A New Vision of the Adriatic Dense Water Future under Extreme Warming

We employ the Adriatic Sea and Coast (AdriSC) fine-resolution atmosphere-ocean model, operating at the kilometer scale, to assess the effects of a far-future extreme warming scenario on the formation, transport, and accumulation of the Adriatic dense and deep water. It is well-established that North Adriatic Dense Water (NAddW) is spreading across the entire basin and accumulates within the Jabuka Pit, while Adriatic Deep Water (AdDW) is only located within the Southern Adriatic Pit (SAP). However, unlike earlier studies that relied on coarser-resolution Mediterranean climate models, our approach incorporates updated thresholds for defining dense and deep water, reflecting far-future background density shifts due to increased sea surface temperatures.

Our analysis reveals a 15% increase in surface buoyancy losses at NAddW generation sites under extreme warming, driven primarily by evaporation, despite a 25% decline in both the intensity and spatial extent of the winter windstorms responsible for the surface cooling. Consequently, far-future NAddW formation is projected to remain comparable to present-day conditions. However, heightened stratification in the far-future scenario is expected to reduce the volume of dense water retained in the Jabuka Pit. Furthermore, the transport of dense water between the Jabuka Pit and the SAP's deepest regions is likely to cease, as future NAddW will be less dense than the AdDW.

Regarding the exchanges between the Adriatic and Ionian Seas, we find that the Bimodal Oscillation System's influence on Adriatic salinity variability will persist under extreme warming. Nonetheless, future AdDW dynamics will primarily be driven by density changes in the northern Ionian Sea.

These findings underscore the intricate nature of climate change impacts on Adriatic atmosphere-ocean interactions and highlight the necessity of higher resolution models for producing more reliable far-future projections at the coastal scale.