Speich Sabrina

Speich Sabrina
Ecole Normale Supérieure de Paris | ENS · Département de Géosciences

PhD, HDR

About

204
Publications
86,363
Reads
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11,075
Citations
Citations since 2016
94 Research Items
9054 Citations
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Introduction
Sabrina Speich is full professor of Oceanography and Climate Sciences at the Ecole Normale Supérieure (ENS) of Paris. She is member of the French climate Institute Pierre Simon Laplace (IPSL) and LMD. Her research focuses on ocean scale-interactions, atmosphere-ocean dynamics, and how they affect the Earth climate and marine ecosystems under global warming. She is a world-recognized expert in ocean modeling as well as in organizing wide programs of in situ observations.
Additional affiliations
December 2013 - present
Ecole Normale Supérieure de Paris
Position
  • Professor (Full)
Description
  • Dean of Studies
October 1995 - December 2013
Université de Bretagne Occidentale
Position
  • Professor (Full)
September 1995 - December 2013
Université de Bretagne Occidentale
Position
  • Professor (Full)

Publications

Publications (204)
Preprint
Full-text available
The variability of the South Atlantic meridional overturning circulation and meridional heat transport measured across 34.5°S during 2013–2017 differs significantly between observational and ocean reanalysis estimates. Variability in an ocean reanalysis ensemble and an eddy-resolving reanalysis is similar to an altimeter-based estimate, but smaller...
Article
Full-text available
The Copernicus Ocean State Report is an annual publication of the Copernicus Marine Service, established in 2014 by the European Commission for Copernicus 1 and renewed in 2021 for Copernicus 2. The report provides a comprehensive, state-of-the-art, scientific overview on the current conditions, natural variations, and ongoing changes in the global...
Preprint
Full-text available
Satellite remote sensing from space is a powerful way to monitor the global dynamics of marine plankton. Previous research has focused on developing models to predict the size or taxonomic groups of phytoplankton. Here we present an approach to identify representative communities from a global plankton network that included both zooplankton and phy...
Article
Full-text available
The key processes driving the air-sea CO2 fluxes in the western tropical Atlantic (WTA) in winter are poorly known. WTA is a highly dynamic oceanic region, expected to have a dominant role in the variability in CO2 air-sea fluxes. In early 2020 (February), this region was the site of a large in situ survey and studied in wider context through satel...
Article
DNA viruses are increasingly recognized as influencing marine microbes and microbe-mediated biogeochemical cycling. However, little is known about global marine RNA virus diversity, ecology, and ecosystem roles. In this study, we uncover patterns and predictors of marine RNA virus community- and "species"-level diversity and contextualize their eco...
Article
Viruses are suspected to be lynchpins in ecosystem function, but so far we can only guess at their significance. DNA viruses are increasingly being recognized as significant components of biogeochemical cycling in the oceans. Dominguez-Huerta et al. explored global patterns of marine RNA virus occurrence by extracting virus sequences from Tara Ocea...
Article
DNA viruses are increasingly recognized as influencing marine microbes and microbe-mediated biogeochemical cycling. However, little is known about global marine RNA virus diversity, ecology, and ecosystem roles. In this study, we uncover patterns and predictors of marine RNA virus community- and "species"-level diversity and contextualize their eco...
Article
Full-text available
Testing hypothesis about the biogeography of genes using large data resources such as Tara Oceans marine metagenomes and metatranscriptomes requires significant hardware resources and programming skills. The new release of the ‘Ocean Gene Atlas’ (OGA2) is a freely available intuitive online service to mine large and complex marine environmental gen...
Article
Full-text available
Motivated by the recurrent formation of eddies in the eastern upwelling areas, we examine cross-basin connectivity that is promoted by coherent, long-lived and long-propagating mesoscale eddies in the Atlantic Ocean. By applying the TOEddies detection and tracking algorithm to daily satellite observations (AVISO/DUACS) of Absolute Dynamic Topograph...
Article
Marine planktonic eukaryotes play critical roles in global biogeochemical cycles and climate. However, their poor representation in culture collections limits our understanding of the evolutionary history and genomic underpinnings of planktonic ecosystems. Here, we used 280 billion Tara Oceans metagenomic reads from polar, temperate, and tropical s...
Article
Whereas DNA viruses are known to be abundant, diverse, and commonly key ecosystem players, RNA viruses are insufficiently studied outside disease settings. In this study, we analyzed ≈28 terabases of Global Ocean RNA sequences to expand Earth's RNA virus catalogs and their taxonomy, investigate their evolutionary origins, and assess their marine bi...
Article
Full-text available
The Brazil-Malvinas Confluence (BMC) is the region where opposing and intense western boundary currents meet along the Southwestern Atlantic slope at about 38◦S, generating one of the most energetic mesoscale regions of the global ocean. Based on shipborne observations acquired within the Uruguayan Economic Exclusive Zone (EEZ), combined with satel...
Preprint
Full-text available
In early 2020, an international team set out to investigate trade wind cumulus and their coupling to the large-scale circulation through the field campaign EUREC4A: ElUcidating the RolE of Clouds‐Circulation Coupling in ClimAte. Focused on the western tropical Atlantic near Barbados, EUREC4A deployed a number of innovative observational strategies,...
Article
Full-text available
We present in this study a detecting algorithm that enables to identify both the ocean surface mixed layer depth (MLD) and mode water from the Argo profiling data. This algorithm proposes a detection based on the calculation of the first and second derivatives for each temperature (or density) profile. Low gradients reveal segments of water mass ho...
Article
Full-text available
The role of the Arctic Ocean ecosystem in climate regulation may depend on the responses of marine microorganisms to environmental change. We applied genome-resolved metagenomics to 41 Arctic seawater samples, collected at various depths in different seasons during the Tara Oceans Polar Circle expedition, to evaluate the ecology, metabolic potentia...
Preprint
Full-text available
The North Brazil Current (NBC) flows northward across the Equator, passes the mouth of the Amazon River, and forms large oceanic eddies near 8° N. We investigate the processes driving the variability of air-sea CO2 fluxes at different scales in early 2020 in the region [50° W–59° W–5° N–16° N]. This region is a pathway between the equatorial and No...
Article
The science guiding the EUREC⁴A campaign and its measurements is presented. EUREC⁴A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC⁴A marked a turning point in our abi...
Article
Full-text available
Deep Chlorophyll Maxima (DCM) are ubiquitous features in stratified oceanic systems. Their establishment and maintenance result from hydrographical stability favoring specific environmental conditions with respect to light and nutrient availability required for phytoplankton growth. This stability can potentially be challenged by mesoscale eddies i...
Article
Full-text available
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and mo...
Article
Full-text available
In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and mo...
Article
jats:p>Abstract. The science guiding the EUREC4A campaign and its measurements are presented. EUREC4A comprised roughly five weeks of measurements in the downstream winter trades of the North Atlantic – eastward and south-eastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4A marked a tu...
Article
Full-text available
Sea-level rise (SLR) will be one of the major climate change-induced risks of the 21st century for coastal areas. The large uncertainties of ice sheet melting processes bring in a range of unlikely – but not impossible – high-end sea-level scenarios (HESs). Here, we provide global to regional HESs exploring the tails of the distribution estimates o...
Article
Full-text available
Variations in the mass and heat transported by the meridional overturning circulation (MOC) have important, well‐documented, influences on global and regional climate, weather, ecosystems, and coastal sea levels. However, continuous, high‐frequency, observations of these quantities have been limited to date. Multiple years of full‐depth daily obser...
Article
Full-text available
In the framework of the EUREC4A (Elucidating the role of clouds–circulation coupling in climate) campaign that took place in January and February 2020, integrated water vapour (IWV) contents were retrieved over the open tropical Atlantic Ocean using Global Navigation Satellite System (GNSS) data acquired from three research vessels (R/Vs): R/V Atal...
Article
Full-text available
In February 2020, a 120 km-wide freshwater plume was documented by satellite and in situ observations near the Demerara Rise (7°N/54-56°W). It was initially stratified in the upper 10 m with a freshwater content of 2 to 3 meters of Amazon water distributed down to 40 m. On February 2nd, ship transects indicate an inhomogeneous shelf structure with...
Article
Full-text available
To advance the understanding of the interplay among clouds, convection, and circulation, and its role in climate change, the Elucidating the role of clouds–circulation coupling in climate campaign (EUREC4A) and Atlantic Tradewind Ocean–Atmosphere Mesoscale Interaction Campaign (ATOMIC) collected measurements in the western tropical Atlantic during...
Article
Full-text available
The variability of the Atlantic Meridional Overturning Circulation (AMOC) has considerable impacts on the global climate system. Past studies have shown that changes in the South Atlantic control the stability of the AMOC and drive an important part of its variability. That is why significant resources have been invested in a South (S)AMOC observin...
Preprint
Full-text available
The science guiding the EUREC4A campaign and its measurements are presented. EUREC4A comprised roughly five weeks of measurements in the downstream winter trades of the North Atlantic – eastward and south-eastward of Barbados. Through its ability to characterize processes operating across a wide range of scales, EUREC4A marked a turning point in ou...
Article
Full-text available
This article is part of the special issue “Elucidating the role of clouds–circulation coupling in climate:datasets from the 2020 (EUREC4A) field campaign”. It is not associated with a conference.
Preprint
Full-text available
In the framework of the EUREC4A (Elucidating the role of clouds-circulation coupling in climate) campaign that took place in January and February 2020, integrated water vapour (IWV) contents were retrieved over the open Tropical Atlantic Ocean using Global Navigation Satellite Systems (GNSS) data acquired from three research vessels (R/Vs): R/V Ata...
Preprint
Full-text available
Oceans play a key role in the climate system and are also affected by climate change. As confirmed by the recent IPCC special report on ocean and cryosphere, ocean dynamics are a major modulator of weather and climate including future trends and extremes. However, there are still uncertainties in the understanding and quantification of key climate-...
Article
Full-text available
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...
Book
Full-text available
En este volumen se presenta un resumen del diagnóstico realizado en el foco temático Océanos y Recursos Hidrobiológicos y se incluyen lineamientos para diseñar políticas públicas, estrategias, misiones emblemáticas y proyectos, encaminados a mejorar el desarrollo humano sostenible y a generar oportunidades socioeconómicas basadas en conocimiento ci...
Article
Full-text available
The Agulhas leakage of Indian Ocean waters into the Atlantic has been shown to be a key link in global ocean circulation and climate; an increased understanding of this process is therefore of more than just of local interest. While knowledge of the Agulhas leakage has increased over the past 30 years, the precise mechanisms at play and water prope...
Preprint
Full-text available
To advance the understanding of the interplay among clouds, convection, and circulation, and its role in climate change, the EUREC4A and ATOMIC field campaigns collected measurements in the western tropical Atlantic during January and February 2020. Upper-air radiosondes were launched regularly (usually 4-hourly) from a network consisting of the Ba...
Article
Full-text available
Motivated by the recurrent formation and intensification of the Ierapetra anticyclones in the southeast of Crete, we investigated with a reduced gravity model the response of the oceanic surface layer to a seasonal wind jet that varies slowly (over several weeks or months) and mimics the Etesian winds. Our study answers why the oceanic response to...
Article
Full-text available
The Meridional Overturning Circulation (MOC) is a primary mechanism driving oceanic heat redistribution on Earth, thereby affecting Earth’s climate and weather. However, the full-depth structure and variability of the MOC are still poorly understood, particularly in the South Atlantic. This study presents unique multiyear records of the oceanic vol...
Technical Report
Full-text available
La Misión Internacional de Sabios 2019 fue convocada por el Gobierno de Colombia en el mes de febrero de 2019. Estuvo conformada por un grupo de expertos independientes y ad honorem en diferentes campos y de diferentes nacionalidades. La Misión recibió el encargo de trazar una hoja de ruta para el desarrollo de la ciencia, la tecnología y la innova...
Article
Full-text available
The transfer of Indian Ocean thermocline and intermediate waters into the South Atlantic via the Agulhas leakage is generally believed to be primarily accomplished through mesoscale eddy processes, essentially anticyclones known as Agulhas Rings. Here we take advantage of a recent eddy tracking algorithm and Argo float profiles to study the evoluti...
Article
Full-text available
Mesoscale eddies, having a characteristic radius equal or larger than the local deformation radius, are generally considered to be geostrophic. Even if this is true for most of them, there are few cases where the ageostrophic velocity components induced by the local curvature of the streamlines are not negligible. In order to account for this ageos...
Article
The ocean is home to myriad small planktonic organisms that underpin the functioning of marine ecosystems. However, their spatial patterns of diversity and the underlying drivers remain poorly known, precluding projections of their responses to global changes. Here we investigate the latitudinal gradients and global predictors of plankton diversity...
Preprint
Full-text available
Motivated by the recurrent formation and intensification of the Ierapetra anticyclones in the southeast of Crete, we investigated with a reduced gravity model the response of the oceanic surface layer to a seasonal wind jet that varies slowly (over several weeks or months) and mimics the Etesian winds. Our study answers why the oceanic response to...
Article
Full-text available
Ocean microbial communities strongly influence the biogeochemistry, food webs, and climate of our planet. Despite recent advances in understanding their taxonomic and genomic compositions, little is known about how their transcriptomes vary globally. Here, we present a dataset of 187 metatranscriptomes and 370 metagenomes from 126 globally distribu...
Poster
Full-text available
TriAtlas Project Presentation at OceanObs19 Overall objective and plan Cross-Atlantic Network of Excellence in Marine Science (CANEMS). The TRIATLAS key challenge. To develop the understanding and the capacity (observational, modelling, and human) to best predict changes in the tropical Atlantic marine ecosystem and its societal impacts. To as...
Article
Full-text available
Advances in ocean observing technologies and modeling provide the capacity to revolutionize the management of living marine resources. While traditional fisheries management approaches like single-species stock assessments are still common, a global effort is underway to adopt ecosystem-based fisheries management (EBFM) approaches. These approaches...
Article
Full-text available
Considerable advances in the global ocean observing system over the last two decades offers an opportunity to provide more quantitative information on changes in heat and freshwater storage. Variations in these storage terms can arise through internal variability and also the response of the ocean to anthropogenic climate change. Disentangling thes...