scholarly journals Characterization of the submesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of high-resolution MCS data

2016 ◽  
Vol 43 (12) ◽  
pp. 6461-6468 ◽  
Author(s):  
Valenti Sallares ◽  
Jhon F. Mojica ◽  
Berta Biescas ◽  
Dirk Klaeschen ◽  
Eulàlia Gràcia
Keyword(s):  
Spectral Analysis ◽  
High Resolution ◽  
Energy Cascade ◽  
Alboran Sea ◽  
Alborán Sea

scholarly journals Rapid climatic variability in the west Mediterranean during the last 25 000 years from high resolution pollen data

2009 ◽  
Vol 5 (3) ◽  
pp. 503-521 ◽  
Author(s):  
N. Combourieu Nebout ◽  
O. Peyron ◽  
I. Dormoy ◽  
S. Desprat ◽  
C. Beaudouin ◽  
...  
Keyword(s):  
High Resolution ◽  
North Atlantic ◽  
Climate Reconstruction ◽  
Mediterranean Vegetation ◽  
Pollen Record ◽  
Alboran Sea ◽  
Climatic Fluctuations ◽  
The Holocene ◽  
The Mediterranean ◽  
Alborán Sea

Abstract. High-temporal resolution pollen record from the Alboran Sea ODP Site 976, pollen-based quantitative climate reconstruction and biomisation show that changes of Mediterranean vegetation have been clearly modulated by short and long term variability during the last 25 000 years. The reliability of the quantitative climate reconstruction from marine pollen spectra has been tested using 22 marine core-top samples from the Mediterranean. The ODP Site 976 pollen record and climatic reconstruction confirm that Mediterranean environments have a rapid response to the climatic fluctuations during the last Termination. The western Mediterranean vegetation response appears nearly synchronous with North Atlantic variability during the last deglaciation as well as during the Holocene. High-resolution analyses of the ODP Site 976 pollen record show a cooling trend during the Bölling/Allerød period. In addition, this period is marked by two warm episodes bracketing a cooling event that represent the Bölling-Older Dryas-Allerød succession. During the Holocene, recurrent declines of the forest cover over the Alboran Sea borderlands indicate climate events that correlate well with several events of increased Mediterranean dryness observed on the continent and with Mediterranean Sea cooling episodes detected by alkenone-based sea surface temperature reconstructions. These events clearly reflect the response of the Mediterranean vegetation to the North Atlantic Holocene cold events.

scholarly journals Preliminary characterization of echinoderm assemblages in circalittoral and bathyal soft bottoms of the northern Alboran Sea

2016 ◽  
Vol 3 ◽  
Author(s):  
Moya-Urbano Elena ◽  
Moya Francina ◽  
Mateo-Ramírez Ángel ◽  
Gallardo-Núñez Marina ◽  
Ordines Francesc ◽  
...  
Keyword(s):  
Alboran Sea ◽  
Preliminary Characterization ◽  
Soft Bottoms ◽  
Alborán Sea

Analysis of Vertical Velocities Development through High-resolution Simulation and Glider Observations in the Alboran Sea

2021 ◽  
Author(s):  
Maximo Garcia-Jove ◽  
Baptiste Mourre ◽  
Nikolaos Zarokanellos ◽  
Pierre F. J. Lermusiaux ◽  
Daniel L. Rudnick ◽  
...  
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Naval Research ◽  
Alboran Sea ◽  
Surface Ocean ◽  
Office Of Naval Research ◽  
Research Initiative ◽  
Spatio Temporal ◽  
Alborán Sea ◽  
Resolution Simulation

<p>Vertical velocities associated with meso- and submeso-scale structures generate important vertical fluxes of carbon and other biogeochemical tracers from the surface layer to depths below the mixed layer. Vertical velocities are very weak and characterized by small scales which make them difficult to measure. The project entitled Coherent Lagrangian Pathways from the Surface Ocean to Interior (CALYPSO, Office of Naval Research initiative) addresses the challenge of observing, understanding, and predicting the vertical velocities and three-dimensional pathways on subduction processes in the frontal regions of the Alboran Sea. Within the framework of the CALYPSO project, we analysed the processes that give rise to vertical velocities in the Western Alboran Gyre Front (WAGF) and Eastern Alboran Gyre Front (EAGF). The periods of frontal intensification were analyzed in the perspective of the frontogenesis, instabilities, non-linear Ekman effects, and filamentogenesis using multi-platform in-situ observations and a high-resolution simulation in spring 2018. The spatio-temporal characteristics of the WAGF indicate a wider, deeper, and longer-lasting front than the EAGF. The WAGF intensification and vertical velocities development are explained through i) frontogenesis, ii) conditions for symmetric and ageostrophic baroclinic instabilities generation, and iii) nonlinear Ekman effects. These mechanisms participate to generate and strengthen an ageostrophic secondary circulation responsible for vertical velocities intensification in the front. In the case of the EAGF, the intensification and vertical velocities development are explained by filamentogenesis in both the model and glider observations. The EAGF intensification is characterized by a sharp and outcropping density gradient at the center of the filament, where two asymmetrical ageostrophic cells develop across the front with narrow upwelling region in the middle.</p>

scholarly journals High-resolution diapycnal mixing map of the Alboran Sea thermocline from seismic reflection images

Ocean Science ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 403-415 ◽  
Author(s):  
Jhon F. Mojica ◽  
Valentí Sallarès ◽  
Berta Biescas
Keyword(s):  
High Resolution ◽  
Atlantic Water ◽  
Thermocline Depth ◽  
Turbulent Regime ◽  
Alboran Sea ◽  
Diapycnal Mixing ◽  
Acoustic Data ◽  
Mesoscale Structures ◽  
High Resolution Map ◽  
Alborán Sea

Abstract. The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale structures and a complex sequence of processes that entail mixing close to the thermocline. Here we present a high-resolution map of the diapycnal diffusivity around the thermocline depth obtained using acoustic data recorded with a high-resolution multichannel seismic system. The map reveals a patchy thermocline, with spots of strong diapycnal mixing juxtaposed with areas of weaker mixing. The patch size is of a few kilometers in the horizontal scale and of 10–15 m in the vertical one. The comparison of the obtained maps with the original acoustic images shows that mixing tends to concentrate in areas where internal waves, which are ubiquitous in the surveyed area, become unstable and shear instabilities develop, enhancing energy transfer towards the turbulent regime. These results are also compared with others obtained using more conventional oceanographic probes. The values estimated based on the seismic data are within the ranges of values obtained from oceanographic data analysis, and they are also consistent with reference theoretical values. Overall, our results demonstrate that high-resolution seismic systems allow the remote quantification of mixing at the thermocline depth with unprecedented resolution.

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