Semblanzas Ictiológicas Iberoamericanas: Franco Andrés Teixeira de Mello Ramírez

A través desta nova série, tentamos conhecer os diferentes aspectos pessoais dos integrantes da comunidade ictiológica ibero-americana. Esta iniciativa compartilha o espírito e o objetivo das biografias de pesquisadores brasileiros, procurando, informalmente, outro ponto de conexão na “comunidade de ictiólogos ibero-americanos”. Talvez esteja equivocado na minha apreciação, mas creio que esta tentativa compensa, já que, com a colaboração generosa e voluntária dos integrantes deste “universo”, marcaremos um registro no tempo da Ictiologia Neotropical.

Integrating varve and tree-ring time series for southern California climate reconstruction: a 20th century outlook [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Our objective is to combine terrestrial and oceanic records for reconstructing West Coast climate. Tree rings and marine laminated sediments provide high-resolution, accurately dated proxy data on the variability of climate and on the productivity of the ocean and have been used to reconstruct precipitation, temperature, sea level pressure, primary productivity, and other large-scale parameters. We present here the latest Santa Barbara basin varve chronology for the twentieth century as well as a newly developed tree-ring chronology for Torrey pine.

Long-term response of Torrey pine to coastal climate: precipitation, temperature, and fog

EXTRACT (SEE PDF FOR FULL ABSTRACT): Torrey pine (Pinus torreyana Parry ex Carr.) has one of the most limited geographical ranges and population size in the Pinus genus; it is present only on Santa Rosa Island and on the coast between San Diego and Del Mar, where our research was conducted. A 168-year chronology (1827-1994) was developed using 28 increment cores extracted from 15 living and 2 dead stranding trees at Torrey Pines State Reserve, San Diego, California. ... The spatial correlation with western North America winter and spring precipitation, as well as with published tree-ring chronologies, indicates a connection with the American Southwest. Global correlation maps with winter sea level pressure and sea surface temperature are consistent with the hypothesis that San Diego precipitation is affected by a southerly displaced North Pacific storm track and by warmer water farther south, both leading to higher transport of lower latitude moisture.

The near-AD 1600 multi-proxy puzzle

EXTRACT (SEE PDF FOR FULL ABSTRACT): A varve chronology with annual resolution (AD 1117-1992) has been developed recently for Santa Barbara Basin. Varve thickness and water content show an exponential trend consistent with expected patterns in the presence of sediment compaction over time. Annual varve thickness was decomposed into orthogonal components using singular spectrum analysis (SSA) to identify and retrieve inter-decadal oscillations. ... This suggests a connection with global-scale decadal cycles identified in the subtropical Pacific gyre circulation and, possibly, with solar-driven phenomena. The near-1600 AD event coincides with (a) a similarly sudden change of state in nearby Santa Monica Basin that triggered the onset of anoxic conditions and the preservation of laminated sediments, (b) an extreme drought over the American Southwest, (c) a transformation of the age structure in a number of forest populations throughout Arizona and New Mexico. Total organic carbon burial flux in Santa Barbara Basin varves also shows a marked change after AD 1600. A possible climatic link is proposed that involves pathways for moisture transport in the Southwest at decadal and longer time scales.

La corriente de Malvinas. Ramas y frentes oceánicos en el mar patagónico

La corriente de Malvinas corre de sur a norte sobre el borde del talud que marca el fin de la plataforma continental patagónica (océano Atlántico sudoccidental), a lo largo de unos 1800 kilómetros. Su presencia da lugar a una zona del mar con muy rica diversidad biológica y ecológica, lo que incluye pesquerías de importancia económica regional. Los datos satelitales permiten avanzar el estudio del mar patagónico en una zona en que las aguas de la plataforma continental cambian de temperatura por efecto de la corriente fría de Malvinas, lo que influye notablemente sobre la vida marina. Este artículo de divulgación científica incluye información sobre frentes oceánicos del Mar Argentino, datos satelitales y detección de ramas y frentes térmicos, la ecología de las especies marinas, finalizando con lecturas sugeridas.

Perspectivas de la biología marina

La biología marina es una rama de las ciencias del mar de reciente desarrollo en la Argentina (oceáno Atlántico sudoccidental) que está en franco crecimiento. Se muestra un panorama del desarrollo de las diversas disciplinas, como los estudios sobre la biodiversidad marina y de la biología marina y pesquera, así como amenazas a los ambientes marinos y medidas de conservación tomadas. Se incluyen las perspectivas para futuros estudios de biología marina, los beneficios de las iniciativas de divulgación científica, entre otros temas, así como otras lecturas afines sugeridas.