic field by a meridional surface flow

    Science.gov (United States)

    Devore, C. R.; Boris, J. P.; Sheeley, N. R., Jr.

    1984-01-01

    Analytical and numerical solutions to the magnetic flux transport equation in the absence of new bipolar sources of flux are calculated for several meridional flow profiles and a range of peak flow speeds. It is found that a poleward flow with a broad profile and a nominal 10 m/s maximum speed concentrates the large-scale field into very small caps of less than 15 deg half-angle, with average field strengths of several tens of gauss, contrary to observations. A flow which reaches its peak speed at a relatively low latitude and then decreases rapidly to zero at higher latitudes leads to a large-scale field pattern which is consistent with observations. For such a flow, only lower latitude sunspot groups can contribute to interhemispheric flux annihilation and the resulting decay and reversal of the polar magnetic fields.

  13. The Circum-Pacific Teleconnection Pattern in Meridional Wind in the High Troposphere

    Institute of Scientific and Technical Information of China (English)

    WANG Huijun

    2005-01-01

    The Circum-Pacific Teleconnection Pattern (CPTP) is revealed in the meridional wind in the high troposphere via an emprirical orthogonal function (EOF) and correlation analysis on NCEP/NCAR reanalysis data. The CPTP is found to be composed of the North Pacific-North American teleconnection pattern (PNA), the South Pacific-South American teleconnection pattern (PSA), and the teleconnection patterns over the tropical western Pacific and the tropical eastern Pacific (or, Central America, or, tropical Atlantic). There is substantial interannual variability of the CPTP and a typical CPTP can be detected in some years. It is speculated that the zonal wind anomalies over the equatorial region in the western and eastern sides of the Pacific may play a role in linking the two hemispheres. The anomalous convection activities in the Tropics are plausible triggering factors for the zonal wind anomalies that are responsible for the composition of the CPTP.

  14. Tierra y familia en la España meridional, siglos XIII-XIX.

    Directory of Open Access Journals (Sweden)

    Igor Goicovic Donoso

    2011-10-01

    Full Text Available Las siete contribuciones recopiladas por Francisco García Gon-zález en el texto Tierra y familia en la España meridional, siglos XIII-XIX, nos sitúan frente a la historia social a partir de dos inflexiones epistemológicas íntimamente relacionadas en la historia: tierra y familia. Efectivamente, la diada tierra-familia, durante el Antiguo Régimen europeo, se convirtió en un factor explicativo de buena parte de los procesos de articulación de la sociedad. Así, la relación de los sujetos con la propiedad y usufructo de la tierra, y las formas de articulación familiar desplegadas por los mismos, tienden a imbricarse recurrentemente en complejos procesos de reproducción social.

  15. Relationship between real meridional volume transport and Sverdrup transport in the North Subtropical Pacific

    Institute of Scientific and Technical Information of China (English)

    JIANG Hua; WANG Hui; ZHU Jiang; TAN Benkui

    2006-01-01

    The oceanic meridional volume transport (MVT) in the North Subtropical Pacific is calculated directly from an observed velocity field (real MVT) and indirectly from wind stress based on Sverdrup balance, respectively. It is confirmed that the Sverdrup MVT is a good approximation to the real MVT for the North Subtropical Pacific except in the western boundary region, where the difference is expected because of frictional and nonlinear effects.The time evolution of the MVT derived from a revised Sverdrup balance, in which a time delay due to the propagation of the first baroclinic Rossby wave is considered, is well correlated with that of the real MVT on decadal time scale, especially near the western boundary region. It is suggested that the Sverdrup balance can be used to study not only the mean climatology of the oceanic circulation, but also the time-dependent oceanic circulation of the North Subtropical Pacific when the Rossby wave propagation is taken into account.

  16. A method to permanently collapse the Atlantic Meridional Overturning Circulation in climate models

    CERN Document Server

    Cimatoribus, Andrea A; Drijfhout, Sybren S; Dijkstra, Henk A

    2011-01-01

    The sensitivity of the Atlantic Meridional Overturning Circulation (AMOC) to changes in basin integrated net evaporation is highly dependent on the zonal salinity contrast at the southern border of the Atlantic. Biases in the freshwater budget strongly affect the stability of the AMOC. The impact of these biases is investigated in a coupled ocean-atmosphere model by adding local anomaly patterns to the freshwater fluxes at the surface. These anomalies impact the freshwater and salt transport by the different components of the ocean circulation, in particular the basin-scale salt-advection feedback, completely changing the response of the AMOC to arbitrary perturbations. It is found that an appropriate dipole anomaly pattern at the southern border of the Atlantic Ocean can collapse the AMOC entirely even without a further hosing. Based on these results, a method is proposed for permanently collapsing the AMOC in climate models and to systematically test the existence of multiple equilibria in these models.

  17. Effect of wind forcing on the meridional heat transport in a coupled climate model: equilibrium response

    Science.gov (United States)

    Yang, Haijun; Dai, Haijin

    2015-09-01

    The effect of the ocean surface winds on the meridional heat transports is studied in a coupled model. Shutting down the global surface winds causes significant reductions in both wind-driven and thermohaline ocean circulations, resulting in a remarkable decrease in the poleward oceanic heat transport (OHT). The sea surface temperature responds with significant warming in the equator and cooling off the equator, causing an enhancement and equatorward shift in the Hadley cell. This increases the poleward atmospheric heat transport (AHT), which in turn compensates the decrease in the OHT. This compensation implies a fundamental constraint in changes of ocean-atmosphere energy transports. Several other compensation changes are also identified. For the OHT components, the changes in the Eulerian mean and bolus OHT are compensated with each other in the Southern Ocean, since a stronger wind driven Ekman transport is associated with a stronger meridional density gradient (stronger bolus circulation) and vice versa. For the AHT components, the changes in the dry static energy (DSE) and latent energy transports are compensated within the tropics (30°N/S), because a stronger Hadley cell causes a stronger equatorward convergence of moisture. In the extratropics, the changes in the mean and eddy DSE transports show perfect compensation, as a result of the equatorward shift of the Ferrell Cell and enhancement of atmospheric baroclinicity in mid-high latitudes, particularly over the North Atlantic. This work also shows how the Earth's climate is trying to maintain the balance between two hemispheres: the ocean in the Northern Hemisphere is colder than that in the Southern Hemisphere due to much reduced northward heat transports cross the Equator in the Atlantic, therefore, the atmosphere responds to the ocean with temperature colder in the Southern Hemisphere than in the Northern Hemisphere by transporting more heat northward cross the equator over the Pacific, in association

  18. Comparison of high-latitude thermospheric meridional winds I: optical and radar experimental comparisons

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, E.M.; Mueller-Wodarg, I.C.F.; Aruliah, A.; Aylward, A. [Atmospheric Physics Lab., Univ. Coll. London, London (United Kingdom)

    2004-07-01

    Thermospheric neutral winds at Kiruna, Sweden (67.4 N, 20.4 E) are compared using both direct optical fabry-perot interferometer (FPI) measurements and those derived from European incoherent scatter radar (EISCAT) measurements. This combination of experimental data sets, both covering well over a solar cycle of data, allows for a unique comparison of the thermospheric meridional component of the neutral wind as observed by different experimental techniques. Uniquely in this study the EISCAT measurements are used to provide winds for comparison using two separate techniques: the most popular method based on the work of Salah and Holt (1974) and the meridional wind model (MWM) (Miller et al., 1997) application of servo theory. The balance of forces at this location that produces the observed diurnal pattern are investigated using output from the coupled thermosphere and ionosphere (CTIM) numerical model. Along with detailed comparisons from short periods the climatological behaviour of the winds have been investigated for seasonal and solar cycle dependence using the experimental techniques. While there are features which are consistent between the 3 techniques, such as the evidence of the equinoctial asymmetry, there are also significant differences between the techniques both in terms of trends and absolute values. It is clear from this and previous studies that the high-latitude representation of the thermospheric neutral winds from the empirical horizontal wind model (HWM), though improved from earlier versions, lacks accuracy in many conditions. The relative merits of each technique are discussed and while none of the techniques provides the perfect data set to address model performance at high-latitude, one or more needs to be included in future HWM reformulations. (orig.)

  19. MERIDIONAL FLOW IN THE SOLAR CONVECTION ZONE. II. HELIOSEISMIC INVERSIONS OF GONG DATA

    Energy Technology Data Exchange (ETDEWEB)

    Jackiewicz, J. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Serebryanskiy, A. [Ulugh Beg Astronomical Institute, Uzbek Academy of Science, Tashkent 100072 (Uzbekistan); Kholikov, S., E-mail: jasonj@nmsu.edu [National Solar Observatory, Tucson, AZ 85719 (United States)

    2015-06-01

    Meridional flow is thought to play a very important role in the dynamics of the solar convection zone; however, because of its relatively small amplitude, precisely measuring it poses a significant challenge. Here we present a complete time–distance helioseismic analysis of about 2 years of ground-based Global Oscillation Network Group (GONG) Doppler data to retrieve the meridional circulation profile for modest latitudes in an attempt to corroborate results from other studies. We use an empirical correction to the travel times due to an unknown center-to-limb systematic effect. The helioseismic inversion procedure is first tested and reasonably validated on artificial data from a large-scale numerical simulation followed by a test to broadly recover the solar differential rotation found from global seismology. From GONG data, we measure poleward photospheric flows at all latitudes with properties that are comparable with earlier studies and a shallow equatorward flow about 65 Mm beneath the surface, in agreement with recent findings from Helioseismic and Magnetic Imager (HMI) data. No strong evidence of multiple circulation cells in depth or latitude is found, yet the whole phase space has not yet been explored. Tests of mass flux conservation are then carried out on the inferred GONG and HMI flows and compared to a fiducial numerical baseline from models, and we find that the continuity equation is poorly satisfied. While the two disparate data sets do give similar results for about the outer 15% of the interior radius, the total inverted circulation pattern appears to be unphysical in terms of mass conservation when interpreted over modest time scales. We can likely attribute this to both the influence of realization noise and subtle effects in the data and measurement procedure.

  20. Distribution of mycosporine-like amino acids along a surface water meridional transect of the Atlantic.

    Science.gov (United States)

    Llewellyn, Carole A; White, Daniel A; Martinez-Vincente, Victor; Tarran, Glen; Smyth, Tim J

    2012-08-01

    The composition and abundance of mycosporine-like amino acids (MAAs) were investigated in the surface waters along a 13,000-km meridional transect (52° N to 45° S) in the Atlantic Ocean (Atlantic Meridional Transect programme: Cruise AMT 18: 4/10/2008-10/11/2008). MAAs were ubiquitous along the transect, although the composition of the MAAs was variable. Highest concentrations were in the far south (below 40° S; MAA >1 μg L(-1)) and in north subtropical equatorial region (NER: 0-25° N; MAA up to 0.8 μg L(-1)). Highest MAA relative to chlorophyll-a occurred in the NER (MAA/chl-a ratio between 2 and 5). MAA/chl-a significantly correlated with the preceding month's mean daily UV dose and with UV-B/UV-A. In the far south, high MAA concentrations coincided with high phytoplankton biomass, high nutrients and a deep mixed layer associated with the austral spring. Here, the phytoplankton community was dominated by micro- and nano-eukaryotes. At the NER, the high MAA/chl-a coincided with low nutrient concentrations, a shallow mixed layer depth (20-70 m) and to a lesser extent to a shallow nitracline (40-90 m). Here, the phytoplankton consisted primarily of picophytoplankton (0-0.2 μm), dominated by the pico-cyanobacteria Synechococcus sp. and Prochlorococcus sp. and by the nitrogen fixing filamentous cyanobacterium Trichodesmium. The low nitrate concentrations (<0.1 μmol L(-1)) at the NER suggest that nitrogen fixation was required for MAA production. Specific MAAs could not easily be assigned to particular groups of phytoplankton and we could not rule out the possibility that MAAs were associated with symbiotic cyanobacteria contained within heterotrophic dinoflagellates or diatoms.

  1. Ensemble Kalman filter data assimilation in a Babcock-Leighton solar dynamo model: an observation system simulation experiment for reconstructing meridional flow-speed

    CERN Document Server

    Dikpati, Mausumi; Mitra, Dhrubaditya

    2014-01-01

    Accurate knowledge of time-variation in meridional flow-speed and profile is crucial for estimating a solar cycle's features, which are ultimately responsible for causing space climate variations. However, no consensus has been reached yet about the Sun's meridional circulation pattern observations and theories. By implementing an Ensemble Kalman Filter (EnKF) data assimilation in a Babcock-Leighton solar dynamo model using Data Assimilation Research Testbed (DART) framework, we find that the best reconstruction of time-variation in meridional flow-speed can be obtained when ten or more observations are used with an updating time of 15 days and a $\\le 10\\%$ observational error. Increasing ensemble-size from 16 to 160 improves reconstruction. Comparison of reconstructed flow-speed with "true-state" reveals that EnKF data assimilation is very powerful for reconstructing meridional flow-speeds and suggests that it can be implemented for reconstructing spatio-temporal patterns of meridional circulation.

  2. Cloud Effects on Meridional Atmospheric Energy Budget Estimated from Clouds and the Earth's Radiant Energy System (CERES) Data

    Science.gov (United States)

    Kato, Seiji; Rose, Fred G.; Rutan, David A.; Charlock, Thomas P.

    2008-01-01

    The zonal mean atmospheric cloud radiative effect, defined as the difference of the top-of-atmosphere (TOA) and surface cloud radiative effects, is estimated from three years of Clouds and the Earth's Radiant Energy System (CERES) data. The zonal mean shortwave effect is small, though it tends to be positive (warming). This indicates that clouds increase shortwave absorption in the atmosphere, especially in midlatitudes. The zonal mean atmospheric cloud radiative effect is, however, dominated by the longwave effect. The zonal mean longwave effect is positive in the tropics and decreases with latitude to negative values (cooling) in polar regions. The meridional gradient of cloud effect between midlatitude and polar regions exists even when uncertainties in the cloud effect on the surface enthalpy flux and in the modeled irradiances are taken into account. This indicates that clouds increase the rate of generation of mean zonal available potential energy. Because the atmospheric cooling effect in polar regions is predominately caused by low level clouds, which tend to be stationary, we postulate that the meridional and vertical gradients of cloud effect increase the rate of meridional energy transport by dynamics in the atmosphere from midlatitude to polar region, especially in fall and winter. Clouds then warm the surface in polar regions except in the Arctic in summer. Clouds, therefore, contribute in increasing the rate of meridional energy transport from midlatitude to polar regions through the atmosphere.

  3. en Argentina en los noventa

    Directory of Open Access Journals (Sweden)

    Marcelo Fabián Delfini

    2005-01-01

    Full Text Available Se analizan los efectos de la implantación de las políticas económicas neoliberales desde 1990 en Argentina sobre la distribución del ingreso y la pobreza, en un marco en que el crecimiento económico no provocó disminuciones sustantivas sobre las variables en estudio. Se emplea el concepto de “estancamiento dinámico ” para analizar las variables propuestas, pues éste sí permite dar cuenta de las regulaciones vigentes durante la década en estudio.

  4. Bioceres: AG Biotechnology from Argentina

    Directory of Open Access Journals (Sweden)

    Roberto Feeney

    2016-04-01

    Full Text Available In this case we present a business decision-making situation in which the CEO of an Argentine Ag Biotech company, Bioceres, has to decide the best way to commercialize a new drought-tolerant transgenic technology. The company was founded by twenty three farmers, who shared a common dream that Argentina could become a benchmark in the development of Ag biotechnology. The case has strategic and financial implications, as well as decision-making situation involving a joint venture with an American biotechnology company. It also introduces to discussion the business models of Ag biotechnology companies in developing countries.

  5. Paleozoic evolution of active margin basins in the southern Central Andes (northwestern Argentina and northern Chile)

    Science.gov (United States)

    Bahlburg, H.; Breitkreuz, C.

    The geodynamic evolution of the Paleozoic continental margin of Gondwana in the region of the southern Central Andes is characterized by the westward progression of orogenic basin formation through time. The Ordovician basin in the northwest Argentinian Cordillera Oriental and Puna originated as an Early Ordovician back-arc basin. The contemporaneous magmatic arc of an east-dipping subduction zone was presumably located in northern Chile. In the back-arc basin, a ca. 3500 meter, fining-up volcaniclastic apron connected to the arc formed during the Arenigian. Increased subsidence in the late Arenigian allowed for the accomodation of large volumes of volcaniclastic turbidites during the Middle Ordovician. Subsidence and sedimentation were caused by the onset of collision between the para-autochthonous Arequipa Massif Terrane (AMT) and the South American margin at the Arenigian-Llanvirnian transition. This led to eastward thrusting of the arc complex over its back-arc basin and, consequently, to its transformation into a marine foreland basin. As a result of thrusting in the west, a flexural bulge formed in the east, leading to uplift and emergence of the Cordillera Oriental shelf during the Guandacol Event at the Arenigian-Llanvirnian transition. The basin fill was folded during the terminal collision of the AMT during the Oclóyic Orogeny (Ashgillian). The folded strata were intruded post-tectonically by the presumably Silurian granitoids of the "Faja Eruptiva de la Puna Oriental." The orogeny led to the formation of the positive area of the Arco Puneño. West of the Arco Puneño, a further marine basin developed during the Early Devonian, the eastern shelf of which occupied the area of the Cordillera Occidental, Depresión Preandina, and Precordillera. The corresponding deep marine turbidite basin was located in the region of the Cordillera de la Costa. Deposition continued until the basin fill was folded in the early Late Carboniferous Toco Orogeny. The basin

  6. Comparison of acoustic travel-time measurement of solar meridional circulation from SDO/HMI and SOHO/MDI

    Science.gov (United States)

    Duvall, Thomas L.; Liang, Zhi-Chao; Birch, Aaron; Gizon, Laurent; Schou, Jesper

    2017-08-01

    Time-distance helioseismology is one of the primary tools for studying the solar meridional circulation. However, travel-time measurements of the subsurface meridional flow suffer from a variety of systematic errors, such as a center-to-limb variation and an offset due to the P-angle uncertainty of solar images. Here we apply the time-distance technique to contemporaneous medium-degree Dopplergrams produced by SOHO/MDI and SDO/HMI to obtain the travel-time difference caused by meridional circulation throughout the solar convection zone. The P-angle offset in MDI images is measured by cross-correlating MDI and HMI images. The travel-time measurements in the south-north and east-west directions are averaged over the same observation period for the two data sets and then compared to examine the consistency of MDI and HMI travel times after correcting the systematic errors.The offsets in the south-north travel-time difference from MDI data induced by the P-angle error gradually diminish with increasing travel distance. However, these offsets become noisy for travel distances corresponding to waves that reach the base of the convection zone. This suggests that a careful treatment of the P-angle problem is required when studying a deep meridional flow. After correcting the P-angle and the removal of the center-to-limb effect, the travel-time measurements from MDI and HMI are consistent within the error bars for meridional circulation covering the entire convection zone. The fluctuations observed in both data sets are highly correlated and thus indicate their solar origin rather than an instrumental origin. Although our results demonstrate that the ad hoc correction is capable of reducing the wide discrepancy in the travel-time measurements from MDI and HMI, we cannot exclude the possibility that there exist other systematic effects acting on the two data sets in the same way.

  7. 局地经圈环流和沙漠%Local Meridional Circulation and Deserts

    Institute of Scientific and Technical Information of China (English)

    刘平; 吴国雄; 孙菽芬

    2001-01-01

    This paper investigates the dry climatology of Sahara and Northwest China deserts from the viewpoint of local meridional circulation with Xie and Arkin rainfall dada and NCAR / NCEP reanalysis data. Re sults show that there are very dry centers with annual rainfall less than 50 mm over these two deserts while the rainy seasons are very different. In the south part of Sahara desert center and Northwest China desert, over 70% rainfall takes place in June, July and August (JJA). While in the north part of Sahara, rainfall mainly concentrates in December, January and February (DJF). The local biosphere-radiation mechanism proposed by Charney cannot explain the climatology of such very dry centers. Neither can the monsoon-de sert mechanism proposed by Rodwell and Hoskins do for the strongest descent center is much more north ward than the driest center over Sahara in JJA. From the viewpoint of local meridional circulation, the dry ness climatology of Sahara and Northwest China deserts is investigated and compared. It is shown that in DJF, descent of local meridional circulation dominates the two deserts and very dry climate is unavoidable although the relative wet season is weak over the northern part of Sahara due to Mediterranean climate. While in JJA, there is ascent over the two deserts especially over Northwest China. Such ascent can explain the rainy season in south part of Sahara and Northwest China deserts. However, it is the local meridional circulation that takes strong and dry northerly from higher latitudes. The northerly either takes little mois ture to the centers or prevents deep and strong convection over the centers. Such local meridional circulation leads to the dry climatology over the two deserts.%应用Xie和Arkin降水资料和NECP/NCAR再分析资料,研究了撒哈拉和中国西北沙漠地区的干旱气候。结果表明,尽管该两区域都有在年降水量少于50mm的十分干旱的区域,但其年度特征却非常不同。在撒

  8. [The health system of Argentina].

    Science.gov (United States)

    Belló, Mariana; Becerril-Montekio, Victor M

    2011-01-01

    This paper describes the health system of Argentina.This system has three sectors: public, social security and private.The public sector includes the national and provincial ministries as well as the network of public hospitals and primary health care units which provide care to the poor and uninsured population. This sector is financed with taxes and payments made by social security beneficiaries that use public health care facilities. The social security sector or Obras Sociales (OS) covers all workers of the formal economy and their families. Most OS operate through contracts with private providers and are financed with payroll contributions of employers and employees. Finally, the private sector includes all those private providers offering services to individuals, OS beneficiaries and all those with private health insurance.This sector also includes private insurance agencies called Prepaid Medicine Enterprises, financed mostly through premiums paid by families and/or employers.This paper also discusses some of the recent innovations implemented in Argentina, including the program Remediar.

  9. Sistema de salud de Argentina The health system of Argentina

    Directory of Open Access Journals (Sweden)

    Mariana Belló

    2011-01-01

    Full Text Available En este artículo se describe el sistema de salud de Argentina, que está compuesto por tres sectores: público, de seguridad social y privado. El sector público está integrado por los ministerios nacional y provincial, y la red de hospitales y centros de salud públicos que prestan atención gratuita a toda persona que lo demande, fundamentalmente a personas sin seguridad social y sin capacidad de pago. Se financia con recursos fiscales y recibe pagos ocasionales de parte del sistema de seguridad social cuando atiende a sus afiliados. El sector del seguro social obligatorio está organizado en torno a las Obras Sociales (OS, que aseguran y prestan servicios a los trabajadores y sus familias. La mayoría de las OS operan a través de contratos con prestadores privados y se financian con contribuciones de los trabajadores y patronales. El sector privado está conformado por profesionales de la salud y establecimientos que atienden a demandantes individuales, a los beneficiarios de las OS y de los seguros privados. Este sector también incluye entidades de seguro voluntario llamadas Empresas de Medicina Prepaga que se financian sobre todo con primas que pagan las familias y/o las empresas. En este trabajo también se describen las innovaciones recientes en el sistema de salud, incluyendo el Programa Remediar.This paper describes the health system of Argentina.This system has three sectors: public, social security and private.The public sector includes the national and provincial ministries as well as the network of public hospitals and primary health care units which provide care to the poor and uninsured population. This sector is financed with taxes and payments made by social security beneficiaries that use public health care facilities. The social security sector or Obras Sociales (OS covers all workers of the formal economy and their families. Most OS operate through contracts with private providers and are financed with payroll

  10. Along-Strike Variations in Focal Mechanisms of Central Andean Crustal Earthquakes: Northern Peru through the Argentina Sierras Pampeanas

    Science.gov (United States)

    Devlin, S.; Isacks, B. L.

    2003-12-01

    120 shallow focal mechanisms in the crust above the subducted Nazca plate were assembled from the Harvard CMT catalog and published studies covering over 40 years of seismicity. The study area included the Andes crust above three major segments of the subducted plate, the Peruvian and Argentinean flat-slab segments and the intervening segment where the subducted Nazca plate dips more steeply. The most seismically active regions continue to be the thick-skinned foreland thrust belts in the eastern Andes of Peru and the Sierras Pampeanas. The earthquakes there are clearly associated with youthful tectonic structures with strong topographic signatures as revealed by the new 90 m SRTM digital elevation models. The mechanisms are dominantly of the thrust type but include a minority of strike-slip orientations. However the P axes remain consistent. The thin-skinned thrust belts east of the central Andean Plateau show significant activity only near Santa Cruz, Bolivia and northern Argentina; most of the Sub-Andean thrust belt of Bolivia and southern Peru remains aseismic. The central Andean plateau itself also remains aseismic except for the region of southern Peru and two earthquakes in the Puna. The crustal seismicity in southern Peru is largely concentrated on the western side of the plateau. The focal mechanisms show a strong grouping of T axes in a horizontal, north-south orientation. Both normal and strike-slip mechanisms occur in this region, with no obvious correlation with elevation or surface structures. Remarkably, with the exception of one normal fault type mechanism near the Cusco basin, the earthquakes occur in regions of the western parts of the Altiplano that do not exhibit topographic evidence of substantial crustal deformation. These results are consistent with a model in which the Altiplano of southern Peru, with a trend most oblique to the overall direction of convergence, manifests a left-lateral shearing component across the orogen.

  11. Meridional trends in the radiative energy balance of the Venus mesosphere

    Science.gov (United States)

    Lee, Y. J.; Titov, D.; Ignatiev, N.; Tellmann, S.; Paetzold, M.; Piccioni, G.

    2012-04-01

    The Venus clouds play an important role in the radiative energy balance. Thermal cooling to space occurs from the cloud tops. Also almost half of the solar energy received by Venus is deposited at about the same altitude by the unknown UV absorber. Observations revealed the latitudinal trend in the aerosol structure with cloud top altitude decreasing from ~68 km in low latitudes to ~62 km in polar region and aerosol scale height changing from ~4 km to ~1-2 km. This results in significant changes in the radiative energy balance at the cloud tops and the mesosphere as well as global energy balance of the planet. Here we present calculations of the thermal flux in the 0-99 km altitude range using the latitude dependent cloud top structure. Aerosol and temperature profiles are based on the radio science experiment (VeRa) and the thermal spectrometer (VIRTIS) onboard Venus Express [1]. We used radiative transfer model merged with a fast line-by-line routine to calculate thermal fluxes in the broad wavenumber range from 50 to 2590 cm-1 (=3.86-200.0 μm). The cloud layers are responsible for thermal cooling below ~70 km altitude. The meridional changes in the upper clouds result in cooling rate variation 6-10 K/day along the latitude. Contribution of the CO2 emission to the outgoing flux becomes dominant above 70 km altitude. The outgoing flux shows maxima at equator (164 W/m2) and pole (171 W/m2) and a minimum (133 W/m2) in the "cold collar" region (50-60° S). The earlier studies of the solar heating rate were used to derive a meridional trend of the radiative energy balance. The comparison shows dominant thermal cooling in high latitudes and strong solar heating at low latitudes suggesting radiative disequilibrium, that implies a need for another, possibly dynamical, mechanism to maintain the observed temperature and cloud structure [2,3].

  12. Impact of the Indonesian Throughflow on the Atlantic Meridional Overturning Circulation

    Science.gov (United States)

    Le Bars, Dewi; Dijkstra, Henk

    2014-05-01

    Understanding the mechanisms controlling the strength and variability of the Atlantic Meridional Overturning Circulation (AMOC) is one of the main topics of climate science and in particular physical oceanography. Current simple representations of the global ocean overturning separates the surface return flow to the Atlantic basin into a cold water path through the Drake Passage and a warm water path through the Indonesian Throughflow and Agulhas leakage. The relative importance of these two paths has been investigated in non-eddying ocean models. In these models the Agulhas retroflection cannot be modelled properly, which leads to an important overestimation of the Agulhas leakage. Furthermore, it seems that the in these models the relation between the meridional density gradient and the overturning strength is greatly simplified and changes significantly when eddies are resolved (Den Toom et al. 2013). As a result, the impact of the Pacific-Indian Oceans exchange through the Indonesian Throughflow on the AMOC is still unknown. To investigate this question we run a state-of-the-art ocean model, the Parallel Ocean Program (POP), globally, at eddy resolving resolution (0.1º). Using climatological forcing from the CORE dataset we perform two simulations of 110 years, a control experiment with realistic coastlines and one in which the Indonesian Passages are closed. Results show that, for a closed Indonesian Throughflow, the Indian Ocean cools down but its salinity increases. The Agulhas leakage reduces also by 3Sv (Le Bars et al. 2013) and the net effect on the south Atlantic is a cooling down and decrease salinity. The anomalies propagate slowly northward and a significant decrease of the AMOC is found at 26ºN after 50 years. This decrease AMOC also leads to reduced northward heat flux in the Atlantic. These processes are investigated with a detailed analysis of the heat and freshwater balances in the Atlantic-Arctic region and in the region south of 34ºS where

  13. MONUMENTOS FUNERARIOS Y FESTEJOS RITUALES: COMPLEJOS DE RECINTOS Y TÚMULOS TAQUARA/ITARARÉ EN ELDORADO, MISIONES (ARGENTINA (Funerary monuments and celebration rituals: Taquara/Itararé enclosure and mound complexes in Eldorado, Misiones, Argentina

    Directory of Open Access Journals (Sweden)

    Christopher Gillam

    2010-06-01

    Full Text Available A partir de 1000 d. C, durante un periodo de grandes cambios ambientales, surgió en el altiplano meridional brasileño y el noreste argentino una tradición monumental de complejos de recintos geométricos y túmulos funerarios asociados a áreas de festejos rituales mortuorios, donde probablemente se consumía carne asada en hornos de tierra y se tomaban bebidas obtenidas a partir del maíz. Utilizando información etnohistórica sobre las prácticas funerarias de los grupos Jê meridionales y la comparación con sitios arqueológicos del sur de Brasil, este artículo se centra en la interpretación de las nuevas excavaciones realizadas en el sitio PM01, Eldorado, Misiones, Argentina. ENGLISH: Starting around AD 1000, during a period of major environmental changes, a monumental tradition emerged in the southern Brazilian highlands, which was characterized by geometric enclosures and burial mounds associated to the practice of funerary and post-funerary ritual feasting where possibly meat delicacies where cooked in earth ovens and maize-based beverages were drank. Using ethnohistoric information of southern Jê groups’ burial practices as a point of departure this article focuses on the interpretation of the new excavations carried out in site PM01, ElDorado, Misiones, Argentina.

  14. Argentina: entre o Mercosul e a Alca

    Directory of Open Access Journals (Sweden)

    Raúl Bernal-Meza

    2001-12-01

    Full Text Available Este artigo procura mostrar que a Argentina não está numa encruzilhada na sua política externa, tendo que escolher entre Mercosul ou Alca. Ao contrário, a Argentina vê o Mercosul como um caminho que leva à Alca, afirmando uma posição que se tornou possível depois da confluência de outros fatores, como a posição brasileira frente a Alca e o modelo de integração regional proposta para o Mercosul.This article seeks to show that Argentina is not in crossroads in your foreign policy, having to choose between Mercosur and FTAA. In contrast, Argentina sees Mercosur as a way that leads to FTAA, affirming a position that become possible after a confluence of others factors, as the Brazilian position front Alca and the model of regional integration proposal for Mercosur.

  15. China, Argentina agree to further strategic ties

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to Xinhua,China and Argentina have agreed to further enhance mutual trust and their strategic partnership as the two emerging economies are playing an increasingly important role in the world arena.“China will work with Argentina to strengthen strategic mutual trust,expand cooperation and coordination within multilateral frameworks in order to promote bilateral ties and benefit the two peoples,” Vice President Xi Jinping told Argentine Foreign Minister Hector Timerman on September 9.

  16. On the relation between Meridional Overturning Circulation and sea-level gradients in the Atlantic

    Directory of Open Access Journals (Sweden)

    H. Kienert

    2012-04-01

    Full Text Available On the basis of model simulations, we examine what information on changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC can be extracted from associated changes in sea surface height (SSH, specifically from a broad Atlantic north-south gradient as has been suggested previously in the literature. Since a relation between AMOC and SSH changes can only be used as an AMOC diagnostic if it is valid independently of the specific forcing, we consider three different forcing types: increase of CO2 concentration, freshwater fluxes to the northern convection sites and the modification of Southern Ocean winds. We concentrate on a timescale of 100 yr. We find approximately linear and numerically similar relations between a sea-level difference within the Atlantic and the AMOC for freshwater as well as wind forcing. However, the relation is more complex in response to atmospheric CO2 increase, which precludes this sea-level difference as an AMOC diagnostic under climate change. Finally, we show qualitatively to what extent changes in SSH and AMOC strength that are caused by simultaneous application of different forcings correspond to the sum of the changes due to the individual forcings, a potential prerequisite for more complex SSH-based AMOC diagnostics.

  17. Observed decline of the Atlantic Meridional Overturning Circulation 2004 to 2012

    Directory of Open Access Journals (Sweden)

    D. A. Smeed

    2013-09-01

    Full Text Available The Atlantic Meridional Overturning Circulation (AMOC has been observed continuously at 26° N since April 2004. The AMOC and its component parts are monitored by combining a transatlantic array of moored instruments with submarine-cable based measurements of the Gulf Stream and satellite derived Ekman transport. The time series has recently been extended to October 2012 and the results show a downward trend since 2004. From April~2008 to March 2012 the AMOC was an average of 2.7 Sv weaker than in the first four years of observation (95% confidence that the reduction is 0.3 Sv or more. Ekman transport reduced by about 0.2 Sv and the Gulf Stream by 0.5 Sv but most of the change (2.0 Sv is due to the mid-ocean geostrophic flow. The change of the mid-ocean geostrophic flow represents a strengthening of the subtropical gyre above the thermocline. The increased southward flow of warm waters is balanced by a decrease in the southward flow of Lower North Atlantic Deep Water below 3000 m. The transport of Lower North Atlantic Deep Water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year.

  18. Fate of the Atlantic Meridional Overturning Circulation: Strong decline under continued warming and Greenland melting

    Science.gov (United States)

    Bakker, P.; Schmittner, A.; Lenaerts, J. T. M.; Abe-Ouchi, A.; Bi, D.; Broeke, M. R.; Chan, W.-L.; Hu, A.; Beadling, R. L.; Marsland, S. J.; Mernild, S. H.; Saenko, O. A.; Swingedouw, D.; Sullivan, A.; Yin, J.

    2016-12-01

    The most recent Intergovernmental Panel on Climate Change assessment report concludes that the Atlantic Meridional Overturning Circulation (AMOC) could weaken substantially but is very unlikely to collapse in the 21st century. However, the assessment largely neglected Greenland Ice Sheet (GrIS) mass loss, lacked a comprehensive uncertainty analysis, and was limited to the 21st century. Here in a community effort, improved estimates of GrIS mass loss are included in multicentennial projections using eight state-of-the-science climate models, and an AMOC emulator is used to provide a probabilistic uncertainty assessment. We find that GrIS melting affects AMOC projections, even though it is of secondary importance. By years 2090-2100, the AMOC weakens by 18% [-3%, -34%; 90% probability] in an intermediate greenhouse-gas mitigation scenario and by 37% [-15%, -65%] under continued high emissions. Afterward, it stabilizes in the former but continues to decline in the latter to -74% [+4%, -100%] by 2290-2300, with a 44% likelihood of an AMOC collapse. This result suggests that an AMOC collapse can be avoided by CO2 mitigation.

  19. Energetics of IPCC4AR Climate Models: Energy Balance and Meridional Enthalpy Transports

    CERN Document Server

    Lucarini, Valerio

    2009-01-01

    We consider the climate simulations performed using pre-industrial and SRESA1B scenarios and analyse the outputs of the state-of-the-art models included in IPCC4AR. For control simulations, large energy biases are present for several models both when global climate budgets and when energy budgets of the atmospheric, oceanic, and land subdomains are considered. The energy biases depend on the imperfect closure of the energy cycle in the fluid components of the climate system and on issues in the treatment of phase transitions and heat fluxes over land. Additionally, the consequence of a positive global energy bias, which is what most models feature, is the underestimation of the thermodynamic emission temperature of the planet and of the globally averaged surface temperature. This may help explaining the cold bias of climate models. Models agree on the representation of meridional enthalpy transports in terms of location of the peaks of the total and atmospheric transports, whereas quantitative disagreements o...

  20. Comparison of the Atlantic Meridional Overturning Circulation behaviors in HYCOM and POP within the CESM

    Science.gov (United States)

    Bozec, A.; Chassignet, E. P.

    2016-02-01

    For the Coordinated Ocean-ice Reference Experiment (CORE), the HYbrid Coordinate Ocean Model (HYCOM) had been implemented in, what was then, the Community Climate System Model (CCSM3). While the results were reasonable when using the CORE-I climatology as an atmospheric forcing, they showed an almost collapse of the Atlantic Meridional Overturning Circulation (AMOC) when using the CORE-II interannual atmospheric forcing. To understand that behavior, extensive tests were performed using a HYCOM-CICE stand-alone configuration and a more suitable set of parameters was found to improve the AMOC strength. As part of the Earth System Prediction Capability (ESPC), the newest version of HYCOM has been (re-)introduced as an alternative ocean component to POP2 in the latest version of the Community Earth System Model (CESM). The response of HYCOM and POP identically configured (bathymetry, grid and CORE-I forcing) is described in 500-year simulations. Special attention is given to the AMOC strength and variability.

  1. Sub-surface Meridional Flow Results from MWO, GONG, and MDI during Solar Cycle 23

    Science.gov (United States)

    Pinkerton, Stephen; Rhodes, Edward J.; Bogart, Richard S.

    2014-06-01

    Time series of full-disk Dopplergrams were acquired at the 60-Foot Solar tower of the Mount Wilson Observatory every year between 1987 and 2009. Analysis of this archive revealed that the focal plane of the Tower did experience a small amount of systematic rotation, which suggested that the alignment of the optics had changed slightly over the years since its construction in 1907. This has caused some of the initial daily flow maps to possess a so-called “washing machine” effect similar to the pattern that was seen in raw GONG flow maps. We have incorporated a systematic program of ring-diagram analysis in which we have tracked the raw solar images using five differing assumed instrumental rotation rates. We have then gone on to compute synoptic maps of the horizontal flow vectors at several different depths over much of Solar Cycle 23 in order to study how such an instrumental rotation might affect both the zonal and meridional flows as functions of latitude, depth, and time. We compare these results with GONG and MDI flow measurements to empirically determine the regime within which the MWO results are reliable and extend our analysis into Solar Cycle 22.

  2. Wind effect on the Atlantic meridional overturning circulation via sea ice and vertical diffusion

    Science.gov (United States)

    Yang, Haijun; Wang, Kun; Dai, Haijin; Wang, Yuxing; Li, Qing

    2016-06-01

    Effects of wind and fresh water on the Atlantic meridional overturning circulation (AMOC) are investigated using a fully coupled climate model. The AMOC can change significantly when perturbed by either wind stress or freshwater flux in the North Atlantic. This study focuses on wind stress effect. Our model results show that the wind forcing is crucial in maintaining the AMOC. Reducing wind forcing over the ocean can cause immediately weakening of the vertical salinity diffusion and convection in the mid-high latitudes Atlantic, resulting in an enhancement of vertical salinity stratification that restrains the deep water formation there, triggering a slowdown of the thermohaline circulation. As the thermohaline circulation weakens, the sea ice expands southward and melts, providing the upper ocean with fresh water that weakens the thermohaline circulation further. The wind perturbation experiments suggest a positive feedback between sea-ice and thermohaline circulation strength, which can eventually result in a complete shutdown of the AMOC. This study also suggests that sea-ice variability may be also important to the natural AMOC variability on decadal and longer timescales.

  3. Solar activity variations of nocturnal thermospheric meridional winds over Indian longitude sector

    Science.gov (United States)

    Madhav Haridas, M. K.; Manju, G.; Arunamani, T.

    2016-09-01

    The night time F-layer base height information from ionosondes located at two equatorial stations Trivandrum (TRV 8.5°N, 77°E) and Sriharikota (SHAR 13.7°N, 80.2°E) spanning over two decades are used to derive the climatology of equatorial nocturnal Thermospheric Meridional Winds (TMWs) prevailing during High Solar Activity (HSA) and Low Solar Activity (LSA) epochs. The important inferences from the analysis are 1) Increase in mean equatorward winds observed during LSA compared to HSA during pre midnight hours; 25 m/s for VE (Vernal Equinox) and 20 m/s for SS (Summer Solstice), AE (autumnal Equinox) and WS (Winter Solstice). 2) Mean wind response to Solar Flux Unit (SFU) is established quantitatively for all seasons for pre-midnight hours; rate of increase is 0.25 m/s/SFU for VE, 0.2 m/s/SFU for SS and WS and 0.08 m/s/SFU for AE. 3) Theoretical estimates of winds for the two epochs are performed and indicate the role of ion drag forcing as a major factor influencing TMWs. 4) Observed magnitude of winds and rate of flux dependencies are compared to thermospheric wind models. 5) Equinoctial asymmetry in TMWs is observed for HSA at certain times, with more equatorward winds during AE. These observations lend a potential to parameterize the wind components and effectively model the winds, catering to solar activity variations.

  4. Atlantic meridional overturning circulation and the prediction of North Atlantic sea surface temperature

    Science.gov (United States)

    Klöwer, M.; Latif, M.; Ding, H.; Greatbatch, R. J.; Park, W.

    2014-11-01

    The Atlantic Meridional Overturning Circulation (AMOC), a major current system in the Atlantic Ocean, is thought to be an important driver of climate variability, both regionally and globally and on a large range of time scales from decadal to centennial and even longer. Measurements to monitor the AMOC strength have only started in 2004, which is too short to investigate its link to long-term climate variability. Here the surface heat flux-driven part of the AMOC during 1900-2010 is reconstructed from the history of the North Atlantic Oscillation, the most energetic mode of internal atmospheric variability in the Atlantic sector. The decadal variations of the AMOC obtained in that way are shown to precede the observed decadal variations in basin-wide North Atlantic sea surface temperature (SST), known as the Atlantic Multidecadal Oscillation (AMO) which strongly impacts societally important quantities such as Atlantic hurricane activity and Sahel rainfall. The future evolution of the AMO is forecast using the AMOC reconstructed up to 2010. The present warm phase of the AMO is predicted to continue until the end of the next decade, but with a negative tendency.

  5. Sub-Surface Meridional flow, Vorticity and the life time if Solar Active Regions

    CERN Document Server

    Maurya, R A

    2010-01-01

    Solar sub-surface fluid topology provides an indirect approach to examine the internal characteristics of active regions (ARs). Earlier studies have revealed the prevalence of strong flows in the interior of ARs having complex magnetic fields. Using the Doppler data obtained by the Global Oscillation Network Group (GONG) project for a sample of 74 ARs, we have discovered the presence of steep gradients in meridional velocity at depths ranging from 1.5 to 5 Mm in flare productive ARs. The sample of these ARs is taken from the Carrington rotations 1980--2052 covering the period August 2001-January 2007. The gradients showed an interesting hemispheric trend of negative (positive) signs in the northern (southern) hemisphere, i.e., directed toward the equator. We have discovered three sheared layers in the depth range of 0 - 10 Mm, providing an evidence of complex flow structures in several ARs. An important inference derived from our analysis is that the location of the deepest zero vertical vorticity is correlat...

  6. Low-frequency variability of the shallow meridional overturning circulation in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YANG Zhitong; LUO Yiyong

    2016-01-01

    The low-frequency variability of the shallow meridional overturning circulation (MOC) in the South China Sea (SCS) is investigated using a Simple Ocean Data Assimilation (SODA) product for the period of 1900-2010. A dynamical decomposition method is used in which the MOC is decomposed into the Ekman, external mode, and vertical shear components. Results show that all the three dynamical components contribute to the formation of the seasonal and annual mean shallow MOC in the SCS. The shallow MOC in the SCS consists of two cells: a clockwise cell in the south and an anticlockwise cell in the north; the former is controlled by the Ekman flow and the latter is dominated by the external barotropic flow, with the contribution of the vertical shear being to reduce the magnitude of both cells. In addition, the strength of the MOC in the south is found to have a falling trend over the past century, due mainly to a weakening of the Luzon Strait transport (LST) that reduces the transport of the external component. Further analysis suggests that the weakening of the LST is closely related to a weakening of the westerly wind anomalies over the equatorial Pacific, which leads to a southward shift of the North Equatorial Current (NEC) bifurcation and thus a stronger transport of the Kuroshio east of Luzon.

  7. MAPEAMENTO DE UNIDADES DE RELEVO NA MÉDIA SERRA DO ESPINHAÇO MERIDIONAL - MG

    Directory of Open Access Journals (Sweden)

    Éric Andrade Rezende

    2011-04-01

    Full Text Available This paper proposes a mapping of landforms units for the southern portion of the middle third of the Serra do Espinhaço Meridional. The landforms units were delineated from the integrated analysis of thematic maps and satellite images that allowed the observation of changes in morphology, altimetry, slope, lithostructure and organization of the drainage network. The step of digital mapping, processed in the software ArcGIS 9.2, was based in the use of SRTM products (Shuttle Radar Topography Mission. The methodological procedures also included field work and literature research. The taxonomy of geomorphological mapping proposed by IBGE (2009 was applied , through which fourteen Geomorphologycal Units were individualized. The units are distributed amongst five different compartments as follows: two plateaux, two escarpments, six depressions, three sets of ridges and one set of intermediate levels. It was observed that the general layout of the units reflects the strong lithostructural control forced to regional relief. The differentiated resistance of the various lithologies in relation to denudational processes and the influence of neotectonic on landscape evolution are noteworthy.

  8. Linkages between atmospheric blocking, sea ice export through Fram Strait and the Atlantic Meridional Overturning Circulation

    Science.gov (United States)

    Ionita, M.; Scholz, P.; Lohmann, G.; Dima, M.; Prange, M.

    2016-09-01

    As a key persistent component of the atmospheric dynamics, the North Atlantic blocking activity has been linked to extreme climatic phenomena in the European sector. It has also been linked to Atlantic multidecadal ocean variability, but its potential links to rapid oceanic changes have not been investigated. Using a global ocean-sea ice model forced with atmospheric reanalysis data, here it is shown that the 1962–1966 period of enhanced blocking activity over Greenland resulted in anomalous sea ice accumulation in the Arctic and ended with a sea ice flush from the Arctic into the North Atlantic Ocean through Fram Strait. This event induced a significant decrease of Labrador Sea water surface salinity and an abrupt weakening of the Atlantic Meridional Overturning Circulation (AMOC) during the 1970s. These results have implications for the prediction of rapid AMOC changes and indicate that an important part of the atmosphere-ocean dynamics at mid- and high latitudes requires a proper representation of the Fram Strait sea ice transport and of the synoptic scale variability such as atmospheric blocking, which is a challenge for current coupled climate models.

  9. The unusual minimum of sunspot cycle 23 a consequence of Sun's meridional plasma flow variations

    CERN Document Server

    Nandy, Dibyendu; Martens, Petrus C H; 10.1038/nature09786

    2013-01-01

    Direct observations over the past four centuries show that the number of sunspots observed on the Sun's surface vary periodically, going through successive maxima and minima. Following sunspot cycle 23, the Sun went into a prolonged minimum characterized by a very weak polar magnetic field and an unusually large number of days without sunspots. Sunspots are strongly magnetized regions and are generated by a dynamo mechanism which recreates the solar polar field mediated via plasma flows. Here we report results from kinematic dynamo simulations which demonstrate that a fast meridional flow in the early half of a cycle, followed by a slower flow in the latter half, reproduces both the characteristics of the minimum of sunspot cycle 23 - a large number of spotless days and a relatively weak polar field. Our model predicts that, in general, very deep minima are associated with weak polar fields. Sunspots govern the solar radiative energy and radio flux, and in conjunction with the polar field, modulate the solar ...

  10. Comparison of the Atlantic meridional overturning circulation between 1960 and 2007 in six ocean reanalysis products

    Science.gov (United States)

    Karspeck, A. R.; Stammer, D.; Köhl, A.; Danabasoglu, G.; Balmaseda, M.; Smith, D. M.; Fujii, Y.; Zhang, S.; Giese, B.; Tsujino, H.; Rosati, A.

    2017-08-01

    The mean and variability of the Atlantic meridional overturning circulation (AMOC), as represented in six ocean reanalysis products, are analyzed over the period 1960-2007. Particular focus is on multi-decadal trends and interannual variability at 26.5°N and 45°N. For four of the six reanalysis products, corresponding reference simulations obtained from the same models and forcing datasets but without the imposition of subsurface data constraints are included for comparison. An emphasis is placed on identifying general characteristics of the reanalysis representation of AMOC relative to their reference simulations without subsurface data constraints. The AMOC as simulated in these two sets are presented in the context of results from the Coordinated Ocean-ice Reference Experiments phase II (CORE-II) effort, wherein a common interannually varying atmospheric forcing data set was used to force a large and diverse set of global ocean-ice models. Relative to the reference simulations and CORE-II forced model simulations it is shown that (1) the reanalysis products tend to have greater AMOC mean strength and enhanced variance and (2) the reanalysis products are less consistent in their year-to-year AMOC changes. We also find that relative to the reference simulations (but not the CORE-II forced model simulations) the reanalysis products tend to have enhanced multi-decadal trends (from 1975-1995 to 1995-2007) in the mid to high latitudes of the northern hemisphere.

  11. Response of the South Atlantic circulation to an abrupt collapse of the Atlantic meridional overturning circulation

    Energy Technology Data Exchange (ETDEWEB)

    Laurian, Audine [University of Hawai' i at Manoa, International Pacific Research Center, School of Ocean and Earth Science and Technology, Honolulu, HI (United States); Drijfhout, Sybren S. [Royal Netherlands Meteorological Institute, De Bilt (Netherlands)

    2011-08-15

    The South Atlantic response to a collapse of the North Atlantic meridional overturning circulation (AMOC) is investigated in the ECHAM5/MPI-OM climate model. A reduced Agulhas leakage (about 3.1 Sv; 1 Sv = 10{sup 6} m{sup 3} s{sup -1}) is found to be associated with a weaker Southern Hemisphere (SH) supergyre and Indonesian throughflow. These changes are due to reduced wind stress curl over the SH supergyre, associated with a weaker Hadley circulation and a weaker SH subtropical jet. The northward cross-equatorial transport of thermocline and intermediate waters is much more strongly reduced than Agulhas leakage in relation with an AMOC collapse. A cross-equatorial gyre develops due to an anomalous wind stress curl over the tropics that results from the anomalous sea surface temperature gradient associated with reduced ocean heat transport. This cross-equatorial gyre completely blocks the transport of thermocline waters from the South to the North Atlantic. The waters originating from Agulhas leakage flow somewhat deeper and most of it recirculates in the South Atlantic subtropical gyre, leading to a gyre intensification. This intensification is consistent with the anomalous surface cooling over the South Atlantic. Most changes in South Atlantic circulation due to global warming, featuring a reduced AMOC, are qualitatively similar to the response to an AMOC collapse, but smaller in amplitude. However, the increased northward cross-equatorial transport of intermediate water relative to thermocline water is a strong fingerprint of an AMOC collapse. (orig.)

  12. Modulation of western North Pacific tropical cyclone activity by the Atlantic Meridional Mode

    Science.gov (United States)

    Zhang, Wei; Vecchi, Gabriel A.; Villarini, Gabriele; Murakami, Hiroyuki; Rosati, Anthony; Yang, Xiaosong; Jia, Liwei; Zeng, Fanrong

    2017-01-01

    This study examines the year-to-year modulation of the western North Pacific (WNP) tropical cyclones (TC) activity by the Atlantic Meridional Mode (AMM) using both observations and the Geophysical Fluid Dynamics Laboratory Forecast-oriented Low Ocean Resolution Version of CM2.5 (FLOR) global coupled model. 1. The positive (negative) AMM phase suppresses (enhances) WNP TC activity in observations. The anomalous occurrence of WNP TCs results mainly from changes in TC genesis in the southeastern part of the WNP. 2. The observed responses of WNP TC activity to the AMM are connected to the anomalous zonal vertical wind shear (ZVWS) caused by AMM-induced changes to the Walker circulation. During the positive AMM phase, the warming in the North Atlantic induces strong descending flow in the tropical eastern and central Pacific, which intensifies the Walker cell in the WNP. The intensified Walker cell is responsible for the suppressed (enhanced) TC genesis in the eastern (western) part of the WNP by strengthening (weakening) ZVWS. 3. The observed WNPTC-AMM linkage is examined by the long-term control and idealized perturbations experiment with FLOR-FA. A suite of sensitivity experiments strongly corroborate the observed WNPTC-AMM linkage and underlying physical mechanisms.

  13. Soybean biomass produced in Argentina

    DEFF Research Database (Denmark)

    Semino, Stella; Paul, Helena; Tomei, Julia

    Soybean biomass for biodiesel, produced in Argentina amongst other places, is considered by some to reduce greenhouse gas emissions and mitigate climate change when compared with fossil fuel. To ensure that the production of biofuels is ‘sustainable', EU institutions and national governments...... are currently designing certification schemes for the sustainable production of biomass. This paper questions the validity of proposed environmental standards, using the production of Argentine soybean as a case study. The production of soybean production is associated with profound environmental impacts...... generates emissions of N2O. The large quantity of substances, sprayed by terrestrial and aerial means, has negative impacts on biodiversity, water, soil, and human and animal health. The intensive production of soybeans also leads to social impacts, including loss of livelihoods and food sovereignty...

  14. Burle Marx en la Argentina

    Directory of Open Access Journals (Sweden)

    Sonia Berjman

    2014-05-01

    Full Text Available La figura de Roberto Burle Marx, el más grande paisajista brasileño, goza de amplio conocimiento en el ambiente profesional argentino pero sólo a través de sus trabajos en Brasil. El icónico caso de la Plaza Perú de Buenos Aires –hoy totalmente cambiada- es la única excepción. Hubo otras concreciones y proyectos, así como conferencias y presentación de sus obras plásticas, que son desconocidas. Por ello, nos hemos propuesto desentrañar las participaciones de Roberto Burle Marx en la Argentina, todas ellas dentro del área de la región metropolitana.

  15. Poverty and Health in Argentina

    Directory of Open Access Journals (Sweden)

    Maria Alejandra Silva

    2009-06-01

    Full Text Available This article examines health conditions in the rural areas of Central Argentina, the country’s main region for soy-bean production and export. Health conditions are analyzed through the concepts of emerging and re-emerging diseases in a context of increasing poverty. Data on poverty and health was obtained from both primary sources (trade union, government officials, rural doctors and the South Watch/FA/FODEPAL/UNR working group and secondary sources (IPEC/INDEC, IDESA, Consultora Equis, the Argentine Ministry of Employment, ILO, the Ministry of Health, the Ministry of the Environment, toxicology centers and rural doctors. Analysis of rural health conditions gives cause for concern. There is evidence of deterioration in the social determinants of health such as an increase in rural and urban poverty associated with informal employment and child labor. At the same time lack of government epidemiological and toxicological data appears to hide or distort the reality of health conditions.

  16. Spanish Coastal Patrol Ships for Argentina and Mexico (Guardacostas Espanoles para Argentina y Mejico),

    Science.gov (United States)

    1983-12-22

    GABARRUS TRANSLATED BY: LT GREGORY STOVER, USNR-R NISC TRANSLATION UNIT 0166 SOURCE: TECNOLOGIA MILITAR, NO. 4, 1983; PP. 50, 53-54; SPANISH DTIC S ELECTE...SHIPS FOR ARGENTINA AND MEXICO [Ramirez Gabarrus, M.; Guardacostas espaioles para Argentina y Mejico; Tecnologia Militar, No. 4, 1983; pP. 50, 53-54

  17. On the Interaction of a Vigorous Hydrothermal System with an Active Magma Chamber: The Puna Magma Chamber, Kilauea East Rift, Hawaii

    Science.gov (United States)

    Gregory, R. T.; Marsh, B. D.; Teplow, W.; Fournelle, J.

    2009-12-01

    The extent of the interaction between hydrothermal systems and active magma chambers has long been of fundamental interest to the development of ore deposits, cooling of magma chambers, and dehydration of the subducting lithosphere. As volatiles build up in the residual magma in the trailing edge of magmatic solidification fronts, is it possible that volatiles are transferred from the active magma to the hydrothermal system and vice versa? Does the external fracture front associated with vigorous hydrothermal systems sometimes propagate into the solidification front, facilitating volatile exchange? Or is the magma always sealed at temperatures above some critical level related to rock strength and overpressure? The degree of hydrothermal interaction in igneous systems is generally gauged in post mortem studies of δ18O and δD, where it has been assumed that a fracture front develops about the magma collapsing inward with cooling. H.P. Taylor and D. Norton's (1979; J. Petrol.)seminal work inferred that rocks are sealed with approach to the solidus and there is little to no direct interaction with external volatiles in the active magma. In active lava lakes a fracture front develops in response to thermal contraction of the newly formed rock once the temperature drops to ~950°C (Peck and Kinoshita,1976;USGS PP935A); rainfall driven hydrothermal systems flash to steam near the 100 °C isotherm in the solidified lake and have little effect on the cooling history (Peck et al., 1977; AJS). Lava lakes are fully degassed magmas and until the recent discovery of the Puna Magma Chamber (Teplow et al., 2008; AGU) no active magma was known at sufficiently great pressure to contain original volatiles. During the course of routine drilling of an injection well at the Puna Geothermal Venture (PGV) well-field, Big Island, Hawaii, a 75-meter interval of diorite containing brown glass inclusions was penetrated at a depth of 2415 m, continued drilling to 2488 m encountered a melt

  18. Further influence of the eastern boundary on the seasonal variability of the Atlantic Meridional Overturning Circulation at 26N

    Science.gov (United States)

    Baehr, Johanna; Schmidt, Christian

    2016-04-01

    The seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) at 26.5 N has been shown to arise predominantly from sub-surface density variations at the Eastern boundary. Here, we suggest that these sub-surface density variations have their origin in the seasonal variability of the Canary Current system, in particular the Poleward Undercurrent (PUC). We use a high-resolution ocean model (STORM) for which we show that the seasonal variability resembles observations for both sub-surface density variability and meridional transports. In particular, the STORM model simulation density variations at the eastern boundary show seasonal variations reaching down to well over 1000m, a pattern that most model simulations systematically underestimate. We find that positive wind stress curl anomalies in late summer and already within one degree off the eastern boundary result -through water column stretching- in strong transport anomlies in PUC in fall, coherent down to 1000m depth. Simultaneously with a westward propagation of these transport anomalies, we find in winter a weak PUC between 200 m and 500m, and southward transports between 600m and 1300m. This variability is in agreement with the observationally-based suggestion of a seasonal reversal of the meridional transports at intermediate depths. Our findings extend earlier studies which suggested that the seasonal variability at of the meridional transports across 26N is created by changes in the basin-wide thermocline through wind-driven upwelling at the eastern boundary analyzing wind stress curl anomalies 2 degrees off the eastern boundary. Our results suggest that the investigation of AMOC variability and particular its seasonal cycle modulations require the analysis of boundary wind stress curl and the upper ocean transports within 1 degree off the eastern boundary. These findings also implicate that without high-resolution coverage of the eastern boundary, coarser model simulation might not fully

  19. Magmatismo ácido del mioceno superior-cuaternario en el área de Cerro Blanco-La Hoyada, Puna Austral

    Directory of Open Access Journals (Sweden)

    María Carolina Montero López

    2010-11-01

    Full Text Available El volcanismo de composición ácida desarrollado en la Puna Austral entre el Mioceno superior y el Holoceno está representado en el extremo oriental de la cordillera de San Buenaventura (26°25'-27°00'S y 67°25'-67°50' O por dos unidades: Ignimbrita Aguada Alumbrera y Complejo Volcánico Cerro Blanco. Hacia el norte y noroeste de esta área afloran flujos piroclásticos (Ignimbrita Rosada cuyo análisis se presenta aquí a fines comparativos. Estas rocas volcánicas apoyan sobre un basamento metamórfico de mediano a alto grado con intrusivos del Neoproterozoico-Paleozoico inferior y rocas volcánicas de composición intermedia de ca. 9-7 Ma. Las rocas estudiadas abarcan un lapso entre el Mioceno superior (Ignimbrita Aguada Alumbrera e Ignimbrita Rosada hasta el Holoceno (Complejo Volcánico Cerro Blanco, tienen afinidad calcoalcalina y son principalmente de composición riolítica. En este estudio se presentan nuevos datos de campo que permiten ordenar la estratigrafía del sector de estudio, así como resultados de geoquímica. Las ignimbritas del Mioceno Superior-Plioceno estudiadas presentan características similares a las rocas ácidas aflorantes al oeste del área de estudio, las cuales fueron relacionadas por diversos autores a un ambiente de subducción procedentes de fuentes mantélicas con altos porcentajes de contaminación cortical, mientras que el Complejo Volcánico Cerro Blanco podría estar reflejando su procedencia de la fusión directa de la corteza, si bien esta hipótesis debe ser corroborada con mayor cantidad de datos geoquímicos.

  20. Dime cómo escribes y te diré quién eres: Textualizaciones del campesinado indígena de la Puna de Atacama

    Directory of Open Access Journals (Sweden)

    Alejandro F. Haber

    2006-12-01

    Full Text Available Presentamos un análisis de las estrategias textuales de representación del campesinado indígena que se han desarrollado tanto desde la disciplina arqueológica como desde la etnohistoria. Cada una de estas disciplinas, a lo largo del tiempo, ha defendido sus modos diferenciales de acceso al pasado frente a los de la otra. Es nuestra intención mostrar cómo, a pesar de las diferencias marcadas en esas discusiones, ambas disciplinas parten de presupuestos comunes respecto del objeto de estudio por ellas construido. Se tomaron para los análisis diferentes textos referidos a la arqueología, historia o etnohistoria de la Puna de Atacama desde la conquista hasta el siglo XIX y se confrontaron con los resultados de nuestras propias investigaciones. Finalmente argumentamos que los discursos académicos nos dicen más acerca de quién escribe que sobre quienes lo hacen.Archaeological and ethnohistorical textual practices regarding indigenous peasantry are analyzed. Both disciplines, along their history, have defended their own specific methods of approaching the past against the methods of the other. We intend to show how, despite the differences noticed on those discussions, both disciplines are based on common cultural biases about their subject matter. For analytical purposes we use different texts from archaeology, history or ethnohistory of the Atacama Plateau from the Castilian Conquest to the twentieth century, which are also confronted with the results of our own research. It is argued that academic discourses tell us more about who writes than about who is being described.

  1. Composición corporal entre los 6 y 19 años en Susques (Puna jujeña

    Directory of Open Access Journals (Sweden)

    Marrodán, María D.

    2003-01-01

    Full Text Available La localidad de Susques, ubicada a 3675 m.s.n.m. en la Puna desértica jujeña, se ha visto sometida a un importante grado de aislamiento y a condiciones ecológicas adversas que probablemente han influido en la morfofisiología de sus habitantes. El objetivo de este trabajo es valorar de que manera se reflejan dichas características geoclimáticas en la composición corporal durante el crecimiento. A partir de las medidas antropométricas directas se ha estimado la composición corporal total y mesobraquial y el IMC de los escolares entre 6 y 19 años de dicha comunidad. Los resultados muestran cierto retraso en la aparición del dimorfismo sexual en las áreas mesobraquiales y sobre todo en el IMC respecto al porcentaje de grasa total y el peso magro (12 años. El grado de adiposidad general en los varones oscila entre el 19 y 21% de grasa, mientras que la serie femenina alcanza valores de hasta 32,6%. Proporcionalmente, la grasa mesobraquial es significativamente superior a la total hasta los 16 años en los varones y a todas las edades en las mujeres. Puede concluirse, entre otros aspectos, que el tejido graso en esta población tiende a acumularse preferentemente en las extremidades, sobre todo en el tríceps. El retraso observado en el dimorfismo sexual podría relacionarse con el ambiente desfavorable que caracteriza a estos ecosistemas.

  2. Argentina

    Directory of Open Access Journals (Sweden)

    Guillermina Fernández Zambón

    2005-01-01

    Full Text Available La actividad industrial, de cualquier época, tiene una gran importancia para el hombre, pues al igual que el resto de los procesos económicos, es el reflejo del accionar cotidiano de la sociedad sobre el espacio. Considerando esto, el presente articulo tiene como objetivo presentar al patrimonio industrial como recurso para organizar rutas turísticas que permitan en algunos casos recuperar espacios industriales abandonados o usar establecimientos industriales en funcionamiento pero que pueden incorporarse a este tipo de desarrollo turístico. La creación de rutas turísticas puede permitir la reactivación de las economías locales, por constituirse en definitiva en una nueva actividad económica. Para lograr esto es necesario articular el sector público y el privado. De esta forma es posible, a través de la creación de rutas turísticas del patrimonio industrial, generar un desarrollo turístico local sustentable.

  3. Meridional circulation in the solar convection zone: time-distance helioseismic inferences from four years of HMI/SDO observations

    CERN Document Server

    Rajaguru, S P

    2015-01-01

    We present and discuss results from time-distance helioseismic measurements of meridional circulation in the solar convection zone using 4 years of Doppler velocity observations by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO). Using an in-built mass conservation constraint in terms of the stream function we invert helioseismic travel times to infer meridional circulation in the solar convection zone. We find that the return flow that closes the meridional circulation is possibly beneath the depth of $0.77 R_{\\odot}$. We discuss the significance of this result in relation to other helioseismic inferences published recently and possible reasons for the differences in the results. Our results show clearly the pitfalls involved in the measurements of material flows in the deep solar interior given the current limits on signal-to-noise and our limited understanding of systematics in the data. We also discuss the implications of our results for the dynamics of solar interi...

  4. A BABCOCK–LEIGHTON SOLAR DYNAMO MODEL WITH MULTI-CELLULAR MERIDIONAL CIRCULATION IN ADVECTION- AND DIFFUSION-DOMINATED REGIMES

    Energy Technology Data Exchange (ETDEWEB)

    Belucz, Bernadett; Forgács-Dajka, Emese [Eötvös University, Department of Astronomy, 1518 Budapest, Pf. 32 (Hungary); Dikpati, Mausumi, E-mail: bbelucz@astro.elte.hu, E-mail: dikpati@ucar.edu [High Altitude Observatory, National Center for Atmospheric Research, 3080 Center Green, Boulder, CO 80307-3000 (United States)

    2015-06-20

    Babcock–Leighton type-solar dynamo models with single-celled meridional circulation are successful in reproducing many solar cycle features. Recent observations and theoretical models of meridional circulation do not indicate a single-celled flow pattern. We examine the role of complex multi-cellular circulation patterns in a Babcock–Leighton solar dynamo in advection- and diffusion-dominated regimes. We show from simulations that the presence of a weak, second, high-latitude reverse cell speeds up the cycle and slightly enhances the poleward branch in the butterfly diagram, whereas the presence of a second cell in depth reverses the tilt of the butterfly wing to an antisolar type. A butterfly diagram constructed from the middle of convection zone yields a solar-like pattern, but this may be difficult to realize in the Sun because of magnetic buoyancy effects. Each of the above cases behaves similarly in higher and lower magnetic diffusivity regimes. However, our dynamo with a meridional circulation containing four cells in latitude behaves distinctly differently in the two regimes, producing solar-like butterfly diagrams with fast cycles in the higher diffusivity regime, and complex branches in butterfly diagrams in the lower diffusivity regime. We also find that dynamo solutions for a four-celled pattern, two in radius and two in latitude, prefer to quickly relax to quadrupolar parity if the bottom flow speed is strong enough, of similar order of magnitude as the surface flow speed.

  5. A Babcock-Leighton solar dynamo model with multi-cellular meridional circulation in advection- and diffusion-dominated regimes

    CERN Document Server

    Belucz, Bernadett; Forgacs-Dajka, Emese

    2015-01-01

    Babcock-Leighton type solar dynamo models with single-celled meridional circulation are successful in reproducing many solar cycle features. Recent observations and theoretical models of meridional circulation do not indicate a single-celled flow pattern. We examine the role of complex multi-cellular circulation patterns in a Babcock-Leighton solar dynamo in advection- and diffusion-dominated regimes. We show from simulations that presence of a weak, second, high-latitude reverse cell speeds up the cycle and slightly enhances the poleward branch in butterfly diagram, whereas the presence of a second cell in depth reverses the tilt of butterfly wing to an anti-solar type. A butterfly diagram constructed from middle of convection zone yields a solar-like pattern, but this may be difficult to realize in the Sun because of magnetic buoyancy effects. Each of the above cases behaves similarly in higher and lower magnetic diffusivity regimes. However, our dynamo with a meridional circulation containing four cells in...

  6. Simulation of meridional overturning in the upper layer of the South China Sea with an idealized bottom topography

    Institute of Scientific and Technical Information of China (English)

    WANG Dongxiao; LIU Xiongbin; WANG Wenzhi; DU Yan; ZHOU Weidong

    2004-01-01

    The large-scale upper circulations and meridional overturning in the upper layer of the South China Sea (SCS) with idealized bottom topography in winter and summer are investigated. Simulations with the GFDL general circulation model are carried out under the conditions of open or enclosed boundary regarding transport in the Luzon Strait. The intrusion area of Kuroshio, its impact on the meridional overturning in the upper layer of the SCS and seasonal characteristic of this impact are explored, respectively. The model is forced by climatological wind stress and relaxed to monthly mean climatological temperature and salinity. The resultant meridional overturning is non-enclosed, with transporting from north to south in the surface and returning to north at the depth of about 500 m in winter, about 200 m in summer, with amplitudes of 105 m3/s. It shows the transporting path of intermediate water of the SCS and offers an idealized reference for further study on dynamics of wind-driven and thermohaline circulation of the SCS.

  7. Elastic stress interaction between faulting and volcanism in the Olacapato-San Antonio de Los Cobres area (NW Argentina)

    Science.gov (United States)

    Bonali, F. L.; Tibaldi, A.; Corazzato, C.; Lanza, F.; Cavallo, A.; Nardin, A.

    2012-04-01

    The aim of this work is to describe the relationships between Plio-Quaternary tectonics, palaeoseismicity and volcanism along the NW-trending Calama-Olacapato-El Toro (COT) lineament that crosses the Andean chain and the Puna Plateau and continues within the eastern Cordillera at about 24° S. Field and satellite data have been collected from the Chile-Argentina border to a few km east of the San Antonio del Los Cobres village. These data revealed the presence of seven Quaternary NW-striking normal left-lateral fault segments in the southeastern part of the studied area and of a Plio-Quaternary N-S-striking graben structure in the northwestern part. The NW-striking Chorrillos fault (CF) segment shows the youngest motions, of late Pleistocene age, being marked by several fault scarps, sag-ponds and offset Quaternary deposits and landforms. Offset lavas of 0.78±0.1 Ma to 0.2±0.08 Ma indicate fault kinematics characterized by a pitch angle of 20° to 27° SE, a total net displacement that ranges from 31 to 63.8 m, and a slip-rate of 0.16 to 0.08 mm/yr. This fault segment is 32 km long and terminates to the northwest near a set of ESE-dipping thrust faults affecting Tertiary strata, while to the southeast it terminates 10 km further from San Antonio. In the westernmost part of the examined area, in Chile at altitudes of 4000 m, recent N-S-striking normal fault scarps depict the 5-km-wide and 10-km-long graben structure. Locally, fault pitches indicate left-lateral normal kinematics. These faults affect deposits up to ignimbrites of Plio-Quaternary age. Scarp heights are from a few metres to 24 m. Despite this area is located along the trace of the COT strike-slip fault system, which is reported as a continuous structure from Chile to Argentina in the literature, no evidence of NW-striking Plio-Quaternary strike-slip structures is present here. A series of numerical models were developed in an elastic half-space with uniform isotropic elastic properties using the

  8. Tectonic activity revealed by morphostructural analysis: Development of the Sierra de la Candelaria range, northwestern Argentina

    Science.gov (United States)

    Barcelona, H.; Peri, G.; Tobal, J.; Sagripanti, L.; Favetto, A.

    2014-12-01

    The tectonically active broken foreland of NW Argentina is a recent analog of the eastern margin of the Puna plateau during Mio-Pliocene times and likely of other broken forelands worldwide. In order to evaluate active tectonism in the broken foreland of the NW Argentine Andes, we examined the complex geomorphology in the vicinity of the basement-cored Sierra de la Candelaria range at ˜26°S and deciphered multiple episodes of crustal deformation spanning the Pliocene to the Quaternary. Digital elevation models, satellite images and geological data within a GIS environment allowed us to analyze the terrain, drainage networks, river dynamics and structure, as well as to obtain detailed geomorphological mapping, active tectonic indices, longitudinal river profiles and structural sections. Three morphostructural segments were defined based on the structural features, the differential vertical dissection pattern over the basement, the faulted Pliocene to recent deposits, the stepwise propagation of anticlines and the distortion over the fluvial system. By combining the several lines of evidence, we concluded that the Sierra de la Candelaria range was subjected to a multi-stage development. The first stage uplifted the central segment concomitant with the formation of the surrounding ranges and with the main partition phase of the foreland. After a significant time lapse, the mountain range was subjected to southward thick-skinned growth and northward growth via stepwise thin-skinned deformation and exerted control over the dynamics of the Río Rosario. Taking into account the surrounding basins and ranges of the Sierra de la Candelaria, the southern Santa Bárbara System is characterized by partially isolated intramontane basins (Choromoro and Rosario) limited by shielded ranges that caused moisture block and shows continuous deformation. These features were related to early stages of a broken foreland evolution model and modern analogs were found at the northern

  9. The long-term changes in solar meridional circulation as the cause for the long-term changes in the correlation between solar and geomagnetic activity

    CERN Document Server

    Georgieva, K

    2007-01-01

    Since the beginning of the 20th century, the correlation in the 11-year solar cycle between the sunspot number and geomagnetic aa-index has been decreasing, while the lag between the two has been increasing. We show how this can be used as a proxy for the solar meridional circulation, and investigate the long-term changes in the meridional circulation and their role for solar activity and terrestrial climate.

  10. Comparison of high-latitude thermospheric meridional winds II: combined FPI, radar and model climatologies

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, E.M.; Aruliah, A.; Mueller-Wodarg, I.C.F.; Aylward, A. [Atmospheric Physics Lab., Univ. Coll. London, London (United Kingdom)

    2004-07-01

    The climatological behaviour of the thermospheric meridional wind above Kiruna, Sweden (67.4 N, 20.4 E) has been investigated for seasonal and solar cycle dependence using six different techniques, comprising both model and experimental sources. Model output from both the empirical Horizontal Wind Model (HWM) (Hedin et al., 1988) and the numerical coupled thermosphere and ionosphere model (CTIM) are compared to the measured behaviour at kiruna, as a single site example. The empirical International Reference Ionosphere (IRI) model is used as input to an implementation of servo theory, to provide another climatology combining empirical input with a theoretical framework. The experimental techniques have been introduced in a companion paper in this issue and provide climatologies from direct measurements, using fabry-perot interferometers (FPI), together with 2 separate techniques applied to the European incoherent scatter radar (EISCAT) database to derive neutral winds. One of these techniques uses the same implementation of servo theory as has been used with the IRI model. Detailed comparisons for each season and solar activity category allow for conclusions to be drawn as to the major influences on the climatological behaviour of the wind at this latitude. Comparison of the incoherent scatter radar (ISR) derived neutral winds with FPI, empirical model and numerical model winds is important to our understanding and judgement of the validity of the techniques used to derive thermospheric wind databases. The comparisons also test model performance and indicate possible reasons for differences found between the models. In turn, the conclusions point to possible improvements in their formulation. In particular it is found that the empirical models are over-reliant on mid-latitude data in their formulation, and fail to provide accurate estimates of the winds at high-latitudes. (orig.)

  11. Dynamic stability of nearly cylindrical orthotropic shells of revolution subjected to meridional forces

    Science.gov (United States)

    Kukudzhanov, S. N.

    2008-10-01

    We study the natural vibrations and the dynamic stability of nearly cylindrical orthotropic shells of revolution subjected to meridional forces uniformly distributed over the shell ends. We consider shells of medium length for which the shape of the midsurface generatrix is described by a parabolic function. Using the theory of shallow shells, we obtain the resolving equation for the vibrations of the corresponding prestressed shell. In the isotropic case, this equation differs from the well-known equation [1] by an additional term, which can be of the same order as the other terms taken into account. We consider shells of both positive and negative Gaussian curvature. We assumed that the shell ends are freely supported. The formulas and universal curves describing the dependence of the minimum frequency, the wave generation shape, and the dynamic instability domain boundaries on the orthotropy parameters, the preliminary stress, the Gaussian curvature, and the amplitude of the shell deviation from the cylinder are given in dimensionless form. We find that in the case of prestresses the orthotropy parameters and the shell deviation from the cylinder (of the order of thickness) can significantly change the least frequencies, the wave generation shape, and the dynamic instability domain boundaries of the corresponding prestressed orthotropic cylindrical shell. In this case, we note that for convex shells under preliminary compression the influence of the elastic parameter in the axial direction is stronger than the influence of the elastic parameter in the circular direction, while the situation is opposite in the case of concave shells. In the case of preliminary extension, the leading role of any orthotropy parameter can vary depending on the value of the preliminary stress and the Gaussian curvature.

  12. Variations of the Atlantic meridional overturning circulation in control and transient simulations of the last millennium

    Directory of Open Access Journals (Sweden)

    D. Hofer

    2011-02-01

    Full Text Available The variability of the Atlantic meridional overturing circulation (AMOC strength is investigated in control experiments and in transient simulations of up to the last millennium using the low-resolution Community Climate System Model version 3. In the transient simulations the AMOC exhibits enhanced low-frequency variability that is mainly caused by infrequent transitions between two semi-stable circulation states which amount to a 10 percent change of the maximum overturning. One transition is also found in a control experiment, but the time-varying external forcing significantly increases the probability of the occurrence of such events though not having a direct, linear impact on the AMOC. The transition from a high to a low AMOC state starts with a reduction of the convection in the Labrador and Irminger Seas and goes along with a changed barotropic circulation of both gyres in the North Atlantic and a gradual strengthening of the convection in the Greenland-Iceland-Norwegian (GIN Seas. In contrast, the transition from a weak to a strong overturning is induced by decreased mixing in the GIN Seas. As a consequence of the transition, regional sea surface temperature (SST anomalies are found in the midlatitude North Atlantic and in the convection regions with an amplitude of up to 3 K. The atmospheric response to the SST forcing associated with the transition indicates a significant impact on the Scandinavian surface air temperature (SAT in the order of 1 K. Thus, the changes of the ocean circulation make a major contribution to the Scandinavian SAT variability in the last millennium.

  13. The Atlantic Multi-Decadal Oscillation Climate Impact - Zonal and Meridional Coupling

    Science.gov (United States)

    Werner, Rolf; Kirillov, Andrey; Valev, Dimitar; Atanassov, Atanas; Danov, Dimitar; Guineva, Veneta

    2016-07-01

    The Atlantic multi-decadal oscillation (AMO) shows a period of about 60-70 years. Over the time span from 1860 up to 2014 the AMO has had a strong climate impact on the Northern Hemisphere. The AMO is considered to be related to the Atlantic overturning circulation, but the origin of the oscillation is not fully understood up till now. To study the AMO impact on climate, the Hadcrut4, Crut4 and HadSST3 temperature data sets have been employed in the current study. The influence of the AMO on the zonal and meridional temperature distribution has been investigated in detail. The strongest zonal AMO impact was obtained in the Arctic region. The results indicated that the AMO influence on temperature at Southern latitudes was opposite in phase compared to the temperature influence in the Northern Hemisphere, in agreement with the well known heat transfer phenomenon from South to North Atlantic. In the Northern Hemisphere the strongest AMO temperature impact was found over the Atlantic and America. In the West from American continent, over the Pacific, the AMO impact was the lowest obtained over the whole Northern Hemisphere. The Rocky Mountains and Sierra Madre, connected with it southwards, built up an atmospheric circulation barrier preventing a strong propagation of the AMO temperature signal westerly. The amplitude of the AMO index itself was greater during summer-fall. However stronger AMO influence on the Northern Hemisphere temperatures was found during the fall-winter season, when the differences between the Northern Hemisphere temperatures and the temperatures in the tropics were the greatest.

  14. The impact of multidecadal Atlantic meridional overturning circulation variations on the Southern Ocean

    Science.gov (United States)

    Zhang, Liping; Delworth, Thomas L.; Zeng, Fanrong

    2017-03-01

    The impact of multidecadal variations of the Atlantic meridional overturning circulation (AMOC) on the Southern Ocean (SO) is investigated in the current paper using a coupled ocean-atmosphere model. We find that the AMOC can influence the SO via fast atmosphere teleconnections and subsequent ocean adjustments. A stronger than normal AMOC induces an anomalous warm SST over the North Atlantic, which leads to a warming of the Northern Hemisphere troposphere extending into the tropics. This induces an increased equator-to-pole temperature gradient in the Southern Hemisphere (SH) upper troposphere and lower stratosphere due to an amplified tropical upper tropospheric warming as a result of increased latent heat release. This altered gradients leads to a poleward displacement of the SH westerly jet. The wind change over the SO then cools the SST at high latitudes by anomalous northward Ekman transports. The wind change also weakens the Antarctic bottom water (AABW) cell through changes in surface heat flux forcing. The poleward shifted westerly wind decreases the long term mean easterly winds over the Weddell Sea, thereby reducing the turbulent heat flux loss, decreasing surface density and therefore leading to a weakening of the AABW cell. The weakened AABW cell produces a temperature dipole in the SO, with a warm anomaly in the subsurface and a cold anomaly in the surface that corresponds to an increase of Antarctic sea ice. Opposite conditions occur for a weaker than normal AMOC. Our study here suggests that efforts to attribute the recent observed SO variability to various factors should take into consideration not only local process but also remote forcing from the North Atlantic.

  15. Accretion Disks around Black Holes: Dynamical Evolution, Meridional Circulations, and Gamma-Ray Bursts

    Science.gov (United States)

    Lee, William H.; Ramirez-Ruiz, Enrico

    2002-10-01

    We study the hydrodynamic evolution of massive accretion disks around black holes, formed when a neutron star is disrupted by a black hole in a binary system. The initial conditions are taken from three-dimensional calculations of coalescing binaries. By assuming azimuthal symmetry we are able to follow the time dependence of the disk structure for 0.2 s in cylindrical coordinates (r,z). We use an ideal gas equation of state and assume that all the dissipated energy is radiated away. The disks evolve because of viscous stresses, modeled with an α law. We study the disk structure and, in particular, the strong meridional circulations that are established and persist throughout our calculations. These consist of strong outflows along the equatorial plane that reverse direction close to the surface of the disk and converge on the accretor. In the context of gamma-ray bursts (GRBs), we estimate the energy released from the system in neutrinos and through magnetic-dominated mechanisms and find it can be as high as Eν~1052 ergs and EBZ~1051 ergs, respectively, during an estimated accretion timescale of 0.1-0.2 s. The νν annihilation is likely to produce bursts from only a short, impulsive energy input Lνν~t-5/2 and so would be unable to account for a large fraction of bursts that show complicated light curves. On the other hand, a gas mass ~0.1-0.25 Msolar survives in the orbiting debris, which enables strong magnetic fields ~1016 G to be anchored in the dense matter long enough to power short duration GRBs. We highlight the effects that the initial disk and black holes masses, viscosity, and binary mass ratio have on the evolution of the disk structure. Finally, we investigate the continuous energy injection that arises as the black hole slowly swallows the rest of the disk and discuss its consequences on the GRB afterglow emission.

  16. Multi-point optimization on meridional shape of a centrifugal pump impeller for performance improvement

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Ji; Wang, Wen Jie; Yuan, Shouqi [National Research Center of Pumps, Jiangsu University, Zhenjiang (China)

    2016-11-15

    A wide operating band is important for a pump to safely perform at maximum efficiency while saving energy. To widen the operating range, a multi-point optimization process based on numerical simulations in order to improve impeller performance of a centrifugal pump used in nuclear plant applications is proposed by this research. The Reynolds average Navier Stokes equations are utilized to perform the calculations. The meridional shape of the impeller was optimized based on the following four parameters; shroud arc radius, hub arc radius, shroud angle, and hub angle as the design variables. Efficiencies calculated under 0.6Qd, 1.0Qd and 1.62Qd were selected as the three optimized objectives. The Design of experiment method was applied to generate various impellers while 35 impellers were generated by the Latin hypercube sampling method. A Response surface function based on a second order function was applied to construct a mathematical relationship between the objectives and design variables. A multi-objective genetic algorithm was utilized to solve the response surface function to obtain the best optimized objectives as well as the best combination of design parameters. The results indicated that the pump performance predicted by numerical simulation was in agreement with the experimental performance. The optimized efficiencies based on the three operating conditions were increased by 3.9 %, 6.1 % and 2.6 %, respectively. In addition, the velocity distribution, pressure distribution, streamline and turbulence kinetic energy distribution of the optimized and reference impeller were compared and analyzed to illustrate the performance improvement.

  17. Estudios sobre la vegetación del estado de Paraná (Brasil meridional

    Directory of Open Access Journals (Sweden)

    de Bolòs, Oriol

    1991-12-01

    Full Text Available Contribution to knowledge about the vegetation of the state of Paraná in southern Brazil (Serra do Mar, Planaltos, Iguaçu Valley. Numerous plant associations are described and grouped together in the following classes: Pistio-Eichhornietea (communities of floating cormophytes Xyrido-Typhetea (helophytic herbaceous vegetation Polypodio-Tillandsietea (epiphytic and comophytic vegetation Ruderali-Manihotetea (ruderal and segetal vegetation Andropogono-Baccharidetea (savanoid vegetation Rhizophoretea (mangroves Lantano-Chusqueetea (woody marginal communities of the forest Cedrelo-Ocoteetea (rain and mesophilous forest. Special attention is paid to the study of the physiognomy, structure and dynamism of the vegetation and its biogeographical significance.

    Aportación al conocimiento de la vegetación del estado de Paraná en el Brasil meridional (Serra do Mar, Planaltos, valle del Iguaçu. Se describen numerosas asociaciones vegetales agrupadas en las clases siguientes: Pistio-Eichhornietea (comunidades de cormófitos flotantes. Xyrido-Typhetea (vegetación herbácea helofítica. Polypodio-Tillandsietea (vegetación epifítica y comofítica. Ruderali-Manihotetea (vegetación ruderal, viaria y arvense. Andropogono-Baccharidetea (vegetación sabanoide. Rhizophoretea (manglar. Lantano-Chusqueetea (manto marginal leñoso de la selva. Cedrelo-Ocoteetea (selva pluvial y mesófila. Se dedica atención especial al estudio de la fisionomía, estructura y dinamismo de la vegetación y a su significación biogeográfica.

  18. Warm and Saline Events Embedded in the Meridional Circulation of the Northern North Atlantic

    Science.gov (United States)

    Hakkinen, Sirpa; Rhines, Peter B.; Worthen, Denise L.

    2011-01-01

    Ocean state estimates from 1958 to 2005 from the Simple Ocean Assimilation System (SODA) system are analyzed to understand circulation between subtropical and subpolar Atlantic and their connection with atmospheric forcing. This analysis shows three periods (1960s, around 1980, and 2000s) with enhanced warm, saline waters reaching high latitudes, alternating with freshwater events originating at high latitudes. It complements surface drifter and altimetry data showing the subtropical -subpolar exchange leading to a significant temperature and salinity increase in the northeast Atlantic after 2001. The warm water limb of the Atlantic meridional overturning cell represented by SODA expanded in density/salinity space during these warm events. Tracer simulations using SODA velocities also show decadal variation of the Gulf Stream waters reaching the subpolar gyre and Nordic seas. The negative phase of the North Atlantic Oscillation index, usually invoked in such variability, fails to predict the warming and salinization in the early 2000s, with salinities not seen since the 1960s. Wind stress curl variability provided a linkage to this subtropical/subpolar gyre exchange as illustrated using an idealized two ]layer circulation model. The ocean response to the modulation of the climatological wind stress curl pattern was found to be such that the northward penetration of subtropical tracers is enhanced when amplitude of the wind stress curl is weaker than normal. In this case both the subtropical and subpolar gyres weaken and the subpolar density surfaces relax; hence, the polar front moves westward, opening an enhanced northward access of the subtropical waters in the eastern boundary current.

  19. Variability of the Atlantic meridional overturning circulation in the last millennium and two IPCC scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Pablo; Montoya, Marisa; Gonzalez-Rouco, Fidel [Universidad Complutense de Madrid, Ciudad Universitaria, Dpto. Astrofisica y Ciencias de la Atmosfera/Instituto de Geociencias, Facultad de Ciencias Fisicas, Madrid (Spain); Universidad Complutense de Madrid, Ciudad Universitaria, Instituto de Geociencias (UCM-CSIC), Facultad de Ciencias Fisicas, Madrid (Spain); Mignot, Juliette [IPSL/LOCEAN, UPMC/CNRS/IRD/MNHN, Universite Pierre et Marie Curie, Paris Cedex 05 (France); Legutke, Stephanie [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    2012-05-15

    The variability of the Atlantic meridional overturning circulation (AMOC) is investigated in several climate simulations with the ECHO-G atmosphere-ocean general circulation model, including two forced integrations of the last millennium, one millennial-long control run, and two future scenario simulations of the twenty-first century. This constitutes a new framework in which the AMOC response to future climate change conditions is addressed in the context of both its past evolution and its natural variability. The main mechanisms responsible for the AMOC variability at interannual and multidecadal time scales are described. At high frequencies, the AMOC is directly responding to local changes in the Ekman transport, associated with three modes of climate variability: El Nino-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the East Atlantic (EA) pattern. At low frequencies, the AMOC is largely controlled by convection activity south of Greenland. Again, the atmosphere is found to play a leading role in these variations. Positive anomalies of convection are preceded in 1 year by intensified zonal winds, associated in the forced runs to a positive NAO-like pattern. Finally, the sensitivity of the AMOC to three different forcing factors is investigated. The major impact is associated with increasing greenhouse gases, given their strong and persistent radiative forcing. Starting in the Industrial Era and continuing in the future scenarios, the AMOC experiences a final decrease of up to 40% with respect to the preindustrial average. Also, a weak but significant AMOC strengthening is found in response to the major volcanic eruptions, which produce colder and saltier surface conditions over the main convection regions. In contrast, no meaningful impact of the solar forcing on the AMOC is observed. Indeed, solar irradiance only affects convection in the Nordic Seas, with a marginal contribution to the AMOC variability in the ECHO-G runs. (orig.)

  20. Inter-comparison of stratospheric mean-meridional circulation and eddy mixing among six reanalysis datasets

    Directory of Open Access Journals (Sweden)

    K. Miyazaki

    2015-10-01

    Full Text Available The stratospheric mean-meridional circulation (MMC and eddy mixing are compared among six meteorological reanalysis datasets: NCEP-NCAR, NCEP-CFSR, ERA-40, ERA-Interim, JRA-25, and JRA-55 for the period 1979–2012. The reanalysis datasets produced using advanced systems (i.e., NCEP-CFSR, ERA-Interim, and JRA-55 generally reveal a weaker MMC and stronger eddy mixing in the Northern Hemisphere (NH compared with those produced using older systems (i.e., NCEP/NCAR, ERA-40, and JRA-25. In the NH lower stratosphere, the stronger eddy mixing is attributed to stronger planetary-scale mixing in the new datasets, whereas small-scale mixing is weaker in the new datasets. Conventional data assimilation techniques introduce analysis increments without maintaining physical balance, which may have caused an overly strong MMC and spurious small-scale eddies in the old datasets. At the NH mid-latitudes, only ERA-Interim reveals a weakening MMC trend in the deep branch of the Brewer–Dobson Circulation (BDC. The relative importance of the eddy mixing compared with the mean transport in the subtropical lower stratosphere is considered to be important in controlling mean Age-of-Air (AoA variations above, which showed increasing trends in ERA-Interim and JRA-55; this together with the weakened MMC in the deep branch may imply an increasing AoA trend in the NH middle stratosphere in ERA-Interim. Overall, discrepancies between the different variables and trends therein as derived from the different reanalyses are still relatively large, suggesting that more investments into these products are needed in order to obtain a consolidated picture of observed changes in the BDC and the mechanisms that drive them.

  1. Strong and deep Atlantic meridional overturning circulation during the last glacial cycle.

    Science.gov (United States)

    Böhm, E; Lippold, J; Gutjahr, M; Frank, M; Blaser, P; Antz, B; Fohlmeister, J; Frank, N; Andersen, M B; Deininger, M

    2015-01-01

    Extreme, abrupt Northern Hemisphere climate oscillations during the last glacial cycle (140,000 years ago to present) were modulated by changes in ocean circulation and atmospheric forcing. However, the variability of the Atlantic meridional overturning circulation (AMOC), which has a role in controlling heat transport from low to high latitudes and in ocean CO2 storage, is still poorly constrained beyond the Last Glacial Maximum. Here we show that a deep and vigorous overturning circulation mode has persisted for most of the last glacial cycle, dominating ocean circulation in the Atlantic, whereas a shallower glacial mode with southern-sourced waters filling the deep western North Atlantic prevailed during glacial maxima. Our results are based on a reconstruction of both the strength and the direction of the AMOC during the last glacial cycle from a highly resolved marine sedimentary record in the deep western North Atlantic. Parallel measurements of two independent chemical water tracers (the isotope ratios of (231)Pa/(230)Th and (143)Nd/(144)Nd), which are not directly affected by changes in the global cycle, reveal consistent responses of the AMOC during the last two glacial terminations. Any significant deviations from this configuration, resulting in slowdowns of the AMOC, were restricted to centennial-scale excursions during catastrophic iceberg discharges of the Heinrich stadials. Severe and multicentennial weakening of North Atlantic Deep Water formation occurred only during Heinrich stadials close to glacial maxima with increased ice coverage, probably as a result of increased fresh-water input. In contrast, the AMOC was relatively insensitive to submillennial meltwater pulses during warmer climate states, and an active AMOC prevailed during Dansgaard-Oeschger interstadials (Greenland warm periods).

  2. Soil and Terrain Database for Argentina, primary data (version 1.0) - scale 1:1 million (SOTER_Argentina)

    NARCIS (Netherlands)

    Dijkshoorn, J.A.; Huting, J.R.M.

    2014-01-01

    The Soil and Terrain database for Argentina primary data (version 1.0), at scale 1:1 million (SOTER_Argentina), was compiled of enhanced soil information within the framework of the FAO's program Land Degradation Assessment in Drylands (LADA). Primary soil and terrain data for Argentina were

  3. Psychiatry and humanism in Argentina.

    Science.gov (United States)

    Niño Amieva, Alejandra

    2016-04-01

    The authors of the present selection of Latin American Psychiatry texts were characterized by a common deep humanistic attitude. These prolific writers were able to establish or extend the scope of the discipline in which they chose to act, questioning the establishment of rigid boundaries within the framework of a rigorous epistemological reflection. Thus the systematizing spirit of Jose Ingenieros' in the context of positivist evolutionism, resulted in the act of founding a discipline that integrated the biological and the social. In the case of Guillermo Vidal his conception of mental health went beyond the biomedical to consider psychotherapies as an emotional commitment, continence and empathic understanding; with regard to César Cabral his formation and extensive clinical practice resulted in a work defined by the inquiring into the theoretical concepts underlying Psychiatry and Clinical Psychology. This brief selection does not exhaust the issues or the level of ideas and discussions of Psychiatry in Argentina, but constitutes a textual corpus representative of a disciplinary conception understood as scientific and humanistic endeavor.

  4. Argentina to fully privatize state owned YPF

    Energy Technology Data Exchange (ETDEWEB)

    1992-10-05

    Argentina's Congress has voted to fully privatize state petroleum company Yacimientos Petroliferos Fiscales (YPF), a move the government expects to net at least $8 billion. Despite some political opposition, the vote was 119-10 in favor, with one abstention and opposition party members refusing to participate in the vote. Argentina's President Carlos Menem had threatened to authorize YPF privatization by decree if there was no quorum for a vote. YPF is responsible for 40% of Argentina's oil production. The country h as been self-sufficient in crude since 1982. Current production is 563,472 b/d, and proved reserves of oil and gas are valued at $7 billion.

  5. Mechanisms of meridional transport processes in the tropical Atlantic; Mechanismen meridionaler Transportprozesse im tropischen Atlantik

    Energy Technology Data Exchange (ETDEWEB)

    Kroeger, J.

    2001-07-01

    Meridional transport processes of water masses and tracers in the subtropical and tropical Atlantic are investigated using a regional eddy resolving model of the wind driven and thermohaline circulation. Analytical emphasis is on float simulations in the model which, complementary to Eulerian means, represent the Lagrangian view and give further insight into the spreading and pathways of characteristic water masses in this area. In the tropics and subtropics shallow 3-dimensional circulation cells are superimposed on the northward warm water transfer within the deep reaching thermohaline overturning cell (MOC) as part of the global ''Conveyor Belt''. Under present-day climate conditions the model shows that the equatorial thermocline is exclusively ventilated by subsurface flow within the tropical-subtropical cell (STC) of the South Atlantic. Only with a prescribed ''Conveyor-off''-Mode the STC of the North Atlantic contributes to this ventilation process with equal amounts. Throughout the year the interhemispheric transport of surface and central water masses of South Atlantic origin into the Caribbean Sea is dominated by zonal detours to the east as a consequence of the interplay of several retroflection events occuring in the North Atlantic. The eulerian mean flow field in the deep layer postulates the interhemispheric mass transport into the South Atlantic to be confined entirely to the western boundary, whereas Lagrangian means indicate intermittent eastward excursions along the equator, related to seasonally alternating zonal currents due to long Rossby waves. It was suggested that the observed characteristic eastward maximum of tracer concentrations along the equator is a consequence of rectifying effects of single or interacting equatorial waves. The model does not validate this hypothesis. The response to transport anomalies of subpolar origin and long periodicity is subject to different time-scales in both

  6. Link between convection and meridional gradient of sea surface temperature in the Bay of Bengal

    Indian Academy of Sciences (India)

    D Shankar; S R Shetye; P V Joseph

    2007-10-01

    We use daily satellite estimates of sea surface temperature (SST)and rainfall during 1998 –2005 to show that onset of convection over the central Bay of Bengal (88-92°E, 14-18°N)during the core summer monsoon (mid-May to September)is linked to the meridional gradient of SST in the bay.The SST gradient was computed between two boxes in the northern (88-92°E, 18-22°N) and southern (82-88°E, 4-8°N) bay; the latter is the area of the cold tongue in the bay linked to the Summer Monsoon Current.Convection over central bay followed the SST difference between the northern and southern bay ( ) exceeding 0.75°C in 28 cases.There was no instance of exceeding this threshold without a burst in convection.There were,however,five instances of convection occurring without this SST gradient.Long rainfall events (events lasting more than a week)were associated with an SST event ( ≥ 0.75°C);rainfall events tended to be short when not associated with an SST event.The SST gradient was important for the onset of convection, but not for its persistence:convection often persisted for several days even after the SST gradient weakened.The lag between exceeding 0.75°C and the onset of convection was 0-18 days,but the lag histogram peaked at one week.In 75% of the 28 cases,convection occurred within a week of exceeding the threshold of 0.75°C. The northern bay SST, contributed more to but it was a weaker criterion for convection than the SST gradient.A sensitivity analysis showed that the corresponding threshold for was 29°C. We hypothesise that the excess heating (∼1° C above the threshold for deep convection)required in the northern bay to trigger convection is because this excess in SST is what is required to establish the critical SST gradient.

  7. Chaotic variability of the meridional overturning circulation on subannual to interannual timescales

    Directory of Open Access Journals (Sweden)

    J. J.-M. Hirschi

    2012-10-01

    Full Text Available Observations and numerical simulations have shown that the meridional overturning circulation (MOC exhibits substantial variability on sub- to interannual timescales. This variability is not fully understood. In particular it is not known what fraction of the MOC variability is caused by processes such as mesoscale ocean eddies and internal waves which are ubiquitous in the ocean. Here we analyse twin experiments performed with a global ocean model at eddying (1/4° and non-eddying (1° resolutions. The twin experiments are forced with the same surface fluxes for the 1958 to 2001 period but start from different initial conditions. Our results show that on subannual to interannual timescales a large fraction of MOC variability directly reflects variability in the surface forcing. Nevertheless, in the eddy-permitting case there is an initial condition dependent MOC variability (hereinafter referred to as "chaotic" variability of several Sv (1 Sv = 106 m3 s−1 in the Atlantic and the Indo-Pacific. In the Atlantic the chaotic MOC variability represents up to 30% of the total variability at the depths where the maximum MOC occurs. In comparison the chaotic MOC variability is only 5–10% in the non-eddying case. The surface forcing being identical in the twin experiments suggests that mesoscale ocean eddies are the most likely cause for the increased chaotic MOC variability in the eddying case. The exact formation time of eddies is determined by the initial conditions which are different in the two accordance with and as a consequence the mesoscale eddy field is decorrelated in the twin experiments. In regions where eddy activity is high in the eddy-permitting model, the correlation of sea surface height variability in the twin runs is close to zero. In the non-eddying case in contrast, we find high correlations (0.9 or higher over most regions. Looking at the sub- and interannual MOC components separately reveals

  8. Hepatitis C in Argentina: epidemiology and treatment

    OpenAIRE

    Gaite LA; Marciano S; Galdame OA; Gadano AC

    2014-01-01

    Luis Alejandro Gaite, Sebastián Marciano, Omar Andrés Galdame, Adrián Carlos GadanoHepatology Unit, Hospital Italiano de Buenos Aires, Buenos Aires, ArgentinaAbstract: Hepatitis C is the leading cause of chronic hepatitis, cirrhosis, and liver cancer in Argentina, where from 1.5% to 2.5% of adults are infected. Most of the infections were acquired 30–50 years ago. It is estimated that more than half of infected individuals are not aware of their infe...

  9. de la Argentina y notas nomenclaturales

    Directory of Open Access Journals (Sweden)

    Zulma E. Rúgolo de Agrasar

    2006-01-01

    Full Text Available En esta primera revisión del género Deyeuxia para la Argentina se reconocen 58 taxones nativos de América, tres de ellos son endémicos de la Argentina, y los restantes también crecen en Bolivia, Brasil y Chile. Se describen tres nuevos taxones para la ciencia: Deyeuxia alba subsp. breviaristata (Argentina, Brasil y Uruguay; Deyeuxia heterophylla var. puberilemma (Perú; Deyeuxia trichodonta var. hirsuta (Argentina: Salta. Se establece un nuevo nombre: Deyeuxia nana, para en Agrostis caespitosa. Las siguientes once entidades constituyen nuevas citas para Argentina, Bolivia, Chile y Ecuador: Deyeuxia brevifolia var. brevifolia y Deyeuxia brevifolia var. expansa (Chile; Deyeuxia cabrerae var. cabrerae, D. cabrerae var. aristulata (Chile; D. cabrerae var. trichopoda (Chile; Deyeuxia curta (Ecuador; Deyeuxia filifolia (Chile; D. diemii (Chile; Deyeuxia filifolia (Chile; Deyeuxia hackelii (Chile; Deyeuxia minima (Argentina y Ecuador; Deyeuxia sclerantha (Ecuador; Deyeuxia spicigera var. spicigera (Chile; Deyeuxia spicigera var. cephalotes (Argentina y Deyeuxia trichodonta var. trichodonta (Bolivia. Se establecen cinco nuevas combinaciones: Deyeuxia reitzii, Deyeuxia rupestris f. pilosa., Deyeuxia rupestris var. minor, D. tarmensis var. macrochaeta y Deyeuxia velutina var. nardifolia. Se adicionan nuevos sinónimos en las siguientes entidades: Deyeuxia heterophylla (Calama grostis mulleri, Calamagrostis macbridei; Deyeuxia rupestris f. pilosa (Calamagrostis leonardii, Calamagrostis longearistata f. pilosa y Calamagrostis epigeios (Calamagrostis chilensis. Esta revisión incluye una evaluación crítica de los caracteres morfológicos (algunos estudiados con MEB con valor taxonómico para Deyeuxia y sus especies aquí estudiadas, como también una discusión de las relaciones de Deyeuxia con sus géneros más afines. Se presentan en detalle consideraciones nomenclaturales sobre taxones problemáticos, claves dicotómicas para distinguir Deyeuxia de

  10. Ticks infesting humans in Northern Misiones, Argentina.

    Science.gov (United States)

    Lamattina, Daniela; Nava, Santiago

    2016-01-01

    This work presents records of ticks infesting humans in northern Misiones Province, Argentina. Also, notes on potential transmission of tick-borne pathogens are included. A total of 282 ticks attached to researchers were collected and identified by their morphological characters. Eight tick species were found: Amblyomma brasiliense, Amblyomma coelebs, Amblyomma dubitatum, Amblyomma incisum, Amblyomma ovale, Haemaphysalis juxtakochi, Rhipicephalus sanguineus and Rhipicephalus microplus. Some of these species as A. dubitatum, A. ovale and R. sanguineus have been found infected with spotted fever group rickettsiae pathogenic to humans in Brazil and Argentina. The potential role as vectors of humans pathogens of the ticks found attached to humans in this study is discussed.

  11. Glyphium elatum (Ascomycota in Patagonia (Argentina Glyphium elatum (Ascomycota en Patagonia (Argentina

    Directory of Open Access Journals (Sweden)

    Laura E. Lorenzo

    2005-07-01

    Full Text Available The genus Glyphium, represented by G. elatum (Ascomycota is recorded for the first time among the mycobiota of Argentina. Prior to this finding, this species was known in southern South America from southern Chile only. The new record extends its geographic range to the temperate-humid forests in the Andean-Patagonian regions of Argentina. Glyphium elatum is described and illustrated.El género Glyphium (Ascomycota representado por G. elatum, se cita por primera vez para la micobiota de la Argentina. Hasta la fecha, en el sur de Sudamérica, la especie había sido registrada en el sur de Chile solamente. Esta cita extiende su distribución geográfica a la región de los bosques húmedos andino-patagónicos de la Argentina. Glyphium elatum es descripta e ilustrada.

  12. De Indios “Bárbaros” a Vasallos en la Frontera Meridional Chilena Durante el Reformismo Borbónico.

    OpenAIRE

    Chauca García, Jorge

    2017-01-01

    Con la presente Tesis Doctoral abordamos críticamente la visión ilustrada del indígena de la frontera meridional chilena como marco geográfico y la centuria de la Ilustración como coordenada temporal, especialmente su segunda mitad. Un análisis de sus tres familias básicas que no contempla por razones cronológicas a los picunches o gentes del norte, pero sí a los mapuches –gente de la tierra–, huilliches –gente...

  13. "What Controls the Structure and Stability of the Ocean Meridional Overturning Circulation: Implications for Abrupt Climate Change?"

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, Alexey [Yale University

    2013-11-23

    The central goal of this research project is to understand the properties of the ocean meridional overturning circulation (MOC) – a topic critical for understanding climate variability and stability on a variety of timescales (from decadal to centennial and longer). Specifically, we have explored various factors that control the MOC stability and decadal variability in the Atlantic and the ocean thermal structure in general, including the possibility abrupt climate change. We have also continued efforts on improving the performance of coupled ocean-atmosphere GCMs.

  14. Guerra, relaciones de producción y economía en la Galia meridional post-romana

    OpenAIRE

    Pablo Sarachu

    2012-01-01

    La guerra fue un fenómeno generalizado en la Galia meridional durante el siglo VI. Su omnipresencia estuvo alimentada en buena medida por la naturaleza de la dinámica política de los reinos, por la forma de interacción entre reyes y aristócratas. En el presente trabajo se analiza su influencia sobre las relaciones sociales de producción y la economía de la región. Concretamente, se argumenta que la guerra favoreció la inestabilidad de los vínculos de dependencia y –consecuentemente– la contra...

  15. Plantas útiles de Santa Victoria Oeste (Salta, Argentina)

    OpenAIRE

    2008-01-01

    Yavi, en el extremo norte de la provincia de Jujuy y a pasos de la frontera con Bolivia, es un poblado dentro de un pequeño valle irrigado en el corazón del altiplano argentino. Es un lugar visitado por los turistas por su antigua capilla y el museo de la casa donde residió un marqués. Menos personas saben que el camino de ripio que parte hacia el este conduce a un valle con varios miles de habitantes, a poca distancia al mismo tiempo de la selva de las Yungas y la Puna, como s...

  16. Palaeoclimate reconstructions from lacustrine terraces and lake-balance modeling in the southern central Andes: New insights from Salar de Pocitos (Salta Province, Argentina)

    Science.gov (United States)

    Bekeschus, Benjamin; Bookhagen, Bodo; Strecker, Manfred R.; Freymark, Jessica; Eckelmann, Felix; Alonso, Ricardo

    2013-04-01

    The arid Puna Plateau in the southern central Andes of NW-Argentina constitutes the southern part of Earth's second largest orogenic plateau. Numerous internally drained basins are restricted by ranges that peak 5-6 km above sea level, creating a compressional basin and range morphology. The conspiring effects of this structurally controlled topography and the high degree of aridity have resulted in low stream power of the fluvial network and internally drained basins. A steep rainfall gradient exists across this area ranging from a humid Andean foreland (>1m/yr annual rainfall) to progressively drier areas westwards. At the present-day, the interior of the plateau is widely characterized by annual rainfall and high evaporation rates. Thus continuous lacustrine archives are limited and sediments are dominated by evaporites. Several closed basins contain vestiges of moister conditions from past pluvial periods. For example, the staircase morphology of lacustrine shorelines and abrasion platforms in the distal sectors of alluvial fans and pediments at Salar de Pocitos (24.5°S, 67°W, 3650 m asl) records repeated former lake highstands. This intermontane basin has existed since the late Tertiary, constituting a 435 km² salt flat in the region of Salta, NW Argentina. Comparison with palaeoclimate records from the neighboring Salar de Atacama suggests that the terrace systems at Salar de Pocitos were formed during the Late Pleistocene and early Holocene. Here we report on our preliminary results of the extent of several terrace generations in this region. We mapped terraces in the field and on satellite images and determined their elevations during a high-resolution DGPS field survey. Our analysis reveals 3-4 distinct terrace levels associated with individual lake-level highstands. However, basin-wide correlation is difficult due to ongoing tectonism and differential tilting of the basin. The highest lake terrace, ca. 25 m above modern base level, locally comprises a

  17. Payenia volcanic province, southern Mendoza, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin; Llambias, Eduardo Jorge

    2013-01-01

    The Pleistocene to Holocene Payenia volcanic province is a backarc region of 60,000 km2 in Mendoza, Argentina, which is dominated by transitional to alkaline basalts and trachybasalts. We present major and trace element compositions of 139 rocks from this area of which the majority are basaltic...

  18. Argentina and Brazil's Relations to the EU

    DEFF Research Database (Denmark)

    Christensen, Steen Fryba

    Analysen diskuterer Argentina og Brasiliens relationer til EU i nyere tid med udgangspunkt i forhandlingerne om en associeringsaftale mellem EU og Mercosur, der igangsattes efter underskrivelsen af en bi-regional rammeaftale i 1995. Fokus er i særlig grad på, hvordan disse relationer bedst forstå...

  19. MASTER: bright PSN discovered in Argentina

    Science.gov (United States)

    Shumkov, V.; Lipunov, V.; Podesta, R.; Levato, H.; Buckley, D.; Gorbovskoy, E.; Tiurina, N.; Balanutsa, P.; Kuznetsov, A.; Vladimirov, V.; Gress, O.; Ivanov, K.; Chazov, V.; Lopez, C.; Podesta, F.; Saffe, C.; Pogrosheva, T.; Shurpakov, S.

    2016-10-01

    MASTER-OAFA (located in Argentina) auto-detection system ( Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L ) discovered OT source at (RA, Dec) = 22h 01m 01.36s -40d 15m 26.7s on 2016-10-31.08091 UT. The OT unfiltered magnitude is 16.9m (mlim=19.9m).

  20. China Looks to Argentina to Grow Food

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ It might sound perverse for a Chinese company to go halfway round the globe to grow soya and other crops on unproductive land in a dry corner of Argentina. Yet that is what Beidahuang Group, a state-owned farm company based in the north-eastern Chinese province of Heilongjiang, is doing in the Pa-tagonian province of Rio Negro.

  1. Contact dermatitis caused by dimethylfumarate in Argentina.

    Science.gov (United States)

    Lo Balbo, A; Gotelli, M J; Mac Cormack, W P; Kogan, N; Gotelli, C

    2011-07-01

    For the first time in Argentina, we describe an outbreak of contact dermatitis. New pairs of shoes caused intense pruritus, pain, and eruption, followed by edema, blisters, and a severe negative impact on the epidermal barrier of the feet. We identify dimethylfumarate as the causal agent and suggest an analytical method for its fast identification.

  2. Registration of veterinary products in Argentina.

    Science.gov (United States)

    Butler, E; Cané, B G

    1995-12-01

    A scheme for registering pharmaceutical and biological products for veterinary use was introduced in Argentina in 1994, as part of a joint scheme for countries of the Common Market of the South (Mercado Común del Sur: "Mercosur'). The authors describe the main features of these regulations, and the process which led to their development.

  3. Argentina : trade patterns and challenges ahead

    OpenAIRE

    Anos-Casero, Paloma; Rollo, Valentina

    2010-01-01

    Argentinean export growth was impressive during the recent economic boom (2003-2007). However, decomposing export growth reveals that the extensive margin (increases in exports of existing products to existing markets) dominates, while the intensive margin (increases in exports of new products or new markets) contributes little to export growth. Argentina's trade product concentration has ...

  4. Reared Opiinae (Hymenoptera: Braconidae) from Argentina

    NARCIS (Netherlands)

    Achterberg, van C.; Salvo, A.

    1997-01-01

    The results of the identification of a small collection of Opiinae reared from Agromyzidae from Argentina are reported; six new species and one new genus (Lorenzopius gen. nov.; type species: Lorenzopius calycomyzae spec. nov.) are described. A checklist to the species of Opiinae known from

  5. Education Reform Brings New Challenges to Argentina.

    Science.gov (United States)

    Rossetti, Mercedes

    1997-01-01

    A description of recent changes in Argentina's system of education looks at underlying policy, the redesigned schooling system, emphasis placed on English language instruction, the teacher training system, and problems in the process for assuring an adequate flow of qualified English teachers. (MSE)

  6. Sudden death syndrome of soybean in Argentina

    Science.gov (United States)

    Sudden death syndrome (SDS) is one of the most common and widely spread root disease affecting soybean [Glycine max (L.) Merr.] in Argentina where it is an economically important crop. This disease was first discovered in this country in 1992 in the Pampas Region, and the following year in Northwest...

  7. Argentina: Background and U.S. Relations

    Science.gov (United States)

    2008-11-05

    board the plane also intended for the Fernández campaign that was not confiscated by Argentine customs.41 CRS-13 42 Ministerio de Relaciones Exteriores ... Comercio Internacional, Y Culto, Comunicado de la Cancillería Argentina, September 11, 2008. 43 A. Rebossio, "Fernández Acusa al FBI de Desestablizar

  8. [Smoking during pregnancy in Argentina and Uruguay].

    Science.gov (United States)

    Althabe, Fernando; Colomar, Mercedes; Gibbons, Luz; Belizán, José M; Buekens, Pierre

    2008-01-01

    Argentina and Uruguay are among the countries in which a large proportion of young women smoke. The rate of smokers during pregnancy in both countries is not well known, and data on the characteristics of women who quit smoking during pregnancy compared to those who continue smoking are not available. We conducted a survey including 1512 pregnant women > or = 18 years old (796 in Argentina; 716 in Uruguay), during antenatal visits in public hospitals of large urban regions; 44% of the women in Argentina and 53% in Uruguay had been or were regular smokers. 11% of the surveyed women in Argentina and 18% in Uruguay continued smoking during pregnancy. In both countries, the proportion of women who lived with smokers, allowed smoking at home, and were regularly or always exposed to tobacco smoke indoors, were 49%, 46% and 20% in the subgroup of women who never smoked, 67%, 60% and 32% in those who quit, and 78%, 75% and 52% in those who continued smoking, respectively. The study confirms a serious public health problem in both countries, and documents that environmental exposure persists in subgroups of women, even in those who quit smoking. It is important that the public health sector should provide access to effective programs for smoking cessation, to women who smoke during pregnancy. For the development of a new program, any intervention intending to have at least a moderate and sustainable success, it should seriously consider including components targeting the smoking environment of the pregnant women who smoke.

  9. The Atlantic Meridional Transect: Spatially Extensive Calibration and Validation of Optical Properties and Remotely Sensed Measurements of Ocean Colour

    Science.gov (United States)

    Aiken, James; Hooker, Stanford

    1997-01-01

    Twice a year, the Royal Research Ship (RRS) James Clark Ross (JCR) steams a meridional transect of the atlantic Ocean between Grimsly (UK) and Stanley (Falkland Islands) with a port call in Montevideo (Uruguay), as part of the annual research activities of the British Antarctic Survey (BAS). In September, the JCR sails from the UK, and the following April it makes the return trip. The ship is operated by the BAS for the Natural Environment Research Council (NERC). The Atlantic Meridional Transect (AMT) Program exploits the passage of the JCR from approximately 50 deg. N to 50 deg. S with a primary objective to investigate physical and biological processes, as well as to measure the mesi-to-basin-scale bio-optical properties of the atlantic Ocean. The calibration and validation of remotely sensed observations of ocean colour is an inherent objective of these studies: first, by relating in situ measurements of water leaving radiance to satellite measurement, and second, by measuring the bio-optically active constituents of the water.

  10. The development of miocene extensional and short-lived basin in the Andean broken foreland: The Conglomerado Los Patos, Northwestern Argentina

    Science.gov (United States)

    del Papa, Cecilia E.; Petrinovic, Ivan A.

    2017-01-01

    The Conglomerado Los Patos is a coarse-grained clastic unit that crops out irregularly in the San Antonio de los Cobres Valley in the Puna, Northwestern Argentina. It covers different units of the Cretaceous-Paleogene Salta Group by means of an angular unconformity and, in turn, is overlaid in angular unconformity by the Viscachayoc Ignimbrite (13 ± 0.3 Ma) or by late Miocene tuffs. Three lithofacies have been identified in the Corte Blanco locality; 1) Bouldery matrix-supported conglomerate (Gmm); 2) Clast-supported conglomerate (Gch) and 3) Imbricated clast-supported conglomerate (Gci). The stratigraphic pattern displays a general fining upward trend. The sedimentary facies association suggests gravitational flow processes and sedimentation in alluvial fan settings, from proximal to medial fan positions, together with a slope decrease upsection. Provenance studies reveal sediments sourced from Precambrian to Ordovician units located to the southwest, except for volcanic clasts in the Gmm facies that shows U/Pb age of 14.5 ± 0.5 Ma. This new age represents the maximum depositional age for the Conglomerado Los Patos, and it documents that deposition took place simultaneously during a period of increased tectonic and volcanic activity in the area. The structural analysis of the San Antonio de los Cobres Valley and the available thermochronological ages, indicate active N-S main thrusts and NW-SE transpressive and locally normal faults during the middle Miocene. In this context, we interpret the Conglomerado Los Patos to represent sedimentation in a small, extensional and short-lived basin associated with the compressional Andean setting.

  11. Cambios morfológicos en el cráneo debidos a la edad en la población tardía de la Puna de Jujuy

    OpenAIRE

    Fuchs, María Laura; Cocilovo, José Alberto; Varela, Héctor Hugo

    2015-01-01

    En el presente trabajo se evalúan los cambios que experimenta la morfología craneana por el efecto de la edad en la población tardía de la Puna de Jujuy. La muestra consistió en 372 cráneos de ambos sexos, en los cuales se determinaron cinco clases de edad (infantil, juvenil, adulto, adulto maduro y senil). Se midieron 31 variables métricas y se utilizó estadística univariada para realizar el análisis. Los cambios morfológicos producidos por la edad en los individuos puneños se manifestaron e...

  12. Meridional Variation of the 1955-2003 Sea Level Anomalies in the Tropical Pacific Ocean Associated with El Ni(n)o Events

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Sea Level Anomaly-Torque (SLAT, relative to a reference location in the Pacific Ocean), which means the total torque of the gravity forces of sea waters with depths equal to the Sea Level Anomaly (SLA) in the tropical Pacific Ocean, is defined in this study. The time series of the SLAT from merged altimeter data (1993-2003) had a great meridional variation during the 1997-1998 El Ni(n)o event. By using historical upper layer temperature data (1955-2003) for the tropical Pacific Ocean, the temperature-based SLAT is also calculated and the meridional variation can be found in the historical El Ni(n)o events (1955-2003), which suggests that the meridional shifts of the sea level anomaly are also intrinsic oscillating modes of the El Ni(n)o cycles like the zonal shifts.

  13. Sr- and Nd- isotope variations along the Pleistocene San Pedro - Linzor volcanic chain, N. Chile: Tracking the influence of the upper crustal Altiplano-Puna Magma Body

    Science.gov (United States)

    Godoy, Benigno; Wörner, Gerhard; Le Roux, Petrus; de Silva, Shanaka; Parada, Miguel Ángel; Kojima, Shoji; González-Maurel, Osvaldo; Morata, Diego; Polanco, Edmundo; Martínez, Paula

    2017-07-01

    Subduction-related magmas that erupted in the Central Andes during the past 10 Ma are strongly affected by crustal assimilation as revealed by an increase in 87Sr/86Sr isotope ratios with time that in turn are correlated with increased crustal thickening during the Andean orogeny. However, contamination is not uniform and can be strongly influenced locally by crustal composition, structure and thermal condition. This appears to be the case along the NW-SE San Pedro - Linzor volcanic chain (SPLVC) in northern Chile, which straddles the boundary of a major zone of partial melt, the Altiplano_Puna Magma Body (APMB). Herein we report 40Ar/39Ar ages, compositional and isotope data on lavas from the SPLVC that track the influence of this zone of partial melting on erupted lavas with geochronological and geochemical data. Ages reported here indicate that SPLVC has evolved in the last 2 M.y., similar to other volcanoes of the Western Cordillera (e.g. Lascar, Uturuncu, Putana). 87Sr/86Sr ratios increase systematically along the chain from a minimum value of 0.7057 in San Pedro dacites to a maximum of 0.7093-0.7095 for the Toconce and Cerro de Leon dacites in the SE. These changes are interpreted to reflect the increasing interaction of SPLVC parental magmas with partial melt within the APMB eastwards across the chain. The 87Sr/86Sr ratio and an antithetic trend in 143Nd/144Nd is therefore a proxy for the contribution of melt from the APMB beneath this volcanic chain. Similar 87Sr/86Sr increases and 143Nd/144Nd decreases are observed in other transects crossing the boundary of the APMB. Such trends can be recognized from NW to SE between Aucanquilcha, Ollagüe, and Uturuncu volcanoes, and from Lascar volcano to the N-S-trending Putana-Sairecabur-Licancabur volcanic chain to the north. We interpret these isotopic trends as reflecting different degrees of interaction of mafic parental melts with the APMB. High 87Sr/86Sr, and low 143Nd/144Nd reveal zones where the APMB is

  14. Biodiversity information system of the national parks administration of Argentina

    Directory of Open Access Journals (Sweden)

    Leonidas Lizarraga

    2014-06-01

    Full Text Available Introduction The Biodiversity Information System (BIS of the National Parks Administration of Argentina (NPA was launched in 2002, with the support of the Global Environmental Fund (GEF through the Biodiversity Conservation Project in Argentina. The BIS consists of a set of thematic databases and Geographic Information System (GIS set to support management decisions, and to provide information to the general public on the national protected areas of Argentina. Currently, the BIS-NPA progr...

  15. Argentina’s Defaulted Sovereign Debt: Dealing with the Holdouts

    Science.gov (United States)

    2010-02-17

    solution that it felt was commensurate with its deeply diminished economic and social reality. Facing a huge debt burden, Argentina adopted a hard line...34Vulture Funds Lobby Against Argentina," America Latina en Movimiento , August 6, 2009. http://alainet.org/index.phtml Argentina’s Defaulted Sovereign...Service 12 responsibility can have dramatic long-term economic, social , and political consequences. At the financial level, the costs to Argentina have

  16. Explorando la intensidad de uso de las materias primas líticas en Pali Aike (provincia de Santa Cruz, Argentina Exploring the reduction intensity of lithic raw materials in Pali Aike (Santa Cruz province, Argentina

    Directory of Open Access Journals (Sweden)

    Judith Charlin

    2007-12-01

    Full Text Available El objetivo general del presente trabajo es evaluar la intensidad de uso a la que estuvieron sujetas las materias primas líticas utilizadas en la manufactura de artefactos en Pali Aike (sector meridional de la provincia de Santa Cruz, Argentina. La muestra analizada comprende artefactos tallados de formatización unifacial y/o con rastros complementarios que fueron recuperados en diversas localidades del campo volcánico con ocupaciones asignadas al Holoceno tardío. Diversas variables son consideradas como indicadores de la intensidad de uso o grado de reducción de las rocas, tales como la longitud de los artefactos al momento del descarte, el grado de fragmentación de los mismos, el porcentaje de corteza que conservan, la cantidad de filos y/o puntas formatizados y/o con rastros complementarios por artefacto, el ángulo de desgaste y la reactivación de los filos y/o puntas. Los resultados obtenidos señalan la existencia de diferencias en la explotación y aprovechamiento de las materias primas líticas en algunas de estas variables, en tanto que otras no ofrecen un comportamiento diferencial o simplemente no resultan sensitivas a estos factores.The main goal of this paper is to evaluate the intensity of human utilization of lithic raw materials in Pali Aike (southern Santa Cruz Province, Argentina. The sample includes artifacts unifacially retouched and/or with macroscopic edge-wear damage from different Late Holocene localities within Pali Aike. The variables considered include the length of the artifacts, fragmentation, amount of retouched and/or wear damaged edges and/or points by artifact, percentage of cortex, and resharpening. The results show that some variables point to differences in the intensity of exploitation of different raw materials, while others are not sensitive to this variation.

  17. Variability of the Brewer-Dobson circulation's meridional and vertical branch using Aura/MLS water vapor

    Directory of Open Access Journals (Sweden)

    T. Flury

    2012-08-01

    Full Text Available We use Aura/MLS stratospheric water vapor measurements to infer interannual variations in the speed of the Brewer-Dobson circulation (BDC from 2004 to 2011. Stratospheric water vapor (H2O is utilized as a tracer for dynamics and we follow its path along the vertical and meridional branch of the BDC from the tropics to mid-latitudes. We correlate one year time series of H2O in the lower stratosphere at two subsequent altitude levels (68 hPa, ~18.8 km and 56 hPa, ~19.9 km at the Equator and determine the time lag for best correlation. The same calculation is made on the horizontal on the 100 hPa (~16.6 km level by correlating the H2O time series at the Equator with the ones at 40° N and 40° S. From these lag coefficients we derive the vertical and horizontal speeds of the BDC in the tropics and extra-tropics respectively. We observe a clear interannual variability of the vertical and horizontal branch. The variability reflects signatures of the Quasi Biennial Oscillation (QBO. Our measurements confirm the QBO meridional circulation anomalies and show that the speed variations in the two branches of the BDC are out of phase and fairly well anti-correlated. Maximum ascent rates are found during the QBO easterly phase. We also find that the transport towards the Northern Hemisphere (NH is on the average two times faster than to the Southern Hemisphere (SH with a mean speed of 1.15 m s−1 at 100 hPa. Furthermore, the speed towards the NH shows much more variability with an amplitude of about 21% whilst the speed towards the SH varies by only 10%. An amplitude of 21% is also observed in the variability of the ascent rate at the Equator which is on the average 0.2 mm s−1 and hence about 5000 times slower than the meridional branch.

  18. La migracion internacional en Argentina hacia 2010

    Directory of Open Access Journals (Sweden)

    Laura Calvelo

    Full Text Available El artículo presenta los principales lineamientos de la migración internacional en Argentina hacia el año 2010, con detenimiento en el período 2000-2010. En el caso de la inmigración no nativa se basa en información de los censos nacionales de población 2001 y 2010. En el caso de la migración internacional de la población nativa de Argentina el análisis se sustenta en información de censos extranjeros hasta la ronda 2000 y en otras fuentes de datos de los principales países de destino hasta 2010 (Estados Unidos y España.

  19. Vaccines in Argentina: a regulatory view.

    Science.gov (United States)

    Pérez, A C; Diez, R A

    2003-07-28

    In Argentina, vaccines for immuno-preventable diseases are regulated by the national regulatory agency, the Administración Nacional de Medicamentos, Alimentos y Tecnología Médica (the National Administration of Drugs, Food and Medical Devices, or ANMAT) created in 1992 to ensure efficacy and safety of drugs, food and medical devices available in the country, according to Law 16,463 and Decree 150/92. ANMAT has licensed 84 out of 157 vaccines registered in Argentina. Since 1994, ANMAT evaluated, approved and inspected 20 clinical trials with vaccines (1.8% of the 1062 trials approved by the agency since that time). The National System of Pharmaco-vigilance has received 318 communications of eventual adverse post-vaccination events (0.3% of the total). In addition, ANMAT provides support to the National Immunisation Programme. The current procedure is to follow international guidelines in the field, to be prepared for new, rapidly changing scenarios.

  20. Guerra, relaciones de producción y economía en la Galia meridional post-romana

    Directory of Open Access Journals (Sweden)

    Pablo Sarachu

    2012-03-01

    Full Text Available La guerra fue un fenómeno generalizado en la Galia meridional durante el siglo VI. Su omnipresencia estuvo alimentada en buena medida por la naturaleza de la dinámica política de los reinos, por la forma de interacción entre reyes y aristócratas. En el presente trabajo se analiza su influencia sobre las relaciones sociales de producción y la economía de la región. Concretamente, se argumenta que la guerra favoreció la inestabilidad de los vínculos de dependencia y –consecuentemente– la contracción económica que caracterizaron el periodo

  1. Effects of Wind and Freshwater on the Atlantic Meridional Overturning Circulation: Role of Sea Ice and Vertical Diffusion

    Science.gov (United States)

    Wang, Kun; Yang, Haijun; Dai, Haijin; Wang, Yuxing; Li, Qing

    2015-04-01

    Effects of wind and fresh water on the Atlantic meridional overturning circulation (AMOC) are investigated in a fully coupled climate model (CESM1.0). The AMOC can change significantly when perturbing either the wind stress or fresh water flux in the northern North Atlantic. This work pays special attention on the wind stress effect. Our model results show that the wind forcing is a crucial element in maintaining the AMOC. When the wind-stress is reduced, the vertical convection and diffusion are weakened immediately, triggering a salt deficit in the northern North Atlantic that prevents the deep water formation there. The salinity advection from the south, however, plays a contrary role to salt the upper ocean. As the AMOC weakens, the sea ice expends southward and melts, freshening the upper ocean that weakens the AMOC further. There is a positive feedback between the sea ice melting and AMOC strength, which eventually determines the AMOC strength in the reduced wind world.

  2. Prospects for Corn Ethanol in Argentina

    OpenAIRE

    Bruce A. Babcock; Miguel Carriquiry

    2012-01-01

    Countries that export biofuel feedstocks such as grain or sugar and that are also importers of motor fuels will have a natural competitive advantage over other countries in the production of biofuels. Argentina is one of a very few countries that both export potential feedstocks and import gasoline and diesel. This combination means that an Argentine ethanol plant will pay less for feedstock and receive a higher price for ethanol than an ethanol plant located in a country that imports feedsto...

  3. Investment in Renewable Energies in Argentina

    Directory of Open Access Journals (Sweden)

    Marina Recalde

    2017-05-01

    Full Text Available This article analyzes how the enabling conditions of the energy policy of a developing country such as Argentina, are crucial for the deployment of renewable energy investments. The conclusions highlights that the low institutional quality of the country shapes enabling conditions and reduce effect of the instruments of the energy policy, dropping incentives for investment in renewable technologies in the country. Therefore, in order to promote renewable technologies investments efficiently, the institutional framework of countries must be seriously improved.

  4. Journalism studies in Argentina: background and questions

    OpenAIRE

    Adriana Amado; Natalia Pizzolo

    2014-01-01

    This article summarizes the background of empirical journalism studies in Argentina.  In recent publications, researchers have consistently underscored the lack of data on the profession and the scarce development of theoretical frameworks related to journalism studies.  The local investigations have prioritized approaches and methods that do not give the whole picture of the population of journalists. Most of the research tends to equate media analysis and media messages with journalism stud...

  5. SMEs in Argentina: Who are the Exporters?

    OpenAIRE

    Ottaviano, Gianmarco I.P.; Martincus, Christian Volpe

    2009-01-01

    There exists a growing body of literature which looks at export decisions made by firms. Most studies focus on developed countries and do not explore whether different behavioral patterns prevail over the firm size distribution. This paper aims at filling this gap in the literature by analyzing the export behavior of a statistically representative sample of 192 Small and Medium-Size Enterprises (SMEs) in a developing country, Argentina, over the period 1996-1998. We find that the level of emp...

  6. Argentina: Background and U.S. Relations

    Science.gov (United States)

    2016-09-06

    Congressional Research Service Summary Argentina, a South American country with a population of almost 43 million, has had a vibrant democratic tradition...but the country also has a diversified industrial base and a highly educated population . In 2001-2002, a severe economic crisis precipitated by...characterized by robust commercial relations and cooperation in such issues as nonproliferation, human rights, education, and science and technology. Under

  7. ZANTHOXYLUM ARMATUM (RUTACEAE, SU PRESENCIA EN ARGENTINA

    Directory of Open Access Journals (Sweden)

    Marcelo D. Arana

    2009-01-01

    Full Text Available Se cita por primera vez a Zanthoxylum armatum var. armatum como especie asilvestrada para la flora argentina, en la provincia de Córdoba. Se presenta una descripción sobre la base de los ejemplares examinados, ilustraciones, mapa de distribución y observaciones ecológicas, como así también las diferencias con taxones similares.

  8. La izquierda Argentina: nuevamente el fracaso

    Directory of Open Access Journals (Sweden)

    Ángel Rodríguez Kauth

    2004-01-01

    Full Text Available A partir de los acontecimientos políticos y sociales ocurridos en Argentina desde finales de 2001, se estudia el papel protagónico que tuvieron las diversas organizaciones en que se ha atomizado la izquierda vernácula. Esto es no sólo en el plano electoral, sino también en el de las movilizaciones junto a la participación popular que reclamaba su presencia.

  9. Sunflower crop in Argentina to date

    OpenAIRE

    Vasquez A.; de Romano A.

    2006-01-01

    Inside a panorama of a spectacular grain production in the last 10 years in Argentina, sunflower crop participates with an annual production of more than 3,500,000 t. During that period, many advances were made in the improvement of diseases resistance: Verticillium wilt, downy mildew and head rot. Also oil yield per hectare continued to increase. The new hybrids have new qualities, for example imidazolinones resistance, which allows farmers to keep yields, although the soils destined to sunf...

  10. MASTER: 2 OT discovered in Argentina

    Science.gov (United States)

    Shumkov, V.; Pogrosheva, T.; Lipunov, V.; Podesta, R.; Levato, H.; Gorbovskoy, E.; Tiurina, N.; Balanutsa, P.; Kuznetsov, A.; Vladimirov, V.; Gress, O.; Ivanov, K.; Chazov, V.; Lopez, C.; Podesta, F.; Saffe, C.

    2016-10-01

    MASTER-OAFA, located in Argentina, with auto-detection system (Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L) discovered OT source at (RA, Dec) = 03h 19m 42.92s -45d 30m 13.9s on 2016-10-27.27597 UT. The OT unfiltered magnitude is 16.9m (mlim=20.8m).

  11. en Argentina en el Siglo XIX

    Directory of Open Access Journals (Sweden)

    Alicia Itatí Palermo

    2005-01-01

    Full Text Available The process of women accessing the university studies level was given in the midst of a debate regarding education for women and their capacity for knowledge. In this article we describe and interpret the access of women to the Unive sity in Argentina in the Nineteenth century, in a context full of debates about education for women and their capacity for knowledge.

  12. Tierra del Fuego, Argentina, South America

    Science.gov (United States)

    1991-01-01

    The Mitre Peninsula is the easternmost tip of Tierra del Fuego, Argentina, (54.5S, 65.5W). Early winter snow can be seen on this south tip of the Andes Mountains. These same mountains continue underwater to Antarctica. The Strait of Magellan, separating the South American mainland from Tierra del Fuego is off the scene to the north and west, but the Strait of LeMaire, separating Tierra del Fuego from the Isla de los Estados can be seen.

  13. Andes Altiplano, Northwest Argentina, South America

    Science.gov (United States)

    1993-01-01

    This view of the Andes Altiplano in northwest Argentina (25.5S, 68.0W) is dominated by heavily eroded older and inactive volcano peaks. The altiplano is a high altitude cold desert like the Tibetan Plateau but smaller in area. It is an inland extension of the hyperarid Atacama Desert of the west coast of South America and includes hundreds of volcanic edifices (peaks, cinder cones, lava flows, debris fields, lakes and dry lake beds (salars).

  14. Data Assimilation in a Solar Dynamo Model Using Ensemble Kalman Filters: Sensitivity and Robustness in Reconstruction of Meridional Flow Speed

    Science.gov (United States)

    Dikpati, Mausumi; Anderson, Jeffrey L.; Mitra, Dhrubaditya

    2016-09-01

    We implement an Ensemble Kalman Filter procedure using the Data Assimilation Research Testbed for assimilating “synthetic” meridional flow-speed data in a Babcock-Leighton-type flux-transport solar dynamo model. By performing several “observing system simulation experiments,” we reconstruct time variation in meridional flow speed and analyze sensitivity and robustness of reconstruction. Using 192 ensemble members including 10 observations, each with 4% error, we find that flow speed is reconstructed best if observations of near-surface poloidal fields from low latitudes and tachocline toroidal fields from midlatitudes are assimilated. If observations include a mixture of poloidal and toroidal fields from different latitude locations, reconstruction is reasonably good for ≤slant 40 % error in low-latitude data, even if observational error in polar region data becomes 200%, but deteriorates when observational error increases in low- and midlatitude data. Solar polar region observations are known to contain larger errors than those in low latitudes; our forward operator (a flux-transport dynamo model here) can sustain larger errors in polar region data, but is more sensitive to errors in low-latitude data. An optimal reconstruction is obtained if an assimilation interval of 15 days is used; 10- and 20-day assimilation intervals also give reasonably good results. Assimilation intervals \\lt 5 days do not produce faithful reconstructions of flow speed, because the system requires a minimum time to develop dynamics to respond to flow variations. Reconstruction also deteriorates if an assimilation interval \\gt 45 days is used, because the system’s inherent memory interferes with its short-term dynamics during a substantially long run without updating.

  15. Inter-comparison of stratospheric mean-meridional circulation and eddy mixing among six reanalysis data sets

    Science.gov (United States)

    Miyazaki, Kazuyuki; Iwasaki, Toshiki; Kawatani, Yoshio; Kobayashi, Chiaki; Sugawara, Satoshi; Hegglin, Michaela I.

    2016-05-01

    The stratospheric mean-meridional circulation (MMC) and eddy mixing are compared among six meteorological reanalysis data sets: NCEP-NCAR, NCEP-CFSR, ERA-40, ERA-Interim, JRA-25, and JRA-55 for the period 1979-2012. The reanalysis data sets produced using advanced systems (i.e., NCEP-CFSR, ERA-Interim, and JRA-55) generally reveal a weaker MMC in the Northern Hemisphere (NH) compared with those produced using older systems (i.e., NCEP/NCAR, ERA-40, and JRA-25). The mean mixing strength differs largely among the data products. In the NH lower stratosphere, the contribution of planetary-scale mixing is larger in the new data sets than in the old data sets, whereas that of small-scale mixing is weaker in the new data sets. Conventional data assimilation techniques introduce analysis increments without maintaining physical balance, which may have caused an overly strong MMC and spurious small-scale eddies in the old data sets. At the NH mid-latitudes, only ERA-Interim reveals a weakening MMC trend in the deep branch of the Brewer-Dobson circulation (BDC). The relative importance of the eddy mixing compared with the mean-meridional transport in the subtropical lower stratosphere shows increasing trends in ERA-Interim and JRA-55; this together with the weakened MMC in the deep branch may imply an increasing age-of-air (AoA) in the NH middle stratosphere in ERA-Interim. Overall, discrepancies between the different variables and trends therein as derived from the different reanalyses are still relatively large, suggesting that more investments in these products are needed in order to obtain a consolidated picture of observed changes in the BDC and the mechanisms that drive them.

  16. The 20th Century evolution of energy budgets and meridional transports in two AMIP-like experiments

    Science.gov (United States)

    Lembo, Valerio; Folini, Doris; Wild, Martin; Lionello, Piero

    2016-04-01

    The 20th century evolution and spatial patterns of the Top-of-Atmosphere (TOA), atmospheric, and surface energy budgets (EB) are investigated in this work. These are computed as the balance between the radiative and heat fluxes at the TOA and at the surface. Total, atmospheric and oceanic meridional energy transports are computed from the EBs. Two AMIP-like ensemble simulations are considered: Integrated Forecast System (IFS) simulations of the ERA-20CM experiment, and ECHAM5-HAM model simulations. With the latter, additional sensitivity experiments are carried out by constraining either Sea-Surface Temperatures (SST) and Sea-Ice Cover (SIC) or aerosol concentrations to climatological values. The recent decades estimates of the EB are in reasonable agreement in the two models, while they are not for what concerns the global scale evolution. Particularly, in the 1970s ERA-20CM shows a fast transition from negative to positive EBs at Top of Atmosphere (TOA) that is not found in ECHAM5-HAM. The impact of aerosols, as evidenced by the sensitivity experiments with ECHAM5-HAM, is seen to set up an inter-hemispheric gradient in the TOA and surface budget after 1960. This is also reflected by an increased total poleward transport in the Northern Hemisphere and decreased in the Southern Hemisphere. This feature is not found in ERA-20CM. SST variations do not seem to induce long-term variations in the patterns of TOA budget and related total meridional transport. Nevertheless most of the surface and atmospheric budget and transport inter-annual variability is attributable to the evolution of SST, and much more agreement is observed among the two models in this respect. Reference: Lembo V, Doris F, Martin W, and Lionello P (2015) Energy budgets and transports: global evolution and spatial patterns during the 20th Century as estimated in two AMIP-like experiments, Clim. Dyn., subm.

  17. Acute Intermittent Porphyria in Argentina: An Update

    Directory of Open Access Journals (Sweden)

    Gabriela Nora Cerbino

    2015-01-01

    Full Text Available Porphyrias are a group of metabolic diseases that arise from deficiencies in the heme biosynthetic pathway. A partial deficiency in hydroxymethylbilane synthase (HMBS produces a hepatic disorder named Acute Intermittent Porphyria (AIP; the acute porphyria is more frequent in Argentina. In this paper we review the results obtained for 101 Argentinean AIP families and 6 AIP families from foreign neighbour countries studied at molecular level at Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP. Thirty-five different mutations were found, of which 14 were described for the first time in our population. The most prevalent type of mutations was the missense mutations (43% followed by splice defects (26% and small deletions (20%. An odd case of a double heterozygous presentation of AIP in a foreign family from Paraguay is discussed. Moreover, it can be noted that 38 new families were found carrying the most frequent mutation in Argentina (p.G111R, increasing to 55.66% the prevalence of this genetic change in our population and adding further support to our previous hypothesis of a founder effect for this mutation in Argentina. Identification of patients with an overt AIP is important because treatment depends on an accurate diagnosis, but more critical is the identification of asymptomatic relatives to avoid acute attacks which may progress to death.

  18. Argentina: Nuclear power development and Atucha 2

    Energy Technology Data Exchange (ETDEWEB)

    Nogarin, Mauro

    2015-08-15

    In 2014, nuclear energy generated about 5,257 GWh of electricity or a total share of 4.05 % of the total electrical energy of about 129,747.63 GWh kWh produced in Argentina and there has been a trend for this production to increase. Argentina currently has a nuclear production capacity of 1,010 megawatts of electrical energy. However, when the Atucha 2 nuclear power plant is completed and starts commercial operation, it will add 745 megawatts to this electrical production capacity. There are two sites with nuclear power plants in Argentina: Atucha and Embalse. The Embalse nuclear power plant went into operation in 1984. At the Atucha site, the Atucha-1 nuclear power plant started operation in 1974. It was the first nuclear power plant in Latin America. Construction of Atucha-2 started in 1981 but advanced slowly due to funding and was suspended in 1994 when the plant was 81 % built. In 2003, new plans were approved to complete the Atucha 2. I summer 2014 the plant went critical for the first time. The construction was completed under a contract with AECL.

  19. The Case of Argentina, 1993-2000

    Directory of Open Access Journals (Sweden)

    Mario Tonveronachi

    2006-01-01

    Full Text Available El consenso sobre los beneficios netos de la presencia de bancos extranjeros en los países emergentes parece en alguna medida debilitarse a raíz de la experiencia de los años noventa, que constituye una fase de fuerte expansión y fortalecimiento de dicha presencia. Distinguiendo entre la presencia y la dominancia en el mercado local por parte de los bancos extranjeros, el presente trabajo analiza la experiencia argentina en el período 1993-2000. Para este fin, se reconstruyo por primera vez la serie completa de los balances bancarios. Los resultados sugieren que la aumentada presencia de bancos extranjeros no ha producido beneficios significativos, mientras que todo el sistema bancario se ha aventajado por el clima de mayor crecimiento y de estabilidad monetaria. Como parte de la estrategia perseguida por parte del poder público, la creciente dominancia de los bancos extranjeros resulta uno de los factores que han empobrecido la biodiversidad de la banca argentina. De todos modos, parte de los problemas que atormentaron a la economía argentina en los años noventa podrían ser considerados más como el resultado de la adopción de una abertura financiera completa que como consecuencia de la dominancia creciente por parte de los bancos extranjeros.

  20. Corrigendum to "Deep water provenance and dynamics of the (de)glacial Atlantic meridional overturning circulation" [Earth Planet. Sci. Lett. 445 (2016) 68-78

    Science.gov (United States)

    Lippold, Jörg; Gutjahr, Marcus; Blaser, Patrick; Christner, Emanuel; de Carvalho Ferreira, Maria Luiza; Mulitza, Stefan; Christl, Marcus; Wombacher, Frank; Böhm, Evelyn; Antz, Benny; Cartapanis, Olivier; Vogel, Hendrik; Jaccard, Samuel L.

    2017-01-01

    We have reconstructed past modes of the Atlantic Meridional Overturning Circulation (AMOC) by combining two sedimentary proxies, Nd isotopes (εNd) and the 231Pa/230Th ratio over the last deglaciation. Combined down-core 231Pa/230Th and εNd records from six Atlantic Ocean sediment archives are presented (Lippold et al., 2016).

  1. Southern Argentina Agile Meteor Radar: Initial assessment of gravity wave momentum fluxes

    Science.gov (United States)

    Fritts, D. C.; Janches, D.; Hocking, W. K.

    2010-10-01

    The Southern Argentina Agile Meteor Radar (SAAMER) was installed on Tierra del Fuego (53.8°S) in May 2008 and has been operational since that time. This paper describes tests of the SAAMER ability to measure gravity wave momentum fluxes and applications of this capability during different seasons. Test results for specified mean, tidal, and gravity wavefields, including tidal amplitudes and gravity wave momentum fluxes varying strongly with altitude and/or time, suggest that the distribution of meteors throughout the diurnal cycle and averaged over a month allows characterization of both monthly mean profiles and diurnal variations of the gravity wave momentum fluxes. Applications of the same methods for real data suggest confidence in the monthly mean profiles and the composite day diurnal variations of gravity wave momentum fluxes at altitudes where meteor counts are sufficient to yield good statistical fits to the data. Monthly mean zonal winds and gravity wave momentum fluxes exhibit anticorrelations consistent with those seen at other midlatitude and high-latitude radars during austral spring and summer, when no strong local gravity wave sources are apparent. When stratospheric variances are significantly enhanced over the Drake Passage “hot spot” during austral winter, however, MLT winds and momentum fluxes over SAAMER exhibit very different correlations that suggest that MLT dynamics are strongly influenced by strong local gravity wave sources within this “hot spot.” SAAMER measurements of mean zonal and meridional winds at these times and their differences from measurements at a conjugate site provide further support for the unusual momentum flux measurements.

  2. Intercultural Citizenship Education in an EFL Online Project in Argentina

    Science.gov (United States)

    Porto, Melina

    2014-01-01

    In this article, I describe an online intercultural citizenship experience in an English as a Foreign Language (EFL) classroom in Argentina. An action research project on the Malvinas/Falklands war fought between Argentina and the UK in 1982 was carried out in 2012. Through a comparative methodology involving Argentine and English foreign language…

  3. International Reports on Literacy Research: Argentina, Mexico, France

    Science.gov (United States)

    Malloy, Jacquelynn A., Comp.; Mallozzi, Christine, Comp.

    2007-01-01

    This is a compilation of reports on international literacy research. The report includes 3 separate reports on Argentina, Mexico, and France. In the first report, Melina Porto reports on a new implementation of a teacher-education program currently underway in the province of Buenos Aires, Argentina, under the leadership of teacher-researcher…

  4. Pro-Market Educational Governance: Is Argentina a Black Swan?

    Science.gov (United States)

    Beech, Jason; Barrenechea, Ignacio

    2011-01-01

    In this article we explore ways in which pro-market discourses have been interpreted in policy initiatives in Argentina since the 1970s. Our argument is that even though pro-market discourses have guided reforms in many aspects of public policies in Argentina, the arena of education has overall been resistant to taking them up. The first part of…

  5. Prospect for Development of Open Access in Argentina

    Science.gov (United States)

    Miguel, Sandra; Bongiovani, Paola C.; Gomez, Nancy D.; Bueno-de-la-Fuente, Gema

    2013-01-01

    This perspective article presents an overview of the Open Access movement in Argentina, from a global and regional (Latin American) context. The article describes the evolution and current state of initiatives by examining two principal approaches to Open Access in Argentina: "golden" and "green roads". The article will then…

  6. Overview of activities on CANDU fuel in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, L.; Valesi, J., E-mail: lalvarez@cnea.gov.ar [National Commission on Atomic Energy, Fuel Engineering Department (Argentina)

    2013-07-01

    This paper gives an outline of activities on CANDU fuel in Argentina. It discusses the nuclear activities and electricity production in Argentina, evolution of the activities in fuel engineering, fuel fabrication, fuel performance at Embalse nuclear power plant and spent fuel storage options.

  7. 78 FR 47006 - Lemon Juice From Argentina and Mexico

    Science.gov (United States)

    2013-08-02

    ... COMMISSION Lemon Juice From Argentina and Mexico Determination On the basis of the record \\1\\ developed in... investigation on lemon juice from Mexico would not be likely to lead to continuation or recurrence of material... USITC Publication 4418 (July 2013), entitled Lemon Juice from Argentina and Mexico: Investigation...

  8. 78 FR 46610 - Lemon Juice From Argentina and Mexico

    Science.gov (United States)

    2013-08-01

    ... COMMISSION Lemon Juice From Argentina and Mexico Determination On the basis of the record \\1\\ developed in... investigation on lemon juice from Mexico would not be likely to lead to continuation or recurrence of material... USITC Publication 4418 (July 2013), entitled Lemon Juice from Argentina and Mexico: Investigation...

  9. Computing and Education in Argentina, Uruguay and Paraguay.

    Science.gov (United States)

    Sadowsky, Manuel

    Although the report is specifically about Argentina, Uruguay and Paraguay, the considerations presented are valid for all of Latin America. In September, 1969, Argentina had approximately 200 electronic computers. The annual growth is estimated at 15-20% and the implementation of teleprocessing and time-sharing systems have made evident the…

  10. Intercultural Citizenship Education in an EFL Online Project in Argentina

    Science.gov (United States)

    Porto, Melina

    2014-01-01

    In this article, I describe an online intercultural citizenship experience in an English as a Foreign Language (EFL) classroom in Argentina. An action research project on the Malvinas/Falklands war fought between Argentina and the UK in 1982 was carried out in 2012. Through a comparative methodology involving Argentine and English foreign language…

  11. Pro-Market Educational Governance: Is Argentina a Black Swan?

    Science.gov (United States)

    Beech, Jason; Barrenechea, Ignacio

    2011-01-01

    In this article we explore ways in which pro-market discourses have been interpreted in policy initiatives in Argentina since the 1970s. Our argument is that even though pro-market discourses have guided reforms in many aspects of public policies in Argentina, the arena of education has overall been resistant to taking them up. The first part of…

  12. Prospect for Development of Open Access in Argentina

    Science.gov (United States)

    Miguel, Sandra; Bongiovani, Paola C.; Gomez, Nancy D.; Bueno-de-la-Fuente, Gema

    2013-01-01

    This perspective article presents an overview of the Open Access movement in Argentina, from a global and regional (Latin American) context. The article describes the evolution and current state of initiatives by examining two principal approaches to Open Access in Argentina: "golden" and "green roads". The article will then…

  13. Argentina Imp Anti-dumping Duties on Tires from China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    On June 22, Argentina made the final anti-dumping adjudication once tires from China; on July 6, the Argentina authorities released the No. 221 resolution in 2011 issued by the Ministry of Industry: Impose 23% anti-dumping duties off estate car tires, 10% on the tires of machinery or vehicles used for agriculture and forestation,

  14. Argentina v globalizačních procesech

    OpenAIRE

    Chervets, Tamara

    2009-01-01

    The process of globalization is a very important issue these days. This work will describe the process of globalization in Argentina, especially its economic aspect (foreign direct investments, export and import of goods and services, migration of labor force). I will also mention the history of its development and Argentina's membership in most important international and regional organizations.

  15. 75 FR 23674 - Honey from Argentina: Final Results of Antidumping Duty Administrative Review and Determination...

    Science.gov (United States)

    2010-05-04

    ... International Trade Administration A-357-812 Honey from Argentina: Final Results of Antidumping Duty... antidumping duty order on honey from Argentina. See Honey from Argentina: Preliminary Results of Antidumping... preliminary results of the administrative review of the antidumping duty order on honey from Argentina for...

  16. Evidencias bioarqueológicas en patagonia meridional: el sitio Orejas de Burro 1 (Pali Aike, provincia de Santa Cruz Bioarchaeological Evidence In Meridional Patagonia: The Orejas De Burro 1 Site (Pali Aike, Santa Cruz Province

    Directory of Open Access Journals (Sweden)

    Gabriela L. L'Heureux

    2008-12-01

    Full Text Available En este trabajo se presentan los resultados de las excavaciones realizadas recientemente en el sitio Orejas de Burro 1, localizado en el campo volcánico Pali Aike, provincia de Santa Cruz, Argentina. En el mismo se recuperó un entierro humano compuesto por cinco individuos de diferentes edades depositados en un único evento de inhumación. La información desarrollada incluye datos estratigráficos, contextuales, bioarqueológicos e isotópicos, que contribuyen a la evaluación de temas mortuorios y biogeográficos discutidos en el Proyecto Magallania.The results from recent excavations at the Orejas de Burro 1 site (Santa Cruz Province, Argentina are presented in this paper. A human burial was recovered with the remains of five individuals from different age groups that were deposited simultaneously. Stratigraphic, contextual, bioarchaeological, and isotopic data are provided. This data contributes to discussions of mortuary behavior and human biogeography currently being developed within the Magallania Project.

  17. La familia Cyatheaceae (Pteridophyta en Argentina The family Cyatheaceae (Pteridophyta in Argentina

    Directory of Open Access Journals (Sweden)

    Gonzalo J Marquez

    2010-06-01

    Full Text Available La familia Cyatheaceae comprende alrededor de 500 especies de helechos arborescentes. Su distribución es pantropical y en Argentina se encuentra representada por 4 especies, reunidas en los géneros Alsophila y Cyathea: A. setosa, A. odonelliana, C. atrovirens y C. delgadii. En este trabajo se presenta una actualización de la información disponible hasta el momento referente a estas especies. Se exponen microfotografías de las esporas, que presentan la superficie con lomos en Alsophila y con cordones en Cyathea. Se ilustran los indusios y escamas de la base de los pecíolos, que son de importancia fundamental para la diferenciación de las especies estudiadas. Asimismo se presenta un mapa de distribución y una clave de las especies que crecen en Argentina.The family Cyatheaceae comprises about 500 species of tree ferns. Their distribution is pantropical and in Argentina is represented by four species, grouped in genera Alsophila y Cyathea: A. setosa, A. odonelliana, C. atrovirens and C. delgadii. In this paper, an update of the available information of the mentioned species is presented. A key to diferentiate the species growing in Argentina, their descriptions and a distribution map are also given. Spores are ridged in Alsophila and with rodlets in Cyathea. Indusia and scales of petiole basis are also illustrated.

  18. Bibliografia Bibliotecologica Argentina [Hasta 1967] (A Bibliography of Library Science in Argentina [to 1967]).

    Science.gov (United States)

    Matijevic, Nicolas, Comp.

    A guide to library services, management, and organization is offered to professionals in this comprehensive bibliography, written in Spanish, of approximately 2500 items. Published by the Universidad Nacional del Sur (The National University of the South) in Bahia Blanca, Argentina, the list covers books, articles, monographs, manuals, catalogs,…

  19. Cadenas productivas y disponibilidad de alimentos en Argentina Productive chains and food availability in Argentina

    Directory of Open Access Journals (Sweden)

    Malena Giai

    2010-06-01

    Full Text Available En abril de 2009 se conformó en la Asociación Argentina de Dietistas y Nutricionistas Dietistas el Grupo de Estudio sobre Soberanía Alimentaria, constituido por un grupo de Licenciados en Nutrición con interés en el tema. Como primer objetivo, el Grupo se propuso estudiar tres temas: "el Derecho a la Alimentación", "la Producción y Disponibilidad de alimentos en Argentina" y "la Canasta Básica de Alimentos". En el presente artículo se expone un resumen de los avances en el segundo tema mencionado.In April 2009, was formed in the Argentina Association of Dieticians and Nutritionists Dietitians the Study Group on Food Sovereignty, established by a group of graduates in nutrition with interest in the subject. As a first objective, the Group was to examine three issues: "The Right to Food", "Production and Availability of food in Argentina" and "Basic Food Basket." This article is a summary of progress on the second topic mentioned.

  20. Long term monitoring system integrated in an elevational gradient in NW Argentina

    Science.gov (United States)

    Carilla, J.; Malizia, A.; Osinaga, O.; Blundo, C.; Grau, R.; Malizia, L.; Aráoz, E.

    2013-05-01

    Ecological trends and ranges of variability are poorly known in the tropical and subtropical Andes. Long term studies are powerful tools to detect the response of vegetation dynamics, biodiversity and hydrological cycle to these trends. We present a long term monitoring system in NW Argentinean mountains, including forest permanent plots at different elevations and high elevation grasslands, encompassing more than 3.000 m elevation range. Long term studies include: 1) 66 ha of mountain forest permanent plots along the Yungas elevational gradient from c. 400 to 2500 masl , and latitudinal gradient (22-28S) with 45 plots in mature forests and 28 in secondary forests originated in grazing, agriculture and selective logging. Some of these permanent plots have achieved 20 years of monitoring and all of them are included in the "Red de Bosques Andinos" a network created recently, together with c. 10 institutions and more than 130 (c. 120 ha) forest permanent plots from Argentina to Colombia Andes. 2) Two GLORIA (Global Observation Research Initiative in Alpine Environments) sites, above 4000 masl with more than 170 species recorded, including one re-measurement. This system is included in GLORIA network (www.gloria.ac.at) and in GLORIA Andes (http://www.condesan.org/gloria), and 3) more than 15 satellite monitored high Andean lakes and a wide extension of vegas (75800 ha in Argentinean puna). A digital database is being implemented to organize and provide access to the information generated by these three systems coordinated by the Instituto de Ecología Regional (http://www.iecologia.com.ar). These monitoring data are analyzed together with instrumental and dendrochronological data to describe the dynamics of these ecosystems over an area of 20 million hectares distributed between 22 and 28°S. Some of the most significant results to date include: 1) secondary mountain forests are expanding over grasslands and agriculture lands, and tend to converge toward mature forest

  1. Tobacco industry targeting youth in Argentina

    Science.gov (United States)

    Braun, S; Mejia, R; Ling, P M; Pérez-Stable, E J

    2013-01-01

    Background/aim Argentina has one of the highest cigarette smoking rates among both men and women in the Americas and no legislated restrictions on tobacco industry advertising. The tobacco industry has traditionally expanded markets by targeting adolescents and young adults. The objective of this study was to determine whether and how the tobacco industry promotes cigarettes to adolescents in Argentina. Methods We conducted a systematic search of tobacco industry documents available through the internet dated between 1995 and 2004 using standard search terms to identify marketing strategies in Argentina. A selected review of the four leading newspapers and nine magazines with reported high readership among adolescents was completed. The selected print media were searched for tobacco images and these were classified as advertisements if associated with a commercial product or as a story if not. Results The tobacco industry used market segmentation as a strategy to target Argentinean consumers. British American Tobacco (BAT) undertook a young adult psychographic study and classified them as “progressives”, “Jurassics” or “conservatives” and “crudos” or “spoiled brats”. BAT marketed Lucky Strike to the “progressives” using Hollywood movies as a vehicle. The tobacco industry also targeted their national brands to the conservatives and linked these brands with “nationalistic values” in advertising campaigns. Philip Morris promoted Marlboro by sponsoring activities directed at young people and they launched the 10 cigarettes packet as a starter vehicle. Conclusions The tobacco industry used psychographic segmentation of the population and developed advertising strategies focused on youth. Tobacco control researchers and advocates must be able to address these strategies in counter-marketing interventions. PMID:18299308

  2. Surface mapping, organic matter and water stocks in peatlands of the Serra do Espinhaço meridional - Brazil

    Directory of Open Access Journals (Sweden)

    Márcio Luiz da Silva

    2013-10-01

    Full Text Available Peatlands are soil environments that store carbon and large amounts of water, due to their composition (90 % water, low hydraulic conductivity and a sponge-like behavior. It is estimated that peat bogs cover approximately 4.2 % of the Earth's surface and stock 28.4 % of the soil carbon of the planet. Approximately 612 000 ha of peatlands have been mapped in Brazil, but the peat bogs in the Serra do Espinhaço Meridional (SdEM were not included. The objective of this study was to map the peat bogs of the northern part of the SdEM and estimate the organic matter pools and water volume they stock. The peat bogs were pre-identified and mapped by GIS and remote sensing techniques, using ArcGIS 9.3, ENVI 4.5 and GPS Track Maker Pro software and the maps validated in the field. Six peat bogs were mapped in detail (1:20,000 and 1:5,000 by transects spaced 100 m and each transect were determined every 20 m, the UTM (Universal Transverse Mercator coordinates, depth and samples collected for characterization and determination of organic matter, according to the Brazilian System of Soil Classification. In the northern part of SdEM, 14,287.55 ha of peatlands were mapped, distributed over 1,180,109 ha, representing 1.2 % of the total area. These peatlands have an average volume of 170,021,845.00 m³ and stock 6,120,167 t (428.36 t ha-1 of organic matter and 142,138,262 m³ (9,948 m³ ha-1 of water. In the peat bogs of the Serra do Espinhaço Meridional, advanced stages of decomposing (sapric organic matter predominate, followed by the intermediate stage (hemic. The vertical growth rate of the peatlands ranged between 0.04 and 0.43 mm year-1, while the carbon accumulation rate varied between 6.59 and 37.66 g m-2 year-1. The peat bogs of the SdEM contain the headwaters of important water bodies in the basins of the Jequitinhonha and San Francisco Rivers and store large amounts of organic carbon and water, which is the reason why the protection and preservation

  3. Meridional circulation across the Antarctic Circumpolar Current serves as a double 231Pa and 230Th trap

    Science.gov (United States)

    Rutgers van der Loeff, Michiel; Venchiarutti, Celia; Stimac, Ingrid; van Ooijen, Jan; Huhn, Oliver; Rohardt, Gerd; Strass, Volker

    2016-12-01

    Upwelling of Circumpolar Deep Water in the Weddell Gyre and low scavenging rates south of the Antarctic Circumpolar Current (ACC) cause an accumulation of particle reactive nuclides in the Weddell Gyre. A ventilation/reversible scavenging model that successfully described the accumulation of 230Th in this area was tested with other particle reactive nuclides and failed to adequately describe the depth-distributions of 231Pa and 210Pb. We present here a modified model that includes a nutrient-like accumulation south of the Antarctic Polar Front in an upper meridional circulation cell, as well as transport to a deep circulation cell in the Weddell Gyre by scavenging and subsequent release at depth. The model also explains depletion of 231Pa and 230Th in Weddell Sea Bottom Water (WSBW) by ventilation of newly formed deep water on a timescale of 10 years, but this water mass is too dense to leave the Weddell Gyre. In order to quantify the processes responsible for the 231Pa- and 230Th-composition of newly formed Antarctic Bottom Water (AABW) we present a mass balance of 231Pa and 230Th in the Atlantic sector of the Southern Ocean based on new data from the GEOTRACES program. The ACC receives 6.0 ± 1.5 ×106 dpms-1 of 230Th from the Weddell Sea, similar in magnitude to the net input of 4.2 ± 3.0 ×106 dpms-1 from the north. For 231Pa, the relative contribution from the Weddell Sea is much smaller, only 0.3 ± 0.1 ×106, compared to 2.7 ± 1.4 ×106 dpms-1 from the north. Weddell Sea Deep Water (WSDW) leaving the Weddell Gyre northward to form AABW is exposed in the ACC to resuspended opal-rich sediments that act as efficient scavengers with a Th/Pa fractionation factor F ≤ 1. Hydrothermal inputs may provide additional removal with low F. Scavenging in the full meridional circulation across the opal-rich ACC thus acts as a double 231Pa and 230Th trap that preconditions newly formed AABW.

  4. Sexual Politics and Religious Actors in Argentina

    Directory of Open Access Journals (Sweden)

    Mario Pecheny

    2016-12-01

    Full Text Available This article examines the role of religious actors in sexual politics in Argentina. Sexual politics has become a critical battlefield when it comes to the role of religion in the Argentinean liberal-democratic regime, while gender and sexuality have been the main political targets of religious institutions since the 1980s and 1990s. In this context, progressive legislation on gender, sexual, and reproductive rights was passed, including same-sex marriage and the recognition of transgender identities, despite the opposition of the Catholic Church. Paradoxically, abortion remains largely illegal, allowed only in exceptional circumstances.

  5. Taxes and landowners in Argentina: an overview

    OpenAIRE

    Sánchez Román, José Antonio

    2014-01-01

    En este artículo se ofrece un balance de lo que sabemos –y de lo que aún desconocemos- sobre la historia de la relación entre los impuestos y los productores rurales en la Argentina contemporánea. Se lleva a cabo un recorrido por la historiografía sobre los impuestos al mundo agrario en los siglos XIX y XX tanto en el plano nacional como en el provincial y se señalan los aspectos que aún necesitan mayor investigación en este campo. This article provides an overview of our knowledge on the ...

  6. Aedes aegypti resistance to temephos in Argentina.

    Science.gov (United States)

    Seccacini, Emilia; Lucia, Alejandro; Zerba, Eduardo; Licastro, Susana; Masuh, Hector

    2008-12-01

    Monitoring of resistance of Aedes aegypti to temephos was implemented in the provinces of Formosa and Misiones, Argentina, as a response to the need to improve the vigilance for the dengue vector in areas of high risk of dengue. Eggs collected in each locality were reared, and susceptibility to temephos was assayed using larval bioassays. A weak decrease in susceptibility of larvae to temephos was observed in Clorinda and Puerto Iguazú, indicating an incipient resistance with a resistance ratio of 3. No control failures have been observed yet, and this program should allow the early detection of a real problem in our country.

  7. Clientelism and Political Control in Rural Argentina

    Directory of Open Access Journals (Sweden)

    Fernando Landini

    2012-07-01

    Full Text Available Scholarship on clientelism frequently addresses political clientelism using strong ideological presuppositions and/or neglecting its subjective dimension. In this article I explore political clientelism in a rural community of the province of Formosa, Argentina from the peasants' point of view. The results suggest that peasants consider the clientelist relation as one that recognizes their personal needs, while the bureaucracy of the state does not. Thus, they perceive clientelist ties as legitimate, criticizing only the fact that the provision of resources by patrons takes place only during elections.

  8. CIFCA Delegation Visits Brazil and Argentina

    Institute of Scientific and Technical Information of China (English)

    Wang; Bo

    2014-01-01

    <正>At the invitation of the UNALE(National Union of State Legislatures)of Brazi land La Plata City of Argentina,the China International Friendship Cities Association(CIFCA)Delegation,led by Vice President Hu Sishe,visited the two countries from May 4 to 13,during which it attended the 18th Conference of UNALE(18th CNLE)in Brasilia,the Brazilian capital.Broad Attendance at CNLE The CNLE,an annual event sponsored by the UNALE,seeks to promote

  9. Derechos humanos y sexualidad en la Argentina

    OpenAIRE

    Mario Pecheny; Mónica Petracci

    2006-01-01

    Este artículo presenta un panorama de la situación de los derechos que tienen que ver con la sexualidad, en la Argentina contemporánea. Basándose principalmente en la legislación positiva, se presenta en primer lugar una síntesis del sistema legal y político, resumiendo a continuación el proceso de inclusión de los derechos sexuales, sobre todo desde 1983, cuando se recuperó la democracia. Las temáticas abordadas son: igualdad civil y conyugalidad, orientación sexual e identidad de género, re...

  10. MIGRACIONES INTERNACIONALES Y RACISMO CULTURAL EN ARGENTINA

    OpenAIRE

    Gonza, Gilda Ivana; González, Anahí Patricia

    2016-01-01

    El artículo aborda las representaciones sociales sobre la identidad nacional y la “cultura”migrante que construyen docentes y miembros del poder judicial en Argentina, visibilizandoel “racismo” cultural que atraviesa dichas representaciones y las relaciones de conflictoentre nativos y migrantes, vinculadas al acceso a los derechos. Para el análisis se recurrióa entrevistas individuales y grupales realizadas a dichos actores institucionales en BuenosAires, durante los años 2008-2014.

  11. Control tectónico de la red de drenaje de los Andes del norte argentino Tectonic control of the drainage in the Andes of northern Argentina

    Directory of Open Access Journals (Sweden)

    R. Mon

    2005-09-01

    Full Text Available Los ríos transversales que drenan la vertiente oriental de los Andes del norte argentino muestran bruscos desvíos hacia cursos longitudinales, inmediatamente al oeste de la traza de grandes cabalgamientos o de los bordes de láminas levantadas por fallas ubicadas en el lado opuesto de ellos. Los ríos desviados colectan otros ríos transversales antes de emerger en la dirección opuesta y de atravesar el frente montañoso. El desvío de los ríos se interpreta como la respuesta al levantamiento progresivo y al crecimiento lateral de cinturones fallados o de anticlinales propagados a lo largo de fallas ciegas. La mayor parte de los ríos de la región fueron desviados, pocos de ellos mantuvieron sus cursos a través de las estructuras en desarrollo. La reorganización del drenaje por el desarrollo de una topografía controlada estructuralmente influyó en la ubicación y en la concentración de los desagües de los ríos en el frente montañoso. Este segmento de los Andes, que se extiende a lo largo de más de 600 km, tiene sólo tres desagües representados por los ríos troncales Bermejo, Juramento y Salí-Dulce. El drenaje evolucionó desde el levantamiento de la Puna (12- 15 Ma, después de la regresión marina final. El desvío de los ríos puede haber empezado después del levantamiento de la Cordillera Oriental (10 Ma y prosiguió con el levantamiento de nuevas montañas hacia el este. El levantamiento de las cadenas montañosas avanzó de oeste a este. Los cinturones más orientales del Sistema Subandino y de las Sierras Pampeanas septentrionales se levantaron después de los 3 Ma. El levantamiento rápido de los obstáculos tectónicos puede explicar la tendencia al desvío de los ríos de esta región.Transverse rivers draining the eastern flank of the Andes of north Argentina show abrupt diversions to axial courses immediately west of the trace of big thrusts, or the borders of plates uplifted by faults located along the opposite

  12. A meridional dipole in premonsoon Bay of Bengal tropical cyclone activity induced by ENSO: TROPICAL CYCLONES, MONSOON AND ENSO

    Energy Technology Data Exchange (ETDEWEB)

    Balaguru, Karthik [Marine Sciences Laboratory, Pacific Northwest National Laboratory, Seattle Washington USA; Leung, L. Ruby [Atmospheric Sciences and Global Change, Pacific Northwest National Laboratory, Richland Washington USA; Lu, Jian [Atmospheric Sciences and Global Change, Pacific Northwest National Laboratory, Richland Washington USA; Foltz, Gregory R. [Physical Oceanography Division, Atlantic Oceanographic and Meteorological Laboratory, Miami Florida USA

    2016-06-27

    Analysis of Bay of Bengal tropical cyclone (TC) track data for the month of May during 1980-2013 reveals a meridional dipole in TC intensification: TC intensification rates increased in the northern Bay and decreased in the southern Bay. The dipole was driven by an increase in low-level vorticity and atmospheric humidity in the northern Bay, making the environment more favorable for TC intensification, and enhanced vertical wind shear in the southern Bay, tending to reduce TC development. These environmental changes were associated with a strengthening of the monsoon circulation for the month of May, driven by a La Nin˜a-like shift in tropical Pacific SSTs andassociated tropical wave dynamics. Analysis of a suite of climate models fromthe CMIP5 archive for the 150-year historical period shows that most models correctly reproduce the link between ENSO and Bay of Bengal TC activity through the monsoon at interannual timescales. Under the RCP 8.5 scenario the same CMIP5 models produce an El Nin˜o like warming trend in the equatorial Pacific, tending to weaken the monsoon circulation. These results suggest

  13. Changes in Holocene meridional circulation and poleward Atlantic flow: the Bay of Biscay as a nodal point

    Science.gov (United States)

    Mary, Yannick; Eynaud, Frédérique; Colin, Christophe; Rossignol, Linda; Brocheray, Sandra; Mojtahid, Meryem; Garcia, Jennifer; Peral, Marion; Howa, Hélène; Zaragosi, Sébastien; Cremer, Michel

    2017-03-01

    This paper documents the evolution over the last 10 kyr of one of the key parameters of climate: sea-surface temperatures (SSTs) in the North Atlantic. We focus on the southern Bay of Biscay, a highly sensitive oceanographic area regarding the dynamics of the North Atlantic subpolar and subtropical gyres (SPG and STG respectively). This site furthermore offers unique sedimentary environments characterized by exceptional accumulation rates, enabling the study of Holocene archives at (infra)centennial scales. Our results mainly derive from planktonic foraminiferal association analysis on two cores from the southern Landes Plateau. These associations are used as the basis of modern analogue technique transfer functions to track past hydrographical changes. SST reconstructions were thus obtained at an exceptional resolution and compared to a compilation of Holocene records from the northeastern North Atlantic. From this regional perspective are shown fundamental timing differences between the gyre dynamics, nuancing classical views of a simple meridional overturning cell. Our study highlights that western Europe underwent significant oscillations of (annual) SST during the last 10 kyr. During well-known intervals of mild boreal climate, warm shifts of more than 3 °C per century are accurately concomitant with positive sea-surface temperature anomalies and rise of micropalaeontological indicators of gyre dynamics in the northern North Atlantic, pointing to periods of greater intensity of the North Atlantic Current (SPG cell especially). Conversely, the SST signal records short-term cold anomalies which could be related to weaker SPG dynamics.

  14. Análisis de restos bioarqueológicos de la costa meridional de Santa Cruz

    Directory of Open Access Journals (Sweden)

    Suby, Jorge A.

    2007-01-01

    Full Text Available En este trabajo se presentan análisis bioarqueológicos y paleopatológicos de los restos óseos humanos hallados en el marco del proyecto “Variabilidad del registro arqueológico y bioantropológico de la costa atlántica meridional patagónica” (PIP 5576. Fueron estudiados dos esqueletos humanos hallado en la región costera de amortiguación del Parque Nacional Monte León. Los materiales corresponden a un adulto y un niño, sobre los que se analizaron aspectos paleopatológicos a través de estudios macroscópicos y radiológicos. A su vez se estudiaron variables tafonómicas y de conservación. Los restos óseos mostraron, en el caso del individuo adulto, importantes marcadores de stress ocupacional en su columna vertebral, así como signos de traumatismos costales. En los restos pertenecientes al niño no pudieron identificarse alteraciones patológicas significativas. Se discuten los resultados hallados en relación a los antecedentes correspondientes al registro bioarqueológico de la región. Al mismo tiempo, en el marco del proyecto mencionado, se analizan las condiciones de conservación de los restos óseos tratados.

  15. Hosed vs. unhosed: global response to interruptions of the Atlantic Meridional Overturning, with and without freshwater forcing

    Directory of Open Access Journals (Sweden)

    N. Brown

    2015-10-01

    Full Text Available It is well known that glacial periods were punctuated by abrupt climate changes, with large impacts on air temperature, precipitation, and ocean circulation across the globe. However, the long-held idea that freshwater forcing, caused by massive iceberg discharges, was the driving force behind these changes has been questioned in recent years. This throws into doubt the abundant literature on modelling abrupt climate change through "hosing" experiments, whereby the Atlantic Meridional Overturning Circulation (AMOC is interrupted by an injection of freshwater to the North Atlantic: if some, or all, abrupt climate change was not driven by freshwater input, could its character have been very different than the typical hosed experiments? Here, we take advantage of a global coupled ocean–atmosphere model that exhibits spontaneous, unhosed oscillations in AMOC strength, in order to examine how the global imprint of AMOC variations depends on whether or not it is the result of external freshwater input. The results imply that, to first order, the ocean–ice–atmosphere dynamics associated with an AMOC weakening dominate the global response, regardless of whether or not freshwater input is the cause. The exception lies in the impact freshwater inputs can have on the strength of other polar haloclines, particularly the Southern Ocean, to which freshwater can be transported relatively quickly after injection in the North Atlantic.

  16. Changes in the geometry and strength of the Atlantic meridional overturning circulation during the last glacial (20-50 ka)

    Science.gov (United States)

    Burckel, Pierre; Waelbroeck, Claire; Luo, Yiming; Roche, Didier M.; Pichat, Sylvain; Jaccard, Samuel L.; Gherardi, Jeanne; Govin, Aline; Lippold, Jörg; Thil, François

    2016-11-01

    We reconstruct the geometry and strength of the Atlantic meridional overturning circulation during the Heinrich stadial 2 and three Greenland interstadials of the 20-50 ka period based on the comparison of new and published sedimentary 231Pa / 230Th data with simulated sedimentary 231Pa / 230Th. We show that the deep Atlantic circulation during these interstadials was very different from that of the Holocene. Northern-sourced waters likely circulated above 2500 m depth, with a flow rate lower than that of the present-day North Atlantic deep water (NADW). Southern-sourced deep waters most probably flowed northwards below 4000 m depth into the North Atlantic basin and then southwards as a return flow between 2500 and 4000 m depth. The flow rate of this southern-sourced deep water was likely larger than that of the modern Antarctic bottom water (AABW). Our results further show that during Heinrich stadial 2, the deep Atlantic was probably directly affected by a southern-sourced water mass below 2500 m depth, while a slow, southward-flowing water mass originating from the North Atlantic likely influenced depths between 1500 and 2500 m down to the equator.

  17. Zonal and Meridional Ocean Currents at TOPEX/Poseidon and JASON-1 Crossovers around Taiwan: Error Analysis and Limitation

    Directory of Open Access Journals (Sweden)

    Cheinway Hwang

    2008-01-01

    Full Text Available A crossover method for determining zonal and meridional ocean current components is examined using data at three crossovers of TOPEX/Poseidon and JASON-1 ground tracks over 2002 - 2006. To implement this method, a geoid model around Taiwan is constructed using surface and airborne gravity data. The modeled and observed geoidal heights at coastal benchmarks are consistent to 5 cm RMS with the means removed. The error and limitation of this method are discussed, concluding that, in order to obtain current velocities at a 10 cm s-1 accuracy and a 6-km resolution, the dynamic ocean topography (DOT at a mm-level accuracy is needed, which is not possible to achieve today. By filtering DOT to a spatial scale of 100 km or coarser, a 10 cm s-1 accuracy of velocity may be obtained. One crossover (A is situated south of Taiwan and near the Kuroshio, the second (B is at the axis of the Kuroshio and the third is located in the northern Taiwan Strait. These three crossovers feature different ocean current patterns. At a spatial scale of 120 km, the agreement among the altimeter, the Princeton Ocean Model (POM, and the drifter-derived velocities is the best at B, followed by that at A, and then C. In fact, at C the altimeter-derived velocities contradict the POM-derived values, and the tide model error is to be blamed. Further improvement on geoid modeling is suggested.

  18. MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rajaguru, S. P. [Indian Institute of Astrophysics, Koramangala II Block, Bangalore (India); Antia, H. M., E-mail: rajaguru@iiap.res.in [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2015-11-10

    We present and discuss results from time–distance helioseismic measurements of meridional circulation (MC) in the solar convection zone using 4 yr of Doppler velocity observations by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Using a built-in mass conservation constraint in terms of the stream function, we invert helioseismic travel times to infer the MC in the solar convection zone. We find that the return flow that closes the MC is possibly beneath the depth of 0.77 R{sub ⊙}. We discuss the significance of this result in relation to other helioseismic inferences published recently and possible reasons for the differences in the results. Our results show clearly the pitfalls involved in the measurements of material flows in the deep solar interior given the current limits on the signal-to-noise ratio and our limited understanding of systematics in the data. We also discuss the implications of our results for the dynamics of solar interior and popular solar dynamo models.

  19. The influence of glacial ice sheets on Atlantic meridional overturning circulation through atmospheric circulation change under glacial climate

    Science.gov (United States)

    Sherriff-Tadano, Sam; Abe-Ouchi, Ayako; Yoshimori, Masakazu; Oka, Akira; Chan, Wing-Le

    2016-04-01

    Recent coupled modeling studies have shown that the existence of the glacial ice sheets intensifies the Atlantic meridional overturning circulation (AMOC). Since this may play an important role in maintaining a strong AMOC over the last glacial period, which is suggested by recent reconstruction study, it is very important to understand the process by which glacial ice sheets intensify the AMOC. Here, a decoupled simulation is conducted to investigate the effect of wind change due to glacial ice sheets on the AMOC, the crucial region where wind modifies the AMOC and the mechanism, which remained elusive in previous studies. First, from atmospheric general circulation model (AGCM) experiments, the effect of glacial ice sheets on the surface wind is evaluated. Second, from ocean general circulation model (OGCM) experiments, the influence of the wind stress change on the AMOC is evaluated by applying only the changes in the surface wind as a boundary condition, while leaving surface heat and freshwater fluxes unchanged. Moreover, several sensitivity experiments are conducted. Using the AGCM, glacial ice sheets are applied individually. Using the OGCM, changes in the wind are applied regionally or at different magnitudes, ranging from the full glacial to modern levels. These experiments demonstrate that glacial ice sheets intensify the AMOC through an increase in the wind stress curl mainly at the North Atlantic mid-latitudes. This intensification is caused by the increased Ekman upwelling and gyre transport of salt while the change in sea ice transport works as a negative, though minor, feedback.

  20. Impact of the GeoMIP G1 sunshade geoengineering experiment on the Atlantic meridional overturning circulation

    Science.gov (United States)

    Hong, Yu; Moore, John C.; Jevrejeva, Svetlana; Ji, Duoying; Phipps, Steven J.; Lenton, Andrew; Tilmes, Simone; Watanabe, Shingo; Zhao, Liyun

    2017-03-01

    We analyze the multi-earth system model responses of ocean temperatures and the Atlantic Meridional Overturning Circulation (AMOC) under an idealized solar radiation management scenario (G1) from the Geoengineering Model Intercomparison Project. All models simulate warming of the northern North Atlantic relative to no geoengineering, despite geoengineering substantially offsetting the increases in mean global ocean temperatures. Increases in the temperature of the North Atlantic Ocean at the surface (∼0.25 K) and at a depth of 500 m (∼0.10 K) are mainly due to a 10 Wm‑2 reduction of total heat flux from ocean to atmosphere. Although the AMOC is slightly reduced under the solar dimming scenario, G1, relative to piControl, it is about 37% stronger than under abrupt4 × CO2 . The reduction of the AMOC under G1 is mainly a response to the heat flux change at the northern North Atlantic rather than to changes in the water flux and the wind stress. The AMOC transfers heat from tropics to high latitudes, helping to warm the high latitudes, and its strength is maintained under solar dimming rather than weakened by greenhouse gas forcing acting alone. Hence the relative reduction in high latitude ocean temperatures provided by solar radiation geoengineering, would tend to be counteracted by the correspondingly active AMOC circulation which furthermore transports warm surface waters towards the Greenland ice sheet, warming Arctic sea ice and permafrost.

  1. Revisiting Effect of Ocean Diapycnal Mixing on Atlantic Meridional Overturning Circulation Recovery in a Freshwater Perturbation Simulation

    Institute of Scientific and Technical Information of China (English)

    YU Lei; GAO Yongqi; WANG Huijun; Helge DRANGE

    2008-01-01

    The effects of ocean density vertical stratification and related ocean mixing on the transient response of the Atlantic meridional overturning circulation (AMOC) are examined in a freshwater perturbation simula- tion using the Bergen Climate Model (BCM). The results presented here axe based on the model outputs of a previous freshwater experiment: a 300-year control integration (CTRL), a freshwater integration (FW1) which started after 100 years of running the CTRL with an artificially and continuously threefold increase in the freshwater flux to the Greenland-Iceland-Norwegian (GIN) Seas and the Arctic Ocean throughout the following 150-year simulation. In FW1, the transient response of the AMOC exhibits an initial decreasing of about 6 Sv (1 Sv=106m3 s-1) over the first 50-year integration and followed a gradual recovery during the last 100-year integration. Our results show that the vertical density stratification as the crucial property of the interior ocean plays an important role for the transient responses of AMOC by regulating the convective and diapycnal mixings under the enhanced freshwater input to northern high latitudes in BCM in which the ocean diapyenal mixing is stratification-dependent. The possible mechanism is also investigated in this paper.

  2. The effect on Arctic climate of atmospheric meridional energy-transport changes studied based on the CESM climate model

    Science.gov (United States)

    Grand Graversen, Rune

    2016-04-01

    The Arctic amplification of global warming and the pronounced Arctic sea-ice retreat constitute some of the most alarming signs of global climate change. These Arctic changes are likely a consequence of a combination of several processes, for instance enhanced uptake of solar radiation in the Arctic due to a lowering of the planetary albedo, and increase in the local Arctic greenhouse effect due to enhanced moister flux from lower latitudes. Many of the proposed processes appear to be dependent on each other, for instance an increase in water-vapour advection to the Arctic enhances the greenhouse effect in the Arctic and the longwave radiation to the surface which melts the sea ice and causes an increase in absorption of solar radiation. The effects of albedo changes have been investigated in earlier studies based on model experiments designed to examine these effects specifically. Here we instead focus on the effects of meridional transport changes into the Arctic, both of water vapour and dry-static energy. Hence we here present results of model experiments with the CESM climate model designed specifically to extract the effects of the changes of the two transport components.

  3. 2D photochemical modeling of Saturn's stratosphere. Part I: Seasonal variation of atmospheric composition without meridional transport

    CERN Document Server

    Hue, Vincent; Dobrijevic, Michel; Hersant, Franck; Greathouse, Thomas K

    2015-01-01

    Saturn's axial tilt of 26.7{\\deg} produces seasons in a similar way as on Earth. Both the stratospheric temperature and composition are affected by this latitudinally varying insolation along Saturn's orbital path. A new time dependent 2D photochemical model is presented to study the seasonal evolution of Saturn's stratospheric composition. This study focuses on the impact of the seasonally variable thermal field on the main stratospheric C2 hydrocarbon chemistry (C2H2 and C2H6) using a realistic radiative climate model. Meridional mixing and advective processes are implemented in the model but turned off in the present study for the sake of simplicity. The results are compared to a simple study case where a latitudinally and temporally steady thermal field is assumed. Our simulations suggest that, when the seasonally variable thermal field is accounted for, the downward diffusion of the seasonally produced hydrocarbons is faster due to the seasonal compression of the atmospheric column during winter. This ef...

  4. The use of NAA for chemical characterisation of clay sources within an archaeological ceramic study in the Chaschuil-Abaucan region (Tinogasta, Catamarca, Argentina)

    Energy Technology Data Exchange (ETDEWEB)

    Pla, R.R.; Moreno, M.A. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Tecnicas Analiticas Nucleares; Ratto, N.R. [Universidad de Buenos Aires (Argentina). Facultad de Filosofia y Letras. Seccion Arqueologia; Fuente, G. de la; Orgaz, M. [Universidad Nacional de Catamarca (Argentina). Escuela de Arqueologia

    2002-07-01

    Application of Neutron Activation Analysis (NAA) to provenience studies of archaeological ceramics involves the determination of clay sources used for their production. This work presents the study on raw materials and its relation to sherd results, on samples from Argentine southern Puna,using NAA. An hypothesis was stated that the Puna region of Chaschuil served as a corridor for the circulation of goods, energy and information, interconnecting large areas and relating to facilities at the bottom of the valley, especially at the Bolson de Fiambala. Potential raw material source locations were sampled both in Puna and valley, considering availability, plasticity, workability and textural fractions of the deposits. Factor analysis was used for evaluation of the results. The graphical representation of the first three factors showed a dense grouping of valley clays with Puna samples as outliers. Within the valley group, those clays from La Troya river appeared closely related to each other. XRD of these samples showed 100 % good quality clays for ceramic manufacture and high presence of clay fraction (17 - 45 % concentration values), with excellent properties regarding their plasticity and workability. The evaluation of a matrix composed of clay and sherd analytical results showed that sherds from valley area were manufactured with local raw materials that included the already sampled sources and others still to be located; that most of Puna sherds were manufactured with raw materials from the valley area, mainly La Troya and that Puna sources of raw materials were not used in the manufacture of those sherds sampled at Puna sites. (author)

  5. Yugoslav teachers in Argentina 1939-1944

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    Stefanović-Banović Milesa

    2014-01-01

    Full Text Available In this paper we present reports of Yugoslav teachers who held classes to immigrants in Argentina 1939-1944, organized by the government of Kingdom of Yugoslavia. Teachers’ reports to Yugoslav Embassy in Buenos Aires testify of Kingdom of Yugoslavia efforts to oppose assimilation and promote and strengthen “Yugoslav national unity”. The reports also describe general social circumstances of Yugoslav immigrants, show various details from their everyday life and contain valuable data on numerous political, economic, social and cultural problems of this diaspora in Argentina and their relationship with motherland. We believe that archive materials presented in this paper opens numerous questions which could be topics of separate researches. Some of them could be the following: To which extent the teachers’ reports represented the actual situation and to which they were shaped to match policy and expectations of Kingdom of Yugoslavia? What was the actual influence of teachers to spreading the “national unity” among immigrants? Have their work left trace in Yugoslav diaspora and in which way? Beside all of the open issues, it is certain that teachers’ reports contain valuable data on immigrants’ everyday life, curriculum, schooling conditions, relationship with motherland, etc. [Projekat Ministarstva nauke Republike Srbije, br. 47016: Interdisciplinarno istraživanje kulturnog i jezičkog nasleđa Srbije. Izrada multimedijalnog internet portala "Pojmovnik srpske kulture"

  6. Derechos humanos y sexualidad en la Argentina

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    Mario Pecheny

    2006-12-01

    Full Text Available Este artículo presenta un panorama de la situación de los derechos que tienen que ver con la sexualidad, en la Argentina contemporánea. Basándose principalmente en la legislación positiva, se presenta en primer lugar una síntesis del sistema legal y político, resumiendo a continuación el proceso de inclusión de los derechos sexuales, sobre todo desde 1983, cuando se recuperó la democracia. Las temáticas abordadas son: igualdad civil y conyugalidad, orientación sexual e identidad de género, reproducción, aborto, violencia de género y violencia sexual, VIH/sida, y explotación y trabajo sexual. El artículo concluye con una reflexión sobre las principales deudas pendientes.This paper presents an overview of the situation concerning the rights related to sexuality in contemporary Argentina. Based specially on the positive legislation, it is primarily presented a synthesis of the legal and political system. Next, the paper summarizes the process of inclusion of the sexual rights, mainly since 1983, when democracy has been recovered. The following issues are addressed: civil equality and conjugality; sexual orientation and gender identity; reproduction; abortion; gender a sexual violence; HIV/Aids; and exploitation and sexual work. The paper ends with a consideration about the still remaining doubts.

  7. Ten years of SLR production in Argentina

    Science.gov (United States)

    Pacheco, A.; Podestá, R.; Yin, Z.; Liu, W.; Actis, E.; Adarvez, S.; Quinteros, J.; Podestá, F.

    2017-07-01

    SLR technique is a proved astro-geodetic art with a significant power to contribute to Earth and Space Sciences. Therefore, scientific applications of SLR System are able to perform multiple tasks in the fields of Astrometry, Geodesy and Geophysics. The results we show here were obtained from satellite observations made at SLR 7406 Station of Observatorio Astronómico Félix Aguilar (OAFA) in San Juan, Argentina. The telescope was installed early on 2006, in concordance with an International Cooperation Agreement between Universidad Nacional de San Juan, Argentina and Chinese Academy of Sciences. In this abstract we show the current research being done with ILRS 7406 station: Length of day (LOD) and Angular velocity of Earth Rotation, calculated weekly; Pole Motion. ILRS7406 is daily surveying Pole coordinates x and y; Tracking SLR to GNSS constellations. SLR System contributes to the adjustment and validation of satellite GALILEO, GPS, GLONASS, and BEIDOU orbits. Our station is nowadays member of the new ITRF 2014 frame, and these past years has been one of the 3 highest producing SLR Stations on the ILRS net, composed of about 40 stations distributed all around the world. The obtained results during this first 10 years of experience are useful to enhance the traditional collaboration between OAFA and international services such as ILRS, IERS and NASA.

  8. [Dengue vaccines. A reality for Argentina?].

    Science.gov (United States)

    Orellano, Pablo W; Salomón, Oscar D

    2016-01-01

    Dengue outbreaks have occurred yearly in Argentina since 1998. A number of candidate vaccines have been tested in endemic countries. The most advanced one was licensed in three countries of Latin America for children over 9 years of age. In the present article the benefits and drawbacks of these vaccines as well as the challenges for the implementation of a vaccination strategy in Argentina are discussed. Furthermore, a risk stratification strategy with new criteria and a multidisciplinary vision is suggested as a possible path for the assessment of the pertinence of a vaccination program in areas showing the highest risk of dengue transmission and/or for people at the greatest risk of developing severe dengue. It is also suggested that the definition regarding the status of endemicity should take into account the local realities. Finally, this paper proposes a broad discussion on the evidences, the expected impact and instrumental aspects that would be involved in the incorporation of a dengue vaccine, marketed or in development, into the national immunization program, and especially which subpopulation should be targeted for the immunization strategy to be cost-effective.

  9. Oil and nationalism in Argentina: a history

    Energy Technology Data Exchange (ETDEWEB)

    Solberg, C.E.

    1979-01-01

    This case study of Yacimientos Petroliferos Fiscales, the world's first state-owned oil company, traces the development of Argentina's nationalistic petroleum policy from the discovery of oil on state-owned land in 1907 to the present. The focus is on the period prior to 1930, when the institutions and ideologies that have shaped Argentine petroleum affairs became firmly established. A final chapter summarizes developments since 1930, with emphasis on the impact the Argentine experience has had on other oil-producing countries in Latin America. Prior to World War I, Argentine governments gave little attention to the development of petroleum resources, but the wartime economic crisis demonstrated to many prominent political figures the necessity of shifting from dependence on foreign capital and imported fuel toward greater economic self-sufficiency. A key aspect of this new policy was the founding in 1922 of the state oil agency, YPF, which gradually wrested control of oil resources from the provinces in order to establish a vertically integrated, national petroleum industry. Because of its power and influence, YPF survived the 1930 revolution, became the largest economic enterprise in Argentina, and emerged as the very symbol of national economic independence.

  10. Horizontalidad, autogestión y protagonismo en Argentina

    Directory of Open Access Journals (Sweden)

    Marina Sitrin

    2010-04-01

    Full Text Available Este artículo trata los movimientos sociales autónomos que surgieron después de la crisis económica y la posterior rebelión popular en Argentina en diciembre de 2001. Los movimientos autónomos en la Argentina, como tantos movimientos en el mundo de hoy, son movimientos basados en la creación de nuevas relaciones sociales y comunidades ahora, al mismo tiempo que proyectan nuevas sociedades y las relaciones en y para el futuro. Son movimientos con una concepción diferente del tiempo y el espacio. Son movimientos que entienden lo individual y lo colectivo como vinculados entre sí.Hay mucho en común entre la experiencia en la Argentina y las prácticas e ideas anarquistas. Eso no significa que los que están creando nuevas relaciones y comunidades en la Argentina sean anarquistas. Lo que este artículo intenta hacer es basarse en las experiencias de los movimientos sociales argentinos para iniciar una reflexión sobre las prácticas e ideas que los anarquistas pueden prestar a los distintos movimientos y comunidades autónomas; y, a su vez, sobre lo que los movimientos autónomos en la Argentina puede dar a las ideas y prácticas anarquistas.Palabras Clave: movimientos sociales, rebelión popular, Argentina, Anarquismo, movimientos autónomos_____________________ABSTRACT:This article discusses the autonomous social movements that arose after the economic crisis and subsequent popular rebellion in Argentina in December of 2001. The autonomous movements in Argentina, as so many movements around the world today, are movements based on creating new social relationships and communities now, while simultaneously creating new societies and relationships in and for the future. They are movements with a different conception of time and place. They are movements that see the individual and the collective as linked to one another.There is a great deal in common with the experience in Argentina and anarchist practices and ideas. That does not make

  11. Brazil-Argentina trade and its impacts in brazilian states

    Directory of Open Access Journals (Sweden)

    Eduardo A. Haddad

    2005-11-01

    Full Text Available This paper aims to evaluate a number of spatial aspects of Brazil’s currentcommercial policy, emphasizing those relating to bilateral trade with Argentina,its main trading partner in Mercosur. A national computable general equilibrium modelwas developed and implemented (EFES-ARG —integrated with an interstatetrade model—, in order to evaluate the sectoral/regional impacts of different tradestrategies towards Argentina. The analysis of the short-run regional aspects of Brazil-Argentina trade relations reveals a trend towards concentration of the level of economicactivity in the states of the Brazilian south and southeast.

  12. Overview and perspectives for Open Access development in Argentina

    Directory of Open Access Journals (Sweden)

    Sandra Miguel

    2013-04-01

    Full Text Available This paper provides an overview and perspectives for development of the Open Access movement in Argentina, within the global and regional (Latin American context. It outlines the evolution and current state of initiatives around the two main approaches to Open Access, the golden and green roads. The main Open Access policies and support of OA movement by governments in Latin American region, and particularly in Argentina, are highlighted, while recent studies on publishing practices and authors’ positions regarding Open Access are presented. The paper concludes that the prospects for development of OA in Argentina, both through golden and green roads are favorable, with their strengths and shortcomings

  13. Mecanismos de intercambio en períodos de transición: el caso de los arrendamientos de dos estancias de la Puna jujeña (1813-1819

    Directory of Open Access Journals (Sweden)

    Conti, Viviana E.

    1994-06-01

    Full Text Available Not available.

    Las condiciones de desarrollo y consolidación del sistema colonial mercantilista en los Andes Meridionales se modifican rápidamente en la segunda mitad del XVIII. Pero se trata de una modificación ambigua: renacer de la minería potosina y reverdecer del comercio por un lado, pero reiteradas crisis estructurales -guerras y sequias-« por el otro. En la primera década del XIX es evidente el deterioro de todo el sistema pero también las estrategias asumidas para detenerlo. En este artículo se examinan los arrendamientos de tierras en plena Guerra de Independencia como fuente rentística colonial, acceso alternativo a bienes y moneda y conjunto de estrategias comerciales del campesinado de la Puna jujeña. Se concluye que estos campesinos mantuvieron su producción e intercambios captando moneda en el circuito mercantil. Los arrendamientos, como antes el tributo, marcan el éxito de las estrategias indígenas en el manejo de plata y bienes frente al mercado y al pago mismo de sus obligaciones.

  14. Seasonal variability of the meridional overturning circulation in the South China Sea and its connection with inter-ocean transport based on SODA2.2.4

    Science.gov (United States)

    Zhu, Yaohua; Fang, Guohong; Wei, Zexun; Wang, Yonggang; Teng, Fei; Qu, Tangdong

    2016-05-01

    We have proposed a five-layer-scheme to investigate the volume transport through the South China Sea (SCS) based on the updated Simple Ocean Data Assimilation (SODA2.2.4) product. By demonstrating horizontal transport in each layer, we have revealed different formation mechanisms for the meridional overturning circulation (MOC) in winter and summer in the SCS. Our analysis suggests three meridional circulation systems in the SCS: (1) the seasonal monsoon-driven circulation in the surface layer, i.e., southward circulation in winter and northward in summer, (2) the compensatory transport-induced seasonal intermediate MOC in the central SCS, and (3) the persistent deep MOC in the southern SCS all year round. By examining vertical velocity distribution, we have identified that the major overturning process of the intermediate MOC is located along the continental slope east and southeast of Vietnam, while the major overturning process of the deep MOC is located along the continental slope northwest of Borneo. The downwelling in the intermediate MOC in winter and upwelling in the deep MOC all year round bring different water masses to the intermediate and subintermediate layers to be mixed in the SCS. We found no evidence to suggest that the strength and extent of the MOC south of 18°N are related to inter-ocean volume transport. The surface layer transport in the Luzon Strait has been decreasing since the 1960s. However, the causes of the meridionally staggered and interdecadal alternating acceleration/slowdown of the meridional stream function difference are unknown.

  15. Overturn of the Oceasn Flow in the North Atlantic as a Trigger of Inertia Motion to Form a Meridional Ocean Circulation

    Science.gov (United States)

    Nakamura, Shigehisa

    2010-05-01

    This work is an introduction of a meridional ocean circulation. As for the zonal motions,there have been many contributions. Recent oceanographic works noticed an overturn of the ocean current in the North Atlantic. The author notices this overturn is a trigger to generate a meridional ocean circulation to have a track through the deep Atlantic, the deep circum-polar current, the deep branch flow to the Pacific between the Australian and the South America. The east part of the branch flow relates to the upwelling off Peru, and the west part relates to form a deep water in the Northwest Pacific. THe overturn of the North Atlantic suggests an outflow of the deep water and a storage of the old aged deep water in the Northwest Pacific. The storage water increase in the Northwest Pacific shoould be a trigger of the swelling up of the sea level mid Pacific to affect to the ocean front variations between the coastal waters and the ocean water. In order to keep a hydrodynamic balance on the earth, an increase of the deep water in the Pacific should flow through the Bering Sea and the Arctic Sea to get to the North Atlantic. It should be noted that a budget of the ocean water flow must be hold the condition of the water masses concservation on the earth surface. This inertia motion is maintained once induced after any natural effect or some man-made influences. At this stage, the author has to notice that there has been developed a meridional inertia path of the air particle as well as the ocean water parcel, nevertheless nobody has had pointed out this inertiamotion with a meridional path in the ocean. Air-sea interaction must be one of the main factors for driving the ocean water though the inertia motion in the global scale is more energetic. To the details, the scientists should pursue what geophysical dynamics must be developed in the future.

  16. Aclerdidae (Hemiptera: Coccoidea de la Argentina Aclerdidae (Hemiptera: Coccoidea from Argentina

    Directory of Open Access Journals (Sweden)

    María Cristina Granara de Willink

    2004-12-01

    Full Text Available Se describen e ilustran la hembra adulta, el primer estadio y un estadio intermedio de la hembra de Aclerda colihuensis sp. nov., encontrada sobre Chusquea culeou una Bambusaceae, de los bosques andinopatagónicos. Se brinda una clave para las especies de Aclerda Signoret, de la región Neotropical. Se cita esta familia por primera vez para la Argentina.The female, the first stage, and intermediate female stages of Aclerda colihuensis n. sp., are described and illustrated. A key to the neotropical species for Aclerda Signoret is given. This is the first family report from Argentina. The new species was found on Chusquea culeou Desv. Bambusaceae, from the Patagonia forest.

  17. Tabaquismo durante el embarazo en Argentina y Uruguay Smoking during pregnancy in Argentina and Uruguay

    Directory of Open Access Journals (Sweden)

    Fernando Althabe

    2008-02-01

    Full Text Available Argentina y Uruguay están entre los países con mayor proporción de mujeres jóvenes fumadoras. Se desconoce cuál es la proporción exacta de ellas que fuman durante el embarazo así como las características de las que dejan de fumar y las que continúan fumando durante el embarazo. Realizamos una encuesta administrada por un/a entrevistador/a a 1512 mujeres embarazadas de 18 años o mayores (796 en Argentina; 716 en Uruguay, que concurrían a control prenatal en hospitales públicos de grandes conglomerados urbanos. 44% de las mujeres en Argentina y 53% en Uruguay habían sido o eran fumadoras. Durante el embarazo, 11% de las mujeres en Argentina y 18% en Uruguay continuaron fumando. En ambos países, la proporción de mujeres que vive con fumadores, permite fumar en el hogar y regularmente o siempre se encuentra en lugares cerrados con personas que estén fumando fue 49%, 46% y 20% entre las mujeres que nunca fumaron, 67%, 60% y 32% entre las que dejaron, y 78%, 75% y 52% entre las que continuaron fumando respectivamente. El estudio confirma un importante problema de salud pública y documenta que la exposición ambiental persiste en subgrupos de mujeres, aun en aquéllas que dejaron de fumar. Es importante que el sector de salud pública provea acceso a programas efectivos para dejar de fumar durante el embarazo. Cualquier nueva intervención a desarrollar que intente tener un éxito al menos moderado y sostenible, debiera incluir componentes que actúen sobre el entorno fumador de la mujer embarazada que fuma.Argentina and Uruguay are among the countries in which a large proportion of young women smoke. The rate of smokers during pregnancy in both countries is not well known, and data on the characteristics of women who quit smoking during pregnancy compared to those who continue smoking are not available. We conducted a survey including 1512 pregnant women >18 years old (796 in Argentina; 716 in Uruguay, during antenatal visits in

  18. Primer registro de Aulacaspis tubercularis (Hemiptera: Diaspididae en la Argentina First record of Aulacaspis tubercularis (Hemiptera: Diaspididae from Argentina

    Directory of Open Access Journals (Sweden)

    Cristian Amún

    2012-12-01

    Full Text Available Aulacaspis tubercularis Newstead es una especie polífaga que ataca principalmente los cultivos de Mangifera indica. Se registra por primera vez en la Argentina esta especie de insecto. Los ejemplares estudiados fueron recolectados en árboles de mango, en localidades del noroeste argentino, en enero de 2011 y abril de 2012.Aulacaspis tubercularis Newstead is a polyphagous pest that attacks mainly Mangifera indica. This insect species is reported for the first time in Argentina. The studied specimens were collected from mango trees in different places of NW Argentina, in January 2011 and April 2012.

  19. Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows

    Science.gov (United States)

    Zhao, Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, Alexander; Duvall, T. L., Jr.

    2012-01-01

    We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s-1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

  20. Sediment 231Pa/230Th as a recorder of the rate of the Atlantic meridional overturning circulation: insights from a 2-D model

    Directory of Open Access Journals (Sweden)

    S. E. Allen

    2010-03-01

    Full Text Available A two dimensional scavenging model is used to investigate the patterns of sediment 231Pa/230Th generated by the Atlantic Meridional Overturning Circulation (AMOC and further advance the application of this proxy for ocean paleocirculation studies. The scavenging parameters and the geometry of the overturning circulation cell have been chosen so that the model generates meridional sections of dissolved 230Th and 231Pa consistent with published water column profiles and an additional 12 previously unpublished profiles measured in the North and Equatorial Atlantic. The processes that generate the meridional sections of dissolved and particulate 230Th, dissolved and particulate 231Pa, dissolved and particulate 231Pa/230Th, and sediment 231Pa/230Th are discussed in detail. The results indicate that the relationship between sediment 231Pa/230Th at any given site and the overturning circulation is very complex. They clearly show that constraining past changes in the strength and geometry of the AMOC requires an extensive data set and they suggest strategies to maximize information from a limited number of samples.