scholarly journals Intercomparison of intense cyclogenesis events over the Mediterranean basin based on baroclinic and diabatic influences

2006 ◽  
Vol 7 ◽  
pp. 333-342 ◽  
Author(s):  
Ll. Fita ◽  
R. Romero ◽  
C. Ramis
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Numerical Study ◽  
Eastern Mediterranean ◽  
Geographical Area ◽  
Relative Weight ◽  
High Impact ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. A large number of high impact cyclones all over the Mediterranean basin have been reported on the data base of the MEDEX project (http://medex.inm.uib.es). A numerical study on the impacts and interactions of baroclinic and diabatic factors is carried out through a PV-based system of prognostic equations for 11 intense MEDEX cyclone episodes occurred in different zones of the basin (Western, Central and Eastern Mediterranean). The main aim of the study is to investigate the possible similarities and differences among the selected cases of the relative weight of the considered cyclogenetic factors on the cyclone evolutions as function of cyclone type and geographical area. A crucial role of the baroclinicity over the Mediterranean zone is obtained in most of the cases. A certain distinction can be also established in terms of the cyclogenesis areas (Africa, Mediterranean Sea, and Alpine region), and between west-central and eastern Mediterranean basins. It is generally observed that the considered baroclinic and diabatic factors cooperate most strongly for the cyclone deepening process when the disturbance reaches the Mediterranean sea.

scholarly journals Mediterranean Heathland as a Key Habitat for Fire Adaptations: Evidence from an Experimental Approach

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 748
Author(s):  
Susana Gómez-González ◽  
Maria Paniw ◽  
Mario Durán ◽  
Sergio Picó ◽  
Irene Martín-Rodríguez ◽  
...  
Keyword(s):  
Heat Shock ◽  
Seed Size ◽  
Mediterranean Basin ◽  
Fire Ecology ◽  
Mediterranean Region ◽  
Plant Evolution ◽  
Fire Adaptations ◽  
The Mediterranean ◽  
The Mediterranean Basin

Some fire ecology studies that have focused on garrigue-like vegetation suggest a weak selective pressure of fire in the Mediterranean Basin compared to other Mediterranean-type regions. However, fire-prone Mediterranean heathland from the western end of the Mediterranean Basin has been frequently ignored in the fire ecology literature despite its high proportion of pyrogenic species. Here, we explore the evolutionary ecology of seed traits in the generalist rockrose Cistus salviifolius L. (Cistaceae) aiming to ascertain the role of the Mediterranean heathland for fire adaptations in the Mediterranean Region. We performed a germination experiment to compare the relationship of seed size to (i) heat-stimulated germination, (ii) dormancy strength, and (iii) heat survival in plants from ‘high-fire’ heathland vs. ‘low-fire’ coastal shrubland. Germination after heat-shock treatment was higher in large seeds of both ‘high-fire’ and ‘low-fire’ habitats. However, dormancy was weaker in small seeds from ‘low-fire’ habitats. Finally, seed survival to heat shock was positively related to seed size. Our results support that seed size is an adaptive trait to fire in C. salviifolius, since larger seeds had stronger dormancy, higher heat-stimulated germination and were more resistant to heat shock. This seed size–fire relationship was tighter in ‘high-fire’ Mediterranean heathland than ‘low-fire’ coastal shrubland, indicating the existence of differential fire pressures and evolutionary trends at the landscape scale. These findings highlight the Mediterranean heathland as a relevant habitat for fire-driven evolution, thus contributing to better understand the role of fire in plant evolution within the Mediterranean region.

scholarly journals Genetic flow among olive populations within the Mediterranean basin

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5260 ◽  
Author(s):  
Valentina di Rienzo ◽  
Sara Sion ◽  
Francesca Taranto ◽  
Nunzio D’Agostino ◽  
Cinzia Montemurro ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Resources ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Olive Tree ◽  
Gene Pools ◽  
The North ◽  
The Mediterranean ◽  
And Migration ◽  
The Mediterranean Basin

Background The olive tree is a typical crop of the Mediterranean basin where it shows a wide diversity, accounting for more than 2,600 cultivars. The ability to discriminate olive cultivars and determine their genetic variability is pivotal for an optimal exploitation of olive genetic resources. Methods We investigated the genetic diversity within 128 olive accessions belonging to four countries in the Mediterranean Basin (Italy, Algeria, Syria, and Malta), with the purpose of better understanding the origin and spread of the olive genotypes across Mediterranean Basin countries. Eleven highly polymorphic simple sequence repeat (SSR) markers were used and proved to be very informative, producing a total of 179 alleles. Results Cluster analysis distinguished three main groups according to their geographical origin, with the current sample of Maltese accessions included in the Italian group. Phylogenetic analysis further differentiated Italian and Maltese olive accessions, clarifying the intermediate position of Maltese accessions along the x/y-axes of principal coordinate analysis (PCoA). Model-based and neighbor clustering, PCoA, and migration analysis suggested the existence of two different gene pools (Algerian and Syrian) and that the genetic exchange occurred between the Syrian, Italian and Maltese populations. Discussion The close relationship between Syrian and Italian and Maltese olives was consistent with the historical domestication and migration of olive tree from the North Levant to eastern Mediterranean basin. This study lays the foundations for a better understanding of olive genetic diversity in the Mediterranean basin and represents a step toward an optimal conservation and exploitation of olive genetic resources.

scholarly journals Review Article: Atmospheric conditions inducing extreme precipitation over the Eastern and Western Mediterranean

2015 ◽  
Vol 3 (6) ◽  
pp. 3687-3732 ◽  
Author(s):  
U. Dayan ◽  
K. M. Nissen ◽  
U. Ulbrich
Keyword(s):  
Extreme Precipitation ◽  
Mediterranean Basin ◽  
Heavy Rainfall ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Atmospheric Conditions ◽  
Synoptic Scale ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes producing heavy rain storms. It distinguishes the Western and Eastern Mediterranean in order to point at specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger scale circulations. The synoptic systems (tropical and extra-tropical) accounting for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper-level synoptic-scale troughs, and meso-scale convective systems. Under tropical air mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

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>

Seasonal ecosystem vulnerability to climatic anomalies in the Mediterranean

2021 ◽  
Author(s):  
Johannes Vogel
Keyword(s):  
Soil Moisture ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Ecosystem Productivity ◽  
Data Set ◽  
Ecosystem Vulnerability ◽  
Dry Conditions ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>The ecosystems of the Mediterranean Basin are particularly prone to climate change and related alterations in climatic anomalies. The seasonal timing of climatic anomalies is crucial for the assessment of the corresponding ecosystem impacts; however, the incorporation of seasonality is neglected in many studies. We quantify ecosystem vulnerability by investigating deviations of the climatic drivers temperature and soil moisture during phases of low ecosystem productivity for each month of the year over the period 1999 – 2019. The fraction of absorbed photosynthetically active radiation (FAPAR) is used as a proxy for ecosystem productivity. Air temperature is obtained from the reanalysis data set ERA5 Land and soil moisture and FAPAR satellite products are retrieved from ESA CCI and Copernicus Global Land Service, respectively. Our results show that Mediterranean ecosystems are vulnerable to three soil moisture regimes during the course of the year. A phase of vulnerability to hot and dry conditions during late spring to midsummer is followed by a period of vulnerability to cold and dry conditions in autumn. The third phase is characterized by cold and wet conditions coinciding with low ecosystem productivity in winter and early spring. These phases illustrate well the shift between a soil moisture-limited regime in summer and an energy-limited regime in winter in the Mediterranean Basin. Notably, the vulnerability to hot and dry conditions during the course of the year is prolonged by several months in the Eastern Mediterranean compared to the Western Mediterranean. Our approach facilitates a better understanding of ecosystem vulnerability at certain stages during the year and is easily transferable to other study areas and ecoclimatological variables.</p>

scholarly journals Review Article: Atmospheric conditions inducing extreme precipitation over the eastern and western Mediterranean

2015 ◽  
Vol 15 (11) ◽  
pp. 2525-2544 ◽  
Author(s):  
U. Dayan ◽  
K. Nissen ◽  
U. Ulbrich
Keyword(s):  
Extreme Precipitation ◽  
Mediterranean Basin ◽  
Heavy Rainfall ◽  
Eastern Mediterranean ◽  
Western Mediterranean ◽  
Atmospheric Conditions ◽  
Synoptic Scale ◽  
Extreme Precipitation Events ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. This review discusses published studies of heavy rainfall events over the Mediterranean Basin, combining them in a more general picture of the dynamic and thermodynamic factors and processes that produce heavy rain storms. It distinguishes the western and eastern Mediterranean in order to point out specific regional peculiarities. The crucial moisture for developing intensive convection over these regions can be originated not only from the adjacent Mediterranean Sea but also from distant upwind sources. Transport from remote sources is usually in the mid-tropospheric layers and associated with specific features and patterns of the larger-scale circulations. The synoptic systems (tropical and extratropical) that account for most of the major extreme precipitation events and the coupling of circulation and extreme rainfall patterns are presented. Heavy rainfall over the Mediterranean Basin is caused at times in concert by several atmospheric processes working at different atmospheric scales, such as local convection, upper synoptic-scale-level troughs, and mesoscale convective systems. Under tropical air-mass intrusions, convection generated by static instability seems to play a more important role than synoptic-scale vertical motions. Locally, the occurrence of torrential rains and their intensity is dependent on factors such as temperature profiles and implied instability, atmospheric moisture, and lower-level convergence.

scholarly journals Mapping Flood-Related Mortality in the Mediterranean Basin. Results from the MEFF v2.0 DB

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2196 ◽  
Author(s):  
Vinet ◽  
Bigot ◽  
Petrucci ◽  
Papagiannaki ◽  
Llasat ◽  
...  
Keyword(s):  
Population Density ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Balearic Islands ◽  
Fatality Rate ◽  
Southern France ◽  
Rainfall Frequency ◽  
The Mediterranean ◽  
The Mediterranean Basin ◽  
Related Mortality

Recent events in Western Attica in Greece (24 deaths in November 2017), in the Balearic Islands (13 deaths in October 2018), and in southern France (15 deaths in October 2018) show that flood-related mortality remains a major concern in Mediterranean countries facing flash floods. Over the past several years, many initiatives have arisen to create databases on flood-related mortality. An international initiative started in 2011 pooling regional and national databases on flood mortality from region and/or countries bordering the Mediterranean Sea. The MEditerranean Flood Fatality Database (MEFF DB) brings together, in 2018, six Mediterranean regions/countries: Catalonia (Spain), Balearic Islands (Spain), Southern France, Calabria (Italy), Greece, and Turkey, and covers the period 1980–2018. MEFF DB is on progress and, every year, new data are included, but for this study, we kept only the preliminary data that were geolocated and validated on 31st of December 2018. This research introduces a new step in the analysis of flood-related mortality and follows the statistical description of the MEFF DB already published. The goals of this paper are to draw the spatial distribution of flood mortality through a geographical information system (GIS) at different spatial scales: country, NUTS 3 (Nomenclature of Territorial Units for Statistics. Level 3) regions, catchment areas, and grid. A fatality rate (F: number of deaths/year/million of inhabitants) is created to help this analysis. Then, we try to relate mortality to basic (human or physical) drivers such as population density, rainfall seasonality, or rainfall frequency across the Mediterranean Basin. The mapping of F shows a negative mortality gradient between the western and the eastern parts of the Mediterranean Sea. The south of France appears to be the most affected region. The maps also highlight the seasonality of flood-related deaths with the same west–east gradient. It confirms that flood mortality follows the climatological seasonal patterns across the Mediterranean Basin. Flood-related fatalities mainly occur during the early fall season in the western part of the Mediterranean area, while the Easter Basin is affected later, in November or during the winter season. Eastern Turkey introduces another pattern, as mortality is more severe in summer. Mortality maps are then compared with factors that potentially contribute to the occurrence of flood fatalities, such as precipitation intensity (rainfall hazard), to explain geographical differences in the fatality rate. The density of a fatal event is correlated to the population density and the rainfall frequency. Conversely, the average number of deaths per event depends on other factors such as prevention or crisis management.

scholarly journals Anthropogenic and natural CO<sub>2</sub> exchange through the Strait of Gibraltar

2009 ◽  
Vol 6 (4) ◽  
pp. 647-662 ◽  
Author(s):  
I. E. Huertas ◽  
A. F. Ríos ◽  
J. García-Lafuente ◽  
A. Makaoui ◽  
S. Rodríguez-Gálvez ◽  
...  
Keyword(s):  
Time Series ◽  
Atlantic Ocean ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Inorganic Carbon ◽  
Strait Of Gibraltar ◽  
Anthropogenic Carbon ◽  
The Mediterranean ◽  
The Mediterranean Basin ◽  
Mediterranean Water

Abstract. The exchange of both anthropogenic and natural inorganic carbon between the Atlantic Ocean and the Mediterranean Sea through Strait of Gibraltar was studied for a period of two years under the frame of the CARBOOCEAN project. A comprehensive sampling program was conducted, which was design to collect samples at eight fixed stations located in the Strait in successive cruises periodically distributed through the year in order to ensure a good spatial and temporal coverage. As a result of this monitoring, a time series namely GIFT (GIbraltar Fixed Time series) has been established, allowing the generation of an extensive data set of the carbon system parameters in the area. Data acquired during the development of nine campaigns were analyzed in this work. Total inorganic carbon concentration (CT) was calculated from alkalinity-pHT pairs and appropriate thermodynamic relationships, with the concentration of anthropogenic carbon (CANT) being also computed using two methods, the ΔC* and the TrOCA approach. Applying a two-layer model of water mass exchange through the Strait and using a value of −0.85 Sv for the average transport of the outflowing Mediterranean water recorded in situ during the considered period, a net export of inorganic carbon from the Mediterranean Sea to the Atlantic was obtained, which amounted to 25±0.6 Tg C yr−1. A net alkalinity output of 16±0.6 Tg C yr−1 was also observed to occur through the Strait. In contrast, the Atlantic water was found to contain a higher concentration of anthropogenic carbon than the Mediterranean water, resulting in a net flux of CANT towards the Mediterranean basin of 4.20±0.04 Tg C yr−1 by using the ΔC* method, which constituted the most adequate approach for this environment. A carbon balance in the Mediterranean was assessed and fluxes through the Strait are discussed in relation to the highly diverse estimates available in the literature for the area and the different approaches considered for CANT estimation. This work unequivocally confirms the relevant role of the Strait of Gibraltar as a controlling point for the biogeochemical exchanges occurring between the Mediterranean Sea and the Atlantic Ocean and emphasizes the influence of the Mediterranean basin in the carbon inventories of the North Atlantic.

SMOS-based estimation and validation of Total Alkalinity in the Mediterranean basin

2020 ◽  
Author(s):  
Roberto Sabia ◽  
Estrella Olmedo ◽  
Giampiero Cossarini ◽  
Aida Alvera-Azcárate ◽  
Veronica Gonzalez-Gambau ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Total Alkalinity ◽  
Surface Salinity ◽  
Carbonate System ◽  
The Mediterranean ◽  
The Mediterranean Basin

&lt;p&gt;ESA SMOS satellite [1] has been providing first-ever Sea Surface Salinity (SSS) measurements from space for over a decade now. Until recently, inherent algorithm limitations or external interferences hampered a reliable provision of satellite SSS data in semi-enclosed basin such as the Mediterranean Sea. This has been however overcome through different strategies in the retrieval scheme and data filtering approach [2, 3]. This recent capability has been in turn used to infer the spatial and temporal distribution of Total Alkalinity (TA - a crucial parameter of the marine carbonate system) in the Mediterranean, exploiting basin-specific direct relationships existing between salinity and TA.&lt;/p&gt;&lt;p&gt;Preliminary results [4] focused on the differences existing in several parameterizations [e.g, 5] relating these two variables, and how they vary over a seasonal to interannual timescale.&lt;/p&gt;&lt;p&gt;Currently, to verify the consistency and accuracy of the derived products, these data are being validated against a proper ensemble of in-situ, climatology and model outputs within the Mediterranean basin. An error propagation exercise is also being planned to assess how uncertainties in the satellite data would translate into the final products accuracy.&lt;/p&gt;&lt;p&gt;The resulting preliminary estimates of Alkalinity in the Mediterranean Sea will be linked to the overall carbonate system in the broader context of Ocean Acidification assessment and marine carbon cycle.&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;[1] J. Font et al., &quot;SMOS: The Challenging Sea Surface Salinity Measurement From Space,&quot; in Proceedings of the IEEE, vol. 98, no. 5, pp. 649-665, May 2010. doi: 10.1109/JPROC.2009.2033096&lt;/p&gt;&lt;p&gt;[2] Olmedo, E., J. Martinez, A. Turiel, J. Ballabrera-Poy, and M. Portabella,&amp;#160; &amp;#8220;Debiased non-Bayesian retrieval: A novel approach to SMOS Sea Surface Salinity&amp;#8221;. Remote Sensing of Environment 193, 103-126 (2017).&lt;/p&gt;&lt;p&gt;[3] Alvera-Azc&amp;#225;rate, A., A. Barth, G. Parard, J.-M. Beckers, Analysis of SMOS sea surface salinity data using DINEOF, In Remote Sensing of Environment, Volume 180, 2016, Pages 137-145, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2016.02.044.&lt;/p&gt;&lt;p&gt;[4] Sabia, R., E. Olmedo, G. Cossarini, A. Turiel, A. Alvera-Azc&amp;#225;rate, J. Martinez, D. Fern&amp;#225;ndez-Prieto, Satellite-driven preliminary estimates of Total Alkalinity in the Mediterranean basin, Geophysical Research Abstracts, Vol. 21, EGU2019-17605, EGU General Assembly 2019, Vienna, Austria, April 7-12, 2019.&lt;/p&gt;&lt;p&gt;[5] Cossarini, G., Lazzari, P., and Solidoro, C.: Spatiotemporal variability of alkalinity in the Mediterranean Sea, Biogeosciences, 12, 1647-1658, https://doi.org/10.5194/bg-12-1647-2015, 2015.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Satellite Observations of the Seasonal Evolution of Total Precipitable Water Vapour over the Mediterranean Sea

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
J. L. Palau ◽  
F. Rovira ◽  
M. J. Sales
Keyword(s):  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Precipitable Water ◽  
Satellite Observations ◽  
Annual Variability ◽  
Total Precipitable Water ◽  
New Findings ◽  
Precipitation Regimes ◽  
The Mediterranean

This study shows satellite observations and new findings on the time and spatial distribution of the Total Precipitable Water (TPW) column over the Mediterranean Sea throughout the year. Annual evolution and seasonality of the TPW column are shown and compared to the estimated net evaporation over the Mediterranean Sea. Daily spatiotemporal means are in good agreement with previous short-term field campaigns and also corroborate hypothesis and conclusions reached from previous mesoscale modelling studies: (a) from a meteorological point of view, Mediterranean Basin should be considered as two different subbasins (the Western and the Eastern Mediterranean); (b) accumulation processes may affect the radiative balance at regional scale and the summer precipitation regimes. Furthermore, these satellite observations constitute strong empirical evidences that, (a) from late May to early October, contrary to what happens in the Eastern Mediterranean Basin (EMB), there is a net accumulation of TPW on the Western Mediterranean Basin (WMB) that favours the instability of the atmosphere, (b) there is a seasonal anticorrelation between the seasonal variability of the TPW column over the two Mediterranean subbasins, (c) solar radiation can not be the only driver for the annual variability of the TPW column over the Mediterranean Sea, and (d) both previous features are seasonally dependent and, therefore, their effects on the TPW column are attenuated by annual variability.

Sign in / Sign up

Export Citation Format

Share Document