Hydrodynamic provinces and oceanic connectivity from a transport network help designing marine reserves

Oceanic dispersal and connectivity have been identified as crucial factors for structuring marine populations and designing Marine Protected Areas (MPAs). Focusing on larval dispersal by ocean currents, we propose an approach coupling Lagrangian transport and new tools from Network Theory to characterize marine connectivity in the Mediterranean basin. Larvae of different pelagic durations and seasons are modeled as passive tracers advected in a simulated oceanic surface flow from which a network of connected areas is constructed. Hydrodynamical provinces extracted from this network are delimited by frontiers which match multi-scale oceanographic features. By examining the repeated occurrence of such boundaries, we identify the spatial scales and geographic structures that would control larval dispersal across the entire seascape. Based on these hydrodynamical units, we study novel connectivity metrics for existing reserves. Our results are discussed in the context of ocean biogeography and MPAs design, having ecological and managerial implications

Oceanus.

v. 26, no. 4 (1983

Strong Mixing and Recirculation in the Northwestern Argentine Basin

The Atlantic component of the Meridional Overturning Circulation (AMOC) is a key contributor to the global meridional transport of volume, salt, and heat, and thus plays a central role in global climate. As part of ongoing efforts to monitor the intensity and variability of the AMOC in the South Atlantic, hydrographic sections have been regularly occupied since 2009 near the western boundary along a zonal line at 34.5°S. Here this high-quality, high-resolution data set is analyzed to establish the average hydrographic conditions of the northwestern Argentine Basin and the water mass spatial and temporal variability. The water mass analysis also reveals the pathways of the flow in this region, which are further corroborated by full-depth direct velocity measurements. The repeated hydrographic sections capture an extremely rich vertical structure, characterized by seven distinct water mass layers of northern and southern origin, each with unique property signatures. Almost all of these layers exhibit a sharp zonally banded structure, which is indicative of recirculation cells offshore from the western boundary. The circulation at intermediate levels includes a previously undetected recirculation cell confined very close to the western boundary and superimposed on the classical intermediate water pathway beneath the South Atlantic subtropical gyre. The deep level flow is characterized by the Deep Western Boundary Current (DWBC) and a northward recirculation ~500 km east from the slope.Fil: Valla, Daniel. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; ArgentinaFil: Piola, Alberto Ricardo. 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; ArgentinaFil: Meinen, Christopher S.. Atlantic Oceanographic and Meteorological Laboratory; Estados UnidosFil: Campos, Edmo. Universidade de Sao Paulo; Brasi

Oceanic response to Hurricane Irma (2017) in the Exclusive Economic Zone of Cuba and the eastern Gulf of Mexico

An understanding of the oceanic response to tropical cyclones is of importance for studies on climate change, ecological variability and environmental protection. Hurricane Irma (2017, Atlantic Ocean) broke many records, including the fact that it was the first category 5 hurricane making landfall in Cuba since 1924. In this study, we assess the oceanic response of the waters of the Cuban Exclusive Economic Zone (EEZ) and the eastern Gulf of Mexico (GoM) to the passage of this hurricane. Overall, Irma led to a weak sea surface cooling in the EEZ, which was associated with the thermal structure of its waters and the fact that it was affected by the left-side quadrants of this hurricane. This cooling was driven by mixing and upwelling processes. In contrast, the chlorophyll-a (chl-a) concentration increase was comparable with climatological records, suggesting that horizontal advection of coastal waters and entrainment of chl-a rich waters from remote regions of the GoM influenced the post-storm chl-a concentration. Moreover, Irma increased the chl-a concentration in the northeastern GoM and stimulated the offshore transport of these chl-a-rich waters to the interior GoM. A high chl-a plume (HCP) extended southward across the eastern GoM during the first post-storm week of Irma, and these waters reached the northwestern Cuban coast following the Loop Current. An intensification of the geostrophic currents of an anticyclonic eddy at the upper front of the Loop Current, the formation of an anticyclonic-cyclonic eddy pair in the northeastern GoM and wind-driven advection governed the extension of this HCP

PICES Press, Vol. 5, No. 2, July 1997

WG 10 Fukuoka Workshop Pacific salmon:climate-linked long-term stock fluctuations The state of the eastern North Pacific in the second half of 1996 The state of the western North Pacific in the second half of 1996 The status of the Bering Sea in the second half of 1996 Yutaka Nagata Eulogy A brief look at mechanisms for support of oceanographic research in the United States Research interests and the funding system for the new Ministry of Maritime Affairs and Fisheries of the Republic of Korea PICES and electronic communication Japan Meteorological Agency: oceanographic activitie

Oceanus.

v. 26, no. 2 (1983

Collection of relevant results obtained with the ERTS-1 satellite images by the Institute for Space Research (INPE), volume 1

There are no author-identified significant results in this report