scholarly journals The Mediterranean is becoming saltier

Ocean Science ◽  
2014 ◽  
Vol 10 (4) ◽  
pp. 693-700 ◽  
Author(s):  
M. Borghini ◽  
H. Bryden ◽  
K. Schroeder ◽  
S. Sparnocchia ◽  
A. Vetrano
Keyword(s):  
Deep Water ◽  
Mediterranean Basin ◽  
Western Mediterranean ◽  
Intermediate Water ◽  
Deep Water Formation ◽  
The Past ◽  
Western Mediterranean Sea ◽  
Deep Waters ◽  
Western Mediterranean Basin ◽  
Water Formation

Abstract. The deep waters of the western Mediterranean Sea have become saltier and warmer for at least the past 40 years at rates of about 0.015 and 0.04 °C per decade. Here we show that two processes contribute to these increases in temperature and salinity. On interannual timescales, deep water formation events in severe winters transmit increasingly salty intermediate waters into the deep water. The second process is a steady downward flux of heat and salt associated with salt finger mixing down through the halocline–thermocline that connects the Levantine Intermediate Water with the deep water. We illustrate these two processes with observations from repeat surveys of the western Mediterranean basin we have made over the past 10 years.

scholarly journals The Mediterranean is getting saltier

2014 ◽  
Vol 11 (1) ◽  
pp. 735-752 ◽  
Author(s):  
M. Borghini ◽  
H. Bryden ◽  
K. Schroeder ◽  
S. Sparnocchia ◽  
A. Vetrano
Keyword(s):  
Deep Water ◽  
Mediterranean Basin ◽  
Western Mediterranean ◽  
Intermediate Water ◽  
Deep Water Formation ◽  
The Past ◽  
Deep Waters ◽  
Western Mediterranean Basin ◽  
Water Formation ◽  
The Mediterranean

Abstract. The deep waters of the Mediterranean Sea have been getting saltier and warmer for at least the past 40 yr at rates of about 0.015 and 0.04 °C per decade. Here we show that two processes contribute to these increases in temperature and salinity. On interannual time scales, deep water formation events in severe winters transmit increasingly salty intermediate waters into the deep water. The second process is a steady downward flux of heat and salt through the halocline-thermocline that connects the Levantine Intermediate Water with the deep water. We illustrate these two processes with observations from repeat surveys of the western Mediterranean basin we have made over the past 10 yr.

scholarly journals Will deep water formation collapse in the North Western Mediterranean Sea by the end of the 21st century?

2021 ◽  
Author(s):  
Iván Manuel Parras Berrocal ◽  
Ruben Vazquez ◽  
William David CabosNarvaez ◽  
Dimitry Sein ◽  
Oscar Alvarez Esteban ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
21St Century ◽  
Deep Water ◽  
Western Mediterranean ◽  
Deep Water Formation ◽  
The North ◽  
Western Mediterranean Sea ◽  
Water Formation ◽  
North Western

scholarly journals Characterizing, modelling and understanding the climate variability of the deep water formation in the North-Western Mediterranean Sea

2016 ◽  
Vol 51 (3) ◽  
pp. 1179-1210 ◽  
Author(s):  
Samuel Somot ◽  
Loic Houpert ◽  
Florence Sevault ◽  
Pierre Testor ◽  
Anthony Bosse ◽  
...  
Keyword(s):  
Climate Variability ◽  
Mediterranean Sea ◽  
Deep Water ◽  
Western Mediterranean ◽  
Deep Water Formation ◽  
The North ◽  
Western Mediterranean Sea ◽  
Water Formation ◽  
North Western

scholarly journals Hydrological variations of the intermediate water masses of the western Mediterranean Sea during the past 20 ka inferred from neodymium isotopic composition in foraminifera and cold-water corals

2016 ◽  
Author(s):  
Quentin Dubois-Dauphin ◽  
Paolo Montagna ◽  
Giuseppe Siani ◽  
Eric Douville ◽  
Claudia Wienberg ◽  
...  
Keyword(s):  
Cold Water ◽  
Western Mediterranean ◽  
Intermediate Water ◽  
Alboran Sea ◽  
The Past ◽  
Western Mediterranean Sea ◽  
Deep Waters ◽  
Balearic Sea ◽  
Intermediate Waters ◽  
Alborán Sea

Abstract. The neodymium isotopic composition (εNd) of mixed planktonic foraminifera species and scleractinian cold-water corals (CWC; Madrepora oculata, Lophelia pertusa) collected at 280–620 m water depth in the Balearic Sea, the Alboran Sea and the south Sardinian continental margin was investigated to constrain hydrological variations at intermediate depths in the western Mediterranean Sea during the last 20 ka. Planktonic (Globigerina bulloides) and benthic (Cibicidoides pachyderma) foraminifera were also analyzed for stable oxygen (δ18O) and carbon (δ13C) isotopes. The foraminiferal and coral εNd values from the Balearic Sea and the Alboran Sea are comparable over the past ~ 13 ka, with mean values of −8.94 ± 0.26 (1σ; n = 24) and −8.91 ± 0.18 (1σ; n = 25), respectively. Before 13 ka BP, the foraminiferal εNd values are slightly lower (−9.28 ± 0.15) and tend to reflect a higher mixing between intermediate and deep waters, characterized by more unradiogenic εNd values. The slight εNd increase after 13 ka BP is associated to a marked difference in the benthic foraminiferal δ13C composition of intermediate and deeper depths, which started at ~ 16 ka BP. This suggests an earlier stratification of the water masses and a subsequent reduced contribution of unradiogenic εNd from deep waters. The CWC from the Sardinia Channel show a much larger scattering of εNd values, from −8.66 ± 0.30 to −5.99 ± 0.50, and a lower average (−7.31 ± 0.73; n = 19) compared to the CWC and foraminifera from the Alboran Sea and Balearic Sea, indicative of intermediate waters sourced from the Levantine basin. At the time of sapropel S1 deposition (10.2 to 6.4 ka), the εNd values of the Sardinian CWC become more unradiogenic (−8.38 ± 0.47; n = 3 at ~ 8.7 ka BP), suggesting a significant contribution of intermediate waters originated from the western basin. Accordingly, we propose here that western Mediterranean intermediate waters replaced the Levantine Intermediate Water (LIW), which was strongly reduced during the mid-sapropel (~ 8.7 ka BP). This observation supports a notable change of Mediterranean circulation pattern centered on sapropel S1 that needs further investigations to be confirmed.

scholarly journals Transformation of Levantine Intermediate Water tracked by MedArgo floats in Western Mediterranean

2006 ◽  
Vol 3 (3) ◽  
pp. 569-584 ◽  
Author(s):  
M. Emelianov ◽  
J. Font ◽  
A. Turiel ◽  
J. Solé ◽  
P. Poulain ◽  
...  
Keyword(s):  
Mediterranean Basin ◽  
General Circulation ◽  
Western Mediterranean ◽  
Intermediate Water ◽  
Thermohaline Structure ◽  
Western Mediterranean Basin ◽  
Intermediate Waters ◽  
Good Agreement

Abstract. A clustering methodology is applied to investigate the thermohaline structure of Levantine Intermediate Water (LIW) in the western Mediterranean basin. 16 free-drifting hydrographic profilers were deployed in the framework of the MFSTEP project (MedArgo component) from September 2003. A total of 925 CTD profiles data collected until the beginning of February 2006 have been used in the analysis. The results are in good agreement with the general circulation scheme for intermediate waters in the basin and confirm the hypothesis about a "discrete-continuous" thermohaline structure of LIW.

scholarly journals Observations of new western Mediterranean deep water formation using Argo floats 2004–2006

Ocean Science ◽  
2008 ◽  
Vol 4 (2) ◽  
pp. 133-149 ◽  
Author(s):  
R. O. Smith ◽  
H. L. Bryden ◽  
K. Stansfield
Keyword(s):  
Mediterranean Sea ◽  
Deep Water ◽  
Temperature Increase ◽  
Deep Convection ◽  
Western Mediterranean ◽  
Deep Water Formation ◽  
Western Basin ◽  
Water Formation ◽  
Salinity Increase ◽  
Mixed Layers

Abstract. The deep convection that occurs in the western basin of the Mediterranean Sea was investigated using Argo float data over two consecutive winters in 2004–2005 and 2005–2006. The results showed deep mixed layers reaching 2000 m in surprising locations, namely the eastern Catalan subbasin (39.785° N, 4.845° E) and the western Ligurian subbasin (43.392° N, 7.765° E). Subsequently, new deep water was formed in March of 2005 and 2006 with θ=12.89–12.92°C, S=38.48–38.49 and σθ=29.113 kg m−3. The deep water produced in the Ligurian subbasin during 2006 was more saline, warmer and denser than any historical observations of western Mediterranean deep water. The results show S, θ and σθ in the western Mediterranean deep water are higher than 1990s values, with a salinity increase of 1.5×10−3 yr−1, a temperature increase of 3.6×10−3 °C yr−1 and a density increase of 4.0×10−4 kg m−3 yr−1 apparent from a dataset of western Mediterranean deep water properties spanning 1955–2006.

scholarly journals Meso-Alpha Scale Tropospheric Interactions within the Western Mediterranean Basin: Statistical Results Using 15-Year NCEP/NCAR Reanalysis Dataset

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
J. L. Palau ◽  
F. Rovira
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Meteorological Data ◽  
Western Mediterranean ◽  
Linkage Test ◽  
Reanalysis Dataset ◽  
Seasonal Evolution ◽  
Western Mediterranean Sea ◽  
Western Mediterranean Basin ◽  
Daily Oscillation

After a 15-year average of the reanalyses meteorological data provided by NCEP/NCAR, this paper shows the mean seasonal evolution, between April and October, of the tropospheric dynamics in the Western Mediterranean Basin (WMB). As shown in this paper, it is the result of the meso-alpha interaction between the daily oscillation of coastal thermally driven circulations around the basin and the daily pulsation of sinking speeds over areas of the Western Mediterranean Sea. Furthermore, from the 15-year average, a statistically significant correlation has been found between these processes (the daily oscillation of sea breezes and the daily pulsation of subsidence/convergence on the WMB). The quantification of this persistent link between these tropospheric processes elucidates their teleconnection at the meso-alpha scale and the seasonal evolution of the strength of this linkage. Test statistics are greater than critical values for the 5% significance level of the F-distribution. Besides, we have estimated a generalised diurnal compensatory subsidence over the Western Mediterranean Sea with a maximum mean sinking (subsidence) motion of up to −0.2 cm/s at 18:00 h UTC and 1000 hPa and a nocturnal generalised mean upward (convergence) motion of up to 0.05 cm/s at 00:00 h UTC and 1000 hPa.

scholarly journals Modelling deep-water formation in the North-West Mediterranean Sea with a new air-sea coupled model: sensitivity to turbulent flux parameterizations

2017 ◽  
Author(s):  
Léo Seyfried ◽  
Patrick Marsaleix ◽  
Evelyne Richard ◽  
Claude Estournel
Keyword(s):  
Deep Water ◽  
Turbulent Flux ◽  
Western Mediterranean ◽  
Observation Data ◽  
Strong Wind ◽  
Deep Water Formation ◽  
The North ◽  
Ocean Atmosphere ◽  
Water Formation ◽  
North Western

Abstract. In the north western Mediterranean, the strong, dry, cold winds, the Tramontane and Mistral, produce intense heat and moisture exchange at the interface between the ocean and the atmosphere leading to the formation of deep dense waters, a process that occurs only in certain regions of the world. The purpose of this study is to demonstrate the ability of a new coupled ocean-atmosphere modelling system based on MESONH-SURFEX-SYMPHONIE to simulate a deep-water formation event in real conditions. The study focuses on summer 2012 to spring 2013, a favourable period that is well documented by previous studies and for which many observations are available. Model results are assessed through detailed comparisons with different observation data sets, including measurements from buoys, moorings and floats. The good overall agreement between observations and model results shows that the new coupled system satisfactorily simulates the formation of deep dense water and can be used with confidence to study ocean-atmosphere coupling in the north-western Mediterranean. In addition, to evaluate the uncertainty associated with the representation of turbulent fluxes in strong wind conditions, several simulations were carried out based on different parameterizations of the flux bulk formulas. The results point out that the choice of turbulent flux parameterization strongly influences the simulation of the deep water convection and can modify the calculated volume of the deep water formed by up to one order of magnitude.

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