lunes, septiembre 09, 2019

DEFENSA DE TFM: JENNIFER IVANOFF

El pasado día 5 de Septiembre, la estudiante de Máster Interuniversitario en Oceanografía, en la Facultad de Ciencias del Mar de la Universidad de Las Palmas de Gran Canaria, defendió su Trabajo Final de Máster titulado: Transports and budgets of anthropogenic CO2 in the Eastern North Atlantic Subtropical Gyre during 2009

Este trabajo fue realizado en el grupo de investigación QUIMA del Instituto de Oceanografía y Cambio Global, dirigido por los catedráticos Melchor González-Dávila y J. Magdalena Santana-Casiano. 

El resumen del trabajo se presenta a continuación: 

During ORCA 1009 project in the eastern boundary of the North Atlantic subtropical gyre, pH, total alkalinity and total inorganic carbon were measured along the three section in the area between 29-37oN and 9-24oW. The anthropogenic carbon content, Cant, was computed applying the back-calculation techniques TrOCA 2007 and 𝜑𝐶0T methods. Slightly higher concentrations of Cant in surface and intermediate waters was obtained by the TrOCA 2007. In contrast, lower concentrations were estimated in depth waters. The differences between the methods are mainly related to the different parameterizations of the pre-industrial and preformed properties and from the disequilibrium parameterizations. The large inflow of Cant to the region is through the western section (712 kmol-1) caused by the Azores Current. The Azores Current mostly feed the Canary Current at surface waters, the reasons behind the relatively high output of Cant estimated for this current (-440 kmol-1). In the northern transect, we observed a southward flow of -50 kmol s-1 influenced by the Portugal Current and finally, the MOW (in the eastern section) as goes out of the Mediterranean, deeps at intermediate waters, and intensifies the Azores Countercurrent (eastward) by –70 kmol s-1.


lunes, septiembre 02, 2019

QUIMA EN GOLDSCHMIDT 2019

Nuestro grupo de investigación ha participado activamente en el reciente congreso internacional Goldschmidt 2019 que se ha celebrado en Barcelona entre los días 18 y 23 de Agosto.

Dentro de las actvidades en las que hemos participado destacamos la organización de la sesión 10k: Trace Metal Cycling and Radioisotope Tracers of Ocean Biogeochemistry (GEOTRACES). Esta sesión ha estado dirgida por Aridane G. González, Hannah Whitby, Amber Annett, Emilie Le Roy y Maxi Castrillejo Iridoy. Ha sido una sesión enmarcada dentro del programa internacional GEOTRACES. El resumen de la sesión es el siguiente:

This session will highlight recent advances in marine trace element chemistry and the use of radionuclides as tracers in the marine system. In particular, we focus on the speciation and ligand-binding reactions of trace metals, and investigation of both micro- and macro-nutrient cycles and fluxes using natural and anthropogenic radionuclides. The GEOTRACES program, which aims to map the world's oceans for trace elements and their isotopes with unprecedented resolution, has facilitated rapid progress in these research areas. Radioisotopes are becoming increasingly powerful tracers for studying the biogeochemical cycles of carbon, nutrients, trace elements and isotopes in the world’s oceans. These tracers can be naturally-occurring or anthropogenic, with a wide range of half-lives allowing their application to a broad array of processes. Methodological advances and standardization (e.g. through GEOTRACES and RiO5) are contributing to increasing spatial coverage and temporal resolution of data of many marine radioisotopes. In order to understand the processes behind trace metal fluxes and export, we must also understand the physico-chemical interactions and organic speciation of trace metals, which play an important role in their biogeochemical cycling. The GEOTRACES effort has vastly increased the database of metal-binding organic ligand distributions, demonstrating key features and distinct regional trends. However the identification of these ligands, as well as their effect on the redox reactions and bioavailability of trace metals in natural waters, are still largely unconfirmed. In this session, we invite observational, experimental and modelling contributions on the distribution and characterization of organic ligands in the ocean, as well as their effect on the redox reactions of metals in seawater. In tandem, this session brings together studies using radionuclides to investigate aspects of marine biogeochemistry from local to global scale: fluxes and export of particulate material, sources and sinks of macro- and micro-nutrients, elemental cycles at ocean margins (e.g. estuaries, sediments, hydrothermal vents, air-sea interface), or rates of biological processes (e.g. biological export and remineralisation). Studies presenting advances in methodology, novel applications of radionuclide tracers, or using radioisotopes to quantify human impacts on ocean biogeochemistry are also welcome.


Además, el grupo QUIMA presentó diversos trabajos científicos desarrollados en la línea de química de metales traza. El primero de ellos se titula: The Role of Polyphenols on the Fe Chemistry in Seawater. Este trabajo describe el papel que diversos polifenoles juegan en la reducción de Fe(III) a Fe(II) en el océano, permitiendo que sea biodisponible por más tiempo. en el siguiente enlace puede descargar el resumen del trabajo (enlace).

El segundo trabajo se titula: Organic Matter Effect on Fe(II) Oxidation Kinetics in the Labrador Sea. En este estudio se presentan resultados sobre la oxidación de Fe(II9 en la columna de agua a lo largo del Mar del Labrador en el Atlántico Norte. Para más detalles se puede consultar el resumen en este enlace.