Variability of Thermohaline Characteristics at 26.5° N in Reanalyses and Oceanographic Section Data

Abstract

The most common methods for studying the variability of ocean parameters are field measurements and numerical modeling. Due to the insufficient availability of ocean measurement data, it is not always possible to verify the reliability of modeling results. Changes in temperature and salinity of the Atlantic Ocean water masses at 26.5° N in the recent 30 and 70 years are estimated. The estimation is based on the data of SODA, ORAS4, ECCO, GECCO reanalyses, EN4 and WOA13 objective analyses, and six regular oceanographic sections. In 1992 to 2016, all reanalyses simulate an increase in temperature and salinity of surface water for the entire section, which is consistent with field data. On average, the reanalyses overestimate temperature by 0.1–0.3°C and salinity by 0.02–0.05 psu. The closest values to field data are reproduced by the ORAS4 reanalysis and EN4 objective analysis. Trends in temperature and salinity coincide best with the EN4 results.