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2. Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems

Author

Caputi, L, Carradec, Q, Eveillard, D, Kirilovsky, A, Pelletier, E, Pierella Karlusich, JJ, Rocha Jimenez Vieira, F, Villar, E, Chaffron, S, Malviya, S, Scalco, E, Acinas, SG, Alberti, A, Aury, JM, Benoiston, AS, Bertrand, A, Biard, T, Bittner, L, Boccara, M, Brum, JR, Brunet, C, Busseni, G, Carratalà, A, Claustre, H, Coelho, LP, Colin, S, D'Aniello, S, Da Silva, C, Del Core, M, Doré, H, Gasparini, S, Kokoszka, F, Jamet, JL, Lejeusne, C, Lepoivre, C, Lescot, M, Lima-Mendez, G, Lombard, F, Lukeš, J, Maillet, N, Madoui, MA, Martinez, E, Mazzocchi, MG, Néou, MB, Paz-Yepes, J, Poulain, J, Ramondenc, S, Romagnan, JB, Roux, S, Salvagio Manta, D, Sanges, R, Speich, S, Sprovieri, M, Sunagawa, S, Taillandier, V, Tanaka, A, Tirichine, L, Trottier, C, Uitz, J, Veluchamy, A, Veselá, J, Vincent, F, Yau, S, Kandels-Lewis, S, Searson, S, Dimier, C, Picheral, M, Bork, P, Boss, E, de Vargas, C, Follows, MJ, Grimsley, N, Guidi, L, Hingamp, P, Karsenti, E, Sordino, P, Stemmann, L, Sullivan, MB, Tagliabue, A, Zingone, A, Garczarek, L, d'Ortenzio, F, Testor, P, Not, F, d'Alcalà, MR, Wincker, P, Bowler, C, and Iudicone, D

Subjects
Genetics, Atmospheric Sciences, Geochemistry, Meteorology & Atmospheric Sciences, Oceanography
Abstract

Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment.

Published
2019

3. The Tropical Atlantic Observing System

Author

Foltz, GR, Brandt, P, Richter, I, Rodríguez-Fonseca, B, Hernandez, F, Dengler, M, Rodrigues, RR, Schmidt, JO, Yu, L, Lefevre, N, Da Cunha, L Cotrim, McPhaden, MJ, Araujo, M, Karstensen, J, Hahn, J, Martín-Rey, M, Patricola, CM, Poli, P, Zuidema, P, Hummels, R, Perez, RC, Hatje, V, Lübbecke, JF, Polo, I, Lumpkin, R, Bourlès, B, Asuquo, FE, Lehodey, P, Conchon, A, Chang, P, Dandin, P, Schmid, C, Sutton, A, Giordani, H, Xue, Y, Illig, S, Losada, T, Grodsky, SA, Gasparin, F, Lee, T, Mohino, E, Nobre, P, Wanninkhof, R, Keenlyside, N, Garcon, V, Sánchez-Gómez, E, Nnamchi, HC, Drévillon, M, Storto, A, Remy, E, Lazar, A, Speich, S, Goes, M, Dorrington, T, Johns, WE, Moum, JN, Robinson, C, Perruche, C, de Souza, RB, Gaye, AT, López-Parages, J, Monerie, P-A, Castellanos, P, Benson, NU, Hounkonnou, MN, Duhá, J Trotte, Laxenaire, R, and Reul, N

Subjects
Earth Sciences, Oceanography, Atmospheric Sciences, Life Below Water, Climate Action, tropical Atlantic Ocean, observing system, weather, climate, hurricanes, biogeochemistry, ecosystems, coupled model bias, Ecology, Geology
Abstract

The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world's largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set of research priorities and operational challenges. This paper discusses the tropical Atlantic observing system, including emerging scientific questions that demand sustained ocean observations, the potential for further integration of the observing system, and the requirements for sustaining and enhancing the tropical Atlantic observing system.

Published
2019

4. Oceanic Fronts Driven by the Amazon Freshwater Plume and Their Thermohaline Compensation at the Submesoscale.

Author

Coadou‐Chaventon, S., Speich, S., Zhang, D., Rocha, C. B., and Swart, S.

Subjects
FRONTS (Meteorology), FRESH water, OCEANOGRAPHIC maps, OCEAN color, RESEARCH vessels, DEEP-sea moorings, TEMPERATURE effect, SEAWATER salinity, OCEAN-atmosphere interaction
Abstract

Upper ocean fronts are dynamically active features of the global ocean playing a key role in the air‐sea exchanges of properties and their transport in the ocean interior. With scales ranging from the submesoscale (0.1–10 km) to the mesoscale (10–100s km) and a temporal variability from hours to months, collecting in situ observations of these structures is challenging and this has limited our understanding of their associated processes and impacts. During the EUREC4A‐OA/ATOMIC field experiment, which took place in the northwest tropical Atlantic in January–February 2020, a large number of uncrewed platforms, including five Saildrones, were deployed to provide a detailed picture of the upper‐ocean fine‐scale variability. This region is strongly influenced by the outflow of the Amazon River, even in winter, which is the minimum outflow season. Here, the generation of fine‐scale horizontal thermohaline gradients is driven by the stirring of this freshwater river input by large anticyclonic eddies, the so‐called North Brazil Current Rings. Vertical shear estimates using the Saildrones ADCP show that partial temperature compensation occurs along restratifying submesoscale salinity‐dominated fronts. The distribution of surface along‐track gradients, as sampled by different horizontal length‐scales, reveals the prevalence of submesoscale fronts. This is supported by a flattening of the spectral slopes of surface density at the submesoscale. This study emphasizes the need to resolve the upper ocean at high spatial resolution to understand its impact on the broader circulation and to properly represent air‐sea interactions. Plain Language Summary: Oceanic eddies and filaments that range between 10 and 100 km in size can be identified in the study region of the northwestern tropical Atlantic using ocean color as viewed from space (a proxy for chlorophyll‐a). The ocean color maps show that these eddies and filaments are associated with the detachment from the shelf of a freshwater Amazon plume and its interaction with the larger oceanic motions O $\mathcal{O}$(100 km). Field observations from different measurements acquired from research vessels and five uncrewed surface vehicles (USVs) reveal the prevalence and scale of upper ocean fronts, whose magnitude results from the combined effect of temperature and salinity. The Amazon freshwater plume is key to the formation of strong salinity‐driven density fronts. However, when looking at O $\mathcal{O}$(1 km) scales, we detect horizontal temperature variations along slumping fronts that partially counteract the effect of salinity. This leads to a damping of the lateral density fronts. This study contributes to the development of a detailed picture of the ocean fine scales, which is necessary to improve our understanding of air‐sea interactions over frontal regions. Key Points: Vertical shear sections from the Saildrone ADCP data reveal that temperature compensation develops along restratifying submesoscale frontsTemperature and salinity spectra show an increased temperature contribution to salinity‐dominated fronts at the submesoscaleA flattening of the density spectra from ~−3 to ~−2 at the submesoscale (1–10 km) is observed in the Boulevard des Tourbillons [ABSTRACT FROM AUTHOR]

Published
2024
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6. On the importance of the atmospheric coupling to the small-scale ocean in the modulation of latent heat flux

Author

Fernández, P, Speich, S, Borgnino, M, Meroni, A, Desbiolles, F, Pasquero, C, Fernández, Pablo, Speich, Sabrina, Borgnino, Matteo, Meroni, Agostino, Desbiolles, Fabien, Pasquero, Claudia, Fernández, P, Speich, S, Borgnino, M, Meroni, A, Desbiolles, F, Pasquero, C, Fernández, Pablo, Speich, Sabrina, Borgnino, Matteo, Meroni, Agostino, Desbiolles, Fabien, and Pasquero, Claudia

Published
2023

7. Lessons learned from the EUREC4A-OA experiment on the impact of ocean small scales on air-sea interactions in the Northwest Tropical Atlantic

Author

Speich, S, Karstensen, J, Reverdin, G, Olivier, L, Fernandez, P, L'Hégaret, P, Coadou, S, Laxenaire, R, Zhang, D, Gentemann, C, Landschutzer, P, Boutin, J, Bellenger, H, Pasquero, C, Meroni, A, Borgnino, M, Acquistapace, C, Bopp, L, Speich, Sabrina, Karstensen, Johannes, Reverdin, Gilles, Olivier, Léa, Fernandez, Pablo, L'Hégaret, Pierre, Coadou, Solange, Laxenaire, Rémi, Zhang, Dongxiao, Gentemann, Chelle, Landschutzer, Peter, Boutin, Jacqueline, Bellenger, Hugo, Pasquero, Claudia, Meroni, Agostino, Borgnino, Matteo, Acquistapace, Claudia, Bopp, Laurent, Speich, S, Karstensen, J, Reverdin, G, Olivier, L, Fernandez, P, L'Hégaret, P, Coadou, S, Laxenaire, R, Zhang, D, Gentemann, C, Landschutzer, P, Boutin, J, Bellenger, H, Pasquero, C, Meroni, A, Borgnino, M, Acquistapace, C, Bopp, L, Speich, Sabrina, Karstensen, Johannes, Reverdin, Gilles, Olivier, Léa, Fernandez, Pablo, L'Hégaret, Pierre, Coadou, Solange, Laxenaire, Rémi, Zhang, Dongxiao, Gentemann, Chelle, Landschutzer, Peter, Boutin, Jacqueline, Bellenger, Hugo, Pasquero, Claudia, Meroni, Agostino, Borgnino, Matteo, Acquistapace, Claudia, and Bopp, Laurent

Published
2023

8. Multi-decadal Records of the South Atlantic Meridional Overturning and Heat Transport Derived from in-situ and Satellite Observations and Recent Applications

Author

Dong, S., Perez, R., Kersale, M., Goes, M., Goni, G., Speich, S., Piola, A., Lamont, T., Campos, E., Ansorge, I., Chidichimo, M., Sato, O., Meinen, C., Le Henaff, M., and Garzoli, S.

Abstract

The South Atlantic Meridional Overturning Circulation (SAMOC) observing system has evolved tremendously since 2007, and has substantially improved our understanding of the dynamics and variability of the upper, deep, and abyssal South Atlantic circulation from daily to interannual time-scales. However, the SAMOC daily time series derived from moored arrays are still relatively short and are only available at 11°S and 34.5°S. To expand the SAMOC time series in space and time, we derived monthly zonal trans-basin temperature (T) and salinity (S) sections since 1993 at four latitudes (20°S, 25°S, 30°S, and 34.5°S) based on historical relationships between T, S, and satellite sea level. The resulting meridional overturning circulation (MOC) and meridional heat transport (MHT) estimates at 20°S, 25°S, and 30°S are significantly correlated with each other at near zero lag, however correlations with the estimates at 34.5°S are somewhat lower. Although the overturning contribution dominates changes in the MHT at all four latitudes, the gyre contribution increases southward, reaching 30% of the explained MHT variability at 34.5°S. These 30-year monthly records indicate that the dominant mechanism controlling the MOC/MHT variability alternates between wind forcing and internal ocean dynamics. Therefore, both mechanisms must be monitored to fully capture changes in the MOC/MHT. These estimates demonstrate a linkage between the tropical Pacific forcing and heat content changes in the subtropical South Atlantic, as well as the impact of the MOC/MHT on extreme weather events, and provide context for measurements obtained from the SAMOC moored arrays., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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9. The East Asian monsoon provides a natural shield against the super typhoon along China's coast

Author

Ma, T., Yu, W., and Speich, S.

Abstract

Super typhoons (SuperTYs) generated in the Northwest Pacific (WNP) constantly undergo a sharp weakening after crossing the Philippines-Taiwan into the South China Sea (SCS), thus acting as a natural “buffer” to protect the south-eastern coast of China from severe typhoons due to the blockage of the mountains and the unique atmospheric andoceanic environmental fields. This study examines the determinants of this buffer zone and speculates on the response of this part of the SuperTYs in future climate change. Here, we show that the strong vertical wind shear accompanying the South China Sea summer monsoon is a determining factor in the weakening of SuperTYsinto the buffer zone, with a linear correlation up to 0.71. Although most studies suggest that the risk of severe typhoons will increase with global warming, our diagnosis of the latest Sixth Coupled Model Intercomparison Project (CMIP6)multi-model ensemble shows that the decisive factor, vertical wind shear, will not change in trend even in the worst scenario. Therefore, the risk of a severe typhoon making landfall off the southeast coast of China is not getting any worse in future global warming., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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10. EUREC4A

Author

Stevens, B, Bony, S, Farrell, D, Ament, F, Blyth, A, Fairall, C, Karstensen, J, Quinn, P, Speich, S, Acquistapace, C, Aemisegger, F, Albright, A, Bellenger, H, Bodenschatz, E, Caesar, K, Chewitt-Lucas, R, De Boer, G, Delanoe, J, Denby, L, Ewald, F, Fildier, B, Forde, M, George, G, Gross, S, Hagen, M, Hausold, A, Heywood, K, Hirsch, L, Jacob, M, Jansen, F, Kinne, S, Klocke, D, Kolling, T, Konow, H, Lothon, M, Mohr, W, Naumann, A, Nuijens, L, Olivier, L, Pincus, R, Pohlker, M, Reverdin, G, Roberts, G, Schnitt, S, Schulz, H, Pier Siebesma, A, Stephan, C, Sullivan, P, Touze-Peiffer, L, Vial, J, Vogel, R, Zuidema, P, Alexander, N, Alves, L, Arixi, S, Asmath, H, Bagheri, G, Baier, K, Bailey, A, Baranowski, D, Baron, A, Barrau, S, Barrett, P, Batier, F, Behrendt, A, Bendinger, A, Beucher, F, Bigorre, S, Blades, E, Blossey, P, Bock, O, Boing, S, Bosser, P, Bourras, D, Bouruet-Aubertot, P, Bower, K, Branellec, P, Branger, H, Brennek, M, Brewer, A, Brilouet, P, Brugmann, B, Buehler, S, Burke, E, Burton, R, Calmer, R, Canonici, J, Carton, X, Cato, G, Charles, J, Chazette, P, Chen, Y, Chilinski, M, Choularton, T, Chuang, P, Clarke, S, Coe, H, Cornet, C, Coutris, P, Couvreux, F, Crewell, S, Cronin, T, Cui, Z, Cuypers, Y, Daley, A, Damerell, G, Dauhut, T, Deneke, H, Desbios, J, Dorner, S, Donner, S, Douet, V, Drushka, K, Dutsch, M, Ehrlich, A, Emanuel, K, Emmanouilidis, A, Etienne, J, Etienne-Leblanc, S, Faure, G, Feingold, G, Ferrero, L, Fix, A, Flamant, C, Flatau, P, Foltz, G, Forster, L, Furtuna, I, Gadian, A, Galewsky, J, Gallagher, M, Gallimore, P, Gaston, C, Gentemann, C, Geyskens, N, Giez, A, Gollop, J, Gouirand, I, Gourbeyre, C, De Graaf, D, De Groot, G, Grosz, R, Guttler, J, Gutleben, M, Hall, K, Harris, G, Helfer, K, Henze, D, Herbert, C, Holanda, B, Ibanez-Landeta, A, Intrieri, J, Iyer, S, Julien, F, Kalesse, H, Kazil, J, Kellman, A, Kidane, A, Kirchner, U, Klingebiel, M, Korner, M, Kremper, L, Kretzschmar, J, Kruger, O, Kumala, W, Kurz, A, L'Hegaret, P, Labaste, M, Lachlan-Cope, T, Laing, A, Landschutzer, P, Lang, T, Lange, D, Lange, I, Laplace, C, Lavik, G, Laxenaire, R, Lebihan, C, Leandro, M, Lefevre, N, Lena, M, Lenschow, D, Li, Q, Lloyd, G, Los, S, Losi, N, Lovell, O, Luneau, C, Makuch, P, Malinowski, S, Manta, G, Marinou, E, Marsden, N, Masson, S, Maury, N, Mayer, B, Mayers-Als, M, Mazel, C, Mcgeary, W, Mcwilliams, J, Mech, M, Mehlmann, M, Meroni, A, Mieslinger, T, Minikin, A, Minnett, P, Moller, G, Avalos, Y, Muller, C, Musat, I, Napoli, A, Neuberger, A, Noisel, C, Noone, D, Nordsiek, F, Nowak, J, Oswald, L, Parker, D, Peck, C, Person, R, Philippi, M, Plueddemann, A, Pohlker, C, Portge, V, Poschl, U, Pologne, L, Posyniak, M, Prange, M, Melendez, E, Radtke, J, Ramage, K, Reimann, J, Renault, L, Reus, K, Reyes, A, Ribbe, J, Ringel, M, Ritschel, M, Rocha, C, Rochetin, N, Rottenbacher, J, Rollo, C, Royer, H, Sadoulet, P, Saffin, L, Sandiford, S, Sandu, I, Schafer, M, Schemann, V, Schirmacher, I, Schlenczek, O, Schmidt, J, Schroder, M, Schwarzenboeck, A, Sealy, A, Senff, C, Serikov, I, Shohan, S, Siddle, E, Smirnov, A, Spath, F, Spooner, B, Katharina Stolla, M, Szkolka, W, De Szoeke, S, Tarot, S, Tetoni, E, Thompson, E, Thomson, J, Tomassini, L, Totems, J, Ubele, A, Villiger, L, Von Arx, J, Wagner, T, Walther, A, Webber, B, Wendisch, M, Whitehall, S, Wiltshire, A, Wing, A, Wirth, M, Wiskandt, J, Wolf, K, Worbes, L, Wright, E, Wulfmeyer, V, Young, S, Zhang, C, Zhang, D, Ziemen, F, Zinner, T, Zoger, M, Stevens B., Bony S., Farrell D., Ament F., Blyth A., Fairall C., Karstensen J., Quinn P. K., Speich S., Acquistapace C., Aemisegger F., Albright A. L., Bellenger H., Bodenschatz E., Caesar K. -A., Chewitt-Lucas R., De Boer G., Delanoe J., Denby L., Ewald F., Fildier B., Forde M., George G., Gross S., Hagen M., Hausold A., Heywood K. J., Hirsch L., Jacob M., Jansen F., Kinne S., Klocke D., Kolling T., Konow H., Lothon M., Mohr W., Naumann A. K., Nuijens L., Olivier L., Pincus R., Pohlker M., Reverdin G., Roberts G., Schnitt S., Schulz H., Pier Siebesma A., Stephan C. C., Sullivan P., Touze-Peiffer L., Vial J., Vogel R., Zuidema P., Alexander N., Alves L., Arixi S., Asmath H., Bagheri G., Baier K., Bailey A., Baranowski D., Baron A., Barrau S., Barrett P. A., Batier F., Behrendt A., Bendinger A., Beucher F., Bigorre S., Blades E., Blossey P., Bock O., Boing S., Bosser P., Bourras D., Bouruet-Aubertot P., Bower K., Branellec P., Branger H., Brennek M., Brewer A., Brilouet P. -E., Brugmann B., Buehler S. A., Burke E., Burton R., Calmer R., Canonici J. -C., Carton X., Cato G., Charles J. A., Chazette P., Chen Y., Chilinski M. T., Choularton T., Chuang P., Clarke S., Coe H., Cornet C., Coutris P., Couvreux F., Crewell S., Cronin T., Cui Z., Cuypers Y., Daley A., Damerell G. M., Dauhut T., Deneke H., Desbios J. -P., Dorner S., Donner S., Douet V., Drushka K., Dutsch M., Ehrlich A., Emanuel K., Emmanouilidis A., Etienne J. -C., Etienne-Leblanc S., Faure G., Feingold G., Ferrero L., Fix A., Flamant C., Flatau P. J., Foltz G. R., Forster L., Furtuna I., Gadian A., Galewsky J., Gallagher M., Gallimore P., Gaston C., Gentemann C., Geyskens N., Giez A., Gollop J., Gouirand I., Gourbeyre C., De Graaf D., De Groot G. E., Grosz R., Guttler J., Gutleben M., Hall K., Harris G., Helfer K. C., Henze D., Herbert C., Holanda B., Ibanez-Landeta A., Intrieri J., Iyer S., Julien F., Kalesse H., Kazil J., Kellman A., Kidane A. T., Kirchner U., Klingebiel M., Korner M., Kremper L. A., Kretzschmar J., Kruger O., Kumala W., Kurz A., L'Hegaret P., Labaste M., Lachlan-Cope T., Laing A., Landschutzer P., Lang T., Lange D., Lange I., Laplace C., Lavik G., Laxenaire R., LeBihan C., Leandro M., Lefevre N., Lena M., Lenschow D., Li Q., Lloyd G., Los S., Losi N., Lovell O., Luneau C., Makuch P., Malinowski S., Manta G., Marinou E., Marsden N., Masson S., Maury N., Mayer B., Mayers-Als M., Mazel C., McGeary W., McWilliams J. C., Mech M., Mehlmann M., Meroni A. N., Mieslinger T., Minikin A., Minnett P., Moller G., Avalos Y. M., Muller C., Musat I., Napoli A., Neuberger A., Noisel C., Noone D., Nordsiek F., Nowak J. L., Oswald L., Parker D. J., Peck C., Person R., Philippi M., Plueddemann A., Pohlker C., Portge V., Poschl U., Pologne L., Posyniak M., Prange M., Melendez E. Q., Radtke J., Ramage K., Reimann J., Renault L., Reus K., Reyes A., Ribbe J., Ringel M., Ritschel M., Rocha C. B., Rochetin N., Rottenbacher J., Rollo C., Royer H., Sadoulet P., Saffin L., Sandiford S., Sandu I., Schafer M., Schemann V., Schirmacher I., Schlenczek O., Schmidt J., Schroder M., Schwarzenboeck A., Sealy A., Senff C. J., Serikov I., Shohan S., Siddle E., Smirnov A., Spath F., Spooner B., Katharina Stolla M., Szkolka W., De Szoeke S. P., Tarot S., Tetoni E., Thompson E., Thomson J., Tomassini L., Totems J., Ubele A. A., Villiger L., Von Arx J., Wagner T., Walther A., Webber B., Wendisch M., Whitehall S., Wiltshire A., Wing A. A., Wirth M., Wiskandt J., Wolf K., Worbes L., Wright E., Wulfmeyer V., Young S., Zhang C., Zhang D., Ziemen F., Zinner T., Zoger M., Stevens, B, Bony, S, Farrell, D, Ament, F, Blyth, A, Fairall, C, Karstensen, J, Quinn, P, Speich, S, Acquistapace, C, Aemisegger, F, Albright, A, Bellenger, H, Bodenschatz, E, Caesar, K, Chewitt-Lucas, R, De Boer, G, Delanoe, J, Denby, L, Ewald, F, Fildier, B, Forde, M, George, G, Gross, S, Hagen, M, Hausold, A, Heywood, K, Hirsch, L, Jacob, M, Jansen, F, Kinne, S, Klocke, D, Kolling, T, Konow, H, Lothon, M, Mohr, W, Naumann, A, Nuijens, L, Olivier, L, Pincus, R, Pohlker, M, Reverdin, G, Roberts, G, Schnitt, S, Schulz, H, Pier Siebesma, A, Stephan, C, Sullivan, P, Touze-Peiffer, L, Vial, J, Vogel, R, Zuidema, P, Alexander, N, Alves, L, Arixi, S, Asmath, H, Bagheri, G, Baier, K, Bailey, A, Baranowski, D, Baron, A, Barrau, S, Barrett, P, Batier, F, Behrendt, A, Bendinger, A, Beucher, F, Bigorre, S, Blades, E, Blossey, P, Bock, O, Boing, S, Bosser, P, Bourras, D, Bouruet-Aubertot, P, Bower, K, Branellec, P, Branger, H, Brennek, M, Brewer, A, Brilouet, P, Brugmann, B, Buehler, S, Burke, E, Burton, R, Calmer, R, Canonici, J, Carton, X, Cato, G, Charles, J, Chazette, P, Chen, Y, Chilinski, M, Choularton, T, Chuang, P, Clarke, S, Coe, H, Cornet, C, Coutris, P, Couvreux, F, Crewell, S, Cronin, T, Cui, Z, Cuypers, Y, Daley, A, Damerell, G, Dauhut, T, Deneke, H, Desbios, J, Dorner, S, Donner, S, Douet, V, Drushka, K, Dutsch, M, Ehrlich, A, Emanuel, K, Emmanouilidis, A, Etienne, J, Etienne-Leblanc, S, Faure, G, Feingold, G, Ferrero, L, Fix, A, Flamant, C, Flatau, P, Foltz, G, Forster, L, Furtuna, I, Gadian, A, Galewsky, J, Gallagher, M, Gallimore, P, Gaston, C, Gentemann, C, Geyskens, N, Giez, A, Gollop, J, Gouirand, I, Gourbeyre, C, De Graaf, D, De Groot, G, Grosz, R, Guttler, J, Gutleben, M, Hall, K, Harris, G, Helfer, K, Henze, D, Herbert, C, Holanda, B, Ibanez-Landeta, A, Intrieri, J, Iyer, S, Julien, F, Kalesse, H, Kazil, J, Kellman, A, Kidane, A, Kirchner, U, Klingebiel, M, Korner, M, Kremper, L, Kretzschmar, J, Kruger, O, Kumala, W, Kurz, A, L'Hegaret, P, Labaste, M, Lachlan-Cope, T, Laing, A, Landschutzer, P, Lang, T, Lange, D, Lange, I, Laplace, C, Lavik, G, Laxenaire, R, Lebihan, C, Leandro, M, Lefevre, N, Lena, M, Lenschow, D, Li, Q, Lloyd, G, Los, S, Losi, N, Lovell, O, Luneau, C, Makuch, P, Malinowski, S, Manta, G, Marinou, E, Marsden, N, Masson, S, Maury, N, Mayer, B, Mayers-Als, M, Mazel, C, Mcgeary, W, Mcwilliams, J, Mech, M, Mehlmann, M, Meroni, A, Mieslinger, T, Minikin, A, Minnett, P, Moller, G, Avalos, Y, Muller, C, Musat, I, Napoli, A, Neuberger, A, Noisel, C, Noone, D, Nordsiek, F, Nowak, J, Oswald, L, Parker, D, Peck, C, Person, R, Philippi, M, Plueddemann, A, Pohlker, C, Portge, V, Poschl, U, Pologne, L, Posyniak, M, Prange, M, Melendez, E, Radtke, J, Ramage, K, Reimann, J, Renault, L, Reus, K, Reyes, A, Ribbe, J, Ringel, M, Ritschel, M, Rocha, C, Rochetin, N, Rottenbacher, J, Rollo, C, Royer, H, Sadoulet, P, Saffin, L, Sandiford, S, Sandu, I, Schafer, M, Schemann, V, Schirmacher, I, Schlenczek, O, Schmidt, J, Schroder, M, Schwarzenboeck, A, Sealy, A, Senff, C, Serikov, I, Shohan, S, Siddle, E, Smirnov, A, Spath, F, Spooner, B, Katharina Stolla, M, Szkolka, W, De Szoeke, S, Tarot, S, Tetoni, E, Thompson, E, Thomson, J, Tomassini, L, Totems, J, Ubele, A, Villiger, L, Von Arx, J, Wagner, T, Walther, A, Webber, B, Wendisch, M, Whitehall, S, Wiltshire, A, Wing, A, Wirth, M, Wiskandt, J, Wolf, K, Worbes, L, Wright, E, Wulfmeyer, V, Young, S, Zhang, C, Zhang, D, Ziemen, F, Zinner, T, Zoger, M, Stevens B., Bony S., Farrell D., Ament F., Blyth A., Fairall C., Karstensen J., Quinn P. K., Speich S., Acquistapace C., Aemisegger F., Albright A. L., Bellenger H., Bodenschatz E., Caesar K. -A., Chewitt-Lucas R., De Boer G., Delanoe J., Denby L., Ewald F., Fildier B., Forde M., George G., Gross S., Hagen M., Hausold A., Heywood K. J., Hirsch L., Jacob M., Jansen F., Kinne S., Klocke D., Kolling T., Konow H., Lothon M., Mohr W., Naumann A. K., Nuijens L., Olivier L., Pincus R., Pohlker M., Reverdin G., Roberts G., Schnitt S., Schulz H., Pier Siebesma A., Stephan C. C., Sullivan P., Touze-Peiffer L., Vial J., Vogel R., Zuidema P., Alexander N., Alves L., Arixi S., Asmath H., Bagheri G., Baier K., Bailey A., Baranowski D., Baron A., Barrau S., Barrett P. A., Batier F., Behrendt A., Bendinger A., Beucher F., Bigorre S., Blades E., Blossey P., Bock O., Boing S., Bosser P., Bourras D., Bouruet-Aubertot P., Bower K., Branellec P., Branger H., Brennek M., Brewer A., Brilouet P. -E., Brugmann B., Buehler S. A., Burke E., Burton R., Calmer R., Canonici J. -C., Carton X., Cato G., Charles J. A., Chazette P., Chen Y., Chilinski M. T., Choularton T., Chuang P., Clarke S., Coe H., Cornet C., Coutris P., Couvreux F., Crewell S., Cronin T., Cui Z., Cuypers Y., Daley A., Damerell G. M., Dauhut T., Deneke H., Desbios J. -P., Dorner S., Donner S., Douet V., Drushka K., Dutsch M., Ehrlich A., Emanuel K., Emmanouilidis A., Etienne J. -C., Etienne-Leblanc S., Faure G., Feingold G., Ferrero L., Fix A., Flamant C., Flatau P. J., Foltz G. R., Forster L., Furtuna I., Gadian A., Galewsky J., Gallagher M., Gallimore P., Gaston C., Gentemann C., Geyskens N., Giez A., Gollop J., Gouirand I., Gourbeyre C., De Graaf D., De Groot G. E., Grosz R., Guttler J., Gutleben M., Hall K., Harris G., Helfer K. C., Henze D., Herbert C., Holanda B., Ibanez-Landeta A., Intrieri J., Iyer S., Julien F., Kalesse H., Kazil J., Kellman A., Kidane A. T., Kirchner U., Klingebiel M., Korner M., Kremper L. A., Kretzschmar J., Kruger O., Kumala W., Kurz A., L'Hegaret P., Labaste M., Lachlan-Cope T., Laing A., Landschutzer P., Lang T., Lange D., Lange I., Laplace C., Lavik G., Laxenaire R., LeBihan C., Leandro M., Lefevre N., Lena M., Lenschow D., Li Q., Lloyd G., Los S., Losi N., Lovell O., Luneau C., Makuch P., Malinowski S., Manta G., Marinou E., Marsden N., Masson S., Maury N., Mayer B., Mayers-Als M., Mazel C., McGeary W., McWilliams J. C., Mech M., Mehlmann M., Meroni A. N., Mieslinger T., Minikin A., Minnett P., Moller G., Avalos Y. M., Muller C., Musat I., Napoli A., Neuberger A., Noisel C., Noone D., Nordsiek F., Nowak J. L., Oswald L., Parker D. J., Peck C., Person R., Philippi M., Plueddemann A., Pohlker C., Portge V., Poschl U., Pologne L., Posyniak M., Prange M., Melendez E. Q., Radtke J., Ramage K., Reimann J., Renault L., Reus K., Reyes A., Ribbe J., Ringel M., Ritschel M., Rocha C. B., Rochetin N., Rottenbacher J., Rollo C., Royer H., Sadoulet P., Saffin L., Sandiford S., Sandu I., Schafer M., Schemann V., Schirmacher I., Schlenczek O., Schmidt J., Schroder M., Schwarzenboeck A., Sealy A., Senff C. J., Serikov I., Shohan S., Siddle E., Smirnov A., Spath F., Spooner B., Katharina Stolla M., Szkolka W., De Szoeke S. P., Tarot S., Tetoni E., Thompson E., Thomson J., Tomassini L., Totems J., Ubele A. A., Villiger L., Von Arx J., Wagner T., Walther A., Webber B., Wendisch M., Whitehall S., Wiltshire A., Wing A. A., Wirth M., Wiskandt J., Wolf K., Worbes L., Wright E., Wulfmeyer V., Young S., Zhang C., Zhang D., Ziemen F., Zinner T., and Zoger M.

Abstract

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 ability to observationally study factors influencing clouds in the trades, how they will respond to warming, and their link to other components of the earth system, such as upper-ocean processes or the life cycle of particulate matter. This characterization was made possible by thousands (2500) of sondes distributed to measure circulations on meso- (200 km) and larger (500 km) scales, roughly 400 h of flight time by four heavily instrumented research aircraft; four global-class research vessels; an advanced ground-based cloud observatory; scores of autonomous observing platforms operating in the upper ocean (nearly 10 000 profiles), lower atmosphere (continuous profiling), and along the air-sea interface; a network of water stable isotopologue measurements; targeted tasking of satellite remote sensing; and modeling with a new generation of weather and climate models. In addition to providing an outline of the novel measurements and their composition into a unified and coordinated campaign, the six distinct scientific facets that EUREC4A explored - from North Brazil Current rings to turbulence-induced clustering of cloud droplets and its influence on warm-rain formation - are presented along with an overview of EUREC4A's outreach activities, environmental impact, and guidelines for scientific practice. Track data for all platforms are standardized and accessible at 10.25326/165 , and a film documenting the campaign is provided as a video supplement.

Published
2021

11. GCOS 2022 Implementation Plan

Author

Chao, Qingchen, Han Dolman, Albertus Johannes, Herold, Martin, Krug, Thelma, Speich, Sabrina, Suda, Kazuto, Thorne, Peter, Yu, Weidong, Zemp, Michael; https://orcid.org/0000-0003-2391-7877, Chao, Q ( Qingchen ), Han Dolman, A J ( Albertus Johannes ), Herold, M ( Martin ), Krug, T ( Thelma ), Speich, S ( Sabrina ), Suda, K ( Kazuto ), Thorne, P ( Peter ), Yu, W ( Weidong ), Zemp, M ( Michael ), Chao, Qingchen, Han Dolman, Albertus Johannes, Herold, Martin, Krug, Thelma, Speich, Sabrina, Suda, Kazuto, Thorne, Peter, Yu, Weidong, Zemp, Michael; https://orcid.org/0000-0003-2391-7877, Chao, Q ( Qingchen ), Han Dolman, A J ( Albertus Johannes ), Herold, M ( Martin ), Krug, T ( Thelma ), Speich, S ( Sabrina ), Suda, K ( Kazuto ), Thorne, P ( Peter ), Yu, W ( Weidong ), and Zemp, M ( Michael )

Published
2022

14. Eukaryotic plankton diversity in the sunlit ocean

Author

de Vargas, C., Audic, S., Henry, N., Decelle, J., Mahé, F., Logares, R., Lara, E., Berney, C., Le Bescot, N., Probert, I., Carmichael, M., Poulain, J., Romac, S., Colin, S., Aury, J.-M., Bittner, L., Chaffron, S., Dunthorn, M., Engelen, S., Flegontova, O., Guidi, L., Horák, A., Jaillon, O., Lima-Mendez, G., Lukeš, J., Malviya, S., Morard, R., Mulot, M., Scalco, E., Siano, R., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Acinas, S. G., Bork, P., Bowler, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Raes, J., Sieracki, M. E., Speich, S., Stemmann, L., Sunagawa, S., Weissenbach, J., Wincker, P., and Karsenti, E.

Published
2015

15. Determinants of community structure in the global plankton interactome

Author

Lima-Mendez, G., Faust, K., Henry, N., Decelle, J., Colin, S., Carcillo, F., Chaffron, S., Ignacio-Espinosa, J. C., Roux, S., Vincent, F., Bittner, L., Darzi, Y., Wang, J., Audic, S., Berline, L., Bontempi, G., Cabello, A. M., Coppola, L., Cornejo-Castillo, F. M., dʼOvidio, F., De Meester, L., Ferrera, I., Garet-Delmas, M.-J., Guidi, L., Lara, E., Pesant, S., Royo-Llonch, M., Salazar, G., Sánchez, P., Sebastian, M., Souffreau, C., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Gorsky, G., Not, F., Ogata, H., Speich, S., Stemmann, L., Weissenbach, J., Wincker, P., Acinas, S. G., Sunagawa, S., Bork, P., Sullivan, M. B., Karsenti, E., Bowler, C., de Vargas, C., and Raes, J.

Published
2015

16. Structure and function of the global ocean microbiome

Author

Sunagawa, S., Coelho, L. P., Chaffron, S., Kultima, J. R., Labadie, K., Salazar, G., Djahanschiri, B., Zeller, G., Mende, D. R., Alberti, A., Cornejo-Castillo, F. M., Costea, P. I., Cruaud, C., dʼOvidio, F., Engelen, S., Ferrera, I., Gasol, J. M., Guidi, L., Hildebrand, F., Kokoszka, F., Lepoivre, C., Lima-Mendez, G., Poulain, J., Poulos, B. T., Royo-Llonch, M., Sarmento, H., Vieira-Silva, S., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Bowler, C., de Vargas, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Jaillon, O., Not, F., Ogata, H., Pesant, S., Speich, S., Stemmann, L., Sullivan, M. B., Weissenbach, J., Wincker, P., Karsenti, E., Raes, J., Acinas, S. G., and Bork, P.

Published
2015

17. Environmental characteristics of Agulhas rings affect interocean plankton transport

Author

Villar, E., Farrant, G. K., Follows, M., Garczarek, L., Speich, S., Audic, S., Bittner, L., Blanke, B., Brum, J. R., Brunet, C., Casotti, R., Chase, A., Dolan, J. R., dʼOrtenzio, F., Gattuso, J.-P., Grima, N., Guidi, L., Hill, C. N., Jahn, O., Jamet, J.-L., Le Goff, H., Lepoivre, C., Malviya, S., Pelletier, E., Romagnan, J.-B., Roux, S., Santini, S., Scalco, E., Schwenck, S. M., Tanaka, A., Testor, P., Vannier, T., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Acinas, S. G., Bork, P., Boss, E., de Vargas, C., Gorsky, G., Ogata, H., Pesant, S., Sullivan, M. B., Sunagawa, S., Wincker, P., Karsenti, E., Bowler, C., Not, F., Hingamp, P., and Iudicone, D.

Published
2015

18. Patterns and ecological drivers of ocean viral communities

Author

Brum, J. R., Ignacio-Espinoza, J. C., Roux, S., Doulcier, G., Acinas, S. G., Alberti, A., Chaffron, S., Cruaud, C., de Vargas, C., Gasol, J. M., Gorsky, G., Gregory, A. C., Guidi, L., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Poulos, B. T., Schwenck, S. M., Speich, S., Dimier, C., Kandels-Lewis, S., Picheral, M., Searson, S., Oceans Coordinators, Tara, Bork, P., Bowler, C., Sunagawa, S., Wincker, P., Karsenti, E., and Sullivan, M. B.

Published
2015

19. Ship- and island-based atmospheric soundings from the 2020 EUREC(4)A field campaign [Data paper]

Author

Stephan, C. C., Schnitt, S., Schulz, H., Bellenger, H., de Szoeke, S. P., Acquistapace, C., Baier, K., Dauhut, T., Laxenaire, R., Morfa-Avalos, Y., Person, Renaud, Melendez, E. Q., Bagheri, G., Bock, T., Daley, A., Guttler, J., Helfer, K. C., Los, S. A., Neuberger, A., Rottenbacher, J., Raeke, A., Ringel, M., Ritschel, M., Sadoulet, P., Schirmacher, I., Stolla, M. K., Wright, E., Charpentier, B., Doerenbecher, A., Wilson, R., Jansen, F., Kinne, S., Reverdin, G., Speich, S., Bony, S., and Stevens, B.

Abstract

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 (EUREC(4)A) and Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC) 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 Barbados Cloud Observatory (BCO) and four ships within 6-16 degrees N, 51-60 degrees W. From 8 January to 19 February, a total of 811 radiosondes measured wind, temperature, and relative humidity. In addition to the ascent, the descent was recorded for 82% of the soundings. The soundings sampled changes in atmospheric pressure, winds, lifting condensation level, boundary layer depth, and vertical distribution of moisture associated with different ocean surface conditions, synoptic variability, and mesoscale convective organization. Raw (Level 0), quality-controlled 1 s (Level 1), and vertically gridded (Level 2) data in NetCDF format (Stephan et al., 2020) are available to the public at AERIS (https://doi.org/10.25326/137). The methods of data collection and post-processing for the radiosonde data set are described here.

Published
2021

20. Formation and evolution of a freshwater plume in the northwestern tropical Atlantic in February 2020

Author

Reverdin, G., Olivier, L., Foltz, G. R., Speich, S., Karstensen, J., Horstmann, J., Zhang, D., Laxenaire, R., Carton, Xavier, Branger, H., Carrasco, R., Boutin, J., Reverdin, G., Olivier, L., Foltz, G. R., Speich, S., Karstensen, J., Horstmann, J., Zhang, D., Laxenaire, R., Carton, Xavier, Branger, H., Carrasco, R., and Boutin, J.

Abstract

In February 2020, a 120km‐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 a propagating front in its midst, whereas minimum salinity close to 30 pss was observed close to the shelf break on February 5th. The salinity minimum eroded in time but was still observed 13 to 16 days later with 33.3 pss minimum value up to 400 km from the shelf break. At this time, the mixed layer depth was close to 20 m. The off‐shelf flow lasted 10 days, contributing to a plume area extending over 100000 km2 and associated with a 0.15 106 m3 s‐1 freshwater transport. The off‐shelf plume was steered northward by a North Brazil Current ring up to 12°N and then extended westward toward the Caribbean Sea. Its occurrence followed 3 days of favourable wind direction closer to the Amazon estuary, which contributed to north‐westward freshwater transport on the shelf. Other such events of freshwater transport in January‐March are documented since 2010 in salinity satellite products in 7 out of 10 years, and in 6 of those years, they were preceded by a change in wind direction between the Amazon estuary and the Guianas favouring the north‐westward freshwater transport toward the shelf break. Plain Language Summary This paper documents how freshwater from the Amazon reaches the deep ocean up to 12°N in the northwest tropical Atlantic in January‐March. The classical view is that the water is channelled along the shelf to the Caribbean Sea. Here, we document a freshwater plume from in situ and satellite observations during the EUREC4A‐OA/ATOMIC program in 2020. This plume separated from the shelf near 55°W north of French Guiana on February 2‐5. This fresher water was stirred by a North Brazil Current ring up to 12°N before mostly

Published
2021
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21. The EUREC4A-Ocean/Atmosphere campaign: status

Author

Karstensen, J, Speich, S, Renault, L, Giordani, H, Meroni, A, Pasquero, C, Desbiolles, F, Bellenger, H, Bopp, L, Lapeyre, G, Gentemann, C, Zhang, D, Laxenaire, R, von Storch, J, Reverdin, G, Thompson, E, Heywood, K, Bourras, D, Thomson, J, Foltz, G, Hubert, B, Bigorre, S, Clayson, C, Sullivan, P, Mcwilliams, J, Zhang, C, Rocha, C, Acquistapace, C, Fairall, C, Zuidema, P, Horstmann, J, Schutte, F, Olivier, L, L'Hegaret, P, Carton, X, Rudloff, D, Baranowski, D, Landschuetzer, P, Lange, D, Wulfmeyer, V, Behrendt, A, Labbri, G, Farrell, D, Karstensen, Johannes, Speich, Sabrina, Renault, Lionel, Giordani, Herve, Meroni, Agostino, Pasquero, Claudia, Desbiolles, Fabien, Bellenger, Hugo, Bopp, Laurent, Lapeyre, Guillaume, Gentemann, Chelle, Zhang, Dongxiao, Laxenaire, Remi, von Storch, Jin-Song, Reverdin, Gilles, Thompson, Elizabeth, Heywood, Karen, Bourras, Denis, Thomson, James, Foltz, Gregory, Hubert, Branger, Bigorre, Sebastien, Clayson, Carol, Sullivan, Peter, McWilliams, James, Zhang, Chidong, Rocha, Cesar, Acquistapace, Claudia, Fairall, Chris, Zuidema, Paquita, Horstmann, Jochen, Schutte, Florian, Olivier, Lea, L'Hegaret, Pierre, Carton, Xavier, Rudloff, Daniel, Baranowski, Darek, Landschuetzer, Peter, Lange, Diego, Wulfmeyer, Volker, Behrendt, Andreas, Labbri, Giacomo, Farrell, David, Karstensen, J, Speich, S, Renault, L, Giordani, H, Meroni, A, Pasquero, C, Desbiolles, F, Bellenger, H, Bopp, L, Lapeyre, G, Gentemann, C, Zhang, D, Laxenaire, R, von Storch, J, Reverdin, G, Thompson, E, Heywood, K, Bourras, D, Thomson, J, Foltz, G, Hubert, B, Bigorre, S, Clayson, C, Sullivan, P, Mcwilliams, J, Zhang, C, Rocha, C, Acquistapace, C, Fairall, C, Zuidema, P, Horstmann, J, Schutte, F, Olivier, L, L'Hegaret, P, Carton, X, Rudloff, D, Baranowski, D, Landschuetzer, P, Lange, D, Wulfmeyer, V, Behrendt, A, Labbri, G, Farrell, D, Karstensen, Johannes, Speich, Sabrina, Renault, Lionel, Giordani, Herve, Meroni, Agostino, Pasquero, Claudia, Desbiolles, Fabien, Bellenger, Hugo, Bopp, Laurent, Lapeyre, Guillaume, Gentemann, Chelle, Zhang, Dongxiao, Laxenaire, Remi, von Storch, Jin-Song, Reverdin, Gilles, Thompson, Elizabeth, Heywood, Karen, Bourras, Denis, Thomson, James, Foltz, Gregory, Hubert, Branger, Bigorre, Sebastien, Clayson, Carol, Sullivan, Peter, McWilliams, James, Zhang, Chidong, Rocha, Cesar, Acquistapace, Claudia, Fairall, Chris, Zuidema, Paquita, Horstmann, Jochen, Schutte, Florian, Olivier, Lea, L'Hegaret, Pierre, Carton, Xavier, Rudloff, Daniel, Baranowski, Darek, Landschuetzer, Peter, Lange, Diego, Wulfmeyer, Volker, Behrendt, Andreas, Labbri, Giacomo, and Farrell, David

Published
2021

22. Multi‐Year Estimates of Daily Heat Transport by the Atlantic Meridional Overturning Circulation at 34.5°S

Author

Kersalé, M., primary, Meinen, C. S., additional, Perez, R. C., additional, Piola, A. R., additional, Speich, S., additional, Campos, E. J. D., additional, Garzoli, S. L., additional, Ansorge, I., additional, Volkov, D. L., additional, Le Hénaff, M., additional, Dong, S., additional, Lamont, T., additional, Sato, O. T., additional, and van den Berg, M., additional

Published
2021
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24. The South Atlantic Meridional Overturning Circulation and Mesoscale Eddies in the First GO‐SHIP Section at 34.5°S

Author

Manta, G., primary, Speich, S., additional, Karstensen, J., additional, Hummels, R., additional, Kersalé, M., additional, Laxenaire, R., additional, Piola, A., additional, Chidichimo, M. P., additional, Sato, O. T., additional, Cotrim da Cunha, L., additional, Ansorge, I., additional, Lamont, T., additional, van den Berg, M.A., additional, Schuster, U., additional, Tanhua, T., additional, Kerr, R., additional, Guerrero, R., additional, Campos, E., additional, and Meinen, C. S., additional

Published
2021
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25. Highly variable upper and abyssal overturning cells in the South Atlantic

Author

Kersalé, M., Meinen, C. S., Perez, Rc, Le Hénaff, M., Valla, D., Lamont, T., Sato, O. T., Dong, S., Terre-terrillon, Thierry, Van Caspel, M., Chidichimo, M. P., Van Den Berg, M., Speich, S., Piola, A. R., Campos, E. J. D., Ansorge, I., Volkov, D. L., Lumpkin, R., Garzoli, S. L., Kersalé, M., Meinen, C. S., Perez, Rc, Le Hénaff, M., Valla, D., Lamont, T., Sato, O. T., Dong, S., Terre-terrillon, Thierry, Van Caspel, M., Chidichimo, M. P., Van Den Berg, M., Speich, S., Piola, A. R., Campos, E. J. D., Ansorge, I., Volkov, D. L., Lumpkin, R., and Garzoli, S. L.

Abstract

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 volume transport of both the upper (<~3100 meters) and abyssal (>~3100 meters) overturning cells based on daily moored measurements in the South Atlantic at 34.5°S. The vertical structure of the time-mean flows is consistent with the limited historical observations. Both the upper and abyssal cells exhibit a high degree of variability relative to the temporal means at time scales, ranging from a few days to a few weeks. Observed variations in the abyssal flow appear to be largely independent of the flow in the overlying upper cell. No meaningful trends are detected in either cell.

Published
2020
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27. Highly variable upper and abyssal overturning cells in the South Atlantic

Author

Kersalé, M., primary, Meinen, C. S., additional, Perez, R. C., additional, Le Hénaff, M., additional, Valla, D., additional, Lamont, T., additional, Sato, O. T., additional, Dong, S., additional, Terre, T., additional, van Caspel, M., additional, Chidichimo, M. P., additional, van den Berg, M., additional, Speich, S., additional, Piola, A. R., additional, Campos, E. J. D., additional, Ansorge, I., additional, Volkov, D. L., additional, Lumpkin, R., additional, and Garzoli, S. L., additional

Published
2020
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29. The Tropical Atlantic Observing System

Author

Foltz, G. R., Brandt, P., Richter, I., Rodríguez-fonseca, B., Hernandez, F., Dengler, M., Rodrigues, R. R., Schmidt, J. O., Yu, L., Lefevre, N., Da Cunha, L. Cotrim, Mcphaden, M. J., Araujo, M., Karstensen, J., Hahn, J., Martín-rey, M., Patricola, C. M., Poli, P., Zuidema, P., Hummels, R., Perez, Rc, Hatje, V., Lübbecke, J. F., Polo, I., Lumpkin, R., Bourlès, Bernard, Asuquo, F. E., Lehodey, P., Conchon, A., Chang, P., Dandin, P., Schmid, C., Sutton, A., Giordani, H., Xue, Y., Illig, S., Losada, T., Grodsky, S. A., Gasparin, F., Lee, T., Mohino, E., Nobre, P., Wanninkhof, R., Keenlyside, N., Garcon, V., Sánchez-gómez, E., Nnamchi, H. C., Drévillon, M., Storto, A., Remy, E., Lazar, A., Speich, S., Goes, M., Dorrington, T., Johns, W. E., Moum, J. N., Robinson, C., Perruche, Coralie, De Souza, R. B., Gaye, A. T., López-parages, J., Monerie, P.-a., Castellanos, P., Benson, N. U., Hounkonnou, M. N., Duhá, J. Trotte, Laxenaire, R., Reul, Nicolas, Foltz, G. R., Brandt, P., Richter, I., Rodríguez-fonseca, B., Hernandez, F., Dengler, M., Rodrigues, R. R., Schmidt, J. O., Yu, L., Lefevre, N., Da Cunha, L. Cotrim, Mcphaden, M. J., Araujo, M., Karstensen, J., Hahn, J., Martín-rey, M., Patricola, C. M., Poli, P., Zuidema, P., Hummels, R., Perez, Rc, Hatje, V., Lübbecke, J. F., Polo, I., Lumpkin, R., Bourlès, Bernard, Asuquo, F. E., Lehodey, P., Conchon, A., Chang, P., Dandin, P., Schmid, C., Sutton, A., Giordani, H., Xue, Y., Illig, S., Losada, T., Grodsky, S. A., Gasparin, F., Lee, T., Mohino, E., Nobre, P., Wanninkhof, R., Keenlyside, N., Garcon, V., Sánchez-gómez, E., Nnamchi, H. C., Drévillon, M., Storto, A., Remy, E., Lazar, A., Speich, S., Goes, M., Dorrington, T., Johns, W. E., Moum, J. N., Robinson, C., Perruche, Coralie, De Souza, R. B., Gaye, A. T., López-parages, J., Monerie, P.-a., Castellanos, P., Benson, N. U., Hounkonnou, M. N., Duhá, J. Trotte, Laxenaire, R., and Reul, Nicolas

Abstract

The tropical Atlantic is home to multiple coupled climate variations covering a wide range of timescales and impacting societally relevant phenomena such as continental rainfall, Atlantic hurricane activity, oceanic biological productivity, and atmospheric circulation in the equatorial Pacific. The tropical Atlantic also connects the southern and northern branches of the Atlantic meridional overturning circulation and receives freshwater input from some of the world’s largest rivers. To address these diverse, unique, and interconnected research challenges, a rich network of ocean observations has developed, building on the backbone of the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). This network has evolved naturally over time and out of necessity in order to address the most important outstanding scientific questions and to improve predictions of tropical Atlantic severe weather and global climate variability and change. The tropical Atlantic observing system is motivated by goals to understand and better predict phenomena such as tropical Atlantic interannual to decadal variability and climate change; multidecadal variability and its links to the meridional overturning circulation; air-sea fluxes of CO2 and their implications for the fate of anthropogenic CO2; the Amazon River plume and its interactions with biogeochemistry, vertical mixing, and hurricanes; the highly productive eastern boundary and equatorial upwelling systems; and oceanic oxygen minimum zones, their impacts on biogeochemical cycles and marine ecosystems, and their feedbacks to climate. Past success of the tropical Atlantic observing system is the result of an international commitment to sustained observations and scientific cooperation, a willingness to evolve with changing research and monitoring needs, and a desire to share data openly with the scientific community and operational centers. The observing system must continue to evolve in order to meet an expanding set

Published
2019
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30. Anticyclonic eddies connecting the western boundaries of Indian and Atlantic Oceans

Author

Laxenaire, R., Speich, S., Blanke, B., Chaigneau, A., Pegliasco, C., Stegner, A., Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, eddy tracking, mesoscale dynamics, interocean exchange, ComputingMilieux_MISCELLANEOUS, Agulhas Rings
Abstract

The Indo‐Atlantic interocean exchanges achieved by Agulhas Rings are tightly linked to global ocean circulation and climate. Yet, they are still poorly understood because they are difficult to identify and follow. We propose here an original assessment on Agulhas Rings, achieved by TOEddies, a new eddy identification and tracking algorithm that we applied over 24 years of satellite altimetry. Its main novelty lies in the detection of eddy splitting and merging events. These are particularly abundant and significantly impact the concept of a trajectory associated with a single eddy, which becomes less obvious than previously admitted. To overcome this complication, we have defined a network of segments that group together in relatively complex trajectories. Such a network provides an original assessment of the routes and history of Agulhas Rings. It links 730 481 eddies into 6 363 segments that cluster into Agulhas Ring trajectories of different orders. Such an order depends on the affiliation of the eddies and segments, in a similar way as a tree of life. Among them, we have identified 122 “order 0” trajectories that can be considered as the major trajectories associated to a single eddy, albeit it has undergone itself splitting and merging events. Despite the disappearance of many eddies in the altimeter signal in the Cape Basin, a significant fraction can be followed from the Indian Ocean to the South Brazil Current with, on average, 3.5 years to cross the entire South Atlantic. Plain Language Summary Mesoscale eddies are ubiquitous structures in the ocean and are one of the major sources of ocean variability. They play a crucial role in physically shaping the ocean general circulation, in transporting and mixing energy, chemicals and other materials within and among ocean basins. This should be true, in particular, south of Africa where the largest mesoscale eddies, the so‐called Agulhas Rings, are shed from the Agulhas Current into the Cape Basin conveying Indian warm and salty waters into the Southeast Atlantic Ocean. However, due to their small‐scale and highly variable nature, ocean eddies are inadequately sampled and poorly reproduced in numerical models. Hence, we still lack a good assessment of their population and an appropriate understanding of their dynamics and exact role in the Earth's climate.We propose here an original assessment on Agulhas Rings achieved by a tracking algorithm that we applied over 24 years of satellite altimetry. Its main novelty lies in the detection of eddy separation and coalescence events that replace the concept of trajectories by the consideration of an eddy network. Such a network provides an original assessment of the routes and history of Agulhas Rings longer and more complex than previously described.

Published
2018

31. EUREC4A: a field campaign to elucidate the couplings between clouds, convection and circulation

Author

Bony, S., Stevens, B., https://orcid.org/0000-0003-3795-0475, Ament, F., Crewell, S., Delanoe, J., Farrell, D., Flamant, C., Gross, S., Hirsch, L., Mayer, B., Nuijens, L., Ruppert, J., Sandu, I., Siebesma, P., Speich, S., Szczap, F., Vogel, R., Wendisch, M., and Wirth, M.

Subjects
Physics::Atmospheric and Oceanic Physics
Abstract

Trade-wind cumuli constitute the cloud type with the highest frequency of occurrence on Earth, and it has been shown that their sensitivity to changing environmental conditions will critically influence the magnitude and pace of future global warming. Research over the last decade has pointed out the importance of the interplay between clouds, convection and circulation in controling this sensitivity. Numerical models represent this interplay in diverse ways, which translates into different responses of trade-cumuli to climate perturbations. Climate models predict that the area covered by shallow cumuli at cloud base is very sensitive to changes in environmental conditions, while process models suggest the opposite. To understand and resolve this contradiction, we propose to organize a field campaign aimed at quantifying the physical properties of trade-cumuli (e.g., cloud fraction and water content) as a function of the large-scale environment. Beyond a better understanding of clouds-circulation coupling processes, the campaign will provide a reference data set that may be used as a benchmark for advancing the modelling and the satellite remote sensing of clouds and circulation. It will also be an opportunity for complementary investigations such as evaluating model convective parameterizations or studying the role of ocean mesoscale eddies in air-sea interactions and convective organization.

Published
2017

36. Decadal-scale thermohaline variability in the Atlantic sector of the Southern Ocean

Author

Hutchinson, K., Swart, S., Meijers, A., Ansorge, I., Speich, S., Hutchinson, K., Swart, S., Meijers, A., Ansorge, I., and Speich, S.

Abstract

An enhanced Altimetry Gravest Empirical Mode (AGEM), including both adiabatic and diabatic trends, is developed for the Antarctic Circumpolar Current (ACC) south of Africa using updated hydrographic CTD sections, Argo data, and satellite altimetry. This AGEM has improved accuracy compared to traditional climatologies and other proxy methods. The AGEM for the Atlantic Southern Ocean offers an ideal technique to investigate the thermohaline variability over the past two decades in a key region for water mass exchanges and transformation. In order to assess and attribute changes in the hydrography of the region, we separate the changes into adiabatic and diabatic components. Integrated over the upper 2000 dbar of the ACC south of Africa, results show mean adiabatic changes of 0.16 ± 0.11°C decade−1 and 0.006 ± 0.014 decade−1, and diabatic differences of −0.044 ± 0.13°C decade−1 and −0.01 ± 0.017 decade−1 for temperature and salinity, respectively. The trends of the resultant AGEM, that include both adiabatic and diabatic variability (termed AD-AGEM), show a significant increase in the heat content of the upper 2000 dbar of the ACC with a mean warming of 0.12 ± 0.087°C decade−1. This study focuses on the Antarctic Intermediate Water (AAIW) mass where negative diabatic trends dominate positive adiabatic differences in the Subantarctic Zone (SAZ), with results indicating a cooling (−0.17°C decade−1) and freshening (−0.032 decade−1) of AAIW in this area, whereas south of the SAZ positive adiabatic and diabatic trends together create a cumulative warming (0.31°C decade−1) and salinification (0.014 decade−1) of AAIW.

Published
2016

39. Tracers of physical and biogeochemical processes, past changes and ongoing anthropogenic impacts: The 43rd International Liege Colloquium on Ocean Dynamics, Liege, Belgium, May 2–6, 2011 A joint Liège Colloquium — Geotraces–BONUS–GoodHope meeting

Author

Gregoire, M., Anderson, B., Delille, B., Jeandel, C., Speich, S., GEOMAR LEGOS, Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospshere-ocean-sediment interactions, Mathematical modelling, Tracers of physical and biogeochemical, processes, Tracers of physical and biogeochemical processes, Pollution, Trace elements and isotopes
Abstract

ISI Document Delivery No.: 223DT Times Cited: 0 Cited Reference Count: 10 Cited References: DEMINA L, 2013, J MARINE SYST, V126, P94 Gaultier L, 2013, J MARINE SYST, V126, P33, DOI 10.1016/j.jmarsys.2012.02.014 Perianez R, 2013, J MARINE SYST, V126, P82, DOI 10.1016/j.jmarsys.2012.08.001 Prego R, 2013, J MARINE SYST, V126, P69, DOI 10.1016/j.jmarsys.2012.05.008 Racape V, 2013, J MARINE SYST, V126, P24, DOI 10.1016/j.jmarsys.2012.12.005 Speich S., 2013, BONUS GOODHOPE IPY P Speich S., 2008, MD 166 BONUS GOODHOP Srinivas B, 2013, J MARINE SYST, V126, P56, DOI 10.1016/j.jmarsys.2012.11.004 Trevisiol A, 2013, J MARINE SYST, V126, P43, DOI 10.1016/j.jmarsys.2012.10.012 van Hulten MMP, 2013, J MARINE SYST, V126, P3, DOI 10.1016/j.jmarsys.2012.05.005 Gregoire, Marilaure Anderson, Bob Delille, Bruno Jeandel, Catherine Speich, Sabrina 0 ELSEVIER SCIENCE BV AMSTERDAM J MARINE SYST SI

Published
2013

42. Differential retention of dissolved barium and silicon in the Atlantic, Indian and Australian sectors of the Southern Ocean

Author

Dehairs, F., Jacquet, S., Fripiat, F., Cardinal, D., Hoppema, M., Jeandel, C., Monnin, C., Navez, J., Cavagna, A.-J., Speich, S., Boyé, M., Fahrbach, E., Blain, S., Rutgers van der Loeff, M., De Baar, H., and Rintoul, S.

Abstract

Since the GEOSECS cruises in the 1970s it is well known that dissolved barium and silicon in the water column correlate tightly, but also that slight differences exist between ocean basins, reflecting differences in the biogeochemical cycling of these elements. The cycles of these two elements differ because different players are controlling their water column distributions - biogenic Ba-barite being associated with undefined plankton detritus while the silicon distribution is mainly determined by diatoms. In the Southern Ocean the combination of an intermediate and a deep water re-circulation cell (Toggweiler et al., 2006) favors diatom predominance and an efficient retention of Si (Sarmiento et al., 2007). It is not known to what extent these conditions also control the distribution of Ba in the Southern Ocean. Here we investigate the variability of Si and Ba between the major Southern Ocean basins and along water circulation pathways. For this purpose, we compiled dissolved barium and silicon data from 10 Southern Ocean cruises that took place between 1987 and 2008 in the Atlantic, Indian and Australian sectors, the Weddell Gyre, Prydz Bay and Drake Passage. The comparison of spatially weighted average concentrations between major systems revealed characteristic Si and Ba signatures as well as a clear gradient of Si enrichment vs. Ba from the Weddell Gyre eastward along the path of the Antarctic Circumpolar Current (ACC), reflecting a less efficient retention of Ba in the Southern Ocean domain relative to Si. This synoptic picture of Si/Ba behaviour is still incomplete since Ba data for the ACC in the Pacific sector are very scarce. The few Drake Passage data, however, reveal some enrichment again of Ba and Si (but slightly more so for Si) compared to the Australian sector, stressing the need for Ba data in the pacific ACC. The GEOTRACES programme would represent a nice opportunity to fill this gap.

Published
2011

44. OCEAN DYNAMICS, BIOGEOCHEMISTRY AND AIR-SEA INTERACTIONS IN THE SOUTHERN OCEAN SOUTH OF AFRICA: RESULTS FROM THE IPY BONUS-GOODHOPE TRANSECT

Author

Speich, S., Dehairs, Frank, Shipboard team, BGH, Chemistry, Analytical and Environmental Chemistry, Earth System Sciences, and Analytical, Environmental & Geo-Chemistry

Abstract

Prior to 1990, Southern Ocean (SO) observations were very few and sparse. Since then, an intense monitoring effort has been undertaken in two of the three SO chokepoints. The one south of Africa, which is the largest, has been undersampled despite its suspected importance in the Meridional Overturning Circulation (MOC). There, the SO plays a unique role in providing the export channel for North Atlantic Deep Water to the global ocean and by importing heat, salt and biogeochemical tracers from the Indian and Pacific oceans. This region is influenced by the largest turbulence ever observed and very efficient air-sea exchanges. Here the atmosphere and ocean are equally dynamic: the complex fronts, eddies and filaments in the ocean are matched by tight fronts, storm passages, and highly variable moisture contents in the atmosphere. Transfer of heat to the atmosphere from the ocean north of the polar front contributes to the dominance of cumuliform cloud types in this region. These local small-scale processes and the derived meridional fluxes constitute the major link between the Atlantic and the other ocean basins. To assess the role of SO in climate, all these phenomena need to be fully understood and to be integrated together with biological and biogeochemical estimates. Conceived in this framework the enhanced multidisciplinary IPY cruise, BONUS-GoodHope, was realized in early 2008. By coupling the ocean and atmosphere dynamics with biogeochemistry observations of the full-depth water column, the atmosphere and the sediments including trace metals and isotopes, BONUS-GoodHope preliminary results provide significant progresses in the complementary understanding of the physical, chemical and biological processes as well as on air-sea and inter-ocean properties exchanges. Here are listed some examples of the project preliminary outcomes. During the cruise we observed particular intense expressions of oceanic mesoscale turbulence responsible of properties exchange across frontal regions with important consequences on heat and fresh water budgets, biogeochemical cycles and air-sea exchanges. The observed turbulence showed an enhanced signature in air-sea fluxes, CO2, DIC, nutrients, trace elements and chlorophyll subsurface maxima. Trace elements revealed the influence of slope currents and eddy-like features on the advection of lithogenic and biogenic compounds from the continental margin to the open ocean. For example, Agulhas eddies were observed to advect and therefore inject high subsurface gas concentrations into the South Atlantic giving rise to an inter subtropic-gyre connectivity and inter-basin lateral fluxes. Mesoscale ocean features are correlated not only with high heat exchange rates, but also show a strong influence on the overlaying atmosphere structure and dynamics, reaching up to 200 hPa. The high resolution ocean-atmosphere data set highlighted the dominance of mid- altocumulus clouds north of the subtropical front, while south of the sub-antarctic front, low-level cumulus clouds become more prevalent. South of the polar front, the predominant cloud type is low-level stratocumulus (often 8 oktas) with extended periods of total overcast stratus cloud, which is similar to the cloud patterns found in Arctic atmospheres Over the entire cruise, the mean air-sea temperature difference was -0.47K, with a standard deviation of 1.3K; this means that there were many instances where the atmosphere was warmer than the ocean, despite the fact that we never encountered sea ice; this is unusual compared to the rest of the global ocean, where the air-sea temperature difference is mostly negative with very few positive excursions. The ocean was, at times, warmer than the atmosphere by as much as 6K.

Published
2010

45. Consistency of the current global ocean observing systems from an Argo perspective

Author

von Schuckmann, K., Sallée, J.-B., Chambers, D., Le Traon, P.-Y., Cabanes, C., Gaillard, F., Speich, S., Hamon, M., von Schuckmann, K., Sallée, J.-B., Chambers, D., Le Traon, P.-Y., Cabanes, C., Gaillard, F., Speich, S., and Hamon, M.

Abstract

Variations in the world's ocean heat storage and its associated volume changes are a key factor to gauge global warming and to assess the Earth's energy budget. It is also directly link to sea level change, which has a direct impact on coastal populations. Understanding and monitoring heat and sea level change is therefore one of the major legacies of current global ocean observing systems. In this study, we present an inter-comparison of the three of these global ocean observing systems: the ocean temperature/salinity network Argo, the gravimeter GRACE and the satellite altimeters. Their consistency is investigated at global and regional scale during the period 2005–2010 of overlapping time window of re-qualified data. These three datasets allow closing the recent global ocean sea level budget within uncertainties. However, sampling inconsistencies need to be corrected for an accurate budget at global scale. The Argo network allows estimating global ocean heat content and global sea level and reveals a positive change of 0.5 ± 0.1W m−2 and 0.5 ± 0.1 mm yr−1 over the last 8 yr (2005–2012). Regional inter-comparison of the global observing systems highlights the importance of specific ocean basins for the global estimates. Specifically, the Indonesian Archipelago appears as a key region for the global ocean variability. Both the large regional variability and the uncertainties in the current observing systems, prevent us to shed light, from the global sea level perspective, on the climatically important deep ocean changes. This emphasises, once more, the importance of continuing sustained effort in measuring the deep ocean from ship platforms and by setting up a much needed automated deep-Argo network.

Published
2014

47. Basin‐Wide Oceanographic Array Bridges the South Atlantic

Author

Ansorge, I. J., primary, Baringer, M. O., additional, Campos, E. J. D., additional, Dong, S., additional, Fine, R. A., additional, Garzoli, S. L., additional, Goni, G., additional, Meinen, C. S., additional, Perez, R. C., additional, Piola, A. R., additional, Roberts, M. J., additional, Speich, S., additional, Sprintall, J., additional, Terre, T., additional, and Van den Berg, M. A., additional

Published
2014
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48. [Assessment of eating disorders-related risk in a cohort of adolescents living in Northern Italy. Results from a multicenter study]

Author

alberto pellai, Brizzi L, Curci R, Sancini S, Saporetti G, Speich S, and Tosetto C

Subjects
Cohort Studies, Feeding and Eating Disorders, Male, Adolescent, Italy, Risk Factors, Surveys and Questionnaires, Humans, Female, Risk Assessment
Abstract

Clinical evidence and epidemiological research show an increasing number of subjects trying to become lean and reaching consequently harmful weight conditions. Aim of this paper is to assess the risk for eating disorders during adolescence.In a multicentric study high school students of 5 different districts of Northern Italy have been asked to fill up anonymously the Italian version of the American YRBSS (Youth Risk Behaviour Surveillance System) questionnaire. For each school a section has been selected and between January and March 1999, students of every level have been involved. The data enrollected have been analysed using EpiInfo6.The study involved 4135 adolescents (57% girls and 43% boys) coming from 260 classes and 47 different schools. The proportion of boys perceiving themselves as overweight and underweight was the same (22%), while the proportion of girls considering themselves overweight raised up to 42%. The majority of the girls (53%) is trying to slim making use of physical activity (48%), diets (32%), vomiting (8%) and drugs (5%).Our data suggest that specific projects focusing on primary and secondary prevention of eating disorders should be considered for high schools. In addition, further studies are suggested to understand characteristics and behaviours related to eating disorders.

Published
2002

49. Assessing wind contribution to the Southern Benguela interannual dynamics

Author

Blanke, Bruno, Roy, Claude, Penven, Pierrick, Speich, S., McWilliams, J., and Nelson, G.

Subjects
TEMPERATURE DE SURFACE, VARIATION INTERANNUELLE, CIRCULATION OCEANIQUE, VARIATION SAISONNIERE, RESSOURCES HALIEUTIQUES, VENT, TENSION DU VENT, HYDRODYNAMIQUE, UPWELLING, MODELISATION
Published
2002

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