Schütte, Florian; Schulz, Marco; Brandt, Peter; Hahn, Johannes (eds.): Near-equatorial low-oxygen extremes: Long-term time series of dissolved oxygen measurements from the upper 500 m depth of the eastern tropical North Atlantic [dataset editorial publication]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.987397 (dataset in review)

Long-term time series of dissolved oxygen (DO) measurements from the upper 500 m depth of the eastern tropical North Atlantic (ETNA), collected over a period of up to 15 years at three different mooring sites, reveal recurring extreme low-oxygen events lasting for several weeks. Similarly, observations from 15 individual meridional ship sections between 6°N and 12°N along 23°W show DO concentrations far below 60 µmol kg⁻¹ in the upper 200 m - significantly lower than the climatological values at this depth (>80 µmol kg⁻¹). Two-third of these low-oxygen events could be related with high-baroclinic-mode vorticies (HBVs) with their cores located well below the mixed layer. Since none of the observed HBVs exhibit a surface signature, a substantial portion of the near-equatorial eddy field may remain undetected by satellites, yet still exert significant influence on local ocean ecosystems and biogeochemical cycles.