Heat Reserve of the Active Layer in the Black Sea Coastal Zone at the Gelendzhik Study Site and Its Evolution during the Warm Period of the Year

The relative heat content (heat reserve) of the active layer of the sea and its variation in the warm period from April to November were estimated based on CTD data collected in 2010–2023 in the northeastern Black Sea at the Gelendzhik study site of the Shirshov Institute of Oceanology, Russian Academy of Sciences. The heat content of the upper mixed layer and the seasonal thermocline, which together make up the active layer, were calculated separately. The estimates based on real data were compared with calculations of the total heat flow based on the ERA5, NCEP CFSv2, and WHOI OAFlux reanalysis data. It was shown that the NCEP CFSv2 reanalysis data provide the result closest to the real data.