Water Masses and Circulation in the Tropical Pacific off Central Mexico and Surrounding Areas

13 páginas, 8 figuras, 2 tablasThe seasonal variations and the interactions of the water masses in the tropical Pacific off central Mexico (TPCM) and four surrounding areas were examined based on an extensive new hydrographic database. The regional water masses were redefined in terms of absolute salinity (SA) and conservative temperature (Θ) according to the Thermodynamic Equation of Seawater 2010 (TEOS-10). Hydrographic data and the evaporation minus (precipitation + runoff) balance were used to investigate the origin and seasonality of two salinity minima in the area. The shallow (50–100 m) salinity minimum originates with the California Current System and becomes saltier as it extends southeastward and mixes with tropical subsurface waters while the surface salinity minimum extends farther north in the TPCM in summer and fall because of the northward advection of tropical surface waters. The interactions between water masses allow a characterization of the seasonal pattern of circulation of the Mexican Coastal Current (MCC), the tropical branch of the California Current, and the flows through the entrance of the Gulf of California. The seasonality of the MCC inferred from the distribution of the water masses largely coincides with the geostrophic circulation forced by an annual Rossby waveThis is a product of the project CONACyT (SEP2011–168034-T), with collaboration from the following sources: CONACyT Projects 168034-T, T-9201, 4271P-T, 38797-T, 26653-T, 1076-T9201, 4271PT9601, C01–25343; 38834-T, C02-44870F,G34601-S, and 103898; Naval Postgraduate School; NOC-US; NOAA (GC04– 219); and the regular UABC budget through Projects 4009, 4015, 0324, 0333, and 0352. Funding came from CONACyT, México through the Grant 1329234 for the Ph.D. studies of Esther PortelaPeer reviewe

Informe de actividades 2001

1 archivo PDF (53 páginas)Informe de Actividades 2001 de la Rectoría de la Unidad Azcapotzalco, el cual tiene el doble objetivo de servir de instrumento de análisis, reflexión y balance de las acciones emprendidas, así como de seguimiento y comparación entre las instancias académicas y de a poyo

Disonancia colectiva ante la incertidumbre de vivir en zonas de riesgo

El presente artículo realiza un análisis acerca de la toma de decisiones, basadas en las creencias que poseen los individuos en su entorno, en este caso, en zonas de riesgo. Dichas decisiones son tomadas bajo la existencia de incertidumbre externa e interna en un contexto de interacción entre sujetos y en un marco analítico proporcionado por la teoría de juegos, en su esquema de juegos subjetivos no-cooperativos

Anuario estadístico 2001

1 archivo PDF (163 páginas)"Con el propósito de proporcionar elementos objetivos para el análisis de la vida académica de la Unidad Azcapotzalco. La Coordinación General de Planeación (COPLAN) pone a disposición de los interesados el anuario estadístico 2001. El presente documento contiene información relevante del sistema educativo nacional, matrícula, académicos, docencia, investigación, vinculación y presupuesto. Dicha información está presentada mediante cuadros con series de cinco años (1 997-2001 ) así como por gráficas de barras y circulares. El anuario estadístico 2001 contribuye a integrar el sistema de información de la UAM-A. también pretende ser un instrumento que apoye un conocimiento más amplio de nuestra unidad. La integración de la información del anuario estadístico 2001 fue posible gracias a la participación de instancias de la unidad tales como la Coordinación de Sistemas Escolares, Coordinación de Recursos Humanos, Coordinación de Vinculación, Coordinación de Servicios Administrativos y Secretarías académicas divisionales. Asimismo. se dispuso de información proporcionada por la dirección de sistemas escolares de Rectoría General. Reconocemos y agradecemos a todas las personas que colaboraron en este proyecto.

Distribution of calanoid copepods across the mesoscale frontal zone of tropical-subtropical convergence off México

8 pages, 1 table, 7 figuresThe distribution of calanoid copepods was investigated in the convergence zone between the California Current Water and Transitional Tropical Water in June 2010 to understand how this zooplankton community responds to mesoscale environmental structure. Hydrographic conditions and zooplankton profiles were measured along two transects which crossed a mesoscale front and adjacent structures, visible in sea surface temperature and ocean color satellite images. The hydrographic structure showed strong temperature (~2 °C) and oxygen (50 μmol kg−1) gradients in the frontal zone (~90 km) associated with a sinking of the thermocline and oxycline, from ~30 m depth in the Transitional Tropical Water, to ~ 90 m depth in the California Current Water. The front was marked by a salinity minimum (<34.3 g kg−1) that sank along the sloping thermocline. High chlorophyll-a concentrations associated with the thermocline were detected in the Transitional Tropical Water, where a cyclonic eddy was defined. These concentrations decreased as the thermocline depth increased. Multivariate analysis defined three calanoid copepod habitats related to the hydrographic structure. A habitat with the highest copepod concentration (24,704 copepods 1000 m−3) was found on the tropical water side associated with a cyclonic eddy. Subeucalanus subtenuis and Centropages furcatus, indicator species, were concentrated between the thermocline (~30 m depth) and the sea surface. On the subtropical water side, where the thermocline was deeper, a habitat with the lowest copepod concentration (3304 copepods 1000 m−3, an order of magnitude smaller), characterized by Euchaeta indica and Centropages elongates, was observed. As an unexpected result, the habitat located in the frontal zone, characterized by Scolecithrix bradyi and Heterorhabdus papilliger had low copepod concentration (4453 copepods.1000 m-3). This low concetration could be due to the steep thermocline slope in the frontal zone, which could cause the thermocline depth to rapidly exceed the photic zone depth, and therefore affect the availability of food for calanoid copepods. It is concluded that the definition of the calanoid copepod habitats, was not only caused by the front itself, but by its interaction with other fine-scale mechanisms that generate oceanographic conditions leading to development of different food webs depending on the structure of water columnThis work was made possible thanks to the financial support of SEP-CONACyT (contracts 2014-236864, LSV), and Fronteras de la Ciencia-CONACyT (contracts 2015-2-280, LSV)Peer reviewe

Larval fish habitats in a mesoscale dipole eddy in the gulf of California

12 pages, 10 figures, 2 tablesThe three-dimensional distribution of larval fish habitats in a mesoscale dipole eddy was analyzed in the Southern Gulf of California in July 2010. Detection of the characteristic mushroom-shape using chlorophyll and sea surface temperature satellite images was used to direct sampling of two transects across the structure with conductivity, temperature, depth casts and stratified oblique zooplankton hauls with opening-closing net. The latter sampled every 17 m layer down to the thermocline and every 50 m layer from the thermocline down to 200 m depth. Lowered Acoustic Doppler Current Profiler velocities revealed that the dipole structure persisted down to 800 m depth. The “cap” showed two opposite poles: one cyclonic with diameter ~50 km, and the other anticyclonic with diameter~80 km. It had a vigorous central jet with speeds>25 cm/s. The Θ-SA properties were consistent with formation of the structure outside the Gulf of California in Tropical Surface and Subtropical Subsurface water masses. In this context, three larval fish habitats were statistically defined (P<0.001). One habitat, located in the surface mixed layer (~15 m depth), was characterized by the highest species richness, high abundance of the mesopelagic species Vinciguerria lucetia and the presence of epipelagic species like Auxis sp.; this habitat was correlated with the warm (24–25 °C) and oxygenated (4–5 mL/L) Tropical Surface Water. The other two larval fish habitats were defined below the thermocline (between ~15 and 50 m depth) and comprised mainly by mesopelagic species. One of them occurred in the cyclonic pole and central jet zone with the highest larval abundance, dominated by Diogenichthys laternatus; the other habitat was located in the dipole margins, or zones of return flow, with the lowest larval abundance, characterized by Psenes sio and Bathylagoides wesethi, species frequent outside of the Gulf of California. These two habitats were correlated with cooler (~13–22 °C) and hypoxic (0.03–1 mL/L) Subtropical Subsurface water masses. The results suggest that during the formation of the dipole, water masses dominated by different species were trapped, forming larval fish habitats.This work was made possible thanks to the financial support of SEP-CONACyT (contracts 2014-236864), and by the Instituto Poli-técnico Nacional (Multidisciplinary Project 2014-0539).Peer reviewe

Incursiones en torno a la relación entre Neuroética y la elección individual

En la presente investigación se argumenta acerca de una alternativa a la elección racional, esto a partir de un mecanismo de elección que toma en cuenta los avances en neuroética, vistos como la capacidad innata y evolutiva de los humanos de formarse una condición axiológica de la vida, es decir, la capacidad de registro de los valores morales para la identificación de lo bueno y lo malo, que permita presentar un mecanismo de elección am-pliado, basado en la toma en cuenta de los valores morales como parámetros que permitan expresar las valoraciones subjetivas de intensidad de un valor moral determinado a través de funciones probabilísticas de creencia cognitiva. Donde la preferencia revelada del valor o del antivalor en su métrica permite observar intersubjetivamente cuál es el proceso deelección de cosas a partir de la propia subjetividad del individuo