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INTERNATIONAL FORUM

THE FRAGILITY OF THE MEDITERRANEAN ECOSYSTEM

A CONFLICT OF USES AND RESOURCES

VILANOVA I LA GELTRU, 12-13 MARCH 1997

PHYSICAL ASPECTS OF THE MEDITERRANEAN VERSUS INTEGRATED SUSTAINABLE COASTAL AND MARINE DEVELOPMENT

by D.S. Rosen, Israel Oceanographic & Limnological Research, Haifa, Israel, Chairman, Joint IOC/CIESM Group of Experts on MedGLOSS

ABSTRACT

This paper reviews the progress in physical oceanography in the Mediterranean and new plans for future physical studies of the Mediterranean, to provide information necessary for integrated sustainable coastal and marine development in this region. Details are given on the new pilot stage of the MedGLOSS Monitoring Network System for Systematic Sea-Level Measurements in the Mediterranean and Black Seas, and expected applications.

Introduction

The Mediterranean basin represents for millenniums, a major center of dense human habitat and activity. Present trends of coastal and marine development, like expansion or construction of new ports, marinas, cooling basins for power plants, offshore airports, artificial islands and the like on one hand, and sewage discharges into the sea, accelerated coastal erosion, sea level rise forecasts, ground water storage deterioration due to sea-water intrusion in coastal aquifers, increase in crude oil sea pollution hazard due to increased marine traffic, climate change impact on evaporation rates, storm patterns and sea-level rise, population growth and related pollution, etc. on the other hand, impose proper knowledge of the physical characteristics of the Mediterranean basin, as well as its neighboring seas to enable to develop correct criteria for integrated sustainable development of the area.

Any sea-level changes in the Mediterranean or in its companion, the Black Sea, as well as the water masses circulation and air-sea interaction processes taking place in this region are of utmost importance to the people living along the coasts of the Mediterranean and the Black Seas. Although the Mediterranean and the Black seas represent a relatively small size body when comparing their water volume to those of the oceans, effect of the sea-water exchange of the Mediterranean with the Atlantic Ocean has significance on the global scale. Furthermore, the water balance and exchange between the Mediterranean and its companion with the Red Sea through the Suez Canal and in particular with the Atlantic Ocean and with the atmosphere, can use as a “wave tank” scaled model for studies of world water exchange processes.

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In the following sections we will attempt first a review of the progress reached so far in the physical oceanography of the Mediterranean and future expectations for better understanding and forecasting of processes in the basin. Secondly we will review present trends of coastal and marine development in this basin with examples of existing and future projects along the coasts of the Mediterranean, their environmental impacts with guidelines for integrated sustainable development via building with Nature (the nowadays Dutch advocated method which was implemented already some 2,000 ago by King Herod’s roman engineers in the construction of the antic Caesarea Maritima port on the Mediterranean coast of Israel). Next the MedGLOSS international programme and its pilot monitoring network, innitiated jointly by the Intergovenmental Oceanographic Commission (IOC) of UNESCO and the Commision Internationale pour l’Exploration Scientifique de la Mer Mediterranee (CIESM) will be presented, together with expected outcomes of this program to the coastal states of the Mediterranean and Black seas. These should enable better planning of future coastal and marine short and long term development using integrated data analysis for better processes understanding, improved modelling tools and data, taking into account possible impact of forecasted climate change and sea-level rise. Finally, certain recommendations for integrated sustainable development will be presented.

Physical Oceanography of the Mediterranean The progress in understanding the physical oceanography of the Mediterranean can be considered a very latent process until this century, but since than it became a slowly accelerating process. If one remembers that the globe’s continents were once considered to be a layed on a plate (Hall et al.1994), on which until 1712 sailors wouldn’t sail knowingly beyond the horizon fearing to fall in the abyiss, or which until the beginning of this century wouldn’t sail in a steel made ship since steel is heavier than water, and thus it would sink (in spite of the some 5,000 years well known Archimedes principle), it is not so hard to understand why in the past the physical oceanography of the Mediterranean was not so well understood. Yet this is somewhat puzzling if one considers the excellent understanding of coastal processes for designing ports with water recirculation systems for unsilted entrances and pollution prevention, employed by roman engineers some 2,000 years ago (Raban et al.-1990). Only in recent years we became in the possession of a relatively decent bathymetric chart of the Mediterranean.

Perhaps the first to present a map of the circulation of the waters in the Mediterranean was Nielsen (1912) after a two years expedition in the Mediterranean. One may note that his description of the circulation between the Strait of Gibraltar and Strait of Sicilly is much more detailed and well described that that in the Eastern Mediterranean basin, where only a cyclonic circulation is depicted. Ovchinnikov and Fedoseyev (1965), following russian expeditions in the Eastern Mediterranean presented a much more complex circulation in this basin, including a number of the todays well known gyres, among them those of the Mersa-Matruh and Rhodes. Lacombe (1975), probably unaware of the russian work, presented a circulation map of the Mediterranean which until the beginning of the 80’s was considered the be best representation of the water mass exchange and circulation in the Mediterranean. Further inprovement in the understanding of the physical oceanography of the Mediterranean were achieved in the last 10 years with the start of international cooperation such as the experimental works of Hecht et al. (1988), Oszoy et al. (1989) and the application of numerical models (Anaty-1984). A significant progress in the understanding of the physical oceanography of the Mediterranean, including the water masses exchange in the Eastern Mediterranean with the formation of the Levantine Intermediate Waters (LIW) has been achieved by strengthening international cooperation via the UNEP Physical Oceanography of the Eastern Mediterranean (POEM) program (Robinson et al., 1991 and Malanotte-Rizzoli et al.,1994, 1995). Recent data gathered by a parallel russian Mediterranean study program is expected to futher advance this understanding.

Schott et al.(1994) indicate that recent observations within deep convection regimes of the Gulf of Lions and Greenland Sea all confirm the existence of small scale plumes of only a few hundredth meters horizontal scale during cooling periods. The integral effect of the plumes is that of a mixing

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agent, rather than carrying water downward in a mean motion. It depends on the intensity and duration of the cooling how complete the mixing within the depth range of the plumes is. The process defined as preconditioning for the occurance of mixing is explained as follows: “It was established that three factors combine to make Gulf of Lions a prefered site for deep convection: First, the stratification: The water column is basically three-layered, with warmer, less saline water of Atlantic origin on top, which is separated from the weakly stratified deep layer of Western Mediterranean Deeep Water (WMDW) by an intermediate salinity-maximum layer, the Levantine Intermediate Water (LIW) at about 200-500m depth. Second, the baroclinic circulation:The near-surface flow is cyclonic and leads to an uplifting of the isotherms, isohalines and isopycnals in an elongated dome. In the center of the dome, the LIW salinity maximum is brought into shallow enough depths to be exposed to mixed-layer entrainment. This is where the third factor comes in, the strong wind outbursts of the continental air in winter which cause the maximum of storm activity in the Mediterranean to be located over the northwestern part of the basin (Mistral and Tramontane). The important aspect for deep-convection is that the center of the isopycnal dome lies right in the path of both of these strong winds. The combination of these three factors: stratification, circulation and wind combine over the early winter months (November to January) in the so-called preconditioning phase to prepare the water column for subsequent deep convection. The development during the preconditioning phase is shown in Figure 3 (from the author’s publication). During the first part of winter the surface mixed layer on top of the dome is cooled (a). Combined effects of continued cooling and strong winds increase the mixed layer depth in the later part of the winter, leading to entrainment of higher salinity water out of the LIW layer upwards (b). The combined effects of further mixed-layer deepening and cooling lead to decrease the stability of the underlying weakly stratified sublayer, such that the cold air outbreaks in late winter can produce enough loss of buoyancy which leads to deep convection (c ). “ Garret(1994), refering to the flow process through the Strait of Gibraltar pointed out that the key issue is wheather the circulation in the Mediterranean is estuarine, with surface outflow trough the Strait of Gibraltar, or lagoonal, with surface inflow. According to him, at present the circulation is lagoonal, largely due to an excess of evaporation over precipitation and inputs of fresh water from rivers, but also due to a slight net cooling of the sea surface. Analysis of bottom sediments in the Eastern Mediterranean however has suggested that some 8,000 years ago the circulation was estuarine, presumably due to much higher rainfall. The present exchange through the Strait of Gibraltar, with the outflow being cooler and saltier than the inflow, suggests that the surface of the Mediterranean must be experiencing net cooling and evaporation if the heat and salt content of the sea are not changing significantly. The present outflow of salty water from the Mediterranean entrains enough Atlantic water to settle out at about 1,000 m in the North Atlantic. Some of it also flows north, and may enhance deep convection in the Norwegian-Greenland Sea and perhaps even influence global ocean circulation.

The complexity of the circulation in the Mediterranean was last described by the work of the POEM group after processing some of the data of the second phase of the POEM programm which included also parallel bio-chemical properties measurements (Malanotte-Rizzoli et al.-1996). The results enabled to obtain a complete time history picture of the water mixing processes, including the formation of a convective chimney in the Rhodes gyre during preconditioning, mixing and spreading phases.

Brenner (1997), developed over the past few years a numerical circulation model for the Levantine Basin of the Eastern Mediterranean. The purpose of the model is to provide first an advanced theoretical tool for studies and simulations of the circulation in the Eastern Mediterranean and secondly to serve as a basisfor operational ocean forecast system. The model employed is the Princeton Ocean Model (POM) which is now considered a state of the art of numerical circulation model. POM has been constantly evolving over the past 10-15 years and is being used as a research

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model by many groups arround the world. Its mathematical and computational schemes are described by Blumberg and Mellor (1987) as well as by others. Briefly it is a fully nonlinear, three dimensional, primitive euations model with an imbedded higher order turbulence closure scheme. The turbulence submodel allows for realistic simulation of vertical mixing in the surface mixed layer and the bottom boundary layer. It covers the entire Eastern Mediterranean east of 25 E, having a resolution of ¼ deg (for research and testing) and 1/8 deg (forecasting), with 21 sigma layers in the vertical dimension and using a bathymetry interpolated from the 5’ resolution US Navy data set. The models uses as initial conditions the idealized profiles of temperature and salinity or objectively analyzed fields of real data, and as surface forcing monthly mean climatological or daily synoptic wind stress and heat flux. It is expected that application of the model over all Mediterranean will be possible in the forthcoming years leading to short and long term forecasting capabilities. Another model application worth to mention is the WAM wave forrecasting model applied among many groups also by a number of Mediterranean bordering countries like Spain, Italy, Greece and Israel. Recently Gertman (1997) developed a new scheme for the application of the WAM model using direct inputs of wind pressure forcasts from Global Weather Model forecasts. The progress comes from the fast determination of wind fields over the model domain and boundaries, together with feed-back capabilities via near-real time wave field boundary conditions updating. Yet, this study is in the research phase with further improvement needed during the fast passage of fronts, when the simulations are less satisfactory when compared to ground-true data.

Coastal & Marine Integrated Sustainable Development As a heavily habitated environment, the Mediterranean is one of the world regions were coastal and marine development is a constantly accelerating activity. The implications of the so-called “greenhouse effect” of climate warming due to CO2 accumulation in the atmosphere as a result of the increased industrial development and deforestation, are climate change and sea-level rise on a global scale. These may separately and jointly adversly affect coastal and marine developments by inducing shift of storm tracks and strengths which may lead to changes in directions of wave approaches consequently leading possibly to desequilibrium of coastal sediment transport regimes and hence acceleration of erosion rates, changes in the evaporation and river discharges and aquifers salination and ultimately to population shifting especially in low-lying coastal areas like river deltas. Over these, one may add the natural shift of tectonic plates which in conbination with the above may lead to more significant relative sea-level vertical changes, beyond those estimated under the “most probable scenario” assumption on a world wide average scale by the IPCC (1992) of some +20 cm in 2030 and some +50 cm to +70 cm in 2100. To this indirect antropogenic activity one can add the direct impact of coastal and marine developments along the borders of the Mediterranean, which may lead to almost non-reversible environmental impacts. Such one we may quote to be the resulting Nile delta erosion after the completion of the High Aswan Dam (1964) in Egypt, due to cesation of sand feeding to the Mediterranean coast of Egypt which as a consequence, led to significant recesion of the Nile delta coast. Another example of antropogenic coastal impact is the construction of the port of Ashdod on the Mediterranean coast of Israel, which presently extends to -15 m contour line. During its life (32 years) it blocked the passage of some 4.5 million cubic meters of sand, yet only about 50% of the total net longshore transport in this period. Beach mining until 1965 in Israel for construction purposes (mainly concrete), led to further deterioration of the sand transport equilibrium on the northern part of the beaches of Israel. Recent archaeological findings in the nearshore zone and inner continental shelf of Israel, confirmed what was suspected for quite some time, that the Israeli coastline is in a negative sedimentological balance. Fragile items such as human skeletons from the Neolithic, found on the sea

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bottom at 8 m water depth, or a 2,000 year old merchant boat with all its merchandise intact, found in the surf zone, could not have survived for such a long period of time, had they not been protected by a thick layer of sand. These and other findings were possible due to the removal of the protective thick sand layer, which has not been replaced by other sand, thus indicating the present negative sedimentological balance. Further coastal development like marinas, stilling basins for cooling water at power stations and the like further affected the coastal morphologic regime, each trapping a certain amount from the longshore sediment transport. Similar sand beach mining in Lebanon left the beaches there mostly denuded of sand, with only few sandy beach pockets. Also many of the European coasts of the Mediterranean suffer of similar coastal erosion. On the other hand, the pressures on land reclamation from the sea, both as coastal developments and as offshore developments are expected to increase. During the Ocean Cities congress in November 1995 in Monaco, many offshore development plans were presented. Among those one may quote offshore floating island cities, deep-water on piles island off Monaco, fill islands off Israels coast, etc. All these indicate that the utilization of the nearshore coastal and marine environment for reclamation is a growing trend. We may quote such reclamation for the construction of the Nice airport in France, yet not very large when compared to the construction of over 80 islands in Japan, including the Kansai airport in the Osaka bay, as well as the new offshore airports at Hong-Kong and at Seoul. Also the Spanish coast, inclusive that of the Mediterranean passed in recent years a significant face uplifting by artificial sand nourishment of its denuded coasts. However such a positive activity is not always possible if suitable sources of sand can not be found at a reasonable cost. Israel’s Ashdod port is planned to be expanded soon reaching at the entrance a water depth of more than 20 m, its main breakwater cutting probably almost completely the longshore sand transport, and in particular the coarse fraction which protects the beach face. Consequently it is foreseen that together with its expansion, a sand by-passing mechanical or hydraulic system will have to be adopted to prevent further adverse impact to the beaches north to it. A proposed series of offshore islands vis-avis the Tel-Aviv and northern coasts of Israel in relatively shallow waters (-10 m to -24m), in order to answer the future needs for near-sea land resources due to the fast growing rate of Israel’s population in the coastal region, are too expected to trap sand by the same process of sheltering and spit formation known at detached breakwaters parallel to the shore. In such a case, sand by-passing will be again a must. A similar scenario is forecasted for the development of the port of Gaza, located into an even higher net rate of longshore sediment transport in the Nile littoral cell. These coasts and other along the Mediterranean may face problems to find suitable sand for reclamation or nourishment purposes. For example, in Israel reasonable price land based sand sources for construction are due within a few years, possible other sources contemplated now being sand import from Jordan or from Egypt’s Sinai dunes (if suitable size and affordable prices will be determined) as well as deep sea mining beyond the active coastal sediment transport zone (beyond -30 m). The author (Rosen-1996) proposed an alternative coastal reclamation scheme to the islands scheme based on integrated sustainable coastal development, via building with nature. According to this scheme, when needed, coastal reclamation will be performed by construction of peninsulas protected at their offshore side (-30m, some 2.5 km offshore) by shore parallel breakwaters. Keeping a distance of about 12 to 15 km between adjacent peninsulas heads, would create bay shaped beaches, which as is well known, when laying between headlands generate stable beaches, in morpho-dynamic and sedimentologic equilibrium, requiring only an initial sand nourishment to the final shape scheme. The development would start from the northern end of the Nile littoral cell, to enable meanwhile undisturbed longshore net transport, till such land needs would arive. In this way, some 6 to 8 peninsulas can be built along this coastal stretch. Such principle can be adopted for other coasts of the Mediterranean.

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Other aspects to be considered in regards to coastal and marine development are sewage discharges into the sea, development of intensive mariculture in open-sea fish cages, the ground water storage deterioration, induced by sea-level rise and corresponding sea-water intrusion in coastal aquifers, increase in crude oil sea pollution hazard due to increased marine traffic. All these impose proper knowledge of the physical characteristics of the Mediterranean basin, as well as its neighboring seas to enable to develop correct criteria for integrated sustainable development of the area. Recognizing the potential threat of the predicted climatic change and sea-level rise and the accelerating coastal and marine development in the Mediterranean, the Oceans and Coastal Areas Programme Activity Centre of the Uited Nations Environment Programe (UNEP), in cooperation with the Intergovernmental Oceanographic Commission (IOC) of UNESCO, started by the end of 1987 a systematic study of the likely impacts of climatic changes, setting up teams for 11 regions, one of them dedicated to the Mediteranean environment. In a series of four generations of case studies of the coasts of the Mediterranean (the 4th being implemented now), 19 coastal sectors have been placed in the focus of intensive coastal research and analysis (Jeftic et al.-1996). The overall objectives of the studies were determined to be : (a) identification and assessment of possible climate change on natural and antropogenic terestrial, aquatic and marine systems; population, including public health and demographic changes; land and sea utilization practices; coastal structures; and economic activities and development plans, (b) determination of the most vulnerable areas, systems and activities likely to be affected, and ( c) propose suitable policies and preventing measures to reduce, avoid or enable to adapt to the negative foreseen effects of the forecasted impacts by appropriate changes in planning and management of coastal areas and resources. As a result of this ongoing effort, the major potential impacts in each study sector were identified. Beyond the site specific effects, general impacts determined have been increased coastal erosion, potential damage to coastal structures, reduced soil fertility and increased salinity penetration and innundation of low lying areas like deltas and estuaries. Among the recent outcomes of the studies performed is the need for changes to codes and standards such as those covering construction and engineering works and the necessity to include the identified potential impacts in the planning and decision making process of future planning and management plans of the coastal and marine areas and resources. In short, they call for an integrated sustainable development and management of the coastal and marine resources and activities. Such a management policy has been adopted in Israel since the late 80’s by the enforcement of the performance of environmental impact statements (EIS) for any major coastal or marine development or activity. For all such cases detailed studies are conducted, based on newly gathered data for a sufficient duration if existing data are considered inadequate, including the application of modern modelling physical and numerical tools and integrated sustainable coastal and marine zone management principles. MedGLOSS As mentioned previously, a worldwide eustatic sea-level rise due to the “greenhouse effect” has been forecasted by the WMO/UNEP Intergovernmental Panel on Climate Change (IPCC). Those are due to global warming, leading to water volume expansion as the major component and ice cap melting as the secondary one. However, the report authors also recognized that regional sea-level rise may differ significantly from the globally averaged sea-level rise forecasts, in particular due to tectonic movements, meaning that relative sea-level changes may be as important or even more than those of the absolute sea-level. Responding to these forecasts, a worldwide sea-level monitoring network named Global Sea-Level Observing System (GLOSS), itself a component of the Global Ocean Observing System (GOOS), was initiated by the IOC of UNESCO in 1985. The network emphasized its global character by selecting some 300 sites as major sea-level monitoring stations, most of them along the coasts of oceans and a few along those of marginal seas. The GLOSS network is planned to be readjusted this year (1997), according to new recommendations by the IOC Group of Experts on GLOSS. Regional subsets of GLOSS will be used as cores of regional densified subset networks, consisting of GLOSS stations densified by additional regional stations which can provide GLOSS quality sea-level data, and which will strengthen data reliability, fill data gaps at neighboring stations

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and add boundary conditions information for regional studies of regional sea-level changes, water circulation and air-sea interaction processes. Recognizing the importance of the subject for the region, as well as its capability to serve as a model for the world-wide processes, the IOC and the Commission Internationale pour l’Exploration Scientifique de la mer Mediterranee (CIESM), have agreed in 1996 to jointly cooperate in the study of this important subject by establishing a long-term monitoring network system for systematic sea-level measurements in the Mediterranean and Black Seas. The system, named MedGLOSS (Mediterranean GLOSS subsystem), a monitoring network system for systematic measurements in the Mediterranean and Black Seas, will be developed by applying basic GLOSS requirements and methodology, aiming to provide high-quality standardized data, which can then be directly applied for the various regional and world-wide studies.

A preliminary expert workshop on MedGLOSS was held jointly by CIESM and IOC at CIESM headquarters in Monaco in February 1996. In the summer of 1996 a Memorandum of Understanding was signed between the Director General of CIESM, Prof. Frederic Briand, and the Secretary of IOC, Dr. Gunnar Kulenberg, establishing also a Joint Group of Experts on the MedGLOSS programme, composed of Prof. Suzanna Zerbini (Italy), Mr. Pierre-Yves Le Traon (France), Cdr. M. Emin Ayhan (Turkey) and Mr. Dov S. Rosen (Israel). Later on the author was appointed chairman of this group. Following the recommendations of the Joint Group of Experts on MedGLOSS, at their 1st session on 20-21 January 1997 at the IOC/UNESCO headquarters in Paris, it was decided to start MedGLOSS by launching a pilot network monitoring system. The pilot network would include some 27 stations in 13 countries which have already expressed their interest in joining this international research network. Inclusion of additional stations/countries to the pilot phase by other countries may be considered if they answer the requirements of the pilot stations.

Scope and Objectives of MedGLOSS

Besides meeting the needs of GLOSS and GOOS in general, MedGLOSS aims to meet the demands on regional, sub-regional and national scales. The strategy adopted is to develop a sea-level monitoring network which serves both national and international needs in the perspective of priorities having a Mediterranean/Black Seas wide dimension. In order to ensure network functionality and efficient control on the data gathering, management and transfer mechanisms, five future sub-regions have been identified for the full MedGLOSS network: Western Mediterranean, Adriatic Sea, Central Mediterranean, Eastern Mediterranean and Black Sea. Operational activities envisaged within MedGLOSS are use the of satellite altimetry, assimilation of data in numerical models for weather, rain and ocean forecasting, and establishment of warning mechanisms in vulnerable areas. The following MedGLOSS task were defined:

1. The major task of MedGLOSS is to detect regional long-term relative and absolute sea-level changes trends and acceleration rates, as well as to determine plate tectonic movements in the domain affecting them by the creation of a densified regional long-term sea-level monitoring network in the Mediterranean and Black Seas. The high quality, standardized data gathered by the network will facilitate the performance of regional studies regarding sea-level rise, water exchange and tectonic movements.

2. The regional network will be composed from sea-level monitoring stations already active in the GLOSS strengthened by additional sea-level stations operational in a number of countries around the borders of the Mediterranean and Black Seas, and by new sea-level stations to be installed on the coasts of countries willing to join the MedGLOSS network. Both quasi on-line operating stations and off-line operating stations will be accepted into the network. MedGLOSS will determine priorities, promote and assist suitable stations to upgrade from off-line to quasi on-line status.

3. Due to the relatively small tidal range in the Mediterranean and Black Seas, the determination of long-term trends in sea-level changes at the coastal stations is masked by seasonal and other

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climatic fluctuations such as the steric effect (volumetric change due to sea-water temperature), wind induced set-up, wave induced super-elevation, atmospheric pressure, general circulation, land subsidence or rise due to glacial rebound or overuse of groundwater, etc. To be able to remove the influences of these factors and obtain the sea-level fluctuations, it is also of utmost importance to perform long-term monitoring of the fluctuations of the atmospheric pressure, sea-water temperature, wave height, period and direction, wind speed and direction, current speed and direction, with equipment leading to the same degree of accuracy and resolution in the determination of their contribution to the sea-level as that of the equipment measuring the sea-level. Hence, new sea-level monitoring stations and upgraded existing monitoring stations should include equipment for the parallel measurement of atmospheric pressure and sea-level data. Parallel measurement of additional parameters such as waves, currents, wind, sea-water temperature and salinity (conductivity) are also recommended. Hourly representative values would be appropriate for comparison against monitored sea-levels and atmospheric pressure, for use in regional/all basin air-sea interaction and water circulation studies, as well as for operational oceanography. By this they can significantly strengthen four up of the five GOOS purposes: (a) Climate monitoring, assessment and prediction; (b) Monitoring of coastal zone environment and its changes; (c) Assessment and prediction of the health of the ocean; and (d) Marine meteorological and oceanographic operational services.

4. Data gathered by the MedGLOSS network will be transmitted for quality control, processing and further dissemination and publication to five regional centers. To enable quick availability of the regional sea-level data, a quasi real-time monitoring network system will be adopted, using a software package of quasi real-time sea-level monitoring and transmission system. Data from off-line stations will be transferred periodically every 2 months to the regional centers. Minimum data to be accepted from the off-line stations will consist of diurnal maxima and minima and their times of occurrence, referred to Universal Time (GMT), although preferable data would consist of hourly or even higher rate of recording data.

5. The regional centers will review the data received from the monitoring stations, process and analyze them, inform of suspicious malfunctioning to national coordinators and station operators, and disseminate the results to the national coordinators, to the Permnent Service for Mean Sea-Level (PSMSL) and GLOSS centers. Space altimetry sea-level data regarding the Mediterranean and Black Seas will also be provided to the five regional centers for combined analyses of the sea-level data, the results of which will also be made available to the MedGLOSS members as well as to PSMSL and GLOSS.

6. Thorough monitoring of tectonic movements of the land-based benchmarks of sea-level monitoring stations must be conducted, as well as tying the elevations between the land-based benchmarks and the sea-level sensors. Regional centers will coordinate missions of Global Positioning System (GPS) measurements for Geocentric Coordinates determination and updating every 2 years of the Sea-Level Benchmarks (SLBM) and for selected sites missions of absolute gravimetry measurements to determine rates and accelerations of land movements at the sea-level monitoring stations. The regional centers will also provide assistance in rescue and compilation of historical data.

7. Under joint IOC/UNESCO and CIESM managing board of MedGLOSS, the regional centers will be responsible for providing assistance, education and training in accordance with the GLOSS-V implementation plan TEMA (Training, Education and Mutual Assistance) as follows:

consultation in purchasing and possibly a provision of gauge instruments and spare parts; assistance in site selection for new MedGLOSS stations and upgrading existing stations; assistance in the installation of gauges, in training technicians to maintain the gauges, and

specialists to make maximum local use of the gauge data; assistance in training in the use and applications of new sea level-related technologies (GPS,

altimetry etc.);

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promote/support attendance at relevant regional and international workshops, training courses, etc. provision of training materials and other documents related to MedGLOSS, prepared with the

assistance of IOC and CIESM; provision of sea-level data sets and a wide range of other suitable products.

Funds for these tasks would come from both MedGLOSS allocation via IOC and CIESM cooperation agreement on MedGLOSS as well as by a voluntary co-operation programme of the member countries joining MedGLOSS.

MedGLOSS will first concentrate to eliminate scientific and political barriers for the establishment of a strong platform for its network. The fact that CIESM envelopes amongst its Member States nearly all the countries of the Basin certainly favors initiatives such as MedGLOSS which depend directly on their geographical span for successful implementation. In its initial phase, MedGLOSS will focus on building a structure that will benefit from existing national initiatives, providing scope for mutual support and coordinating individual efforts in synergy with plans for a future regional role.

To achieve its scientific objectives, MedGLOSS will promote transfer of knowledge and equipment from the more technologically advanced Euro-Mediterranean neighbors to the less advanced countries in closer proximity, on the coasts of the North-African and South-Eastern Mediterranean and Black Seas, for a strengthened and concrete “cooperation-through-participation” scheme. A strong training component is essential both as a means of providing a visible gain to the participating countries as well as a sound investment towards ensuring high-quality data in the network. Initially, training will focus on overall knowledge and up-dating on methods and state-of-the-art

equipment for precise water level recording, maintenance of high standards of data acquisition and processing, optimal station maintenance, bench mark leveling and reference,and optimal data archiving.

In a second training stage, training will be directed specifically to data interpretation and assimilation of sea-level products into feasibility studies, marine modeling/forecasting and coastal environmental assessments.

In both stages, adequate manuals will be made available to trainees in order to achieve a common basis for standardized and precise sea-level data measurements. These include, initially, IOC’s manuals and guidelines on sea-level measurements, and then additional software and manuals, to be prepared by the Joint Group of Experts, as determined necessary thereafter.

Launching of the Pilot Phase of MedGLOSS Network

The network will start by a pilot phase including a carefully selected number of about 27 sea-level monitoring stations located in 13 countries along the coastlines of the Mediterranean and Black Seas which already expressed their interest in joining MedGLOSS. The network is intended to become operational and provide initial useful results within the next 12 months, to serve as a model to the countries along the coasts of the Mediterranean and Black Seas, with respect to the attributes and gains expected from all Mediterranean and Black Sea countries joining the MedGLOSS. The pilot network will include the 5 GLOSS sea-level monitoring stations available in the basin area, and a limited number of sea-level monitoring stations located in those countries which already expressed their interest in joining MedGLOSS.

The pilot plan calls for a minimum of two visits of GPS missions and gravimetry at all sites, of which a limited number is planned to become permanent stations, daily transmitting to IGS.

The requirements regarding equipment at the pilot sea-level monitoring stations include the following capabilities: sea-level monitoring equipment with digital output for logging on a PC computer (386DX with

4Mbyte memory, 420Mbyte hard disk, 31/2” floppy drive and monochrome screen - minimum). minimum sea-level measurement accuracy 1cm, minimum resolution 1cm.

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atmospheric barometer with RS-232 digital output, range 800-1100 mbar, minimum accuracy 0.02% of full scale.

Availability of a storage housing near the benchmark, preferably with electricity and telephone line. Commitment to provide long-term maintenance of the sea-level monitoring station, the benchmarks

and data transfer to the MedGLOSS network. The following stations were selected for inclusion, on a provisory basis, to become permanent after commitment confirmation from the scientists operating the respective sites. They are listed in a clockwise survey along the coasts of the Mediterranean and Black Seas, starting from Gibraltar.

LIST OF SELECTED STATIONS FOR THE MedGLOSS PILOT NETWORK Station

No. Station Name State Present

status Past Data

Since Sea Level

Sensor Type

Digital Data

GPS plans

1 Gibraltar U.K. GLOSS 1961 visit 2 Alicante Spain 1916 fix 3 Palma Spain 1964 visit 4 Marseille France GLOSS 1885 visit 5 Genoa Italy 1884 fix 6 Naples Italy 1899 visit 7 Catania Italy 1960 fix 8 Brindisi Italy visit 9 Trieste Italy 1905 visit 10 Split Croatia 1954 visit 11 Dubrovnik Croatia 1956 fix 12 Preveza Greece 1975 Float visit 13 Kalamata Greece 1936 Float visit 14 Piraieuss Greece 1933 Float visit 15 Soudhas Greece 1973 Float fix 16 Rodhos Greece 1981 Float visit 17 Burgas Bulgaria visit 18 Katsively Ukraine visit 19 Tuapse Russia GLOSS 1917 fix 20 Erdek Turkey 1985 Float visit 21 Mentes Turkey 1986 Float visit 22 Bodrum Turkey 1986 Float visit 23 Antalya Turkey 1986 Float visit 24 Hadera Israel GLOSS 1993 (1958) Pressure yes fix 25 Alexandria Egypt 1958 visit 26 Mellieha Bay Malta 1990 Pressure yes visit 27 Ceuta Spain GLOSS 1944 visit

It was decided that all stations which will join the pilot network will submit daily the measured data via telephone with the aid of the ISRAMAR data gathering/communication and presentation software package developed by the author at the Israel Oceanographic & Limnological Research (IOLR), after software input format and modem characteristics adjustment for each station. The sea-level data will be gathered by daily downloading of hourly sea-level, atmospheric pressure and other data available, to a temporary regional center at IOLR-Israel under the supervision of D. Rosen. After data quality verification, these data will be processed on a basin scale and provided to the participants via File Transfer Protocol (FTP) on the Internet. The geodetic data (GPS & absolute gravimetry) will be submitted to a temporary regional center at the Dept. of Physics, Univ. of Bologna, Italy, under the supervision of S. Zerbini. Satellite altimetry will be received and processed at the CNES/CNRS, Toulouse, France under the supervision of Y-P. Le Traon, who will provide sea-level via satellite altimetry derived data to the participating countries via Internet. The outcome of the data processing

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and applications will be jointly presented at the forthcoming CIESM Congress in Dubrovnik in June 1998. At that time all Mediterranean and Black Seas bordering countries will be invited to join the MedGLOSS network. Expected outcomes of the MedGLOSS pilot network would be rates of tectonic movements, seasonal maps of relative sea-levels and relative sea-level changes based on ground-true and satellite altimetry, and other wave and circulation maps based on preliminary application of the gathered data in regional numerical models. Among those the use of the POM and WAM models are considered for general Mediterranean and Black seas application on a “hot model” basis.

Conclusions

The Mediterranean environment is expected to undergo an accelerated process of coastal and marine development one one hand, and be affected by climatic change and possible relative sea-level change on the other hand. To preserve this environment for the future generations in a reasonable status of utilization, namely to provide for a sustainable integrated development and resources utilization, it is necessary (a) to strengthen the research eforts regarding the assessment of future changes via monitoring of the environment and comprehensive regional studies and (b) the implement integrated sustainable development and coastal and marine management principles and guidelines. Among those, cooperation on the international and regional level between countries and their research and policy making authorities are considered an unconditional activity.

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Bethoux J. P., and Gentili B., 1994, “The Mediterranean Sea, A Test Area For Marine And Climatic Interactions”, in Malanotte-Rizzoli P. and Robinson A. R. (eds.), Ocean Processesin Climate Dynamics: Global and Mediterranean Examples, pp.239-254, KluverAcademic Publishers, Netherlands.

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Gertman I., 1997, “Application of the WAM Model for the Mediterranean Using Pressure Determined Wind Fields”, IOLR (in preparation).

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Ovchinnikov I. M., and Fedoseyev A. F., 1965, “The Horizontal Circulation of the Water of the Mediterranean Sea during the Summer and Winter Seasons” in Basic Features of the Geological Structure, Hydrological Regime and Biology of the Mediterranean, L.M. Fomin (ed.), Translation by the Institute for Modern Languages of the USN Oceanography Office, pp.185-201.

Robinson A. R., Golnaraghi M., Leslie W. G., Artegiani A., Hecht A., Lazzoni E., Michelato A., Sansone E., Theocharis A., and Unluata U., 1991, “The Eastern Mediterranean General Circulation: Features, Structure and Variability”, Dynamics of Atmospheres and Oceans, Vol. 15, pp.215-240.

Robinson A. R., and Golnaraghi M., 1994, “The Physical and Dynamical Oceanography of the Mediterranean Sea”, in Malanotte-Rizzoli P. and Robinson A. R. (eds.), Ocean Processesin Climate Dynamics: Global and Mediterranean Examples, pp.255-306, KluverAcademic Publishers, Netherlands.

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Rosen D.S., Radomir M., and Harari P. 1996, "Field Monitoring of Wave Transformation at Haifa Port Versus Numerical Computations", Abstracts 25th Intl. Conf. on Coastal Engineering, Orlando, USA, September 1996, ASCE.

Rosen D. S., 1997, “Launching of the Pilot Phase of MedGLOSS Network, Outcome of 1st Meeting of the Joint IOC/CIESM Group of Experts onMedGLOSS”, Intergovernmental Oceanographic Commission, UNESCO, (in print), 7pp.

Rozentraub Z., 1997, “Current Measurements and Current Profile off the Mediterranean Shelf of Israel Using a Ship-Mounted Accoustic Doppler Current Profiler ”, IOLR., (in preparation).

Schott F., Visbeck M., and Send U., 1994, “Open Ocean Deep Convection, Mediterranean and Greenland Seas”, in Malanotte-Rizzoli P. and Robinson A. R. (eds.), Ocean Processes in Climate Dynamics: Global and Mediterranean Examples, pp.203-225, KluverAcademic Publishers, Netherlands.

Zerbini S., Plag H-P., Baker T., Becker M., Billiris H., Burki B., Kahle H-G., Marson I., Pezzoli L., Richter B., Romagnoli C., Sztobryn M., Tomasi P., Tsimplis M., Veis G., Verrone G., 1996, “Sea-Level in the Mediterranean: A First Step Towards Separating Crustal Movements and Absolute Sea-Level Variations”, Global and Planetary Change, A daughter Journal of Palaeogeography, Palaeoclimatology, Palaeoecology, Elsevier Science, Vol. 14, pp.1-48.

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Figure 1 - Ancient maps (from Hall et al.-1994)

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Figure 2 - Old models of the circulation in the Mediterranean

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Figure 3 - Schematic of preconditioning (from Schott et al. -1996)

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Figure 4 - Example of WAM simulation (from Gertman-1997)

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Figure 5 - Example of simulation outcome with POM (from Brenner-1997)

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Figure 6 - Location of stations for MedGLOSS pilot network