An ensemble of models for identifying climate change scenarios in the Gulf of Gabes, Tunisia

Abstract

Climate change is likely to increase the pressure on the environment and on human systems that are requiring new assessment tools aimed at supporting decision-makers and stakeholders towards a more sustainable and effective management of the coastal environment and its resources. This research appraises an ensemble of models that integrates complex interactions of climate and anthropogenic impacts on vulnerable Mediterranean coastal areas with application to the Gulf of Gabes, Tunisia. Starting from Global and Regional Circulation Models, the models’ ensemble includes simulations of marine and atmospheric dynamics and biogeochemical processes in coastal waters under expected anthropogenic forcings, with a spatial domain ranging from subnational to local. In the case study area, the simulations showed that atmospheric temperature increase is likely to be around 4 °C in the summer months of 2100, relative to 1961–1990. In order to obtain the most reliable estimate of sea-level rate variations, satellite altimetry data have been processed over a period of 15 years (1993–2007) showing that sea-level changes on the Tunisian shelf were of the order of 2 mm/year. This value was considered as a reference for the sea-level change scenarios. As far as the water quality is concerned, the areas most impacted by pollution are located near major towns and human infrastructures, such as harbours. The set of results obtained by the proposed models’ ensemble may be suitable for supporting a scientific dialogue with stakeholders and for the implementation of exposure scenarios supporting a regional risk assessment approach to the entire Gulf of Gabes area

The Regional Earth System Model RegCM‐ES: Evaluation of the Mediterranean Climate and Marine Biogeochemistry

“…It can also be employed to simulate the dynamics of the carbonate system and exchanges of O 2 /CO 2 between atmosphere and ocean. BFM has been extensively applied to the study of the dynamics of NO 3 , PO 4 , Chlorophyll-a and Net primary production (Lazzari et al, 2012(Lazzari et al, , 2016 in the Mediterranean Sea, marine carbon sequestration (Canu et al, 2015), spatial and temporal variability of alkalinity (Cossarini et al, 2015), extreme events in marine biogeochemistry (Di Biagio, 2017), impacts of climate change on the biogeochemical dynamics of marine ecosystems (Lamon et al, 2014;Lazzari et al, 2014) as well as for biogeochemical projections in the Mediterranean Copernicus system (Teruzzi et al, 2016).…”

Assessment of Climate Change Impacts in the North Adriatic Coastal Area. Part I: A Multi-Model Chain for the Definition of Climate Change Hazard Scenarios

“…Sea-level rise could have devastating impacts on marine-coastal environments and (e.g., groundwater level variation, variations of nitrate infiltration), Baruffi et al [18] applied an integrated modeling approach in the Upper Veneto and Friuli plain (Italy). Lamon et al [19] used an ensemble of oceanic and atmospheric models to identify precipitation, temperature, and evapotranspiration scenarios in the Gulf of Gabes (Tunisia). This was the first example of a model-chain applied to climate risk assessment in coastal areas, although no downscaling techniques were used in the experiment.…”

Acidification, deoxygenation, nutrient and biomasses decline in a warming Mediterranean Sea

“…The BFM biogeochemical reactor considers co-occurring effects of multi-nutrient interactions and energy/material fluxes through the classical food chain and the microbial food web which are both very important in the Mediterranean Sea (Bethoux et al, 1998). BFM has been extensively applied to the studies of the dynamics of dissolved nutrients, chlorophyll-a and net primary production in the Mediterranean Sea (Lazzari et al, 2012;Di Biagio et al, 2019;Reale et al, 2020a), marine carbon sequestration and alkalinity (Canu et al, 2015;Cossarini et al, 2015;Butenschön et al, 2021), impacts of climate change on the biogeochemical dynamics of marine ecosystems (Lazzari et al, 2014;Lamon et al, 2014;Solidoro et al, 2021), influence of large-scale atmospheric circulation patterns on nutrient dynamics (Reale et al, 2020b) and operational shortterm forecasts for the Mediterranean Sea biogeochemistry (Teruzzi et al 2018;Salon et al, 2019). The version adopted here is the v5.…”