Variability and motion of the Brazil-Malvinas front

The temporal evolution of the thermal field associated with frontal motions in the South Western Atlantic is studied. The analysis is based on data collected with an array of inverted echo sounders (IES) deployed during the Confluence Program (1988-1990) at the Brazil/Malvinas Confluence. The travel time series obtained with the IES are scaled to mean temperatures of the upper 500 m (Tsoo) of the ocean and series of T500 horizontal distributions are constructed. A description of the evolution of the thermal field, emphasizing the frontal motions and some mesoscaie features, is presented. Three well-defined northward penetrations of the Malvinas current with fairly variable periods of permanence (15-60 days) and mean frontal motion velocities of 0.2 m/s are observed. Cross-correlation of the T500 time series analysis leads to a plausible explanation of some features of the observed variability. Comparison with previous results in the area indicate a marked interannual variability and sources of variability are discussed.Se estudia la evolución temporal del campo de isotermas asociados con movimientos frontales en el océano Atlántico Sudoccidental. El análisis está basado en datos obtenidos de ecosondas invertidos (IES) fondeados durante la ejecución del Programa Confluencia (1988-1990) en la confluencia de las corrientes de Malvinas y Brasil. Las series de tiempo obtenidas con los IES fueron estandarizados con las temperaturas medias de los primeros 500 m (T500) del océano y de esta forma se obtuvo la distribución horizontal de T500. Se presenta una descripción de la evolución del campo térmico en relación con los movimientos frontales y las características de mesoescala de esa zona. Se observaron tres penetraciones bien definidas de la corriente de Malvinas con períodos variables de permanencia (15 -60 días) y velocidades del frente de 0.2 m/s. Del análisis de la correlación cruzada de la serie de T500 se obtiene una posible explicación de la variabilidad observada. La comparación con resultados previos indican una variabilidad interanual. Se discuten las fuentes de variabilidad.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Distribution of sea-air CO 2 fluxes in the Patagonian Sea: Seasonal, biological and thermal effects

Sea-air CO2 fluxes (FCO2) in the Patagonian Sea (PS) were studied using observations collected in 2000-2006. Based on the PS frontal structures and the thermal and biological contributions to FCO2 we present a regional subdivision between distinct regimes that provide new insights on the processes that control these fluxes. The coastal regime (CR) is a net source of atmospheric CO2 (4.9 x 10-3mol.m-2.d-1) while the open shelf regime (SHR) is a net CO2 sink (-6.0 x 10-3mol.m-2.d-1). The interface between these two regions closely follows the location of along-shore fronts. In addition, based on the nature of the processes that drive the FCO2, the PS is subdivided between northern (NR) and southern (SR) regions. Both, NR and SR are CO2 sinks, but the CO2 uptake is significantly higher in NR (-6.4 x 10-3mol.m-2.d-1) than in SR (-0.5 x 10-3mol.m-2.d-1). The data reveal a strong seasonality in FCO2. The mean CO2 capture throughout the PS in austral spring is -5.8 x 10-3mol.m-2.d-1, reaching values lower than -50 x 10-3mol.m-2.d-1 in NR, while in winter FCO2 is close to equilibrium in SR. The analysis of the biological and thermal effects (BE and TE, respectively) on seasonal pCO2 variability indicates that regions of CO2 emission are dominated by the TE while regions of CO2 uptake are dominated by the BE. Our results indicate that the biological pump is the dominant process determining the sea-air CO2 flux in the PS.Fil: Kahl, Lucía Carolina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Bianchi, Alejandro A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Osiroff, Ana Paula. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; ArgentinaFil: Pino, Diana Ruiz. Universite Pierre et Marie Curie; FranciaFil: Piola, Alberto Ricardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Spring and winter water mass composition in the Brazil-Malvinas Confluence

Hydrographic data of the Confluence 1 cruise collected during austral spring (November 1988) have been analyzed to estimate relative mixing proportions of the various water masses of the Brazil-Malvinas Confluence region using a multiparameter analysis. Seven source water types (SWT) are identified in this region, and all are retained for the analysis: Thermocline Water (TW), Subantarctic Surface Water (SASW), Antarctic Intermediate Water (AAIW), Upper Circumpolar Deep Water (UCDW), North Atlantic Deep Water (NADW), Lower Circumpolar Deep Water (LCDW) and Weddell Sea Deep Water (WSDW). Tracers selected are temperature, salinity, dissolved oxygen and nutrients. Mixing proportions are quantified and plotted along five zonal sections at 35.4, 36.5, 37.9, 41 and 41.6S. The solution obtained during the springtime cruise is consistent with the wintertime (September 1989) data set (Maamaatuaiahutapu et al., 1992): both show the large local recirculation of AAIW and the separation of NADW from the coast south of the thermocline front. However, noticeable changes in water mass mixing proportions can be detected between the winter of 1989 and the preceding spring. The seasonal change for the upper layers of TW and SASW is related to temporal and spatial fluctuations of the thermohaline front. The marked differences in SWT proportions between the two seasons occur at the same location for TW, SASW and AAIW; suggesting that the upper waters have a large impact on the AAIW movement. The deep waters undergo great spatial changes between the two cruises. The variation of the deep convergence position (revealed by the variation of spatial occupancy of the CDW and NADW) seems influenced by the movement of the thermocline front

Variability and motion of the Brazil-Malvinas front

The temporal evolution of the thermal field associated with frontal motions in the South Western Atlantic is studied. The analysis is based on data collected with an array of inverted echo sounders (IES) deployed during the Confluence Program (1988-1990) at the Brazil/Malvinas Confluence. The travel time series obtained with the IES are scaled to mean temperatures of the upper 500 m (Tsoo) of the ocean and series of T500 horizontal distributions are constructed. A description of the evolution of the thermal field, emphasizing the frontal motions and some mesoscaie features, is presented. Three well-defined northward penetrations of the Malvinas current with fairly variable periods of permanence (15-60 days) and mean frontal motion velocities of 0.2 m/s are observed. Cross-correlation of the T500 time series analysis leads to a plausible explanation of some features of the observed variability. Comparison with previous results in the area indicate a marked interannual variability and sources of variability are discussed.Se estudia la evolución temporal del campo de isotermas asociados con movimientos frontales en el océano Atlántico Sudoccidental. El análisis está basado en datos obtenidos de ecosondas invertidos (IES) fondeados durante la ejecución del Programa Confluencia (1988-1990) en la confluencia de las corrientes de Malvinas y Brasil. Las series de tiempo obtenidas con los IES fueron estandarizados con las temperaturas medias de los primeros 500 m (T500) del océano y de esta forma se obtuvo la distribución horizontal de T500. Se presenta una descripción de la evolución del campo térmico en relación con los movimientos frontales y las características de mesoescala de esa zona. Se observaron tres penetraciones bien definidas de la corriente de Malvinas con períodos variables de permanencia (15 -60 días) y velocidades del frente de 0.2 m/s. Del análisis de la correlación cruzada de la serie de T500 se obtiene una posible explicación de la variabilidad observada. La comparación con resultados previos indican una variabilidad interanual. Se discuten las fuentes de variabilidad.Material digitalizado en SEDICI gracias a la colaboración de la Facultad de Ciencias Astronómicas y Geofísicas (UNLP).Asociación Argentina de Geofísicos y Geodesta

Role of plankton communities in sea-air variations in pCO2 in the SW Atlantic Ocean

The influence of the plankton community structure on carbon dynamics was studied in the surface waters of the Argentinean continental shelf (SW Atlantic Ocean) in summer and fall 2002, 2003 and 2004, The horizontal changes in plankton community respiration (R), net community production (NCP) and gross primary production (GPP) were (1) compared with the difference in the partial pressure of CO2 (pCO2) between the sea surface and the atmosphere (ΔpCO2), (2) compared with oxygen saturation and (3) related to the microscopic phytoplankton assemblages, This area, which has recently been shown to be a CO2 sink, had an average surface oxygen saturation of 108.1%, indicating that net photosynthesis could have played a dominant role in the CO2 dynamics. At most stations, the production:respiration (GPP:R) ratio was greater than 1, indicating that planktonic communities were autotrophic; the average GPP:R ratio for the whole study was 2.99, Phytoplankton biomass (chlorophyll a) and NCP showed an inverse relationship with ΔpCO2 and a direct relationship with %O 2 saturation when phytoplankton assemblages were dominated by diatoms (30% of the stations), This was not the case when small (≤5 μm) flagellates were the most abundant organisms, Although NCP was mostly positive for both groups of stations (i.e. diatom-dominated or small flagellate- dominated), other physical and biological processes are thought to modify the CO2 dynamics when small flagellates are the prevailing phytoplankton group.Facultad de Ciencias Naturales y Muse

Role of plankton communities in sea-air variations in pCO2 in the SW Atlantic Ocean

The influence of the plankton community structure on carbon dynamics was studied in the surface waters of the Argentinean continental shelf (SW Atlantic Ocean) in summer and fall 2002, 2003 and 2004, The horizontal changes in plankton community respiration (R), net community production (NCP) and gross primary production (GPP) were (1) compared with the difference in the partial pressure of CO2 (pCO2) between the sea surface and the atmosphere (ΔpCO2), (2) compared with oxygen saturation and (3) related to the microscopic phytoplankton assemblages, This area, which has recently been shown to be a CO2 sink, had an average surface oxygen saturation of 108.1%, indicating that net photosynthesis could have played a dominant role in the CO2 dynamics. At most stations, the production:respiration (GPP:R) ratio was greater than 1, indicating that planktonic communities were autotrophic; the average GPP:R ratio for the whole study was 2.99, Phytoplankton biomass (chlorophyll a) and NCP showed an inverse relationship with ΔpCO2 and a direct relationship with %O 2 saturation when phytoplankton assemblages were dominated by diatoms (30% of the stations), This was not the case when small (≤5 μm) flagellates were the most abundant organisms, Although NCP was mostly positive for both groups of stations (i.e. diatom-dominated or small flagellate- dominated), other physical and biological processes are thought to modify the CO2 dynamics when small flagellates are the prevailing phytoplankton group.Facultad de Ciencias Naturales y Muse

A multi-decade record of high quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) “living data” publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT_V3_GRID

Lysine harvesting is an antioxidant strategy and triggers underground polyamine metabolism

Both single and multicellular organisms depend on anti-stress mechanisms that enable them to deal with sudden changes in the environment, including exposure to heat and oxidants. Central to the stress response are dynamic changes in metabolism, such as the transition from the glycolysis to the pentose phosphate pathway—a conserved first-line response to oxidative insults1,2. Here we report a second metabolic adaptation that protects microbial cells in stress situations. The role of the yeast polyamine transporter Tpo1p3,4,5 in maintaining oxidant resistance is unknown6. However, a proteomic time-course experiment suggests a link to lysine metabolism. We reveal a connection between polyamine and lysine metabolism during stress situations, in the form of a promiscuous enzymatic reaction in which the first enzyme of the polyamine pathway, Spe1p, decarboxylates lysine and forms an alternative polyamine, cadaverine. The reaction proceeds in the presence of extracellular lysine, which is taken up by cells to reach concentrations up to one hundred times higher than those required for growth. Such extensive harvest is not observed for the other amino acids, is dependent on the polyamine pathway and triggers a reprogramming of redox metabolism. As a result, NADPH—which would otherwise be required for lysine biosynthesis—is channelled into glutathione metabolism, leading to a large increase in glutathione concentrations, lower levels of reactive oxygen species and increased oxidant tolerance. Our results show that nutrient uptake occurs not only to enable cell growth, but when the nutrient availability is favourable it also enables cells to reconfigure their metabolism to preventatively mount stress protection

Globalisation from Above? Corporate Social Responsibility, the Workers' Party and the Origins of the World Social Forum

In its assessment of the origins and early development of the World Social Forum this article challenges traditional understandings of the Forum as representing ‘globalisation from below’. By tracing the intricate relations among elements of business, civil society, and the Workers’ Party in the first years of the Forum, this article reveals the major role played by a corporate movement stemming from the Brazilian democratisation process in the 1980s, and how this combined with the transformed agenda of the Workers’ Party as it gained higher political offices to constrain the Forum’s activities from the outset. In so doing, this article challenges not only widespread conceptions of the Forum as a counter‐hegemonic alternative but also current critiques concerning its subsequent limitations. Furthermore, it reveals how traditional understandings of the World Social Forum and of global civil society are underpinned by flawed assumptions which typecast political activities in the global ‘South’

Modelos de combustibles para arbustales de la Región Andina de las provincias de Río Negro, Chubut y Santa Cruz

En este folleto de divulgación, se dan a conocer las principales herramientas para el modelado de los combustibles vegetales en relación con sus respuestas al fuego.  Está escrito de una manera sencilla para que pueda ser interpretado por jefes de cuadrillas o de brigadas de combatientes de incendios forestales.  En el mismo de describe una metodología común y replicable para la obtención de los llamados "modelos de combustible".   Se dan ejemplos de 6 de estos modelos desarrollados para arbustales del ecotono bosque-estepa de la Patagonia. en base a información científica y empírica.Fil: Rey, Marcelo A.. Provincia de Río Negro. Servicio Provincial de Lucha contra Incendios Forestales; ArgentinaFil: Cuevas, Jorge. Provincia de Río Negro. Servicio Provincial de Lucha contra Incendios Forestales; ArgentinaFil: Sales, Bruno. Provincia de Río Negro. Servicio Provincial de Lucha contra Incendios Forestales; ArgentinaFil: Muñoz, Miriam M.. Provincia de Santa Cruz. Consejo Agrario; ArgentinaFil: Méndez, Mario. Provincia de Santa Cruz. Consejo Agrario; ArgentinaFil: Antequera, Silvio. Provincia de Chubut. Dirección General de Bosques y Parques; ArgentinaFil: Casas, Ángel Leandro. Provincia de Chubut. Dirección General de Bosques y Parques; ArgentinaFil: Lencinas, José Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia del Chubut. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Mohr Bell, Diego Alejandro. Provincia del Chubut. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Gómez, Mariano. Provincia del Chubut. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Defossé, Guillermo Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ingeniería - Sede Esquel. Departamento de Ingeniería Forestal; ArgentinaFil: Bianchi, Lucas Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, Norberto. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Díaz, María Cecilia. Plan Nacional de Manejo del Fuego; ArgentinaFil: Dentoni, María del Carmen. Plan Nacional de Manejo del Fuego; ArgentinaFil: Zacconi, Gabriel. Plan Nacional de Manejo del Fuego; Argentin