Climate change scenario of Mediterranean sea level: a multi-component regional climate modelling approach

Major destination for international tourism, characterized by growing immigration, the coasts of the Mediterranean Basin are highly vulnerable to rising sea levels and therefore closely monitored. However, numerical climate simulations do not agree on future sea-level elevation. “They examine global geophysical effects but are unable to accurately describe the local processes that affect water masses – and therefore sea level,” explained Dr. Adloff. To bridge this gap, she is participating in developing a new regional ocean model which incorporates all factors that contribute to the variations in Mediterranean sea level, such as water exchange through the Strait of Gibraltar and atmospheric circulation. This type of model, combined with studies on coastal erosion in particular, will contribute to mapping areas at risk for the decades to come. There is thus an imperative need to use high resolution regional climate modelling to answer the question of ongoing Mediterranean sea level change.Up to now, any regional climate model does represent all the above-mentioned processes acting on sea level variations in the Mediterranean. The effects from the global ocean, the atmospheric pressure and the global steric component are missing. We propose to fill this lack and simulate the future climate of the Mediterranean region through a high resolution multi-component regional climate modelling approach, including all the above-mentioned missing processes.
Mediterranean sea level is influenced by various complex processes such as mass fluctuations, variation in the density structure (steric effect), changes in circulation, waves, atmospheric pressure variations and changes of the hydrographic conditions of incoming Atlantic water.So far, the question about future sea level change in the Mediterranean remains open. The resolution of global models from the IPCC do not allow the representation of small scales processes acting over the Mediterranean region, which are important to get the water masses of the basin well-represented, the latter's being a basic prerequisite to achieve a good sea level representation in the model. Additionally, the water exchange at Gibraltar is often parameterized, although its variations strongly influence the circulation and the changes in sea level in the Mediterranean Sea.