Southern Ocean Time Series Dissolved and Particulate Zinc Seasonal Stable Isotope Cycling from March 2018 to March 2019.

Zinc is an important trace metal in the oceans as it is used in enzymes related to carbon uptake. The Southern Ocean has large zinc stocks due to the Antarctic Circumpolar Current and global thermohaline circulation. The Southern Ocean Time Series site (SOTS) is situated at 47^oS 144^oE, located just south of the subtropical front in subantarctic zone. We will present data from 3 voyages to the SOTS site in March 2018, September 2018 and March 2019. The March sampling is at the end of the summer bloom when nutrients and trace metals are depleted, and the September sampling is just before the onset of the spring diatom bloom when nutrients have built up over winter. During these voyages dissolved and particulate zinc profiles were collected and complemented with nutrient and biological measurements. We will present the total particulate and dissolved Zn distributions from each voyage to the SOTS site, in addition to Zn isotopic fractionation of the dissolved and particulate phases. The intra- and interannual variations in zinc concentrations and isotopes will be assessed.