Elisa Lovecchio

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Lovecchio

First Name

Elisa

ORCID

0000-0002-7183-4761

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Publications 1 - 9 of 9

ENSO and the fate of coastal production in the California Current System from 1979 to 2015
Frischknecht, Martin; Münnich, Matthias; Lovecchio, Elisa; et al. (2016)
Long range offshore transport of organic carbon from the Canary Upwelling System, an eddy-resolving modeling study
Lovecchio, Elisa (2018)
The marine biological pump, consisting of organic carbon production, export and remineralization, is an essential component of the global carbon cycle and exerts an important control on atmospheric carbon concentrations. Lateral fluxes of organic carbon out of their region of production, especially from coastal regions, may explain the large rates of remineralization in regions of low productivity, but they are currently unaccounted by export and budget estimates. Here I quantify and characterize this lateral offshore transport of organic carbon from the north-western African coast of the Canary Upwelling System (CanUS) up to the middle of the oligotrophic North Atlantic Gyre. To this aim, I run the physical Regional Oceanic Modeling System (ROMS) coupled with the biogeochemical-ecosystem Nutrient Phytoplankton Zooplankton Detritus (NPZD) model on an Atlantic telescopic grid. This newly developed grid covers the entire Atlantic basin, allowing to study the lateral transport on very large spatial scales, and is eddy resolving in the region of interest thanks to a strong grid refinement towards the north-western African coast. With the use of climatological model simulations I study the magnitude, reach, pattern and impact of the total long range offshore flux of organic carbon, and study in detail the special role of mesoscale eddies and filaments in this transport, with a particular attention to the evolution of the eddy organic carbon budget. The results of my work indicate that, on average, more than 1/3 of the net community production of the first 100 km from the CanUS coast is laterally exported away from this region towards the open waters in the euphotic layer (100 m depth). On average in the CanUS, the divergence of this offshore flux is the largest lateral input of organic carbon in the open waters up to 1500 km from the coast and represents up to 1/3 of the large-scale mean offshore production in the open waters. This divergence even exceeds half of the mean offshore production in the euphotic layer of the central CanUS subregion, a key zonal band for the alongshore collection and offshore redistribution of the biogeochemical tracers. In the 100 m - 200 m depth layer, the offshore transport continues to dominate the lateral fluxes of organic carbon, displacing it further towards the center of the north Atlantic gyre. The long-range offshore transport of organic carbon results in a spatial decoupling of its sources and sinks, corresponding to a strongly net autotrophic watercolumn on the shelf, and a net heterotrophic watercolumn offshore, the latter stemming from the fueling of extra deep heterotrophic activity. My results demonstrate also that mesoscale activity has a fundamental role in the offshore redistribution of the organic carbon in the euphotic layer. Coastal upwelling filaments, identified with a newly developed algorithm, contribute 80% to the zonal fluxes at 100 km offshore and are the main advective source of organic carbon in the first 500 km from the coast, but their contribution declines to zero at 1000 km offshore. Mesoscale eddies, instead, represent about 20% of the offshore flux between 500 km from the coast and the middle of the North Atlantic gyre. Despite their slow drift, eddies account for 30 % of the of the total organic carbon of the offshore euphotic layer (2/3 found in cyclonic eddies), thus contributing significantly to the carbon reservoir in the open ocean. In the eddy-rich northern region of the CanUS, the long lasting organic carbon reservoir of cyclonic eddies is sustained in large part by the efficient trapping of organic carbon and nutrients at formation. These core-centric and laterally-isolated structures lose organic carbon along their way to the open ocean via sinking, while rejunevating the organic carbon reservoir through local recycling and through the use of the trapped nutrients. Anticyclonic eddies, instead, are high in organic carbon at their rim; new production in this kind of eddies is allowed by the lateral stirring of the large scale regional gradient of nutrients combined with substantial vertical mixing. Overall, the results of this work demonstrate the importance of accounting for the three-dimensionality of the marine biological pump, and highlight the essential role of the coastal ocean in the global carbon cycle. Moreover, they clarify the role of mesoscale activity in the lateral redistribution of the organic carbon from the coast, identifying the diversity of underlying mechanisms that regulate the organic carbon budget of mesoscale eddies.
Mesoscale contribution to the long-range offshore transport of organic carbon from the Canary Upwelling System to the open North Atlantic
Lovecchio, Elisa; Gruber, Nicolas; Münnich, Matthias (2018)
Biogeosciences
Role of Eddies and Filaments in the Offshore Transport of Organic Carbon in the Canary Upwelling System: a Modeling Study
Lovecchio, Elisa; Gruber, Nicolas; Münnich, Matthias (2018)
Ocean Sciences Meeting Abstract
Long-range offshore transport of Organic Carbon from the Canary Upwelling System to the open North Atlantic
Lovecchio, Elisa; Frischknecht, Martin; Byrne, David; et al. (2016)
The 3D biological pump in EBUS regions: long-range offshore transport of organic carbon from the northwestern African coast to the open Atlantic
Lovecchio, Elisa; Gruber, Nicolas; Münnich, Matthias; et al. (2018)
On the Processes Sustaining Biological Production in the Offshore Propagating Eddies of the Northern Canary Upwelling System
Lovecchio, Elisa; Gruber, Nicolas; Münnich, Matthias; et al. (2022)
Journal of Geophysical Research: Oceans
Oceanic mesoscale eddies constitute ephemeral hotspots for marine life and are pivotal for the lateral transport of nutrients and organic matter. Here, we use a high-resolution coupled physical-biogeochemical model to study the processes sustaining biological production and export in long-living cyclonic (CE) and anticyclonic (AE) eddies of the northern Canary Upwelling System (CanUS). We track the eddies for 18 months as they propagate offshore, and study their composite properties in time in a Lagrangian manner. Our model shows that long-living CEs sustain their production with the nitrogen that they initially trap in the nearshore nutrient-rich waters and keep isolated in their cores. The vertical input of nitrate from below tends to be comparatively small, and is mostly driven by mixing. In contrast, AEs tend to start with low nutrient concentrations in their core as they do not trap coastal waters, but have elevated concentrations at their periphery. In AEs, stirring is responsible for both the building up of the positive nitrate anomaly at depth and the enhanced lateral input of organic nitrogen in the near-surface. Compared to CEs, the input of nitrate into the euphotic zone by vertical mixing is substantially more important. Though regenerated production dominates in both types of eddies, new production is higher than the regional average in CE cores and at the rim of AEs, partially compensating for the intense losses due to sinking. Both cyclonic trapping and transport and anticyclonic stirring shape the regional pattern of organic matter and nutrients in the northern CanUS.
Drivers and impact of the seasonal variability of the organic carbon offshore transport in the Canary upwelling system
Bonino, Giulia; Lovecchio, Elisa; Gruber, Nicolas; et al. (2021)
Biogeosciences
The Canary upwelling system (CanUS) is a productive coastal region characterized by strong seasonality and an intense offshore transport of organic carbon (Corg) to the adjacent oligotrophic offshore waters. There, the respiration of this Corg substantially modifies net community production (NCP). While this transport and the resulting coupling of the biogeochemistry between the coastal and open ocean has been well studied in the annual mean, the temporal variability, and especially its seasonality, has not yet been investigated. Here, we determine the seasonal variability of the offshore transport of Corg, its mesoscale component, latitudinal differences, and the underlying physical and biological drivers. To this end, we employ the Regional Ocean Modeling System (ROMS) coupled to a nutrient–phytoplankton–zooplankton–detritus (NPZD) ecosystem model. Our results reveal the importance of the mesoscale fluxes and of the upwelling processes (coastal upwelling and Ekman pumping) in modulating the seasonal variation of the offshore Corg transport. We find that the region surrounding Cape Blanc (21∘ N) hosts the most intense Corg offshore flux in every season, linked to the persistent, and far reaching Cape Blanc filament and its interaction with the Cape Verde Front. Coastal upwelling filaments dominate the seasonality of the total offshore flux up to 100 km from the coast, contributing in every season at least 80 % to the total flux. The seasonality of the upwelling modulates the offshore Corg seasonality hundreds of kilometers from the CanUS coast via lateral redistribution of nearshore production. North of 24.5∘ N, the sharp summer–fall peak of coastal upwelling results in an export of more than 30 % of the coastal Corg at 100 km offshore due to a combination of intensified nearshore production and offshore fluxes. To the south, the less pronounced upwelling seasonality regulates an overall larger but farther-reaching and less seasonally varying lateral flux, which exports between 60 % and 90 % of the coastal production more than 100 km offshore. Overall, we show that the temporal variability of nearshore processes modulates the variability of Corg and NCP hundreds of kilometers offshore from the CanUS coast via the offshore transport of the nearshore production.
Filament and eddy contribution to the offshore transport of organic carbon
Lovecchio, Elisa; Gruber, Nicolas; Münnich, Matthias (2018)

Publications 1 - 9 of 9

Elisa Lovecchio

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