I am currently a Ramón y Cajal with double affiliation (IMEDEA / UIB, Mallorca, SPAIN) since summer 2022. Previously, I have been a Senior Research Associate at Oregon State University, in the CEOAS department since 2010.
I got my Phd from Georgia Tech (Atlanta) in 2010 and an engineering degree in Hydraulics from the ENSEEIHT (France) in 2005.
I am specialized in modeling realistic ocean flows in regional and coastal seas including the Gulf of Alaska, California Current, Peru Chile Current system, Patagonian shelf and Southeast Atlantic.
I am particularly interested in the low frequency ocean variability, coastal and shelfbreak upwellings, eddy dynamics, transport of nutrient rich shelf water to the deep ocean and remote sensing.
Recently, I have also been working on physical-biological interactions of the Southwest Atlantic, a project that aims to better understand and assess the sources of the limiting factor to phytoplankton growth: iron.
For more information see my list of publications and C.V.
Abstract: The Patagonia shelf-break front presents sharp offshore changes in surface temperature, salinity, chlorophyll, and horizontal velocity shear. In summer, the cross-shore temperature and salinity changes are not uniform, suggesting the existence of multiple fronts. In winter, the offshore changes are fairly uniform, displaying a single thermohaline front located just offshore from the shelf-break. Cross-front temperature and salinity present significant seasonal variations associated with intense vertical stratification over the shelf during summer. The thermocline provides a density interval for cross-front isopycnal exchange, which may fertilize the outer shelf waters. The salinity front extends from the surface to the bottom and is observed year-round. Frontal displacements occur throughout the water column. The high surface chlorophyll along the front suggests a sustained nutrient flux to the shelf-break upper layer. Numerical experiments indicate intense frontal upwelling mediated by the interaction of the Malvinas Current with the bottom topography and suggest that upwelling in upstream portions of the shelf-break, advected northward along the shelf edge, may further modulate the nutrient fluxes required to sustain frontal productivity. A southward displacement of the northernmost extension of the front observed during the past decades may have biological and biogeochemical impacts.
Abstract: We use altimeter-derived geostrophic velocities, with and without the addition of surface Ekman transports, to create trajectories for virtual parcels in the California Current System (CCS). The goal is to investigate the poleward transport of passive water parcels in the surface 50-100 meters of the nominally equatorward system. Motivation for the study is provided by observations of anomalous biomass of copepods with warm water affinities along the Newport Hydrographic Line off central Oregon (44.7°N) during El Niño years, as well as during and following the 2014-2016 Marine Heat Wave. By backward tracking virtual parcels from 44.7°N, we find that the most distant source of passive water parcels in the upper ocean during a one-year period of travel is from within the Southern California Bight (SCB), north of 30°N. To make that journey, parcels use the Inshore Countercurrent off southern and central California during summer-winter and the Davidson Current off northern California and Oregon during autumn-winter. The inclusion of small-scale eddy diffusion usually increases the number of parcels that reach more northern latitudes, while the inclusion of Ekman velocities more often reduces those numbers. Even so, parcels can travel from the SCB to central Oregon in either the Ekman layer or beneath it in the geostrophic flow. Using backward tracking, we find that parcels arrive at 44.7°N most often in winter-spring, least often in autumn. They arrive from within the large-cape region off northern California (41°-42°N) during all years and all months, from just south of the large-cape region (38°-39°N) during most years but seldom in autumn, from south of Monterey Bay along central California (36°N) and within the SCB (34.5°N) during a third (or less) of the years and only in winter-spring. The shortest average transit times are found in winter: for parcels reaching 44.7°N in February, the average transit time is 2 months for parcels coming from 41°-42°N, 4 months for parcels coming from 38°-39°N and 5-6 months or more for parcels coming from south of 36°N. Transit times increase as the year progresses from winter to autumn. The longest average transit times are for parcels reaching central Oregon in autumn (9-12 months in October for parcels coming from south of 39°N). This makes the journey a multi-generational task for the copepods. Interannual variability in the observed southern copepod species biomass correlates highly with years when more virtual parcels from the south reach central and northern Oregon, providing increased confidence in the results found with the altimeter-derived parcel trajectories.
Abstract:The Southwestern Atlantic Ocean (SWA), is considered one of the most productive areas of the world, with a high abundance of ecologically and economically important fish species. Yet, the biological responses of this complex region to climate variability are still uncertain. Here, using 24 years of satellite-derived Chl-a data, we classified the SWA into 9 spatially coherent regions based on the temporal variability of Chl-a concentration, as revealed by SOM (Self-Organizing Maps) analysis. These biogeographical regions were the basis of a regional trend analysis in phytoplankton biomass, phenological indices, and environmental forcing variations. A general positive trend in phytoplankton concentration was observed, especially in the highly productive areas of the northern shelf-break, where phytoplankton biomass has increased at a rate of up to 0.42 ± 0.04 mg m−3 per decade. Significant positive trends in sea surface temperature were observed in 4 of the 9 regions (0.08–0.26 °C decade−1) and shoaling of the mixing layer depth in 5 of the 9 regions (−1.50 to −3.36 m decade−1). In addition to the generally positive trend in Chl-a, the most conspicuous change in the phytoplankton temporal patterns in the SWA is a delay in the autumn bloom (between 15 ± 3 and 24 ± 6 days decade−1, depending on the region). The observed variations in phytoplankton phenology could be attributed to climate-induced ocean warming and extended stratification period. Our results provided further evidence of the impact of climate change on these highly productive waters.
Abstract:The strong interaction between the Brazil Current and the adjacent shelf is clearly visible in satellite-derived products (sea surface temperature, salinity, and chlorophyll-a concentration). Assessments of circulation features and cross-shelf exchanges from these products are, however, limited to the surface layer. Here we analyze the regional circulation and dynamics using the results of a suite of process-oriented, high-resolution numerical experiments. Passive tracers and Lagrangian floats characterize the exchanges between the shelf and the open ocean, identifying regions of high variability, and assessing the contribution of small-scale eddies to the cross-shelf mass exchanges. We estimate that 0.2-0.4Sv of the shelf transport variability between 34°S and 25°S comes from ocean internal variability which represents ~50%-70% of the total variability. Between 25°S and 21°S, internal ocean variability represents more than 90% of the shelf transport variability. We find that generation of cyclonic eddies is more frequent (>15% of the time) at the shelfbreak bights. The core of these eddies contains fresher, colder, and more nutrient-rich shelf waters. Maps of satellite chlorophyll-a concentration suggest that the horizontal and vertical exchanges of mass associated with these eddies are a critical element of the primary production cycle.
| Attachment (Curriculum) | Size |
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| cv_vincent_combes_english.pdf | 143 KB |
