Recent  

In this study, we analyse and compare the results of four different approaches in modelling bora-driven dense water dynamics in the Adriatic Sea. The study investigated the requirements for appropriate modelling of the ocean circulation in the Adriatic and found that the evaluation run of the Adriatic climate model is able to outperform most aspects of the reanalysis product, the short-term hindcast and the data assimilated simulation, in reproducing the dense water dynamics in the Adriatic Sea.

This study uses the trajectories of water parcels traced within an ocean model simulation to identify the pathways responsible for the seasonal cycle of dense water formation (overturning) in the eastern subpolar North Atlantic. We show that overturning seasonality is due to the fastest water parcels circulating within the eastern basins in less than 8.5 months. Slower pathways set the average strength of overturning in this region since water parcels cannot escape intense wintertime cooling.

Tropical upwelling systems are among the most productive ecosystems globally. The tropical Atlantic upwelling undergoes a strong seasonal cycle that is forced by the seasonal cycle of the zonal wind along the equator and the near-coastal wind field off Africa. Besides the wind forcing that lead to an up- and downward movement of the nitracline, turbulent diffusion results in upward mixing of nutrients. Here, we review the different physical processes responsible for upward nutrient supply.

Understanding whether variations in ocean heat content are driven by air-sea heat fluxes or by ocean dynamics is of crucial importance to enhance climate projections. We use a relatively novel causal method to quantify interactions between ocean heat budget terms based on climate models. We find that low-resolution models overestimate the influence of ocean dynamics in the upper ocean, and that changes in ocean heat content are dominated by air-sea fluxes at high resolution.

Climate change will alter heat and freshwater fluxes and ocean circulation, driving local changes in sea level. This sea-level change component is known as ocean dynamic sea level (DSL), and it is usually projected using computationally expensive General Circulation Models. Statistical models are a cheaper alternative for projecting DSL, but may contain significant errors. Here, we partly remove those errors (driven by natural variability) by using pattern recognition techniques.

The Chukchi continental slope is one of the most energetic regions in the western Arctic Ocean as it is populated with strong boundary currents and mesoscale eddies. Using a set of experiments with an idealized primitive equation numerical model, we find that the ice friction can cause the loss of energy of both the Chukchi Slope Current and mesoscale eddies over a vertical scale of 100 m through Ekman pumping. Some scales for measuring the effects of ice friction are also provided.

This work presents a series of studies conducted by the authors on the application of the Lagrangian approach for the connectivity analysis between different ocean locations in an idealized open-ocean model. We assess how the connectivity properties of typical oceanic flows are affected by the fine-scale circulation, and discuss the challenges facing ocean connectivity estimates related to the spatial resolution. Our results are important to improve the understanding of marine ecosystems.

Surface heat flux is the main driver of the heat budget in the Senegal, Angola and Benguela regions, but not in the Equatorial region. In the Senegal and Benguela regions, freshwater flux governs the salt budget while in Equatorial and Angola regions, oceanic processes are the main drivers. Results from numerical simulation show the important role of mesoscale advection for temperature and salinity variations in the mixed-layer. Non-linear processes unresolved by observations play a key role.

The ocean state is sensitive to the mixing originating from internal tides (IT). To date, our knowledge of the magnitude and spatial distribution of this mixing mostly relies on uncertain modeling. Here, we use novel observations from autonomous floats to validate the spatial variability of the semidiurnal IT in a realistic ocean simulation. The numerical simulation is found to correctly reproduce the main spatial patterns of the observed tidal energy, but to be biased low at the global scale.

France experienced a record-breaking summer in 2022 with several heatwave events exceptional both in terms of intensity and persistence. This study is the first to look back at the events of the summer of 2022 and the responses of the sea surface temperatures using spatial operational data. This study advocates for a continuity in the development efforts in spatial oceanography to provide operational centres with the necessary tools to tackle climate changes consequences.

Hurricane Harvey led to unprecedented rainfall over south central Texas in August/September 2017. We obtained physical and chemical data from the affected offshore area both before and after the hurricane passed. Despite the intense rainfall, the effects on the coastal ocean were apparently only short-lived and we did not observe major blooms of plankton or inputs of nutrients, possibly because of there sheer volume of rainwater that diluted any runoff.

This work uses sea-level observations and a model to reproduce the sea level in the Mediterranean basin. We considered various components, due to astronomical and meteorological forcing. Furthermore, the periods of oscillation of the sea level of the Mediterranean Sea were studied. This research aims to improve sea level prediction to prevent flood events and improve sea level reproduction in past periods, for climatological or other studies.

Satellite altimetry provides a unique technique for observing the sea surface height signature of internal tides from space. The advances in mapping technique, combined with the accumulation of satellite altimetry data, make it possible to construct empirical models for minor internal tide constituents. This paper demonstrates that N₂ internal tides, the fifth largest tidal constituent, are observed using 100 satellite-years of SSH data from 1993 through 2019 by a new mapping procedure.

Recent advances allows us to observe the ocean from space with increasingly higher detail, challenging our knowledge of the ocean's surface height signature. We use a statistical approach to determine the spatial scale at which the sea surface height signal is no longer dominated by geostrophic turbulence but in turn it becomes dominated by wave-type motions. This information helps us to better use the data provided by ocean-observing satellites and to gain knowledge on climate-driving processes.

This study investigates the processes that form dense water in the high latitudes of the North Atlantic to determine how they affect the overturning circulation in the Atlantic. We show for the first time that turbulent mixing is an important driver in the formation of dense water, along with the loss of heat from the ocean to the atmosphere. We point out that the simulation of turbulent mixing in ocean-climate models must improve to better predict the oceans response to climate change.

SWOT has significant potential for detecting mesoscale eddies, but the detecting method, which is used for nadir altimeters, may be not optimal. We propose to improve the method based on the spatial and temporal features of SWOT, to reduce the long-wavelength errors and enhance the high spatial features. The accuracy of gridded results are improved especially when the number of observations is limited. The reconstruction and detected temporal scales of mesoscale eddy variations is also enhanced.

Data assimilation techniques are important for combining observations with numerical models. Here, we improve the adjoint of full sea ice dynamics (adjoint-VP) to replace the simplified adjoint of a free-drift (adjoint-FD) sea ice dynamic for developing an advanced Arctic ocean and sea ice modeling and adjoint-based assimilation system. We find that adjoint-VP provides a better ocean and sea ice estimation than adjoint-FD, considering the residual errors and adjustments of the atmosphere state.

This study investigates the sea-air CO₂ exchange variabilities across the Tropical Maritime Continent between 2010–2019 using numerical model experiment. Model results suggested some periods with higher-than-usual CO₂ degassing to the atmosphere related to Indo-Pacific climatic events over the 2010–2019 course. Study conducted here may give insights about sea-air CO₂ exchange dynamics in the undersampled area that poorly represented in many climate models and global reconstruction product.

Recently, it was found that cold-to-warm changes in the Antarctic shelf sea are possible and lead to higher melt rates of ice shelves. In modeling experiments, we found that if the highest density in front of the ice shelf becomes lower than the density of the warmer water off-shelf at the deepest access to the shelf, the off-shelf water will flow onto the shelf. Our results also indicate that this change will offer some, although not much resistance to reversal and constitutes a tipping point.