A5074505892- Oceanographic and Atmospheric Processes
- Arctic and Antarctic ice dynamics
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Climate variability and models
- Marine and coastal ecosystems
- Ocean Waves and Remote Sensing
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Geophysics and Gravity Measurements
- Climate change and permafrost
- Geological formations and processes
- Geological Studies and Exploration
- Tropical and Extratropical Cyclones Research
- Coral and Marine Ecosystems Studies
- Meteorological Phenomena and Simulations
- Geological and Geophysical Studies
- Atmospheric aerosols and clouds
- Underwater Acoustics Research
- Polar Research and Ecology
- Arctic and Russian Policy Studies
- Marine and environmental studies
- Reservoir Engineering and Simulation Methods
- Hydrocarbon exploration and reservoir analysis
- Analytical Chemistry and Sensors
Sorbonne Université
2014-2024
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
2015-2024
Institut de Recherche pour le Développement
2013-2023
Centre National de la Recherche Scientifique
2013-2023
Institut Pierre-Simon Laplace
2005-2022
Boréa (Sweden)
2015
Laboratoire d’Études en Géophysique et Océanographie Spatiales
2003
Centre National pour la Recherche Scientifique et Technique (CNRST)
1995-1998
Université Paris 8
1998
Université Paris Cité
1993
Abstract The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to thinner and largely seasonal first-year with significant consequences for primary production. One critical challenge understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea during summer, indicating that satellite-based annual production estimates may be significantly underestimated. Here we present unique...
Abstract. The mean dynamic topography (MDT) is a key reference surface for altimetry. It needed the calculation of ocean absolute topography, and under geostrophic approximation, estimation currents. CNES-CLS solutions are calculated by merging information from altimeter data, GRACE, GOCE gravity field oceanographic in situ measurements (drifting buoy velocities, hydrological profiles). objective this paper to present newly updated CNES-CLS18 MDT. main improvement compared previous...
Drake Passage is the narrowest constriction of Antarctic Circumpolar Current (ACC) in Southern Ocean, with implications for global ocean circulation and climate. We review long‐term sustained monitoring programs that have been conducted at Passage, dating back to early part twentieth century. Attention drawn numerous breakthroughs made from these programs, including (1) first determinations complex ACC structure quantifications its transport; (2) realization transport remarkably steady over...
A large retreat of sea-ice in the 'stormy' Atlantic Sector Arctic Ocean has become evident through a series record minima for winter maximum extent since 2015. Results from Norwegian young sea ICE (N-ICE2015) expedition, five-month-long (Jan-Jun) drifting ice station first and second year pack-ice north Svalbard, showcase how this region is frequently affected by passing storms. Here we synthesise interdisciplinary N-ICE2015 dataset, including independent observations atmosphere, snow,...
Abstract An up‐to‐date map of the Antarctic Circumpolar Current (ACC) fronts is constructed from latest version mean dynamic topography (MDT) satellite altimetry and reveals narrowest ACC width in Udintsev Fracture Zone (UFZ), with strongest concentration three major within a limited distance as short 170 km, about 40% narrower than that at Drake Passage. At 144°W, entrance UFZ, which lies between Pacific‐Antarctic Ridge (PAR) its eastwardly offset segment (offset PAR segment), there triple...
Surface thermal fronts in the southwestern Atlantic (SWA) Ocean are examined using 9 years (1987–1995) of advanced very high resolution radiometer data. Fronts detected considering a gradient based edge detector. Sea surface temperature gradients calculated from 4 km 5‐day composite images covering western Argentine Basin south 30°S. Variability position and intensity seasonal to interannual timescales is characterized six regions including different parts Brazil Current Front (BCF)...
The time‐space distribution of chlorophyll a in the southwestern Atlantic is examined using 6 years (1998–2003) sea surface color images from Sea‐viewing Wide Field View Sensor (SeaWiFS). Chlorophyll (chl ) confronted with temperature (SST) fronts retrieved satellite imagery. Histogram analysis color, SST, and SST gradient data sets provides simple procedure for pixel classification which eight biophysical regions SWA are identified, including three new regard to Longhurst (1998) work:...
Abstract Seven ice mass balance instruments deployed near 83°N on different first‐year and second‐year floes, representing variable snow conditions, documented the evolution of conditions in Arctic Ocean north Svalbard January–March 2015. Frequent profiles temperature thermal diffusivity proxy were recorded to distinguish changes depth thickness with 2 cm vertical resolution. Four flooding ‐ formation. Flooding was clearly detectable simultaneous proxy, increased temperature, heat...
Abstract Oceanographic observations from the Eurasian Basin north of Svalbard collected between January and June 2015 N‐ICE2015 drifting expedition are presented. The unique winter a key contribution to existing climatologies Arctic Ocean, show ∼100 m deep mixed layer likely due high sea ice growth rates in local leads. Current for upper ∼200 mostly barotropic flow, enhanced over shallow Yermak Plateau. two branches inflowing Atlantic Water partly captured, confirming that outer Branch...
Abstract A 20 year long volume transport time series of the Antarctic Circumpolar Current across Drake Passage is estimated from combination information in situ current meter data (2006–2009) and satellite altimetry (1992–2012). new method for estimates had to be designed. It accounts dependence vertical velocity structure on surface latitude. Yet unpublished profile Acoustic Doppler Profilers are used provide accurate upper 350 m. The mean cross‐track geostrophic velocities using an...
Abstract Twenty‐five years of high‐resolution (1/12°) ocean reanalysis are used to examine the Confluence Malvinas Current (MC) with Brazil (BC) from synoptic interannual time scales. The model transports MC (38.0 Sv ± 7.4 57 at 41°S) and BC (23.0 11 36°S) agree observations. shows branching near an offshore branch returning south inner sinking below managing continue northward along continental slope. Northward velocities associated subsurface peak 40 cm/s 36°S 700‐m depth. documents...
Abstract Low‐salinity waters in the upper Arctic Ocean, referred to as “freshwaters”, are cold and play a major role isolating sea ice cover from heat stored salty Atlantic Waters (AW) underneath. We examined changes freshwater distribution circulation since 2007 using 1/12° global Mercator Ocean operational model. first evaluated model simulations over water column nearly 20,000 independent situ temperature‐salinity profiles 2007–2020 period. Simulated hydrographic properties mass...
The zonal equatorial circulation of the upper 700 m in central tropical Atlantic is studied based on 11 cross‐equatorial ship sections taken at 23–29°W during 1999 to 2005 and data from a pair moored Acoustic Doppler current profilers deployed equator 23°W February 2004 May 2005. observations reveal existence two mean westward cores Equatorial Intermediate Current below Undercurrent. In contrast 2002 same position intraseasonal variability mooring period dominated by instead meridional...
We present a set of new current meter measurements collected to monitor the Malvinas Current (MC) near its merger with Brazil at 40–41°S from December 2001 February 2003 below Jason‐1 altimeter track. These are compared former obtained 8 years earlier same location; they also provide information on core MC continental slope above 1000‐m isobath where mooring had been previously lost. There, most velocity variation is along‐isobath (80% variance) and shows significant annual cycle. The two...
Abstract An upward‐looking Acoustic Doppler Current Profiler deployed from July 2007 to September 2008 in the Yermak Pass, north of Svalbard, gathered velocity data 570 m up 90 at a location covered by sea ice 10 months out 12. Barotropic diurnal and semidiurnal tides are dominant signals (more than 70% variance). In winter, baroclinic eddies periods between 5 15 days pulses 1–2 month periodicity observed Atlantic Water layer associated with shoaling pycnocline. Mercator‐Ocean global...
We present a set of current meter measurements collected in the southwest Atlantic from December 1993 to June 1995. Four moorings were out monitor Malvinas (Falkland) Current at 40°–41°S, and one mooring was located within Brazil‐Malvinas Front area 38°S. The mean flow has an equivalent barotropic structure, whereas vertical structure variable part is dominated by barotropic‐like empirical mode for regions shallower than 2500 m, surface intensified, which appears as linear combination...
This systematic study of the subtropical mode waters in South Atlantic is based on hydrological data (the basin‐wide Ventilation Experiment, Oceanus, and Ajax sections, World Ocean Circulation Experiment (WOCE) sections Brazil‐Malvinas Confluence region), WOCE expendable bathythermograph set, atmospheric forcing produced by National Centers for Environmental Prediction reanalysis. The main ventilation window gyre lies southwest corresponds to southern part recirculation region overshoot...
An autonomous nutrient analyzer in situ (ANAIS) has been developed to monitor nitrate, silicate, and phosphate concentrations while deployed at sea pressure (down 1000 m). Detection is made by spectrophotometry. The instrument uses solenoid-driven diaphragm pumps propel the sample, standards, reagents through a microconduit, flow injection-style thermostated manifold. analyzers are placed an equipressure container filled with oil. operate until of 100 bar show linear response up 40 microM...
As part of the N-ICE2015 campaign, IAOOS (Ice Atmosphere Ocean Observing System) platforms gathered intensive winter data at entrance Atlantic Water (AW) inflow to Arctic north Svalbard. These are used examine performance 1/12° resolution Mercator global operational ice/ocean model in marginal ice zone Modeled sea-ice extent, ocean heat fluxes, mixed layer depths and AW mass characteristics good agreement with observations. Model outputs then put observations a larger spatial temporal...