Medusa–Aqua system: simultaneous measurement and evaluation of novel potential halogenated transient tracers HCFCs, HFCs, and PFCs in the ocean

Abstract. This study evaluates the potential usefulness of halogenated compounds HCFC-22, HCFC-141b, HCFC-142b, HFC-134a, HFC-125, HFC-23, PFC-14, and PFC-116 as oceanographic transient tracers to better constrain ocean ventilation processes. We do this mainly in terms four aspects characteristics tracers: input function (including atmospheric history historical surface saturation), seawater solubility, feasibility measurement, stability seawater; these, solubility have been investigated previous work. For latter two aspects, we collected samples modified an established analytical technique for Medusa–Aqua system simultaneously measure these compounds. HFC-125 measured depth profiles Mediterranean Sea first time reproducibility Baltic Sea. found that saturation is estimated nearly constant at 94 % based on data. Of compounds, HFC-134a are currently be most promising ocean. The greatest future PFC-14 PFC-116, hampered by low creates challenging conditions, i.e., concentrations. HCFC-22 likely unstable warm seawater, which compromises oceanic tracer, although it possibly useful colder water. were not able fully evaluate their due inconclusive results, especially regarding but also with regard challenges. On other hand, might need considered because there alternative similar histories suited tracers.