scholarly journals The Mean Sea Level Equation and Its Application to the Mediterranean Sea

2014 ◽  
Vol 27 (1) ◽  
pp. 442-447 ◽  
Author(s):  
N. Pinardi ◽  
A. Bonaduce ◽  
A. Navarra ◽  
S. Dobricic ◽  
P. Oddo
Keyword(s):  
Surface Water ◽  
Mediterranean Sea ◽  
Sea Level ◽  
Water Flux ◽  
Mass Conservation ◽  
Volume Transport ◽  
Conservation Equation ◽  
Global Ocean ◽  
Mean Sea Level ◽  
The Mediterranean

Abstract A formalism to obtain a mean sea level equation (MSLE) is constructed for any limited ocean region and/or the global ocean by considering the mass conservation equation with compressible effects and a linear equation of state. The MSLE contains buoyancy fluxes terms representing the steric effects and the mass flux is represented by surface water fluxes and volume transport terms. The MSLE is studied for the Mediterranean Sea case using a simulation experiment for the decade 1999–2008. It is found that the Mediterranean MSL tendency is made of a steric contribution that is almost periodic in time superimposed on a stochastic-like signal due to the mass balance, dominating the MSL tendency. The MSL tendency stochastic-like term is a result of the imbalance between the volume flux at Gibraltar and the area average surface water flux.

scholarly journals Mean sea level and surface circulation variability of the Mediterranean Sea from 2 years of TOPEX/POSEIDON altimetry

1995 ◽  
Vol 100 (C12) ◽  
pp. 25163 ◽  
Author(s):  
Gilles Larnicol ◽  
Pierre-Yves Le Traon ◽  
Nadia Ayoub ◽  
Pierre De Mey
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Mean Sea Level ◽  
Surface Circulation ◽  
The Mediterranean

scholarly journals Seasonal sea level extremes in the Mediterranean Sea and at the Atlantic European coasts

2010 ◽  
Vol 10 (7) ◽  
pp. 1457-1475 ◽  
Author(s):  
M. N. Tsimplis ◽  
A. G. P. Shaw
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Extreme Values ◽  
Western Mediterranean ◽  
Spatial And Temporal Variability ◽  
Atmospheric Forcing ◽  
Mean Sea Level ◽  
The North ◽  
The Mediterranean ◽  
Tidal Signal

Abstract. Hourly sea level data from tide gauges and a barotropic model are used to explore the spatial and temporal variability of sea level extremes in the Mediterranean Sea and the Atlantic coasts of the Iberian peninsula on seasonal time scales. Significant spatial variability is identified in the observations in all seasons. The Atlantic stations show larger extreme values than the Mediterranean Sea primarily due to the tidal signal. When the tidal signal is removed most stations have maximum values of less than 90 cm occurring in winter or autumn. The maxima in spring and summer are less than 60 cm in most stations. The wind and atmospheric forcing contributes about 50 cm in the winter and between 20–40 cm in the other seasons. In the western Mediterranean the observed extreme values are less than 50 cm, except near the Strait of Gibraltar. Direct atmospheric forcing contributes significantly to sea level extremes. Maximum sea level values due to atmospheric forcing reach in some stations 45 cm during the winter. During the summer the contribution of the direct atmospheric forcing is between 10–20 cm. The Adriatic Sea shows a resonant behaviour with maximum extreme observed sea level values around 200 cm found at the northern part. Trends in the 99.9% percentiles are present in several areas, however most of them are removed when the 50% percentile is subtracted indicating that changes in the extremes are in line with mean sea level change. The North Atlantic Oscillation and the Mediterranean Oscillation Index are well correlated with the changes in the 99.9% winter values in the Atlantic, western Mediterranean and the Adriatic stations. The correlation of the NAO and the MOI indices in the Atlantic and western Mediterranean is significant in the autumn too. The correlations between the NAO and MOI index and the changes in the sea level extremes become insignificant when the 50% percentile is removed indicating again that changes in extremes have been dominated by changes in the mean sea level.

Trends and interconnections of physical parameters in the upper layer of the Mediterranean Sea

2020 ◽  
Author(s):  
Milena Menna ◽  
Giulio Notarstefano ◽  
Elena Mauri ◽  
Miroslav Gačić ◽  
Giuseppe Civitarese ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
Global Ocean ◽  
Physical Parameters ◽  
Strong Impact ◽  
Argo Float ◽  
Freshwater Fluxes ◽  
The Mediterranean

<p>The Mediterranean Sea is considered a hot spot of the global warming since it is changing faster than the global ocean, with a strong impact on the marine environment. Recent studies agree on the increase of the sea level, of the Sea Surface Temperature (SST), and of the Sea Surface Salinity (SSS) in the Mediterranean Sea over the last two decade, but no one has yet come to interconnect these and other parameters that contribute to the regulatory effect of the sea on the climate.</p><p>In this study, interannual variability and decadal climatic trends in the upper-layer of the Mediterranean Sea are estimated in the last 26 years using in-situ data (Argo float), satellite (altimetry, SST, wind vorticity, freshwater fluxes, mixed layer depth) and model (SSS) products.</p><p>Spatio-temporal variability is studied performing the Empirical Orthogonal Function analysis on the gridded, monthly, de-seasonalized maps of all satellite and model data. The contribution of the western, central and eastern regions of the Mediterranean Sea to the total trends is assessed. SSS distribution and trends derived from model reanalysis are compared with those derived from Argo float data in the upper layer.</p><p>Possible relationships between the trends in different datasets are delineated and described, i.e. the connection between the sea level rise and the SST, between the freshwater fluxes and the SSS, between the SSS and the ocean dynamics, including Ekman and geostrophic transports as well as vertical entrainment.</p>

A Near-Uniform Basin-Wide Sea Level Fluctuation of the Mediterranean Sea

2007 ◽  
Vol 37 (2) ◽  
pp. 338-358 ◽  
Author(s):  
Ichiro Fukumori ◽  
Dimitris Menemenlis ◽  
Tong Lee
Keyword(s):  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Sea Level ◽  
Ocean Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Level Fluctuation ◽  
Strait Of Gibraltar ◽  
Sea Level Fluctuation ◽  
The Mediterranean

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.

scholarly journals The effect of cyclones crossing the Mediterranean region on sea level anomalies at the Mediterranean Sea coast

2019 ◽  
Author(s):  
Piero Lionello ◽  
Dario Conte ◽  
Marco Reale
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Eastern Mediterranean ◽  
Storm Track ◽  
Western Mediterranean ◽  
Residual Water ◽  
Positive Anomaly ◽  
Western Basin ◽  
Sea Level Anomalies ◽  
The Mediterranean

Abstract. Large positive and negative sea level anomalies at the coast of the Mediterranean Sea are linked to intensity and position of cyclones moving along the Mediterranean storm track, with dynamics involving different factors. This analysis is based on a model hindcast and considers nine coastal stations, which are representative of sea level anomalies with different magnitude and characteristics. When a shallow water fetch is present, the wind around the cyclone center is the main cause of sea level positive and negative anomalies, depending on its onshore or offshore direction. The inverse barometer effect produces a positive anomaly at the coast near the cyclone pressure minimum and a negative anomaly at the opposite side of the Mediterranean Sea, because a cross-basin mean sea level pressure gradient is associated to the presence of a cyclone. Further, at some stations, negative sea level anomalies are reinforced by a residual water mass redistribution within the basin, which is associated with a transient response to the atmospheric pressure forcing. Though the link between presence of a cyclone in the Mediterranean has comparable importance for positive and negative anomalies, the relation between cyclone position and intensity is stronger for the magnitude of positive events. Area of cyclogenesis, track of the central minimum and position at the time of the event differ depending on the location where the sea level anomaly occurs and on its sign. The western Mediterranean is the main cyclogenesis area for both positive and negative anomalies, overall. Atlantic cyclones mainly produce positive sea level anomalies in the western basin. At the easternmost stations, positive anomalies are caused by Cyclogenesis in the Eastern Mediterranean. North Africa cyclogeneses are a major source of positive anomalies at the central African coast and negative anomalies at the eastern Mediterranean and North Aegean coast.

Erosional landforms and biological structures in tectonically stable areas in the Mediterranean basin

2021 ◽  
Author(s):  
Valeria Vaccher ◽  
Stefano Furlani ◽  
Sara Biolchi ◽  
Chiara Boccali ◽  
Alice Busetti ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Mediterranean Basin ◽  
Vertical Position ◽  
Structural Constraints ◽  
Last Interglacial ◽  
Central Mediterranean ◽  
Biological Structures ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The Mediterranean basin displays a variety of neotectonics scenarios leading to positive or negative vertical displacement, which change the vertical position of former coastlines. As a result, the best locations to evaluate former sea levels and validate sea-level models are tectonically stable areas. There are a number of coastal areas considered to be stable based on the elevation of paleo sea-level markers, the absence of historical seismicity, and by their position far from major Mediterranean faults. We report here the results of swim surveys carried out at such locations following the Geoswim approach described by Furlani (2020) in nine coastal sectors of the central Mediterranean Sea (Egadi Island - Marettimo, Favignana, Levanzo, Gaeta Promontory, Circeo Promontory, North Sardinia - Razzoli, Budelli, Santa Maria, NW Sardinia – Capocaccia, Maddalena Archipelago, Tavolara Island, East of Malta - Ahrax Point, Bugibba-Qawra, Delimara, Addura, Palermo, Ansedonia Promontory). All the sites are considered to be tectonically stable, as validated by the elevation of sea-level indicators. In fact, modern and MIS5.5 (last interglacial) m.s.l. altitudes fit well with accepted figures based upon field data and model projections. Starting from precise morphometric parameters such as the size of tidal notches and indicative landforms and biological structures, we have developed a procedure that integrates multiple geomorphological and biological descriptors applicable to the vast spectrum of locally diverse coastal situations occurring in the Mediterranean Sea. We took detailed measurements of features such as modern and MIS5.5 tidal notches at 146 sites in all the areas, the absence of modern tidal notch at Circeo promontory, shore platforms, and MIS5.5 marine terraces at Egadi islands, Malta, and Palermo. Biological structures were also measured. In particular, vermetid platforms at Egadi, Palermo and Malta. The morphometric characteristics of these indicators depend on 1) local geological and structural constraints, 2) local geomorphotypes, 3) climate, sea, and weather conditions that affect geomorphic and biological processes, and 4) the sea level change history.</p>

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