210Po/210Pb Disequilibria and Its Estimate of Particulate Organic Carbon Export Around Prydz Bay, Antarctica

Due to the remoteness and difficulty of sampling, 210 Po Pb data are scarce in Southern Ocean. Here, activity concentrations around Prydz Bay austral summer were determined understand their spatial variation evaluate dynamics particle organic matter (POM). The dissolved (D Po) Pb) range from 0.47 3.20 Bq⋅m –3 1.15 2.97 , respectively, with lower values shelf. particulate (P open ocean increase coastal waters, among which circumpolar deep water (CDW) is lowest. concentration total (T ranges 1.26 3.16 a higher value CDW, ascribed radiogenic production 226 Ra subsequent lateral transport. Occasionally high T occurs (>3.00 ), may be caused by remineralization POM. disequilibria between appears throughout column at most stations. average Po/T A.R. euphotic zone 0.66, reflecting effect strong scavenging. There good positive correlation solid-liquid ratio POC, while does not, indicating that regulates biogeochemical cycle Bay. Based on Po/ disequilibria, export flux POC estimated 0.8–31.9 mmol m –2 d –1