On the wind driven circulation of the Mediterranean Sea

The Mediterranean circulation appears to be the result of three principal forcing factors: the inflow/outflow at Gibraltar strait, the wind stress applied on the ocean surface and the buoyancy fluxes. In this thesis, the focus is on studying the role of the wind in the ocean circulation. Sub-basin scale gyres are driven in different proportions by winds and heat fluxes (Pinardi and Navarra, 1993; Zavatarelli and Mellor, 1995; Roussenov et al., 1995) and locked or modified by topography. Generally the large scale basin circulation is characterized by cyclonic gyres in the northern regions, and by an anticyclonic gyres and eddy-dominated flow fields in its southern parts, with the exception of the Tyrrhenian and the northern Ionian Sea (Pinardi et al., 2015). The decadal variability of the Mediterranean Sea shows a reversal of the current in the Ionian Sea called Northern Ionian Reversal (NIR; Pinardi et al., 2015) and can be connected to changes in the wind stress. To assess the role of the wind stress in Mediterranean circulation and on the NIR phenomenon, Perpetual Year (PY) experiments are carried out with the NEMO ocean model implemented on the SURF model platform (SURF; Trotta et al., 2015). Sensitivity experiments are performed on the physics of the model and on the wind forcing evaluating the relation between the wind stress and the Mediterranean upper circulation. A diagnostic study of the NIR phenomenon is carried through the NIR index. The NIR index uses the difference of the SSH at two points to evaluate the prevailing circulation in the northern Ionian sea. Positive values of the index are connected to anticyclonic circulation, while negative values are related to cyclonic circulation. SSH field from Reanalysis, model output and SLA Satellite observations are analysed and compared. Studies agree in setting the time of the surface reversal to 1997 and this is confirmed by the change of the NIR index sign, both in Reanalysis and Observations

Coastal modelling studies for forecasting and remediation solutions

The coastal area along the Emilia-Romagna (ER), in the Italian side of the northern Adriatic Sea, is considered to implement an unstructured numerical ocean model with the aim to develop innovative tools for the coastal management and a forecasting system for the storm surge risk reduction. The Adriatic Sea has been the focus of several studies because of its peculiar dynamics driven by many forcings acting at basin and local scales. The ER coast is particularly exposed to storm surge events. In particular conditions, winds, tides and seicehs may combine and contribute to the flooding of the coastal area. The global sea level rise expected in the next decades will increase even more the hazard along the ER and Adriatic coast. Reliable Adriatic and Mediterranean scale numerical ocean models are now available to allow the dynamical downscaling of very high-resolution models in limited coastal areas. In this work the numerical ocean model SHYFEM is implemented in the Goro lagoon (named GOLFEM) and along the ER coast (ShyfER) to test innovative solutions against sea related coastal hazards. GOLFEM was succesfully applied to analyze the Goro lagoon dynamics and to assess the dynamical effects of human interventions through the analysis of what-if scenarios. The assessment of storm surge hazard in the Goro lagoon was carried out through the development of an ensemble storm surge forecasting system with GOLFEM using forcing from different operational meteorological and ocean models showing the fundamental importance of the boundary conditions. The ShyfER domain is used to investigate innovative solutions against storm surge related hazard along the ER coast. The seagrass is assessed as a nature-based solution (NBS) for coastal protection under present and future climate conditions. The results show negligible effects on sea level but sensible effects in reducing bottom current velocity

A modeling application of integrated nature based solutions (NBS) for coastal erosion and flooding mitigation in the Emilia-Romagna coastline (Northeast Italy)

Worldwide, climate change adaptation in coastal areas is a growing challenge. The most common solutions such as seawalls and breakwaters are expensive and often lead to unexpected disastrous effects on the neighboring unprotected areas. In recent years, this awareness has guided coastal managers to adopt alternative solutions with lower environmental impact to protect coastal areas, defined as Nature-Based Solutions (NBSs). NBS are quite popular around the world but are often analyzed and implemented individually at pilot sites. This contribution analyzes the effectiveness of two NBS to mitigate coastal impacts (coastal flooding and erosion) under three historical storms along the EmiliaRomagna coasts and the induced improvements due to their potential integration. Through numerical simulations with XBeach, this study demonstrated that the presence of seagrass meadows of Zostera marina produces an average attenuation of 32 % of the storm peak with a maximum attenuation of 89 % in incoming wave height. Seagrass also mitigates flooded areas and maximum inundation depths by 37 % and 58 % respectively. The artificial dune leads to higher mitigation in terms of inundation of the lagoon (up to 75 %), also avoiding any morphological variations behind it. Seagrass has also been shown to be able to reduce beach erosion volumes up to 55 %. The synergic effect of the two NBS improves the capacity to mitigate both inundation (with a benefit of up to 77 % for flooded area attenuation with respect to cases without any defenses) and coastal erosion. Results of the study suggest that the two NBS will work together to produce co-benefits in terms of preservation of their efficiency, development of habitats for organisms and vegetation species, and thereby offering an important social value in terms of possible tourism, recreation and research

Cardiovascular evaluation, including resting and exercise electrocardiography, before participation in competitive sports: cross sectional study

Objective To evaluate the clinical usefulness of complete preparticipation cardiovascular screening in a large cohort of sports participants

Projected climate oligotrophication of the Adriatic marine ecosystems

The Adriatic Sea hosts diverse marine ecosystems, characterized by rich biodiversity and unique ecological dynamics. Its intricate coastal habitats and open waters support a range of species and contribute to the region's ecological and economic significance. Unraveling the consequences of the ongoing climate changes on this delicate environment is essential to ensure the future safeguard of this basin. To tackle this problem, we developed a biogeochemical model for the entire basin, with a horizontal resolution of about 2 km and 120 vertical levels, forced by the projections of atmosphere, hydrology and ocean circulation between 1992 and 2050, under emission scenario RCP8.5. The changes projected between 2031–2050 and 1992–2011 were evaluated on ecoregions characterized by different trophic conditions, identified using a k-medoid classification technique. The results point toward a generalized oligotrophication of the basin, especially intense in the northern estuarine areas, driven by a substantial decrease in river discharge projected for the rivers of the Po Plain. This scenario of unproductive and declining resources, together with the ongoing warming, salinization, and acidification of marine waters, cast doubt on the long-term resilience of the Northern Adriatic food web structure, which has evolved to thrive in high trophic conditions. The outcome of this study provides the stakeholders with a tool to understand how potential long-term decreases in the regimes of the Northern Adriatic Rivers could affect the marine ecosystem and its goods and services in the future

On the management of nature-based solutions in open-air laboratories: new insights and future perspectives

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Storm Surge Ensemble Prediction System for Lagoons and Transitional Environments

We developed a storm surge ensemble prediction system (EPS) for lagoons and transitional environments. Lagoons are often threatened by storm surge events with consequent risks for human life and economic losses. The uncertainties connected with a classic deterministic forecast are many, thus, an ensemble forecast system is required to properly consider them and inform the end-user community accordingly. The technological resources now available allow us to investigate the possibility of operational ensemble forecasting systems that will become increasingly essential for coastal management. We show the advantages and limitations of an EPS applied to a lagoon, using a very high-resolution unstructured grid finite element model and 45 EPS members. For five recent storm surge events, the EPS generally improves the forecast skill on the third forecast day compared to just one deterministic forecast, while they are similar in the first two days. A weighting system is implemented to compute an improved ensemble mean. The uncertainties regarding sea level due to meteorological forcing, river runoff, initial boundaries, and lateral boundaries are evaluated for a special case in the northern Adriatic Sea, and the different forecasts are used to compose the EPS members. We conclude that the largest uncertainty is in the initial and lateral boundary fields at different time and space scales, including the tidal components

A Digital Twin modelling framework for the assessment of seagrass Nature Based Solutions against storm surges

In this paper we demonstrate a novel framework for assessing nature-based solutions (NBSs) in coastal zones using a new suite of numerical models that provide a virtual "replica" of the natural environment. We design experiments that use a Digital Twin strategy to establish the wave, sea level and current attenuation due to seagrass NBSs. This Digital Twin modelling framework allows us to answer "what if" scenario questions such as: (i) are indigenous seagrass meadows able to reduce the energy of storm surges, and if so how? (ii) what are the best seagrass types and their landscaping for optimal wave and current attenuation? An important result of the study is to show that the landscaping of seagrasses is an important design choice and that seagrass does not directly attenuate the sea level but the current amplitudes. This framework reveals the link between seagrass NBS and the components of the disruptive potential of storm surges (waves and sea level) and opens up new avenues for future studies

Downscaling with an unstructured coastal-ocean model to the Goro Lagoon and the Po river delta branches

The Goro Lagoon Finite Element Model (GOLFEM) presented in this paper concentrates on the high-resolution downscaled model of the Goro Lagoon, along with five Po river branches and the coastal area of the Po delta in the northern Adriatic Sea (Italy) where crucial socio-economic activities take place. GOLFEM was validated by means of validation scores (bias – BIAS, root mean square error – RMSE, and mean absolute error – MAE) for the water level, current velocity, salinity and temperature measured at several fixed stations in the lagoon. The range of scores at the stations are: for temperature between −0.8 to +1.2◦C, for salinity from −0.2 to 5 PSU, for sea level 0.1 m. The lagoon is dominated by an estuarine vertical circulation due to a double opening at the lagoon mouth and sustained by multiple sources of freshwater inputs. The non-linear interactions among the tidal forcing, the wind and the freshwater inputs affect the lagoon circulation at both seasonal and daily time scales. The sensitivity of the circulation to the forcings was analyzed with several sensitivity experiments done with the exclusion of the tidal forcing and different configurations of the river connections. GOLFEM was designed to resolve the lagoon dynamics at high resolution in order to evaluate the potential effects on the clam farming of two proposed scenarios of human intervention on the morphology of the connection with the sea. We calculated the changes of the lagoon current speed and salinity, and using opportune fitness indexes related to the clams physiology, we quantified analytically the effects of the interventions in terms of extension and persistence of areas of the clams optimal growth. The results demonstrate that the correct management of this kind of fragile environment relies on both long-term (intervention scenarios) and short-term (coastal flooding forecasts and potential anoxic conditions) modeling, based on a flexible tool that is able to consider all the recorded human interventions on the river connections. This study also demonstrates the importance of designing a seamless chain of models that are capable of integrating local effects into the coarser operational oceanographic models