Far future climate (2060-2100) of the northern Adriatic air-sea heat
transfers associated with extreme bora events
Abstract
The northernmost part of the Mediterranean Sea, the northern Adriatic
shelf, is a complex area where the intensity of dense water formation
and the consequent Adriatic-Ionian thermohaline circulation are shaped
by a combination of extreme wintertime bora winds and substantial
freshwater loads. To better understand the impact of global warming on
extreme bora dynamics and the associated sea surface cooling, we applied
the Adriatic Sea and Coast (AdriSC) kilometer-scale modelling suite to
the far future climate (2060-2100) period. Under both Representative
Concentration Pathway (RCP) 4.5 and RCP 8.5 greenhouse emission
scenarios, the AdriSC simulations are carried out via the combination of
a statistical approach – consisting of an ensemble of 3-day simulations
for 22 extreme bora events, and a pseudo-global warning (PGW)
methodology – imposing a climatological change to the forcing used to
produce the evaluation (present climate) runs. Despite a noteworthy
decrease in intensity of the bora winds (by up to 3 m/s), the intensity
of the negative latent heat fluxes is simulated to increase (by up to
150 W/m2) due to the reduction in relative humidity in the northern
Adriatic (by up to 3%). Consequently, the sea surface cooling
associated with severe bora events and preconditioning the dense shelf
water formation in the northern Adriatic is projected to not
significantly change compared to present climate. Although these results
need to be further confirmed, this study thus provides a new view on the
future of processes driven by sea surface cooling, such as the dense
shelf water formation or the Ionian-Adriatic thermohaline circulation,
that were projected to decrease in the future climate by regional
climate models an order of magnitude coarser than the AdriSC
simulations.