534 research outputs found
The Western Alboran Gyre: an analysis of its properties and its exchange with surrounding water
Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(12), (2020): 3379-3402, https://do.org/10.1175/JPO-D-20-0028.1.One of the largest and most persistent features in the Alboran Sea is the Western Alboran Gyre (WAG), an anticyclonic recirculation bounded by the Atlantic Jet (AJ) to the north and the Moroccan coast to the south. Eulerian budgets from several months of a high-resolution model run are used to examine the exchange of water across the Eulerian WAG’s boundary and the processes affecting the salinity, temperature, and vorticity of the WAG. The volume transport across the sides of the WAG is found to be related to vertical isopycnal movement at the base of the gyre. Advection is found to drive a decay in the salinity minimum and anticyclonic vorticity of the Eulerian WAG. Given the large contributions of advection, a Lagrangian analysis is performed, revealing geometric aspects of the exchange that are hidden in an Eulerian view. In particular, stable and unstable manifolds identify a stirring region around the outer reaches of the gyre where water is exchanged with the WAG on a time scale of weeks. Its complement is an inner core that expands with depth and exchanges water with its surroundings on much longer time scales. The 3D evolution of one parcel, or lobe, of water as it enters the WAG is also described, identifying a general Lagrangian subduction pathway.This work was supported on DOD (MURI) Grant N000141110087, ONR Grant N000141812417, and NSF Grant OCE-1558806.2021-05-1
Numerical modeling of three-dimensional stratified tidal flow over Camarinal Sill, Strait of Gibraltar
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C12026, doi:10.1029/2011JC007093.The baroclinic response to barotropic tidal forcing in the Camarinal Sill area, within the Strait of Gibraltar, is investigated with a three-dimensional, fully nonlinear, nonhydrostatic numerical model. The aim of numerical efforts was the assessment of three-dimensional effects, which are potentially significant in the area because of rather irregular bottom topography, variable background stratification, and complex structure of barotropic tides. Model results reveal a complex baroclinic response under relatively moderate flood tidal currents, which includes the formation of internal hydraulic jumps upstream of the sill, internal cross waves close to the channel walls, and a plunging pycnocline at the lee side of the sill crest. These structures exhibit significant cross-channel spatial dependence and may appear to be aligned together across the channel. This fact makes their identification difficult from the surface pattern captured by remote sensing images. Under strong barotropic forcing (spring tides) the upstream hydraulic jumps are shifted to the lee side of Camarinal Sill, where a single internal hydraulic jump is formed. Significant first- and second-mode hydraulic jumps are also generated near smaller secondary sills in Tangier basin, thus extending the occurrence of intense water mixing and energy dissipation to other zones of the strait.This work is a contribution to the Spanishfunded
National Project INGRES-2 (CTM2006-02326). Partial financial
support from AcciĂłn Complementaria CTM2009-05810/E (Spanish Ministry
of Science and Innovation) and project P08-RNM-3738 from Plan
Andaluz de InvestigaciĂłn (Andalucia regional government) is acknowledged.2012-06-1
What drives the spreading patterns of the Mediterranean Outflow Pattern in the Eastern Gulf of Cádiz, SW Iberian Peninsula?
What drives the spreading pattern of the Mediterranean Outflow Water (MOW) in the eastern Gulf Of Cadiz, SW Iberian Peninsula?
Early transformation of the Mediterranean Outflow Water (MOW) in the Gulf Of Cádiz, SW Iberian Peninsula: pathways, mixing and temporal variability.
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Monitoring the hydrological characteristics of the Mediterranean Outflow. A decade of θ-S data in the bottom layer of the Espartel Sill, Strait of Gibraltar
Hydrodynamic connectivity and dispersal patterns of a transboundary species (Pagellus bogaraveo) in the Strait of Gibraltar and adjacent basins
The blackspot seabream (Pagellus bogaraveo) is a benthopelagic fish species highlyappreciated by consumers and an important target of the Spanish and Moroccan fish-eries in the transcontinental waters of the Strait of Gibraltar area. It is also one of themost exploited resources of the region, which has led to a situation of overex-ploitation and a notable drop of catches. To gain insight into the sustainability of thisresource and certain patterns of the spatial adaptation of the species, a high-resolution circulation model coupled to a Lagrangian tracking module has beenemployed to investigate the dispersal pathways of blackspot seabream, using eggsand larvae (early-life-stages, ELS) as purely passive particles advected by currents.Several spawning scenarios consisting of different spatial (depths and sites) and tem-poral (tidal phase and strength) initial conditions have been analyzed to identify themost likely pathways of ELS dispersion. Eastward transport by the Atlantic Jet exitingthe Strait of Gibraltar is the most influencing process in that dispersion. Regardingtemporal fluctuations, fortnightly tidal modulation is the prevailing factor to deter-mine the horizontal paths of the ELS, spring tides being the cause of the greatestscattering of propagules. Spawning depth in the Strait of Gibraltar is a critical condi-tion, as revealed by the model sensitivity tests. Potential implications of the results ofthe study to improve the assessment and management of this species are discussed.This work was partially funded by the FAO Project: CopeMed phase II
“Coordination to Support Fisheries Management in the Western and
Central Mediterranean” and the General Fisheries Commission of
the Mediterranean GFCM, both with the financial support of
the Directorate-General for Maritime Affairs and Fisheries of the
European Commission (DG-MARE) and the Spanish Ministry of
Agriculture, Fishery and Food. Funding for open access charge was
provided by Universidad de Málaga/CBUA
RAPD-PCR molecular analysis of the threatened Cabrera’s vole populations in the Iberian Peninsula
Optimal management and conservation programs of the threatened Cabrera’s vole require investigating potential molecular genetic markers in the genomic background, if the few remaining fragile populations are to be conserved. A collection of 30 Cabrera’s vole representing four populations in Spain and Portugal was characterized by 134 RAPD-PCR markers. Molecular analyses did not detect low level of the genetic diversity or population bottlenecks in all studied populations, in discordance with the expectation of low level of viability of the Cabrera’s vole. The results described Cabrera’s vole populations as a single genetic unit with slightly restricted gene flow. Phylogenetic reconstruction suggested genetic differentiation between Northern and Southern Cabrera’s vole populations, with the basal branches formed by the southern populations, which may be an evidence of the southern origin of Iberian vole ancestral population. To our knowledge, this is the first study on the genetic diversity of Microtus cabrerae, which may have further application for the conservation programs of this threatened species of Iberian vole.Keywords: Microtus cabrerae, RAPD-PCR, Spain, Portugal, gene flow, genetic diversity, bottleneck, conservationAfrican Journal of Biotechnology Vol. 12(26), pp. 4065-407
Utilidad de los agonistas, moduladores selectivos y antagonistas puros del receptor de estrĂłgenos en estudios morfofuncionales del Ăştero de la rata
De acuerdo con el Instituto Nacional de la Salud, la especie murina es una de las especies más importantes en el estudio de la fisiologĂa y de un gran nĂşmero de procesos que tienen lugar en el organismo, tanto en la especie humana como en los animales. Se estima que en el 90-95 % de los estudios realizados en biomedicina se utilizan ratones y ratas. En la rata, la funciĂłn reproductora es debida a las hormonas esteroideas ováricas, estrĂłgenos (E) y progesterona (P). Durante las distintas fases del ciclo estral, el Ăştero sufre cambios morfolĂłgicos y funcionales que dependen de la acciĂłn de los E y la P y que incluyen la proliferaciĂłn celular y la sĂntesis de receptores de progesterona en el epitelio, y la proliferaciĂłn celular del estroma y su consecuente decidualizaciĂłn, respectivamente. La acciĂłn de los E y la P en el Ăştero está mediada por receptores intracelulares, los receptores de E (RE) y los receptores de P (RP). Ambos receptores tienen dos isofomas, α y β para los RE y A y B para los RP. Estudios previos realizados tanto en ratones knock-out (KO) para una de las isoformas del RE y las dos del RP, como en ratas ovariectomizadas (OVX) a las que se administran agonistas estrogĂ©nicos selectivos para una de las isoformas del RE, han revelado que la mayorĂa de las acciones de los E en el Ăştero son mediadas por la isoforma α del RE, aunque en la actualidad el papel especĂfico de cada una de las isoformas se conoce solo parcialmente. Tanto el conocimiento molecular del RE como los avances farmacolĂłgicos han permitido el desarrollo de nuevos agentes agonistas y antagonistas para las distintas isoformas del RE que hacen posible estudiar la acciĂłn que desempeña en el Ăştero cada una de las isoformas del RE
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