Pierre-Marie Poulain

• Ph.D.
• R&D Manager at National Institute of Oceanography and Applied Geophysics

Two statistical methodologies are introduced for analyzing tidal currents based on direct surface current measurements from freely drifting buoys. Applied to 17 years (2006–2022) of historical drifter data from the Barents Sea and the waters surrounding the Svalbard Archipelago, these approaches provide detailed insights into the spatial distributi...

During the period of 23–28 February 2022, a cyclonic eddy in the Balearic Sea was observed to split into two smaller eddies. Serendipitously, a wealth of data was collected of the event, including satellite chlorophyll maps, Lagrangian drifters at several depths, hydrographic sections intersecting the splitting eddy, and wind speed and direction. S...

The most prominent and persistent feature of the eastern Mediterranean Levantine Basin (LB) is the warm anticyclonic Cyprus Eddy (CE) located above the Eratosthenes Seamount (ESM). This eddy periodically couples with two smaller cyclonic and anticyclonic eddies, the South Shikmona Eddy (SSE) and North Shikmona Eddy (NSE), which form downstream. The...

Currents and pressure records from the DeepLev mooring station and drifter data in the eastern Levantine Basin were analyzed to identify the dominant tidal constituents and their seasonal and depth variability. Harmonic and spectral analysis of seasonal segments of currents and pressure reveal key attributes of the tidal regime: (1) dominant semidi...

The dynamics of dissolved oxygen in the ocean are of crucial importance for understanding marine ecosystems, with influences ranging from exchange with the atmosphere to biological processes and ocean circulation. In this study, we focus on the southern Adriatic Sea, an essential component of the Eastern Mediterranean “conveyor belt”, to investigat...

An array of Lagrangian instruments (more than 100 drifters and a profiling float) were deployed for several days in the coastal waters of the southeastern Ligurian Sea to characterize the near-surface circulation at the submesoscale (< 10 km). The drifters were trapped in an offshore-flowing filament and a cyclonic eddy that developed at the southw...

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-b...

Wavelet ridge analysis was applied to the data of drifters caught in the Cyprus Gyre in the eastern Mediterranean Sea to study surface currents at low (rotating circulation) and high (near-inertial motion) frequencies. Drifter observations indicate that the orbital speed is highest at about 30 km from the gyre center (reaching ~45 cm/s) and that th...

Currents and pressure records from the DeepLev mooring station (Eastern Levantine Basin) are analyzed to identify the dominant tidal constituents and their seasonal and depth variability. Harmonic and spectral analysis on seasonal segments of currents and pressure reveal attributes of the tidal regime in the Eastern Levantine Basin: (1) Dominant se...

An array of Lagrangian instruments (more than 100 drifters and a profiling float) was deployed for several days in the coastal waters of the southeastern Ligurian Sea to characterize the near-surface circulation at the submesoscale (< 10 km). The drifters were trapped in an offshore-flowing filament and a cyclonic eddy that developed at the southwe...

Internal tides are studied in the central Mediterranean Sea using observational data and numerical experiments. Both numerical results and observations indicate that the baroclinic variability in this area is dominated by the K1 diurnal tide. In agreement with previous studies, the diurnal internal tides have the characteristics of Kelvin-like bott...

The attention of the scientific community, policymakers, and public opinion on the Medicanes has recently grown because of their increase in intensity and harmful potential. Although Medicanes may be influenced by pre-existing upper-ocean conditions, uncertainties remain about how such weather extremes influence ocean circulation. This work examine...

Vertical transport pathways in the ocean are still only partially understood despite their importance for biogeochemical, pollutant, and climate applications. Detailed measurements of a submesoscale frontal jet in the Alboran Sea (Mediterranean Sea) during a period of highly variable winds were made using cross‐frontal velocity, density sections an...

Measuring vertical motions represent a challenge as they are typically 3–4 orders of magnitude smaller than the horizontal velocities. Here, we show that surface vertical velocities are intensified at submesoscales and are dominated by high frequency variability. We use drifter observations to calculate divergence and vertical velocities in the upp...

Climatic changes and interannual variability in the Mediterranean overturning circulation are crucially linked to dense water formation in the Levantine Sea, namely the Levantine Intermediate Water whose formation zone, comprising multiple and intermittent sources, extends over fluctuating pathways. To probe into the variability of this water forma...

The deepwater formation in the northern part of the South Adriatic Pit (Mediterranean Sea) is investigated using a unique oceanographic data set. In situ data collected by a glider along the Bari-Dubrovnik transect captured the mixing and the spreading/re-stratification phase of the water column in winter 2018. After a period of about two weeks fro...

The Mediterranean Sea is considered a hot spot of global warming because it has been changing faster than the global ocean, creating a strong impact on the marine environment. Recent studies agree on the increase in the sea level, in the sea surface temperature, and in the sea surface salinity in the Mediterranean Sea over the last two decades. In...

Increasing interest in the acquisition of biotic and abiotic resources from within the deep sea (e.g. fisheries, oil-gas extraction, and mining) urgently imposes the development of novel monitoring technologies, beyond the traditional vessel-assisted, time-consuming, high-cost sampling surveys. The implementation of permanent networks of seabed and...

Instruments drifting at the ocean surface are quasi-Lagrangian, that is, they do not follow exactly the near-surface ocean currents. The currents measured by three commonly-used drifters (CARTHE, CODE and SVP) are compared in a wide range of sea state conditions (winds up to 17 m/s and significant wave height up to 3 m). Nearly collocated and simul...

The presence of invasive species in the Mediterranean Sea is much higher than in other European seas, and understanding the reasons behind the range expansion of this invasive species is important for minimising any possible impacts to the already highly pressurised Mediterranean marine ecosystem. In this work, a brief description of sightings of t...

Summary: https://marine.copernicus.eu/news/ocean-state-report-5-summary-now-available Full report: https://www.tandfonline.com/doi/full/10.1080/1755876X.2021.1946240

An Algerian Eddy, anticyclonic vortex generated by the instability of the Algerian Current in the southwestern Mediterranean Sea, is studied using data provided by drifters (surface currents), Argo floats (temperature and salinity profiles), environmental satellites (absolute dynamic topography maps and ocean color images) and operational oceanogra...

The statistics of submesoscale divergence and vorticity (kinematic properties, KPs) in the Alboran Sea (Mediterranean Sea) are investigated, using data from drifters released during two experiments in June 2018 and April 2019 in the framework of the Coherent Lagrangian Pathways from the Surface Ocean to Interior (CALYPSO) project. Surface drifters...

The circulation of the Eastern Mediterranean Sea is characterized by numerous recurrent or permanent anticyclonic structures, which modulate the pathway of the main currents and the exchange of the water masses in the basin. This work aims to describe the main circulation structures and thermohaline properties of the Eastern Mediterranean with part...

The paper aims to describe the preconditioning and observations of exceptionally high salinity values that were observed in summer and autumn of 2017 in the Adriatic. The observations encompassed CTD measurements carried out along the well-surveyed climatological transect in the Middle Adriatic (the Palagruža Sill, 1961–2020), Argo profiling floats...

The Lagrangian dispersion statistics of the Black Sea are estimated using satellite-tracked drifters, satellite altimeter data and a high-resolution ocean model. Comparison between the in-situ measurements and the model reveals good agreement in terms of the surface dispersion. The mean sub-basin coherent structures and currents of the Black Sea ar...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

Plain Language Summary The Levantine Sea, the easternmost area of Mediterranean Sea, is considered one of the poorest oceans on the Earth in terms of abundance of phytoplankton, the microscopic organisms that fuel the marine food web. However, historical data and satellite maps of chlorophyll (the pigment that reveals phytoplankton presence in the...

Although small in size, the Gulf of Trieste (GoT), a marginal coastal basin in the northern Adriatic Sea, is characterized by very complex dynamics and strong variability of its oceanographic conditions. In April–May 2012, a persistent, large-scale anticyclonic eddy was observed in the GoT. This event was captured by both High Frequency Radar (HFR)...

Horizontal and vertical motions associated with mesoscale (10–100 km) and submesoscale (1–10 km) features, such as fronts, meanders, eddies, and filaments, play a critical role in redistributing physical and biogeochemical properties in the ocean. This study makes use of a multiplatform data set of 82 drifters, a Lagrangian float, and profile times...

Drifter, satellite, expendable bathythermograph (XBT), and Argo float data are used to study the response of the Pacific Sector of the Southern Ocean (PSSO) to the wind stress field in the period 1995–2017, in terms of eddy field, water mass transport, and heat fluxes at large and regional scales. Increasing wind stress over the PSSO in those two d...

Much of the vertical transport near the surface of the ocean, which plays a critical role in the transport of dissolved nutrients and gases, is thought to be associated with ageostrophic submesoscale phenomena. Vertical velocities are challenging not only to model accurately, but also to measure because of how difficult they are to locate in the su...

In the past two decades, the Argo Program has collected, processed, and distributed over two million vertical profiles of temperature and salinity from the upper two kilometers of the global ocean. A similar number of subsurface velocity observations near 1,000 dbar have also been collected. This paper recounts the history of the global Argo Progra...

Surface dispersion properties give an immediate characterization of the spreading of passive and active tracers in the ocean, like pollutant and marine species. The Mediterranean sub-basins (Tyrrhenian, Adriatic, Ionian, Levantine and Aegean) are known as complex dynamic regions due to the presence of coherent structures on different motion scales....

Surface dispersion properties give an immediate characterization of the spreading of passive and active tracers in the ocean, like pollutant and marine species. The Mediterranean sub-basins (Tyrrhenian, Adriatic, Ionian, Levantine and Aegean) are known as complex dynamic regions due to the presence of coherent structures on different motion scales....

In order to improve persistence and acoustic capabilities of a Slocum underwater glider, the wings have been re-designed and a linear array of eight elements has been placed along their leading edges. In this configuration the lift/drag ratio has increased by about 15-20% with an angle of attack (AoA) of 4° with respect to the original wing configu...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

The OceanGliders program started in 2016 to support active coordination and enhancement of global glider activity. OceanGliders contributes to the international efforts of the Global Ocean Observation System (GOOS) for Climate, Ocean Health, and Operational Services. It brings together marine scientists and engineers operating gliders around the wo...

The Mediterranean community represented in this paper is the result of more than 30 years of EU and nationally funded coordination, which has led to key contributions in science concepts and operational initiatives. Together with the establishment of operational services, the community has coordinated with universities, research centers, research i...

The air-sea interface is a key gateway in the Earth system. It is where the atmosphere sets the ocean in motion, climate/weather-relevant air-sea processes occur, and pollutants (i.e., plastic, anthropogenic carbon dioxide, radioactive/chemical waste) enter the sea. Hence, accurate estimates and forecasts of physical and biogeochemical processes at...

The air–sea interface is a key gateway in the Earth system. It is where the atmosphere sets the ocean in motion, climate/weather-relevant air–sea processes occur, and pollutants (i.e., plastic, anthropogenic carbon dioxide, radioactive/chemical waste) enter the sea. Hence, accurate estimates and forecasts of physical and biogeochemical processes at...

Levantine intermediate water (LIW) is formed in the Levantine Sea (Eastern Mediterranean) and spreads throughout the Mediterranean at intermediate depths, following the general circulation. The LIW, characterized by high salinity and relatively high temperatures, is one of the main contributors of the Mediterranean Overturning Circulation and influ...

Oceanic fronts are dynamically active regions of the global ocean that support upwelling and downwelling with significant implications for phytoplankton production and export. However (on time scales ≳ the inertial time scale), the vertical velocity is 10³–10⁴ times weaker than the horizontal velocity and is difficult to observe directly. Using int...

The surface circulation and the thermohaline properties of the water masses of the eastern Levantine Sea (Mediterranean Sea) were monitored with mobile autonomous systems (surface drifters and gliders) during the period September 2016–August 2017. The drifters provided data for more than a year and revealed complex circulation features at scales ra...

This chapter describes the main features of the circulation and properties of the intermediate water masses of the Mediterranean. Interaction with other water masses is also briefly summarised. Both observational and numerical studies described in the literature are used, as well as some more recent, unpublished data sets. It is shown that the main...

Between 2013 and 2016 a drastic change in the vertical salinity structure in the South Adriatic Pit was recorded by Argo floats and ocean gliders. The analysis revealed that high salinity waters characterised 2013 at the surface and intermediate layers, creating the conditions for dense water formation. The year 2014 was instead marked by less sali...

The dynamics of the Sicily Channel and the southern Tyrrhenian Sea are highly influenced by the seasonal variability of the Mediterranean basin-wide circulation, by the interannual variability of the numerous mesoscale structures present in the Channel, and by the decadal variability of the adjacent Ionian Sea. In the present study, all these aspec...

Increasing interest in the acquisition of biotic and abiotic resources from within the deep sea (e.g. fisheries, oil-gas extraction, and mining) urgently imposes the development of novel monitoring technologies, beyond the traditional vessel-assisted, time-consuming, high-cost sampling surveys. The implementation of permanent networks of seabed and...

Dispersion analysis and chaotic turbulent motion in the Mediterranean sub-basins

A network of High-Frequency radar (HFR) stations runs operationally in the Malta-Sicily Channel (MSC), Central Mediterranean Sea, providing sea surface current maps with high temporal (1 h) and spatial (3 × 3 km) resolutions since August 2012. Comparisons with surface drifter data and near-surface Acoustic Doppler Current Profiler (ADCP) observatio...

Direct measurements of the relative water flow near the top and bottom of Coastal Ocean Dynamics Experiment (CODE) drifters were made in the northeast Pacific Ocean and the Mediterranean Sea in wind speeds as large as 15ms ⁻¹ . These measurements confirmed that the CODE drifter is a good Lagrangian drifter with a mean downwind slip of about 0.1% of...

The most prominent oceanographic features in the Central Mediterranean are decadal reversals of the Northern Ionian Gyre (NIG), interpreted in terms of internal processes. Altimetry data, drifter data and model surface salinity products are used in this paper to define some specific features of the circulation related to the anticyclonic or cycloni...

The AlborEX (Alboran Sea Experiment) consisted of a multi-platform, multi-disciplinary experiment carried out in the Alboran Sea (western Mediterranean Sea) between 25 and 31 May 2014. The observational component of AlborEx aimed to sample the physical and biogeochemical properties of oceanographic features present along an intense frontal zone, wi...

Understanding the role of ocean currents in the recruitment of commercially and ecologically important fish is an important step toward developing sustainable resource management guidelines. To this end, we attempt to elucidate the role of surface ocean transport in supplying recruits of European sardine (Sardina pilchardus) to the Gulf of Manfredo...

This work focuses on the Tyrrhenian Intermediate Water, a water mass present in the Tyrrhenian Sea (Western Mediterranean Sea), which approximately lies between 100 m and 200 m of depth, and is characterized by a local minimum of temperature. Here, for the first time, a thorough investigation of the Tyrrhenian Intermediate Water has been performed,...

More than fifty low and medium income countries rely on the sea for their economies. Despite its importance, there is a lack of oceanographic scientific data from these countries due to the high cost of equipment and to the running costs of measurement campaigns. In this paper we present a low-cost drifter based on a LoRa communication platform and...

AlborEX (Alboran Sea Experiment) consisted of a multi-platform, multi-disciplinary experiment carried out in the Alboran Sea (Western Mediterranean Sea) between May 25 and 31, 2014. The observational component of AlborEx aimed to sample the physical and biogeochemical properties of oceanographic features present along an intense frontal zone, with...

Dispersion characteristics in the Western Mediterranean are analyzed using data from Coastal OceanDynamicsExperiment(CODE)andSurfaceVelocityProgram(SVP)surfacedrifters deployed in the period 1986–2017. Results are presented in terms of absolute dispersion A2 (mean-squared displacement of drifter individuals) and of relative dispersion (D2; mean squ...

Velocities of surface drifters are analyzed to study tidal currents throughout the Mediterranean Sea, with main focus on the semi-diurnal tide. Harmonic analysis on 15-day long trajectory segments reveals semi-diurnal tidal amplitudes larger than 5 cm/s in the Alboran Sea, the northern Adriatic Sea, the Sicily Channel and the Gulf of Gabès. Elsewhe...

Understanding the role of ocean currents in the recruitment of commercially and ecologically important fish is an important step toward developing sustainable resource management guidelines. To this end, we attempt to elucidate the role of surface ocean transport in supplying recruits of European sardine (Sardinus pilchardus) to the Gulf of Manfred...

The Vercelli Seamount is an undersea topographic feature of the northern Tyrrhenian Sea which rises from around 2000 m depth to almost the surface (55 m depth). In late spring 2009 the interdisciplinary experiment "Tyrrhenian Seamounts Ecosystems: an integrated study" was conducted around the seamount to investigate its influence on the hydrodynami...

The present work aims to detect Lagrangian transport barriers in the Gulf of Trieste by means of Lyapunov-exponent approach and tensorlines of the Cauchy-Green tensor. Lagrangian Coherent Structures (LCSs) are calculated employing 2D surface velocity fields measured by the coastal radars of the TOSCA EU research project (Tracking Oil Spills & Coast...

The Surface Velocity Program drifter data, collected in the Mediterranean Sea since 1989, are analysed in order to evaluate and, possibly, improve the accuracy of the drogue (sea anchor, attached to the buoy by a long thin tether) presence detection system. Wind products and altimetry data are used to estimate the wind slip from the drifter velocit...

Many technologies have been developed for monitoring the ocean interior. Among them the monitoring approaches based on imaging devices are capable to disclose important data on species behaviour and spatio-temporal variations of richness and evenness. In this context, the Argo programme (http://doi.org/10.17882/42182) is a valuable instrument for m...

The observational part of the REP14-MED experiment was conducted in June 2014 in the Sardo-Balearic Basin west of Sardinia (western Mediterranean Sea). Two research vessels collected high-resolution oceanographic data by means of hydrographic casts, towed systems, and underway measurements. In addition, a vast amount of data was provided by a fleet...

The paper investigates the wintertime dynamics of the coastal northeastern Adriatic Sea and is based on numerical modelling and in situ data collected through field campaigns executed during the winter and spring of 2015. The data were collected with a variety of instruments and platforms (acoustic Doppler current profilers, conductivity–temperatur...

More than fifty low and medium income countries rely on the sea for their economies. Despite its importance, there is a lack of oceanographic scientific data from these countries due to the high cost of equipment and to the running costs of measurement campaigns. In this paper we present a low-cost drifter based on a LoRa communication platform and t...

The Black Sea, the largest semi-enclosed anoxic basin on Earth, can be considered as an excellent natural laboratory for oxic and anoxic biogeochemical processes. The suboxic zone, a thin interface between oxic and anoxic waters, still remains poorly understood because it has been undersampled. This has led to alternative concepts regarding the und...

The Argo Float programme is a valuable instrument for monitoring the deep sea at global scale in space and time. Argo Floats equipped with imaging devices are candidate to become a new monitoring tool for studying macro- and mega- fauna in large areas and for extended periods, potentially providing monitoring results never attained before.

This paper presents a review of the state-of-the-art in understanding and quantification of the Mediterranean heat and mass (i.e. salt and water) budgets. The budgets are decomposed into a basin averaged surface component, lateral boundary components (through the Gibraltar and the Dardanelles Straits), a river input component and a content change c...

A methodology to analyze the spectral content of glider data is proposed by showing the application to time series taken during missions in the Mediterranean Sea. Three missions have been investigated, two in the Tyrrhenian Sea and one south of Cyprus. Fluctuations appearing in temperature series recorded by gliders are studied with the help of the...