DATE2022-05-13 17:51:51
TITLEBiogeochemical dynamics response of the Mediterranean sea under two different levels of global warming: a study using eddy resolving projections for RCP4.5 and RCP8.5 emission scenarios.
AUTHORSMarco Reale (1) ,Gianpiero Cossarini (1) ,Paolo Lazzari (1) ,Tomas Lovato (2) ,Giorgio Bolzon (1) ,Simona Masina (2) ,Cosimo Solidoro (1) ,Stefano Salon (1)
  1. 1) National Institute Of Oceanography And Applied Geophysics - Ogs, Trieste (Italy) ,2) Fondazione Centro Euro-mediterraneo Sui Cambiamenti Climatici, Cmcc, Bologna (Italy)
ABSTRACTEddy resolving projections of the physical and biogeochemical state of the Mediterranean Sea under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 are used to assess the impacts of climate change on the main marine ecosystem properties of the basin in the middle and at the end of 21st century. In both RCP scenarios the numerical simulations project changes in the dissolved nutrient content within the euphotic and intermediate layers of the basin, as well as for net primary production, phytoplankton respiration and carbon stock. In particular, a uniform surface and subsurface reduction in the oxygen concentration occurs as a response to the warming of the water column and the increase in ecosystem respiration. The acidification of the upper water column is driven by the projected increase in the dissolved inorganic carbon content of the water column due to CO2 absorption from the atmosphere and the increase of the ecosystem respiration. The magnitude of projected changes is stronger in the RCP8.5 (worst-case) scenario, with a major impact in the Eastern Mediterranean due to the far limited influence of the exchanges at the Strait of Gibraltar. Conversely, the projections under RCP4.5 emission scenario show, for several variables in the second half of the 21st century, a tendency to recover the values observed at the beginning of the century. This result supports the idea that the reduction of CO2 emission could be, indeed, effective and could contribute to the foundation of ocean sustainability science and policies.