The Northern Adriatic Sea (NAS) is a shallow  enclosed basin located at the northernmost part of the Mediterranean Sea (MS). Its seasonal dynamics  is  highly influenced by the physical and  biogeochemical properties of the large rivers located along the Italian (Po, Adige, Brenta, Piave, Tagliamento and Isonzo). The river runoff is characterized by a well-defined seasonality and its associated nutrient load is responsible for sustaining the largest rates  of primary production for the entire MS basin. The ongoing climate change in the MS and NAS  has been responsible for both  warming trends and for the occurrence of both large positive and negative anomalies of riverine fluxes into the NAS. Future climate projections for the MS region suggest that climate warming will worsen and precipitation changes should drastically impact the seasonal cycle of river runoff too. These large changes in riverine runoff (both fresh water and nutrients) to the NAS could have potential consequences for the physical and biogeochemical local process (e.g., coastal productivity) up to the higher trophic levels and hence fisheries. 

To quantify these impacts here we  show the results from numerical simulations of a coupled MITgcm-BFM ocean physical-biogeochemical model of the NAS region run under both present and future climatic conditions. First, we  present results relative to changes on several aspects of the NAS marine biogeochemistry responding to the extreme events that greatly impacted river runoff and hence the riverine nutrient supply during the recent past. Second, we provide results focusing on future climate scenarios obtained from a high-resolution (500 meter) version of these models of the NAS region. Our analysis focuses particularly on the changes in the seasonal cycle of primary production and air-sea CO₂ fluxes responding to both physical and biogeochemical modifications driven by changing riverine runoff in a  future warmer climate. In our study, we will then explore how both solubility and biological carbon pumps will respond not only to the future anthropogenic perturbations of the water column  (temperature and stratification)  but also to  the riverine nutrient supply depending on modified river runoff in a future warmer climate. Our results from future warmer climate runs will then focus on the mid-century  2040-2050 period when the NAS sea surface temperature warms by up to 4 degree Celsius in our ocean model. We aim to also understand if present differences in net primary production between the coastal zone and open ocean will be either amplified or reduced as the northern MS regional climate warms.