scholarly journals <i>Syracosphaera noroiticus</i> sp. nov., and <i>S. marginaporata</i> sp. nov., (Syracosphaeraceae, Prymnesiophyta), new coccolithophorids from the Mediterranean Sea and North Atlantic Ocean

1993 ◽  
Vol 12 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Michael Knappertsbusch

Abstract. During scanning electron microscope investigations of living coccolithophorids from the Mediterranean Sea and the North Atlantic Ocean, two hitherto undescribed species of the genus Syracosphaera Lohmann, 1902 emend. Gaarder (in Gaarder and Heimdal, 1977) were found. The first species, Syracosphaera noroiticus sp. nov., was recorded in the Gulf of Lyons (Mediterranean Sea), and the second, S. marginaporata sp. nov., was found in the eastern North Atlantic.

1999 ◽  
Vol 14 (5) ◽  
pp. 626-638 ◽  
Author(s):  
Martine Paterne ◽  
Nejib Kallel ◽  
Laurent Labeyrie ◽  
Maryline Vautravers ◽  
Jean-Claude Duplessy ◽  
...  

Ocean Science ◽  
2020 ◽  
Vol 16 (6) ◽  
pp. 1385-1398
Author(s):  
Verónica Morales-Márquez ◽  
Alejandro Orfila ◽  
Gonzalo Simarro ◽  
Marta Marcos

Abstract. The spatial and temporal variability of extreme wave climate in the North Atlantic Ocean and the Mediterranean Sea is assessed using a 31-year wave model hindcast. Seasonality accounts for 50 % of the extreme wave height variability in the North Atlantic Ocean and up to 70 % in some areas of the Mediterranean Sea. Once seasonality is filtered out, the North Atlantic Oscillation and the Scandinavian index are the dominant large-scale atmospheric patterns that control the interannual variability of extreme waves during winters in the North Atlantic Ocean; to a lesser extent, the East Atlantic Oscillation also modulates extreme waves in the central part of the basin. In the Mediterranean Sea, the dominant modes are the East Atlantic and East Atlantic–Western Russia modes, which act strongly during their negative phases. A new methodology for analyzing the atmospheric signature associated with extreme waves is proposed. The method obtains the composites of significant wave height (SWH), mean sea level pressure (MSLP), and 10 m height wind velocity (U10) using the instant when specific climatic indices have a stronger correlation with extreme waves.


2020 ◽  
Author(s):  
Verónica Morales-Márquez ◽  
Alejandro Orfila ◽  
Gonzalo Simarro ◽  
Marta Marcos

Abstract. The spatial and temporal variability of extreme wave climate in the North Atlantic Ocean and the Mediterranean Sea is assessed using a 31-year wave model hindcast. Seasonality accounts for 50 % of the extreme wave height variability in North Atlantic Ocean and up to 70 % in some areas of the Mediterranean Sea. Once seasonality is filtered out, the North Atlantic Oscillation and the Scandinavian Index are the dominant large-scale atmospheric patterns that control the interannual variability of extreme waves during winters in the North Atlantic Ocean; and to a lesser extent, the East Atlantic Oscillation also modulates extreme waves in the central part of the basin. In the Mediterranean Sea, the dominant modes are the East Atlantic and East Atlantic/Western Russia modes which act strongly during their negative phases.


2018 ◽  
Vol 15 (18) ◽  
pp. 5663-5676 ◽  
Author(s):  
Jill N. Sutton ◽  
Gregory F. de Souza ◽  
Maribel I. García-Ibáñez ◽  
Christina L. De La Rocha

Abstract. The stable isotope composition of dissolved silicon in seawater (δ30SiDSi) was examined at 10 stations along the GEOVIDE section (GEOTRACES GA-01), spanning the North Atlantic Ocean (40–60∘ N) and Labrador Sea. Variations in δ30SiDSi below 500 m were closely tied to the distribution of water masses. Higher δ30SiDSi values are associated with intermediate and deep water masses of northern Atlantic or Arctic Ocean origin, whilst lower δ30SiDSi values are associated with DSi-rich waters sourced ultimately from the Southern Ocean. Correspondingly, the lowest δ30SiDSi values were observed in the deep and abyssal eastern North Atlantic, where dense southern-sourced waters dominate. The extent to which the spreading of water masses influences the δ30SiDSi distribution is marked clearly by Labrador Sea Water (LSW), whose high δ30SiDSi signature is visible not only within its region of formation within the Labrador and Irminger seas, but also throughout the mid-depth western and eastern North Atlantic Ocean. Both δ30SiDSi and hydrographic parameters document the circulation of LSW into the eastern North Atlantic, where it overlies southern-sourced Lower Deep Water. The GEOVIDE δ30SiDSi distribution thus provides a clear view of the direct interaction between subpolar/polar water masses of northern and southern origin, and allow examination of the extent to which these far-field signals influence the local δ30SiDSi distribution.


1979 ◽  
Vol 48 (2) ◽  
pp. 111-126 ◽  
Author(s):  
Trudy Pafort-van Iersel ◽  
S. van der Spoel

The phylogenetic relation between Clio pyramidata Linnaeus, 1767, and Cymbulia peroni De Blainville, 1818, has been studied with regard to the structure of their muscle systems. Specimens of both species collected from the North Atlantic Ocean and the Mediterranean were sectioned 5 μm thick and stained with Haematoxilin-Eosin, Crossmon or Azan for histological purposes or they were studied as cleared dissected or entire animals. The columellar muscle and subectodermal wing muscles of both species are described. It is concluded that Clio shows neoteny since it develops without metamorphosis. The asymmetry in anatomy proves that both Clio and Cymbulia descend from spiralised ancestors. For Clio two primitive characters are discussed which may be due to the “larval stage” of the adult but which also affirm the possible relation of molluscs to a coelenterate-like ancestor. Original structures found in Cymbulia are also discussed in the light of a possible phylogenetic relation between Thecosomata and Coelenterata, more in particular Conulata.


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