Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing

The Mediterranean Decision Support System for Marine Safety dedicated to oil slicks predictions

In the Mediterranean sea the risk from oil spill pollution is high due to the heavy traffic of merchant vessels for transporting oil and gas, especially after the recent enlargement of the Suez canal and to the increasing coastal and offshore installations related to the oil industry in general. The basic response to major oil spills includes different measures and equipment. However, in order to strengthen the maritime safety related to oil spill pollution in the Mediterranean and to assist the response agencies, a multi-model oil spill prediction service has been set up, known as MEDESS-4MS (Mediterranean Decision Support System for Marine Safety). The concept behind the MEDESS-4MS service is the integration of the existing national ocean forecasting systems in the region with the Copernicus Marine Environmental Monitoring Service (CMEMS) and their interconnection, through a dedicated network data repository, facilitating access to all these data and to the data from the oil spill monitoring platforms, including the satellite data ones, with the well established oil spill models in the region. The MEDESS-4MS offer a range of service scenarios, multi-model data access and interactive capabilities to suite the needs of REMPEC (Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea) and EMSA-CSN (European Maritime Safety Agency-CleanseaNet)

Impact of climate change scenarios in the Mediterranean Sea from a regional ocean model

Póster presentado en la 2012 General Assembly de la European Geosciences Union (EGU), celebrada del 22 al 27 de abril de 2012 en Viena (Austria)Peer Reviewe

Tropical cyclones over the Mediterranean Sea in climate change simulations

Tropical cyclones form only under specific environmental conditions. Anthropogenic climate change might alter the geographical areas where tropical cyclones can develop. Using an ensemble of regional climate models, we find an increase in the extremes of cyclone intensity over the Mediterranean Sea under a climate change scenario. At least for the most sensitive model, the increase in intensity is clearly associated with the formation of tropical cyclones. Previous studies did not find evidence of changes in the projected areas of formation of tropical cyclones ( Intergovernmental Panel on Climate Change, 2007; Walsh, 2004; Lionello et al., 2002). Those studies were based either on relatively low-resolution global climate models or on one particular regional climate model. The use of a multi-model ensemble of relatively high-resolution regional climate models has allowed us to detect for the first time a risk of tropical cyclone development over the Mediterranean Sea under future climate change conditions. [References: 23

Sensitivity of the Mediterranean sea level and thermohaline circulation to boundary forcings in an ensemble of 21st century climate change scenarios

Comunicación presentada en el 40th CIESM Congress (The Mediterranean Science Commission), celebrada del 28 de octubre al 1 de noviembre de 2013 en Marsella (Francia)We performed 21st century climate change scenario simulations with a Mediterranean regional ocean model in order to assess the sensitivity of changing Mediterranean water masses to boundary forcings. Our study aims to quantify the uncertainty linked to the choice of boundary conditions such as the Atlantic hydrography at the western margin, the river runoffs or the surface fluxes. We particularly focus on changes in mean sea level and thermohaline circulation. Results show that the near-Atlantic hydrographic changes have the strongest influence on the evolution of the Mediterranean water masses.Peer Reviewe

The MEDGIB experiment, a valuable data set to test the MYOCEAN system in the Strait of Gibraltar and Alboran Sea

47th International Liege Colloquium on Marine Environmental Monitoring, Modelling and Prediction, 4-8 May 2015, Liège, BelgiumThe Gibraltar Strait is a hot spot area of maritime traffic being the natural door for the shortest route between Asia and Europe. 1/6 of the global marine trade is passing by the Gibraltar Strait every year. From an oceanographic point of view, the Gibraltar Strait is a challenging place for any operational system because it is the natural connection between the Mediterranean basin circulation and the Atlantic Ocean. On September 2014 an intensive drifter deployment was carried out in the Gibraltar Strait to validate the European MYOCEAN operational system on the frame of MEDESS-4MS project. The experiment consisted on deploying 35 satellite tracked drifters, mostly of CODE type equipped with temperature sensor and at sampling rate of 30 minutes, distributed along the strait and on both sides of the Gibraltar strait. Particular attention was put to perform a spatially quasi-synoptic deployment by coordinating four boats covering an area of about 340 nmˆ2 in 6 h. Up to our knowledge, the obtained set of trajectories gives for the first time a comprehensive lagrangian view of the inflow of the Atlantic waters and their recirculation over the Alboran Sea constituting a valuable data set to validate the operational systems in such challenging area. We show results intercomparing the drifters trajectories against the MY-OCEAN IBI system, the VHF surface radar fields and the regional high resolution SAMPA system. Additionally we test how surface quasigeostrophic theory (SQG) can be a very useful diagnostic tool to obtain operational velocity fields from direct processing of SST imagesPeer Reviewe

The MEDESS-GIB database: tracking the Atlantic water inflow

On 9 September 2014, an intensive drifter deployment was carried out in the Strait of Gibraltar. In the frame of the MEDESS-4MS Project (EU MED Program), the MEDESS-GIB experiment consisted of the deployment of 35 satellite tracked drifters, mostly of CODE-type, equipped with temperature sensor sampling at a rate of 30 min. Drifters were distributed along and on both sides of the Strait of Gibraltar. The MEDESS-GIB deployment plan was designed as to ensure quasi-synoptic spatial coverage. To this end, four boats covering an area of about 680 NM² in 6 h were coordinated. As far as these authors know, this experiment is the most important exercise in the area in terms of number of drifters released. Collected satellite-tracked data along drifter trajectories have been quality controlled and processed to build the presented MEDESS-GIB database. This paper reports the MEDESS-GIB data set that comprises drifter trajectories, derived surface currents and in situ SST measurements collected along the buoys tracks. This series of data is available through the PANGAEA (Data Publisher for Earth and Environmental Science) repository, with the following <a href="http://dx.doi.org/10.1594/PANGAEA.853701" target="_blank">doi:10.1594/PANGAEA.853701</a>. Likewise, the MEDESS-GIB data will be incorporated as part of the Copernicus Marine historical products. The MEDESS-GIB data set provides a complete Lagrangian view of the surface inflow of Atlantic waters through the Strait of Gibraltar and thus, very useful data for further studies on the surface circulation patterns in the Alboran Sea, and their links with one of the most energetic Mediterranean Sea flows: the Algerian Current

The Mediterranean Decision Support System for Marine Safety dedicated to oil slicks predictions

In the Mediterranean sea the risk from oil spill pollution is high due to the heavy traffic of merchant vessels for transporting oil and gas, especially after the recent enlargement of the Suez canal and to the increasing coastal and offshore installations related to the oil industry in general. The basic response to major oil spills includes different measures and equipment. However, in order to strengthen the maritime safety related to oil spill pollution in the Mediterranean and to assist the response agencies, a multi-model oil spill prediction service has been set up, known as MEDESS-4MS (Mediterranean Decision Support System for Marine Safety). The concept behind the MEDESS-4MS service is the integration of the existing national ocean forecasting systems in the region with the Copernicus Marine Environmental Monitoring Service (CMEMS) and their interconnection, through a dedicated network data repository, facilitating access to all these data and to the data from the oil spill monitoring platforms, including the satellite data ones, with the well established oil spill models in the region. The MEDESS-4MS offer a range of service scenarios, multi-model data access and interactive capabilities to suite the needs of REMPEC (Regional Marine Pollution Emergency Response Centre for the Mediterranean Sea) and EMSA-CSN (European Maritime Safety Agency-CleanseaNet). © 2016 Elsevier Lt