scholarly journals About the origin of the Mediterranean Waters warming during the twentieth century

Author(s):  
María del Carmen García-Martínez ◽  
Manuel Vargas-Yáñez ◽  
Francina Moya ◽  
Patricia Zunino ◽  
Begoña Bautista

Abstract. The Mediterranean Sea transforms Atlantic Waters inflowing through the Strait of Gibraltar into saltier, cooler and denser Mediterranean Waters that outflow into the Atlantic Ocean. A theoretical steady state functioning of the Mediterranean Sea would be the result of the balance between the net heat and volume transports through the Strait of Gibraltar and the heat loss to the atmosphere through the sea surface and the net evaporation. The salt transport for the inflow and outflow should be balanced. Changes in the heat content, temperature and salinity of the Mediterranean waters reveal that the present Mediterranean functioning is out of this equilibrium state. A new analysis for MEDAR data shows that the temperature and salinity averaged for the Mediterranean Waters in the whole basin increased at rates of 0.0020 ± 0.0018 ºC/yr and 0.0007 ± 0.0003 psu/yr. This temperature trend is equivalent to a 0.43 ± 0.38 W/m2 heat absorption. This warming trend would have increased during the beginning of the twenty first century at the Western Mediterranean, maybe linked to the Western Mediterranean Transition. Results from a simple box model using heat, volume and salt conservation laws indicate that the observed changes cannot be attributed only to an increase of the net evaporation, nor to a salinity increase of the Atlantic Waters flowing through the Strait of Gibraltar as previous hypotheses suggested. An increase of the net evaporation ranging between 5 and 7 % combined with a reduction of the heat losses to the atmosphere ranging between 0.4 and 0.5 W/m2 could explained the observed changes.

2021 ◽  
Author(s):  
Giusy Fedele ◽  
Elena Mauri ◽  
Giulio Notarstefano ◽  
Pierre Marie Poulain

Abstract. The Atlantic Water (AW) and Levantine Intermediate Water (LIW) are important water masses that play a crucial role in the internal variability of the Mediterranean thermohaline circulation. In particular, their variability and interaction, along with other water masses that characterize the Mediterranean basin, such as the Western Mediterranean Deep Water (WMDW), contribute to modify the Mediterranean Outflow through the Gibraltar Strait and hence may influence the stability of the global thermohaline circulation. This work aims to characterize the AW and LIW in the Mediterranean Sea, taking advantage of the large observational dataset provided by Argo floats from 2001 to 2019. Using different diagnostics, the AW and LIW were identified, highlighting the inter-basin variability and the strong zonal gradient that characterize the two water masses in this marginal sea. Their temporal variability was also investigated focusing on trends and spectral features which constitute an important starting point to understand the mechanisms that are behind their variability. A clear salinification and warming trend have characterized the AW and LIW in the last two decades (~0.007 and 0.008 yr−1; 0.018 and 0.007 °C yr−1, respectively). The salinity and temperature trends found at subbasin scale are in good agreement with previous results. The strongest trends are found in the Adriatic basin in both the AW and LIW properties. A subbasin dependent spectral variability emerges in the AW and LIW salinity timeseries with peaks between 2 and 10 years.


2013 ◽  
Vol 14 (2) ◽  
pp. 384 ◽  
Author(s):  
M. M. GONZÁLEZ-DUARTE ◽  
C. MEGINA ◽  
M. BETHENCOURT

Mature and dense populations of the tropical hydroid species Sertulariamarginata were detected in the Alboran Sea (Western Mediterranean) and in the Atlantic coast of the Strait of Gibraltar. Until now, it had only been recorded in the eastern basin within the Mediterranean Sea.This species has previously been recorded in estuaries and anthropogenichabitats but, in the area studied here, we only found it in natural zones. These observations could indicate an early expansion and naturalization in the Mediterranean Sea. Due to its limited dispersion capacity by its own natural means and the history of its records, the observations provided here support the hypothesis of an arrival and a spread by anthropogenic vectors.A pathway of arrival and dispersion of alien species into the Mediterranean Sea is proposed for future monitoring: from Macaronesia (particularly Canary Islands) to the Atlantic coast of the Strait of Gibraltar and from here into the Mediterranean.


The Festivus ◽  
2018 ◽  
Vol 50 (3) ◽  
pp. 173-177
Author(s):  
Benito Muñoz Sánchez ◽  
José Muñoz Sánchez

The family Cypraeidae is represented in the Mediterranean Sea by four native species: Luria l. lurida; Naria s. spurca; Schilderia a. achatidea; and Zonaria p. pyrum. These species also inhabit the Atlantic coasts of Europe and Africa beyond the Strait of Gibraltar. Besides these, there are a few Lessepsian immigrants found occasionally throughout the central and eastern part of the Mare Nostrum including Naria turdus var. micheloi and Purpuradusta gracilis notata. This article focuses on the subspecies of Z. pyrum insularum (Schilder, 1928); var. nigromarginata (Deprez & Govaert, 2009), whose populations in the Atlantic have recently been the subject of numerous notes and comprehensive revisions (Goutal, 2008, Bergonzoni, 2013).


Author(s):  
Joshua Schreier

This chapter recounts Oran’s history over the longue durée. It speaks of a city situated on the northern coast of Africa, but also on the southern coast of the Mediterranean Sea. Oran was a creation of Spain and southern Europe as well as of Tlemcen, the Sahara, and the African sources of goods that lay beyond it. Indeed, in the first century or two of its existence, Oran owed its existence to its proximity to the Iberian Peninsula. The westernmost section of the Mediterranean, stretching from Cape Tenès in the east to the Straights of Gibraltar in the west, has been described as a medieval “Ibero-African English Channel,” linking North Africa and Spain with a constant flow of commercial ships. Oran’s dependence on larger circuits of western Mediterranean commerce would continue into the nineteenth century.


Author(s):  
M.M. GONZÁLEZ-DUARTE ◽  
C. MEGINA ◽  
M. BETHENCOURT

Mature and dense populations of the tropical hydroid species Sertulariamarginata were detected in the Alboran Sea (Western Mediterranean) and in the Atlantic coast of the Strait of Gibraltar. Until now, it had only been recorded in the eastern basin within the Mediterranean Sea.This species has previously been recorded in estuaries and anthropogenichabitats but, in the area studied here, we only found it in natural zones. These observations could indicate an early expansion and naturalization in the Mediterranean Sea. Due to its limited dispersion capacity by its own natural means and the history of its records, the observations provided here support the hypothesis of an arrival and a spread by anthropogenic vectors.A pathway of arrival and dispersion of alien species into the Mediterranean Sea is proposed for future monitoring: from Macaronesia (particularly Canary Islands) to the Atlantic coast of the Strait of Gibraltar and from here into the Mediterranean.


Author(s):  
SARA RIGHI ◽  
DANIELA PREVEDELLI ◽  
ROBERTO SIMONINI

Global change and the overall raise of seawater temperature are causing a poleward shift in species distribution, increasing the occurrence of warm-water biota in many ecosystems worldwide. In the Mediterranean, the ongoing sea warming is promoting native subtropical species to invader status. The bearded fireworm Hermodice carunculata (Amphinomida) is a thermophilic generalist predator spreading in the Central Mediterranean Sea. Although it is a typical inhabitant of Ionian coasts, several sightings have occurred at more northerly localities along the Tyrrhenian and Adriatic Seas, suggesting that density increases and range expansion are underway. These distributional records are in contrast with historical literature and museum collections, which provide poor sporadic information.The present study aimed at investigating the spatiotemporal changes that have occurred in H. carunculata abundances and distribution in the Mediterranean basins surrounding the Italian peninsula so far. We examined an exhaustive collection of existing information. A total of 857 reports of H. carunculata were collected from 368 localities. These data significantly expand knowledge on the life and feeding habit of H. carunculata. The integration of different data sources allowed the reconstruction of the shifts that have happened over the last 50 years, which are coherent with the consistent warming trend of Mediterranean Sea surface temperatures. Recent colonization events have occurred both along the Adriatic and Western Mediterranean coasts. The present findings provide unique insights into the expansion of H. carunculata, supporting future spreading throughout the Northern and Western Mediterranean. Tracking these changes is critical to assess potential impacts on coastal rocky-benthic communities, public health and commercial fisheries.


2014 ◽  
Vol 89 (6) ◽  
pp. 734-739 ◽  
Author(s):  
S. Mele ◽  
S. Saber ◽  
M.J. Gómez-Vives ◽  
G. Garippa ◽  
F. Alemany ◽  
...  

AbstractThe head region of 72 bullet tuna Auxis rochei from the western Mediterranean Sea (south-east Spain and the Strait of Gibraltar) was examined for parasites. Seven metazoan species were found in the fish from south-east Spain: three monogeneans, two trematodes and two copepods, whereas only three species were isolated in the fish from the Strait of Gibraltar. A comparison of the levels of infection of the parasites according to fish size in south-east Spain showed that the prevalence of Didymozoon auxis and the mean abundance of Allopseudaxine macrova were higher in the larger hosts (range of fork length = 38–44 cm) than in the smaller ones (33–37 cm). A comparison of the parasite infections according to geographical region showed that the mean abundances of Nematobothriinae gen. sp. and Caligus bonito were higher in fish from south-east Spain than in those from the Strait of Gibraltar. A comparison of the parasite fauna of A. rochei from the Mediterranean Sea with the published data on Auxis spp. from the Atlantic, Indian and Pacific Oceans revealed the closest similarity between the Mediterranean A. rochei and the Atlantic A. thazard.


Author(s):  
J.A. Reina-Hervás ◽  
J.E. García Raso ◽  
M.E. Manjón-Cabeza

The capture of a specimen of Sphoeroides spengleri (Osteichthyes: Tetraodontidae), 17 December 2000 and 29·7 mm total length, from the Málaga coast (Alborán Sea, western Mediterranean) represents the first record of a new alien species for Mediterranean waters.


2007 ◽  
Vol 37 (2) ◽  
pp. 338-358 ◽  
Author(s):  
Ichiro Fukumori ◽  
Dimitris Menemenlis ◽  
Tong Lee

Abstract A new basin-wide oscillation of the Mediterranean Sea is identified and analyzed using sea level observations from the Ocean Topography Experiment (TOPEX)/Poseidon satellite altimeter and a numerical ocean circulation model. More than 50% of the large-scale, nontidal, and non-pressure-driven variance of sea level can be attributed to this oscillation, which is nearly uniform in phase and amplitude across the entire basin. The oscillation has periods ranging from 10 days to several years and has a magnitude as large as 10 cm. The model suggests that the fluctuations are driven by winds at the Strait of Gibraltar and its neighboring region, including the Alboran Sea and a part of the Atlantic Ocean immediately to the west of the strait. Winds in this region force a net mass flux through the Strait of Gibraltar to which the Mediterranean Sea adjusts almost uniformly across its entire basin with depth-independent pressure perturbations. The wind-driven response can be explained in part by wind setup; a near-stationary balance is established between the along-strait wind in this forcing region and the sea level difference between the Mediterranean Sea and the Atlantic Ocean. The amplitude of this basin-wide wind-driven sea level fluctuation is inversely proportional to the setup region’s depth but is insensitive to its width including that of Gibraltar Strait. The wind-driven fluctuation is coherent with atmospheric pressure over the basin and contributes to the apparent deviation of the Mediterranean Sea from an inverse barometer response.


Author(s):  
Enric Massutí ◽  
J.A. Reina-Hervás ◽  
Domingo Lloris ◽  
L. Gil de Sola

The capture of five specimens of Solea (Microchirus) boscanion (Osteichthyes: Soleidae), a species previously unrecorded in the Mediterranean, is reported from the Iberian coast (western Mediterranean). The main morphometric and meristic measurements of this species with data of the other sympatric, and morphologically very similar, soleids Microchirus variegatus and Buglossidium luteum are also given. The record is discussed in relation to climate change and competition between species.


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