Abstract
The Mediterranean Sea is considered as a hotspot for climate change because of its location in the temperate region and because it is a semi-enclosed basin surrounded by highly populated and developed countries. Some expected changes include an increase in air temperature and changes in the periodicity and spatial distribution of rainfall. Alongside, demographic and politics changes will alter freshwater quantity and quality. All these changes will have an impact on the ecological status of marine ecosystems in the basin. We use a 3D hydrodynamic-biogeochemical coupled model of the entire Mediterranean Sea to explore potential changes in primary productivity (mean values and spatial distribution) under two emission scenarios (rcp4.5 and rcp8.5).To isolate the effects of changes in atmospheric conditions alone, in this ensemble of simulations rivers conditions (water flow and nutrient concentrations) are kept unchanged and equal to its climatological values for the last 10 years. Despite the significant warming trend, the mean integrated primary production rate in the entire basin remains almost unchanged. However characteristic spatial differences are consistently found in the different simulations. The western basin becomes more oligotrophic associated to a surface density decrease (increase stratification) because of the influence of the Atlantic waters which prevents surface salinity to increase. In the eastern basin, on the contrary, all model runs simulates an increase in surface production linked to a density increase (less stratification) because of the increasing evaporation rate. The simulations presented here demonstrate the basic response patterns of the Mediterranean Sea ecosystem to changing climatological conditions. Although unlikely, they could be considered as a ‘baseline’ of expected consequences of climatic changes on marine conditions in the Mediterranean.
Highlights
The Mediterranean Sea has been described as a hot-spot for climate change (Giorgi, 2006) because of a number of reasons
sea surface temperature (SST) continuously increase in the different scenario runs with the two rcp4.5 runs showing a mean warming of ∼1◦C by 2100 and the two rcp8.5 runs indicating a warming of ∼2.7◦C by 2100 (∼0.32◦C/decade for both MPI and EcEarth)
As expected, simulated SST during the different scenario runs show a continuous warming of the surface Mediterranean basin in concordance with previous works (e.g., Somot et al, 2006; Lazzari et al, 2014)
Summary
The Mediterranean Sea has been described as a hot-spot for climate change (Giorgi, 2006) because of a number of reasons It is located in a temperate region which is expected to become warmer and drier in the nearby future (IPCC, 2013). It is a semi-enclosed basin being, thereby, strongly influenced by continental conditions. At least, be included in the scenario generation process, the atmosphere, the ocean, and the socio-economic activity With such interconnected models, attribution exercises could be performed by isolating sources of variability and assessing potential changes on the variables of interest by the individual forcing factors (e.g., atmospheric conditions, river discharges, or human activities).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
