Water mass transport and transformation in the western SPNA, Cruise No. MSM74, May 25 - June 26, 2018, St. John's (Canada) - Reykjavik (Iceland), Western SPNA transport

The scientific program of the MARIA S. MERIAN MSM74 expedition was dedicated to studies on the intensity of water mass transformation and the southward transport of water masses in the boundary current systems off Labrador and at the southern tip of Greenland. During the expedition we recovered 17/deployed 8 deep sea moorings. Measurements of the vertical structure of temperature, salinity, density, oxygen, optical properties and the flow along selected sections have been surveyed during the MSM74 expedition. Close to the surface, permanent registrations are carried out with the thermosalinograph (temperature, salinity) and meteorological data are continuously collected. Flow measurements up to 1000m depth are performed with the ships installed ADCPs. The expedition is a contribution to national (RACE) and international projects (OSNAP, AtlantOS)

Introduction to the French GEOTRACES North Atlantic transect (GA01): GEOVIDE cruise

© 2018 Author(s). The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this special issue (https://www.biogeosciences.net/special-issue900.html), results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 18 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue

Fixed-Nitrogen and atmospheric N2 contribution to biological productivity in teh Eastern Atlantic Ocean

info:eu-repo/semantics/publishe

Nitrate isotopic composition across a north-south transect in the Eastern Atlantic Ocean: significance of nitrogen input through N2 fixation

info:eu-repo/semantics/nonPublishe

The marine diatom and diazotroph under future climate: Role of Iron.

info:eu-repo/semantics/nonPublishe

Iron biogeochemistry under a changing climate: impact on the phytoplankton growth and the diazotrophic nitrogen fixation.

info:eu-repo/semantics/publishe

The impact of iron biogeochemistry on the phytoplankton growth and the diazotrophic nitrogen fixation under a changing climate.

info:eu-repo/semantics/nonPublishe

Isotopic composition of nitrate from the temperate and subpolar North Atlantic

info:eu-repo/semantics/nonPublishe

Stable isotope composition of calanoid copepods in the open eastern Atlantic Ocean during POLARSTERN cruise ANT-XXIX/1

The majority of global ocean production and total export production is attributed to oligotrophic oceanic regions due to their vast regional expanse. However, energy transfers, food-web structures and trophic relationships in these areas remain largely unknown. Regional and vertical inter- and intra-specific differences in trophic interactions and dietary preferences of calanoid copepods were investigated in four different regions in the open eastern Atlantic Ocean (38°N to 21°S) in October/November 2012 using a combination of fatty acid (FA) and stable isotope (SI) analyses. Mean carnivory indices (CI) based on FA trophic markers generally agreed with trophic positions (TP) derived from d15N analysis. Most copepods were classified as omnivorous (CI ~0.5, TP 1.8 to ~2.5) or carnivorous (CI >=0.7, TP >=2.9). Herbivorous copepods showed typical CIs of =41% DM), mainly accumulated as WE (>=79% TL). C. carinatus and R. nasutus were primarily herbivorous with almost no bacterial input. Despite deviating feeding strategies, R. nasutus clustered with deep-dwelling, carnivorous species, which had high amounts of lipids (>=37% DM) and WE (>=54% TL). Tropical and subtropical calanoid copepods exhibited a wide variety of life strategies, characterized by specialized feeding. This allows them, together with vertical habitat partitioning, to maintain high abundance and diversity in tropical oligotrophic open oceans, where they play an essential role in the energy flux and carbon cycling