Mediterranean Outflow Water analysis through multiple reanalysis and observational data products

As climate change impacts ocean properties, such as temperatures, salinity and stratification, the Atlantic Meridional Overturning Circulation (AMOC) may be at risk of collapse. A weakened AMOC can be connected to shifts in global weather patterns, such as more heatwaves in Europe. The outflow water from the Mediterranean Sea has properties that influence the North Atlantic Ocean hydrodynamics and the AMOC. The Mediterranean Outflow Water (MOW) properties vary due to climate change,  affecting the Atlantic Ocean thermohaline characteristics. 

Using a multi-data approach, this study compares four reanalyses of different horizontal grid resolutions in a seventy years time span (RR 1955-2015 DOI: 10.25423/MEDSEA_REANALYSIS_PHY_006_009, MEDREA16 1987-2018 DOI:10.25423/medsea_reanalysis_phys_006_004, MEDREA24 1987-2024 DOI: 10.25423/CMCC/MEDSEA_MULTIYEAR_PHY_006_004_E3R1, CIGAR-CS 1961-2022 http://cigar.ismar.cnr.it/) to the World Ocean Atlas 2023 climatology (DOI: 10.25921/va26-hv25) and mooring observations at the Espartel Sill. The study evaluates volume, heat and salt transports, temperature and salinity time series at Gibraltar and analyzes the MOW decadal variability in the North Atlantic from 1955 to 2024.

The goal of this research is to assess the consistency and accuracy of multiple reanalysis products in simulating the Mediterranean Sea and Atlantic Ocean interaction and to establish how the model resolution and geometry affect the MOW characteristics. Ultimately, this assists in understanding how MOW variability may impact the AMOC.