FEATURES OF ANTARCTIC BOTTOM WATERS TRANSPORT THROUGH THE VIMA FRACTURE ZONE BASED ON MEASUREMENTS AND NUMERICAL MODELING

This study presents the results of an investigation into the transport characteristics of Antarctic Bottom Water (AABW) through the Vema Fracture Zone in the equatorial Atlantic. The analysis is based on observational data primarily collected during expeditions conducted by the Shirshov Institute of Oceanology of the Russian Academy of Sciences and the Faculty of Geography of Moscow State University. The study incorporates direct current measurements, numerical modeling using the INMOM model, and the GLORYS12v1 reanalysis. A comparative analysis of the data from various sources was carried out to evaluate water transport through the fracture zone. The role of the Vema Fracture Zone in the spreading of AABW was examined, and the main characteristics of near-bottom flows were identified. According to direct measurements, modeling results, and reanalysis data, the transport of AABW through the Vema Fracture Zone - using the θ = 1.7°C isotherm as the upper boundary - amounts to 0.9 Sv (observations), 0.8 Sv (model), and 0.7 Sv (reanalysis). The near-bottom isotherms differ across the data sources. Nevertheless, all data types yield similar estimates of bottom water transport (with a maximum discrepancy of up to 20%), indicating good performance of the numerical modeling in the fracture zone.