A 2-year intercomparison of the WAM-Cycle4 and the WAVEWATCH-III wave models implemented within the Mediterranean Sea

In this work we present the implementation of a wave forecast/hindcast system for the Mediterranean Sea at a 1/10º horizontal resolution and we show a first assessment of its performance by inter-comparing model results to observational data time series at selected points for the period 2000-2001. The system which is part of the POSEIDON-II operational system includes the WAM – Cycle4 and the WAVEWATCH-III wave forecast models (implemented within the same region) one way coupled with the non-hydrostatic version of the ETA atmospheric model which provides at 3-hour intervals the necessary wind velocity fields to the wave models. The same system but based on the WAM-Cycle4 wave model, has been used in the past for the production of the Aegean Sea wind and wave Atlas. Overall, the inter-comparison shows that both wave models are rather skilful in predicting the integral wave parameters with significant wave height skill scores in the range 0.85-0.90 and mean period scores in the range 0.77-0.83. It is also evident that WAM model has a tendency to overestimate mean wave periods while the opposite is true for WAVEWATCH-III model. Differences between the two models simulated spectra exist along the main passage of cyclonic systems over the Mediterranean Sea while in the wind seas dominated areas of the basin (the Aegean Sea for example) the two models show almost the same behavior.

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High-resolution wave model validation over the Greek maritime areas

Natural Hazards and Earth System Science ◽

10.5194/nhess-12-3433-2012 ◽

2012 ◽

Vol 12 (11) ◽

pp. 3433-3440 ◽

Cited By ~ 18

Author(s):

N. Mazarakis ◽

V. Kotroni ◽

K. Lagouvardos ◽

L. Bertotti

Keyword(s):

Large Scale ◽

Aegean Sea ◽

Wave Model ◽

Altimeter Data ◽

Medium Size ◽

Simple Task ◽

Meteorological Model ◽

Satellite Platform ◽

Wave Forecast ◽

Wave Models

Abstract. The increasing maritime activity can be seriously affected by severe weather and sea conditions. To avoid serious damages to ships, marine structures and humans, a good weather and wave forecast is of primary importance. In general the meteorological and the wave models are used to produce forecasts at large scale like the global or the medium-size inner seas. For much smaller environments like the Greek maritime areas, characterized by complicated features like the orography and the presence of islands, the modelisation becomes a not simple task. This study is devoted to the validation of the performance of the WAM wave model over the Ionian and Aegean Seas. The period of validation refers to the first 12 months of operational use of the model at the National Observatory of Athens. The wave model is applied at a resolution of 1/16 degrees and is driven by the 10 m wind, produced by the BOLAM meteorological model operationally run over the same area. Two different sources of data have been used for the verification of the model results. The first dataset is provided by a network of buoys deployed over the Greek maritime areas and the second consists of altimeter data, provided by the OSTM/Jason-2 satellite platform. Although the study area is characterized by complex topography and a large number of islands, the implementation of the WAM model provides very encouraging results. In general, with the exception of the two buoys located in the Ionian Sea, the WAM model tends to underestimate the wave energy in the region of the Aegean Sea. The comparison with the altimeter data shows that the model has a tendency to overestimate the height for waves lower than 2.5 m and to underestimate the waves higher than 3 m.

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New Mediterranean Marine biodiversity records (June 2013)

Mediterranean Marine Science ◽

10.12681/mms.450 ◽

2013 ◽

Vol 14 (1) ◽

pp. 238 ◽

Cited By ~ 7

Author(s):

I. SIOKOU ◽

A.S. ATES ◽

D. AYAS ◽

J. BEN SOUISSI ◽

T. CHATTERJEE ◽

...

Keyword(s):

Mediterranean Sea ◽

Aegean Sea ◽

Marine Biodiversity ◽

Red Data Book ◽

Gulf Of Tunis ◽

The North ◽

Levantine Sea ◽

Data Book ◽

The Mediterranean ◽

Flora Of Cyprus

This paper concerns records of species that have extended their distribution in the Mediterranean Sea. The finding of the rare brackish angiosperm Althenia filiformis in the island of Cyprus is interesting since its insertion in the Red Data Book of the Flora of Cyprus is suggested. The following species enriched the flora or fauna lists of the relevant countries: the red alga Sebdenia dichotoma (Greece), the hydrachnid mite Pontarachna adriatica (Slovenia), and the thalassinid Gebiacantha talismani (Turkey). Several alien species were recorded in new Mediterranean localities. The record of the burrowing goby Trypauchen vagina in the North Levantine Sea (Turkish coast), suggests the start of spreading of this Lessepsian immigrant in the Mediterranean Sea. The findings of the following species indicate the extension of their occurrence in the Mediterranean Sea: the foraminifer Amphistegina lobifera (island of Zakynthos, Greece), the medusa Cassiopea andromeda (Syria), the copepod Centropages furcatus (Aegean Sea), the decapod shrimp Melicertus hathor (island of Kastellorizo, Greece), the crab Menoethius monoceros (Gulf of Tunis), the barnacles Balanus trigonus, Megabalanus tintinnabulum, Megabalanus coccopoma and the bivalves Chama asperella, Cucurbitula cymbium (Saronikos Gulf, Greece).

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Hemiasterella aristoteliana n. sp. (Porifera, Hadromerida) from the Aegean Sea with a discussion on the family Hemiasterellidae

Bijdragen tot de Dierkunde ◽

10.1163/26660644-06101004 ◽

1991 ◽

Vol 61 (1) ◽

pp. 43-49 ◽

Cited By ~ 7

Author(s):

Eleni Voultsiadou-Koukoura ◽

R.W.M. van Soest

Keyword(s):

New Species ◽

Mediterranean Sea ◽

Aegean Sea ◽

Shallow Waters ◽

The Family ◽

The Status ◽

Northern Aegean Sea ◽

The Mediterranean ◽

First Time

A representative of the genus Hemiasterella Carter, 1879 was found for the first time in the Mediterranean Sea during sampling in the shallow waters of the northern Aegean Sea. The new species, H. aristoteliana, is compared with Atlantic Hemiasterella elongata Topsent, 1928. The status of the family Hemiasterellidae is discussed.

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Carbonate System and Acidification of the Adriatic Sea

10.5194/egusphere-egu2020-10977 ◽

2020 ◽

Author(s):

Valentina Turk ◽

Nina Bednarsek ◽

Jadran Faganeli ◽

Blaženka Gasparovic ◽

Michele Giani ◽

...

Keyword(s):

Mediterranean Sea ◽

Adriatic Sea ◽

Microbial Community Composition ◽

Aegean Sea ◽

Total Alkalinity ◽

The Black Sea ◽

Po River ◽

Saturation State ◽

Northern Adriatic ◽

The Mediterranean

Although the marginal seas represent only 7% of the total ocean area, the CO2 fluxes are intensive and important for the carbon budget, exposing to an intense process of anthropogenic ocean acidification (OA). A decline in pH, especially in the estuarine waters, results also from the eutrophication-induced acidification. The Adriatic Sea is currently a CO2 sink with an annual flux of approximately -1.2 to -3 mol C m-2 yr-1 which is twice as low compared to the net sink rates in the NW Mediterranean (-4 to -5 mol C m-2 yr-1). Based on the comparison of two winter cruises carried out in in the 25-year interval between 1983 and 2008, acidification rate of 0.003 pHT units yr&#8722;1 was estimated in the northern Adriatic which is similar to the Mediterranean open waters (with recent estimations of &#8722;0.0028 &#177; 0.0003 units pHT yr&#8722;1) and the surface coastal waters (-0.003 &#177; 0.001 and -0.0044 &#177; 0.00006 pHT units yr&#8722;1). The computed Revelle factor for the Adriatic Sea, with the value of about 10, indicates that the buffer capacity is rather high and that the waters should not be particularly exposed to acidification. Total alkalinity (TA) in the Adriatic (2.6-2.7 mM) is in the upper range of TA measured in the Mediterranean Sea because riverine inputs transport carbonates dissolved from the Alpine dolomites and karstic watersheds. The Adriatic Sea is the second sub-basin (319 Gmol yr-1), following the Aegean Sea (which receives the TA contribution from the Black Sea), that contribute to the riverine TA discharges into the Mediterranean Sea. About 60% of the TA inflow into the Adriatic Sea is attributed to the Po river discharge with TA of ~3 mM and TA decreases with increasing salinity. Saturation state indicates that the waters of the Adriatic are supersaturated with respect to calcite (&#937;Ca) and aragonite (&#937;Ar) throughout the year. However, saturation states are considerably lower in the bottom water layers, due to the prevalence of benthic remineralization processes in the stratification period. The seasonal changes of the chemical and environmental conditions and relatively small size of the Adriatic Sea area the microbial community composition, function (growth, enzymatic activity) and carbon and nitrogen biogeochemical cycles. Significant effects on calcifying organisms and phytoplankton are expected while the effects of possible OA on microbially-driven processes are not known yet.

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A scale-independent model for land-locked seas with application to the Messinian salinity crisis

10.5194/egusphere-egu2020-10494 ◽

2020 ◽

Author(s):

Paul Meijer

Keyword(s):

Mediterranean Sea ◽

Independent Solution ◽

Aegean Sea ◽

Basic Element ◽

Messinian Salinity Crisis ◽

Elevated Salinity ◽

Levantine Basin ◽

The Mediterranean ◽

Atmospheric Heat

While the Mediterranean Sea is, since the Middle Miocene, a nearly completely land-locked basin indeed, it is itself comprised of several smaller semi-enclosed seas. What the Mediterranean Sea as a whole is to the Atlantic Ocean, are the Adriatic Sea or Aegean Sea to the Ionian-Levantine basin, for example. In the discussions regarding the Messinian salinity crisis the marginal basins of the Mediterranean play a prominent role because it is from these parts that the sedimentary record has been uplifted and become exposed.In view of this and with an aim to contribute insight from the field of modelling, we focus on the basic element: a single marginal basin, subject to atmospheric forcing and exchanging water through a seaway with an adjacent larger basin. The equations are derived in dimensionless form and a universal, scale-independent, solution for basin salinity obtained. The analysis yields two dimensionless ratios which control basin behaviour in terms of salinity and response time.&#160;Application of the theoretical model to the Messinian salinity crisis sheds new light on the formation of gypsum in marginal basins that were separated from the main Mediterranean by a sill, gives insight about the role of atmospheric heat exchange, and underlines the previous finding that, at elevated salinity, marginal basins respond to periodic climate variation (e.g. due to precession) with a significant lag.

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Towards a unified framework for maximum wave computation from numerical models: outcomes from the LATEMAR project.

10.5194/egusphere-egu2020-13683 ◽

2020 ◽

Author(s):

Alvise Benetazzo ◽

Francesco Barbariol ◽

Paolo Pezzutto ◽

Luciana Bertotti ◽

Luigi Cavaleri ◽

...

Keyword(s):

Numerical Models ◽

Wave Spectrum ◽

Wave Model ◽

Ocean Waves ◽

Unified Framework ◽

Sea State ◽

Large Wave ◽

Wavewatch Iii ◽

Wave Models ◽

The Impact

Reliable prediction of oceanic waves during severe marine storms has always been foremost for offshore platform design, coastal activities, and navigation safety. Indeed, many damaging accidents and casualties during storms were ascribed to the impact with abnormal and unexpected waves. However, predicting extreme wave occurrence is a challenging task, at first, because of their inherent randomness, and because the observation of large ocean waves, of primary importance to assess theoretical and numerical models, is limited by the costs and risks of deployment during severe open-ocean sea-state conditions.In the context of the EU-based Copernicus Marine Environment Monitoring Service (CMEMS) evolution, the LATEMAR project (https://www.mercator-ocean.fr/en/portfolio/latemar/) aimed at improving the modelling of large wave events during marine storms. Indeed, at present, operational systems only provide average and peak wave parameters, with no information on individual waves whatsoever. However, developments of the state-of-the-art third-generation wave models demonstrated that using the directional wave spectrum moments into theoretical statistical models for wave extremes, forecasters are able to accurately infer the expected shape and likelihood of the maximum waves during storms.The main purpose of the activity is therefore to provide the wave models WAM and WAVEWATCH III with common procedures to explicitly estimate the maximum wave heights for each sea state. LATEMAR achieved this goal by: performing an extensive assessment of the model maximum waves using field observations collected from an oceanographic tower; comparing WAM and WAVEWATCH III maximum wave estimates in the Mediterranean Sea; investigating the sensitivity of the maximum waves on the main sea state parameters. All model developments and evaluations resulting from this research project will be directly applicable to the wave model forecasting systems to expand their catalogue.

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Stochastic bioeconomic modelling of alternative management measures for anchovy in the Mediterranean Sea

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq018 ◽

2010 ◽

Vol 67 (6) ◽

pp. 1291-1300 ◽

Cited By ~ 9

Author(s):

Christos D. Maravelias ◽

Richard Hillary ◽

John Haralabous ◽

Efthymia V. Tsitsika

Keyword(s):

Mediterranean Sea ◽

Aegean Sea ◽

Optimal Level ◽

Fishing Mortality ◽

Alternative Management ◽

Management Measures ◽

Bioeconomic Modelling ◽

The Mediterranean ◽

Age Structured

Abstract Maravelias, C. D., Hillary, R., Haralabous, J., and Tsitsika, E. V. 2010. Stochastic bioeconomic modelling of alternative management measures for anchovy in the Mediterranean Sea. – ICES Journal of Marine Science, 67: 1291–1300. The purse-seine fishery for anchovy in the Aegean Sea consists of two main fleet segments (12–24 and 24–40 m vessels); this paper investigates economically and biologically preferable effort and capacity scenarios for the fishery. Attention is paid to a bioeconomic analysis of fleets composed of segments with varying levels of efficiency (in terms of catch rate) and costs (fixed and variable) and the role this might play in optimal effort allocation at a fleet level. An age-structured stochastic bioeconomic operating model for Aegean anchovy (Engraulis encrasicolus) is constructed. It attempts to account robustly for the multiple uncertainties in the system, including (i) the effort–fishing mortality relationship, (ii) the selectivity, and (iii) the stock–recruit dynamics of the population. A method is proposed for determining the economically optimal level of long-term effort in a fishery such as this, with similar characteristics in terms of stock dynamics, fishery, and markets. Lower values of effort and capacity are predicted to yield greater future profit when viewing the fleet in its entirety, but even lower values may be advisable to maintain the long-term biological integrity of the stock. The results may prove useful in balancing the productivity of the stock with the harvesting capacity of the fleet, while managing to ensure the long-term profitability of the fleet along with the sustainability of the resource.

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The Propagation of Wind Errors Through Ocean Wave Hindcasts

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2828832 ◽

1996 ◽

Vol 118 (3) ◽

pp. 184-189 ◽

Cited By ~ 36

Author(s):

L. H. Holthuijsen ◽

N. Booij ◽

L. Bertotti

Keyword(s):

Sensitivity Analysis ◽

Mediterranean Sea ◽

Wind Field ◽

Ocean Wave ◽

Wind Analysis ◽

Wave Forecast ◽

The Mediterranean ◽

Field Errors

To estimate uncertainties in wave forecast and hindcasts, computations have been carried out for a location in the Mediterranean Sea using three different analyses of one historic wind field. These computations involve a systematic sensitivity analysis and estimated wind field errors. This technique enables a wave modeler to estimate such uncertainties in other forecasts and hindcasts if only one wind analysis is available.

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Case study of the winter 2013/2014 extreme wave events off the west coast of Ireland

Advances in Science and Research ◽

10.5194/asr-15-145-2018 ◽

2018 ◽

Vol 15 ◽

pp. 145-157 ◽

Cited By ~ 4

Author(s):

Jelena Janjić ◽

Sarah Gallagher ◽

Frédéric Dias

Keyword(s):

High Resolution ◽

Mesoscale Model ◽

Wave Model ◽

Horizontal Resolution ◽

Winter Storms ◽

Wavewatch Iii ◽

High Resolution Analysis ◽

Resolution Analysis ◽

Directional Wave

Abstract. Using the third generation WAVEWATCH III wave model in an unstructured formulation, and driven by HARMONIE-AROME mesoscale model hourly winds with a 2.5 km horizontal resolution, we reproduce the winter storms of 2013/2014 and analyse their effect on the western coastline of Ireland. WAVEWATCH III was forced at its ocean boundaries by directional wave spectra obtained from the ECMWF ERA-Interim re-analysis dataset. The wave model has a high resolution grid (up to 225 m resolution in the nearshore) with around 20 000 nodes, producing an abundance of important wave parameters outputted hourly, enabling a high quality, high-resolution analysis of the winter storms of 2013/2014.

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Gonioinfradens paucidentatus (A. Milne Edwards, 1861) (Crustacea, Decapoda, Portunidae): a new alien crab in the Mediterranean Sea

Mediterranean Marine Science ◽

10.12681/mms.80 ◽

2010 ◽

Vol 11 (2) ◽

pp. 331 ◽

Cited By ~ 6

Author(s):

M. CORSINI-FOKA ◽

M.A. PANCUCCI-PAPADOPOULOU ◽

G. KONDILATOS ◽

S. KALOGIROU

Keyword(s):

Mediterranean Sea ◽

Red Sea ◽

Aegean Sea ◽

First Record ◽

Swimming Crab ◽

The Mediterranean

The first record for the Mediterranean Sea of the Red Sea/Indo-Pacific portunid Gonioinfradens paucidentatus (red swimming crab) is documented. A detailed description of the specimens collected at Rodos Island (southeastern Aegean Sea) is given, while possible introduction vectors of the species in the area are discussed.

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