In October 2021, the Sicily Channel and the central-western Ionian Sea were affected by the passa... more In October 2021, the Sicily Channel and the central-western Ionian Sea were affected by the passage of the tropical-like cyclone, or MEDICANE, Apollo. The system reached its maximum intensity between 29 and 30 October 2021 producing several damages, intense precipitations and huge coastal floodings in Sicily and Calabria regions. The surface circulation in the MEDICANE impacted area was characterized by permanent cyclonic vortices, offering the chance to describe the impact of a tropical-like cyclone on a pre-existing cold circulation structure. Atmospheric and ocean reanalyses (ERA5 and Marine Copernicus Service), as well as in-situ data from Argo floats, were used to describe the temporal evolution of Apollo, the resulting air-sea interaction, the thermohaline and biological response to its passage in the upper layer (0-150 m) of the western Ionian Sea. During the event, the core of the marine cyclone was characterized by a dramatic drop in temperature, corresponding to a local maximum in the wind-stress curl, Ekman pumping and current field relative vorticity. The strengthening of the cyclonic circulation led by the wind stress curl produced a strong vertical mixing in the surface layer (from 0 m to the Mixed Layer Depth - MLD) and an upwelling in the subsurface layer below the thermocline (MLD-150 m). The combined effect of vertical mixing and upwelling resulted in a shoaling of MLD, deep chlorophyll-a maximum, nutricline, and halocline. Oxygen and chlorophyll-a concentrations increased at surface, due to the enhanced oxygen solubility in the cooler water and higher productivity due to the increase of nutrients upwelled to the surface layer. These results show that the pre-existing cyclonic vortex along Apollo's trajectory leads to a different physical response compared to the one observed during previous MEDICANEs, confirming the influence of the conditions in place in driving the ocean’s reply to the extreme weather systems.
The variability of the MODIS chlorophyll concentration in the northern Adriatic Sea is described ... more The variability of the MODIS chlorophyll concentration in the northern Adriatic Sea is described between July 2002 and January 2005 and related to the Po River discharge rates and local wind forcing. After interpolation, the MODIS data were decomposed into EOF modes. Significant variability (∼61%) is explained by the first three modes in which mode 1 includes a strong seasonal cycle with enhanced signal in winter for the open sea waters and a second maximum in April–May, and mode 2 separates the coastal and river‐influenced waters, from the open sea area. The temporal amplitude of the modes is significantly correlated with the Po River runoff. The interpolated MODIS data were also correlated with the Po River discharge rates, resulting in significant positive correlation north and south of the delta and off the Croatian Islands. When correlated with wind speed, the MODIS chlorophyll shows positive correlation in the area off Istria, off Croatia and at the edge of the coastal layer north of Ancona. Using wind regimes, similar patterns are found for the Bora‐wind like winds. In contrast, for Sirocco‐like winds, the correlation is significantly positive in the vicinity and north of the Po River delta. The regions off Ancona and Istria have poor correlation with the Po and wind because the MODIS chlorophyll variability is associated with mesoscale instability features not directly related to these forcing parameters. Poor (and even slightly negative) correlations are found off the Po delta. In most areas, correlations reach maximum values after 1–2 days.
ABSTRACT We will introduce GROOM, a European Union funded design study to evaluate the requiremen... more ABSTRACT We will introduce GROOM, a European Union funded design study to evaluate the requirements needed to set up a sustainable glider infrastructure to safely operate individual as well as fleets of gliders. Operations shall be coordinated to fill the gaps left by present marine observation systems on global, regional and coastal scale, with benefits for both fundamental marine research and operational oceanography. To maximize the efficiency and scientific outcome in operating gliders, networking and capacity building for the present as well as future glider community are essential. The networking will overcome the fragmented infrastructure to operate gliders, on a European level, but also globally. The concept and strategies employed by GROOM to streamline the infrastructure development will be outlined. The final system is envisioned to allow for a shared operation of gliders (individuals as well as fleets), a shared maintenance of glider, the free and efficient exchange of information in the network, an exchange of hardware, software and service, and the efficient flow of data with appropriate data quality control procedures, interoperability of the components by standardization of procedures and protocols for sensor calibration. Certain part of this infrastructure can and should be adopted from other observatory platforms, were more mature solution exists or under development (e.g. Argo floats data flow, moorings multiparametric data calibration procedures and data protocols) but given the unique characteristic and requirements of glider operations a specific and dedicated infrastructure is required.
HAL (Le Centre pour la Communication Scientifique Directe), Apr 17, 2016
In the 80s, the POEM (Physical Oceanography of the Eastern Mediterranean) cruises in the Levantin... more In the 80s, the POEM (Physical Oceanography of the Eastern Mediterranean) cruises in the Levantine Basin first revealed the presence of a very pronounced dynamical structure off Cyprus: The Cyprus Warm Core Eddy. Since then, a large amount of data have been collected thanks to the use of autonomous oceanic gliders (+8000 profiles since 2009). Part of those profiles were carried out in the upper layers down to 200 m, and we take benefit of a novel approach named ITCOMP SOM that uses a statistical approach to extend them down to 1000 m (see [1] for more details). This dataset have a particularly good spatio-temporal coverage in 2009 for about a month, thanks to simultaneous deployments of several gliders (up to 6). In this study, we present a set of 3D reconstruction of the dynamical and hydrographical characteristics of the Warm Core Cyprus Eddy between 2009 and 2015. Moreover, chlorophyll-a fluorescence data measured by the gliders give evidence to strong vertical velocities at the edge of the eddy. We discuss possible mechanisms (frontogenesis, symmetric instability) that could generate such signals and provide an assessment of the role of this peculiar circulation feature on the circulation and biogeochemistry of the Levantine basin. Reference: [1] Charantonis, A., P. Testor, L. Mortier, F. D'Ortenzio, S. Thiria (2015): Completion of a sparse GLIDER database using multi-iterative Self-Organizing Maps (ITCOMP SOM), Procedia Computer Science, 51(1):2198-2206. DOI: 10.1016/j.procs.2015.05.496
Skip to main content. AGU Home. FastFind » Lastname: doi:10.1029/ Year: -Select Journal-... Unusu... more Skip to main content. AGU Home. FastFind » Lastname: doi:10.1029/ Year: -Select Journal-... Unusual upwelling event and current reversal off the Italian Adriatic coast in summer 2003. Pierre-Marie Poulain. ...
The Mediterranean Sea is very sensitive to climatic changes due to its semi-enclosed nature and i... more The Mediterranean Sea is very sensitive to climatic changes due to its semi-enclosed nature and is therefore defined as one of the hotspots in future climate change projections. In this study, we use Argo float data to assess climatologies and trends in temperature and Ocean Heat Content (OHC) throughout the Mediterranean Sea and for specific sub-basins (e.g. Western and Eastern Mediterranean, Gulf of Lion, South Adriatic). The amount of the OHC, spatially averaged in bins of 1°x1° over the period from 2001 to 2020, increases from west to east in the Mediterranean Sea. Time series of temperature and OHC from 2005 to 2020, estimated in the surface and intermediate layers (5-700 m) and deeper layer (700-2000 m), reveal significant warming trends and an increase of OHC. The upper 700 m of the Mediterranean Sea show a temperature trend of 0.041 ± 0.012°C·yr-1, corresponding to an annual increase in OHC of 3.59 ± 1.02 W·m-2. The Western Mediterranean Sea (5-700 m) is warming fastest with...
Marine Heatwaves are periods of persistent anomalously warm ocean temperatures, which can have si... more Marine Heatwaves are periods of persistent anomalously warm ocean temperatures, which can have significant impacts on ecosystems as well as coastal communities and economies. Their magnitude and frequency have increased over the last couple of decades as shown by surface satellite observations, but our understanding of the structure of their depth is still limited. The present work investigates the temperature anomaly of the 2022 Marine Heatwave in the Mediterranean Sea down to 2000 m depth using in-situ Argo floats observations. The Ocean Heat Content anomaly of 2022, estimated with respect to a float-derived climatology relative to the period 2001-2020, was used to define the regions most affected by warming in different layers. In these areas (North-Western Med, Central Ionian Sea, Southern Adriatic) float profiles were divided in three categories, based on the heat vertical penetration: category 1 (shallow, 0-150 m), category 2 (intermediate, 150-800 m), category 3 (deep, > 8...
The deepwater formation in the northern part of the South Adriatic Pit (Mediterranean Sea) is inv... more The deepwater formation in the northern part of the South Adriatic Pit (Mediterranean Sea) is investigated using a unique oceanographic dataset. In situ data collected by a glider along the Bari–Dubrovnik transect captured the mixing and the spreading/restratification phase of the water column in winter 2018. After a period of about 2 weeks from the beginning of the mixing phase, a homogeneous convective area of ∼300-m depth breaks up due to the baroclinic instability process in cyclonic cones made of geostrophically adjusted fluid. The base of these cones is located at the bottom of the mixed layer, and they extend up to the theoretical critical depth Zc. These cones, with a diameter on the order of internal Rossby radius of deformation (∼6 km), populate the ∼110-km-wide convective site, develop beneath it, and have a short lifetime of weeks. Later on, the cones extend deeper and intrusion from deep layers makes their inner core denser and colder. These observed features differ fro...
In October 2021, the Sicily Channel and the central-western Ionian Sea were affected by the passa... more In October 2021, the Sicily Channel and the central-western Ionian Sea were affected by the passage of the tropical-like cyclone, or MEDICANE, Apollo. The system reached its maximum intensity between 29 and 30 October 2021 producing several damages, intense precipitations and huge coastal floodings in Sicily and Calabria regions. The surface circulation in the MEDICANE impacted area was characterized by permanent cyclonic vortices, offering the chance to describe the impact of a tropical-like cyclone on a pre-existing cold circulation structure. Atmospheric and ocean reanalyses (ERA5 and Marine Copernicus Service), as well as in-situ data from Argo floats, were used to describe the temporal evolution of Apollo, the resulting air-sea interaction, the thermohaline and biological response to its passage in the upper layer (0-150 m) of the western Ionian Sea. During the event, the core of the marine cyclone was characterized by a dramatic drop in temperature, corresponding to a local maximum in the wind-stress curl, Ekman pumping and current field relative vorticity. The strengthening of the cyclonic circulation led by the wind stress curl produced a strong vertical mixing in the surface layer (from 0 m to the Mixed Layer Depth - MLD) and an upwelling in the subsurface layer below the thermocline (MLD-150 m). The combined effect of vertical mixing and upwelling resulted in a shoaling of MLD, deep chlorophyll-a maximum, nutricline, and halocline. Oxygen and chlorophyll-a concentrations increased at surface, due to the enhanced oxygen solubility in the cooler water and higher productivity due to the increase of nutrients upwelled to the surface layer. These results show that the pre-existing cyclonic vortex along Apollo's trajectory leads to a different physical response compared to the one observed during previous MEDICANEs, confirming the influence of the conditions in place in driving the ocean’s reply to the extreme weather systems.
The variability of the MODIS chlorophyll concentration in the northern Adriatic Sea is described ... more The variability of the MODIS chlorophyll concentration in the northern Adriatic Sea is described between July 2002 and January 2005 and related to the Po River discharge rates and local wind forcing. After interpolation, the MODIS data were decomposed into EOF modes. Significant variability (∼61%) is explained by the first three modes in which mode 1 includes a strong seasonal cycle with enhanced signal in winter for the open sea waters and a second maximum in April–May, and mode 2 separates the coastal and river‐influenced waters, from the open sea area. The temporal amplitude of the modes is significantly correlated with the Po River runoff. The interpolated MODIS data were also correlated with the Po River discharge rates, resulting in significant positive correlation north and south of the delta and off the Croatian Islands. When correlated with wind speed, the MODIS chlorophyll shows positive correlation in the area off Istria, off Croatia and at the edge of the coastal layer north of Ancona. Using wind regimes, similar patterns are found for the Bora‐wind like winds. In contrast, for Sirocco‐like winds, the correlation is significantly positive in the vicinity and north of the Po River delta. The regions off Ancona and Istria have poor correlation with the Po and wind because the MODIS chlorophyll variability is associated with mesoscale instability features not directly related to these forcing parameters. Poor (and even slightly negative) correlations are found off the Po delta. In most areas, correlations reach maximum values after 1–2 days.
ABSTRACT We will introduce GROOM, a European Union funded design study to evaluate the requiremen... more ABSTRACT We will introduce GROOM, a European Union funded design study to evaluate the requirements needed to set up a sustainable glider infrastructure to safely operate individual as well as fleets of gliders. Operations shall be coordinated to fill the gaps left by present marine observation systems on global, regional and coastal scale, with benefits for both fundamental marine research and operational oceanography. To maximize the efficiency and scientific outcome in operating gliders, networking and capacity building for the present as well as future glider community are essential. The networking will overcome the fragmented infrastructure to operate gliders, on a European level, but also globally. The concept and strategies employed by GROOM to streamline the infrastructure development will be outlined. The final system is envisioned to allow for a shared operation of gliders (individuals as well as fleets), a shared maintenance of glider, the free and efficient exchange of information in the network, an exchange of hardware, software and service, and the efficient flow of data with appropriate data quality control procedures, interoperability of the components by standardization of procedures and protocols for sensor calibration. Certain part of this infrastructure can and should be adopted from other observatory platforms, were more mature solution exists or under development (e.g. Argo floats data flow, moorings multiparametric data calibration procedures and data protocols) but given the unique characteristic and requirements of glider operations a specific and dedicated infrastructure is required.
HAL (Le Centre pour la Communication Scientifique Directe), Apr 17, 2016
In the 80s, the POEM (Physical Oceanography of the Eastern Mediterranean) cruises in the Levantin... more In the 80s, the POEM (Physical Oceanography of the Eastern Mediterranean) cruises in the Levantine Basin first revealed the presence of a very pronounced dynamical structure off Cyprus: The Cyprus Warm Core Eddy. Since then, a large amount of data have been collected thanks to the use of autonomous oceanic gliders (+8000 profiles since 2009). Part of those profiles were carried out in the upper layers down to 200 m, and we take benefit of a novel approach named ITCOMP SOM that uses a statistical approach to extend them down to 1000 m (see [1] for more details). This dataset have a particularly good spatio-temporal coverage in 2009 for about a month, thanks to simultaneous deployments of several gliders (up to 6). In this study, we present a set of 3D reconstruction of the dynamical and hydrographical characteristics of the Warm Core Cyprus Eddy between 2009 and 2015. Moreover, chlorophyll-a fluorescence data measured by the gliders give evidence to strong vertical velocities at the edge of the eddy. We discuss possible mechanisms (frontogenesis, symmetric instability) that could generate such signals and provide an assessment of the role of this peculiar circulation feature on the circulation and biogeochemistry of the Levantine basin. Reference: [1] Charantonis, A., P. Testor, L. Mortier, F. D'Ortenzio, S. Thiria (2015): Completion of a sparse GLIDER database using multi-iterative Self-Organizing Maps (ITCOMP SOM), Procedia Computer Science, 51(1):2198-2206. DOI: 10.1016/j.procs.2015.05.496
Skip to main content. AGU Home. FastFind » Lastname: doi:10.1029/ Year: -Select Journal-... Unusu... more Skip to main content. AGU Home. FastFind » Lastname: doi:10.1029/ Year: -Select Journal-... Unusual upwelling event and current reversal off the Italian Adriatic coast in summer 2003. Pierre-Marie Poulain. ...
The Mediterranean Sea is very sensitive to climatic changes due to its semi-enclosed nature and i... more The Mediterranean Sea is very sensitive to climatic changes due to its semi-enclosed nature and is therefore defined as one of the hotspots in future climate change projections. In this study, we use Argo float data to assess climatologies and trends in temperature and Ocean Heat Content (OHC) throughout the Mediterranean Sea and for specific sub-basins (e.g. Western and Eastern Mediterranean, Gulf of Lion, South Adriatic). The amount of the OHC, spatially averaged in bins of 1°x1° over the period from 2001 to 2020, increases from west to east in the Mediterranean Sea. Time series of temperature and OHC from 2005 to 2020, estimated in the surface and intermediate layers (5-700 m) and deeper layer (700-2000 m), reveal significant warming trends and an increase of OHC. The upper 700 m of the Mediterranean Sea show a temperature trend of 0.041 ± 0.012°C·yr-1, corresponding to an annual increase in OHC of 3.59 ± 1.02 W·m-2. The Western Mediterranean Sea (5-700 m) is warming fastest with...
Marine Heatwaves are periods of persistent anomalously warm ocean temperatures, which can have si... more Marine Heatwaves are periods of persistent anomalously warm ocean temperatures, which can have significant impacts on ecosystems as well as coastal communities and economies. Their magnitude and frequency have increased over the last couple of decades as shown by surface satellite observations, but our understanding of the structure of their depth is still limited. The present work investigates the temperature anomaly of the 2022 Marine Heatwave in the Mediterranean Sea down to 2000 m depth using in-situ Argo floats observations. The Ocean Heat Content anomaly of 2022, estimated with respect to a float-derived climatology relative to the period 2001-2020, was used to define the regions most affected by warming in different layers. In these areas (North-Western Med, Central Ionian Sea, Southern Adriatic) float profiles were divided in three categories, based on the heat vertical penetration: category 1 (shallow, 0-150 m), category 2 (intermediate, 150-800 m), category 3 (deep, > 8...
The deepwater formation in the northern part of the South Adriatic Pit (Mediterranean Sea) is inv... more The deepwater formation in the northern part of the South Adriatic Pit (Mediterranean Sea) is investigated using a unique oceanographic dataset. In situ data collected by a glider along the Bari–Dubrovnik transect captured the mixing and the spreading/restratification phase of the water column in winter 2018. After a period of about 2 weeks from the beginning of the mixing phase, a homogeneous convective area of ∼300-m depth breaks up due to the baroclinic instability process in cyclonic cones made of geostrophically adjusted fluid. The base of these cones is located at the bottom of the mixed layer, and they extend up to the theoretical critical depth Zc. These cones, with a diameter on the order of internal Rossby radius of deformation (∼6 km), populate the ∼110-km-wide convective site, develop beneath it, and have a short lifetime of weeks. Later on, the cones extend deeper and intrusion from deep layers makes their inner core denser and colder. These observed features differ fro...
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Papers by Elena Mauri