『Abstract
　We report here the silicon isotopic composition (δ³⁰Si) of dissolved silicon (DSi) from 42 surface water samples from the Drake Passage, the Weddell Gure, other areas south of the Southern Boundary of the Antarctic Circumpolar Current (ACC), and the ACC near the Kerguelen Plateau, taken between the beginning of February and the end of March 2007. From the beginning to end of the cruise (ANTXXIII/9), DSi diminished in the Antarctic by 50μmol L^-1 while concentrations of nitrate + nitrite and phosphate showed no net decline, indicating that the high seasonal Si/N removal ratios well known for the Southern Ocean may be more related to the strength of the silicate pump in the Southern Ocean than to the instantaneous Si/N uptake ratio of diatoms. The δ³⁰Si of DSi in samples containing more than 20μM DSi were strongly negatively correlated to DSi concentrations, supporting the use of δ³⁰Si as a proxy for DSi removal. The “open system” fractionation observed, ε = -1.2±0.11‰, agrees well with results from previous work in other areas, and the estimate of the initial δ³⁰Si of DSi of +1.4‰ is not far off observations of the δ³⁰Si of DSi in Winter Water (WW) in this area. Results were used to model DSi draw down in the past from the δ³⁰Si of sediment cores, although isotopic fractionation during silica dissolution appeared to influence the δ³⁰Si of some surface water samples, inviting further study of this phenomenon.』

1. Introduction
2. Study area
3. Methods
　3.1. Cruise track and sample collection
　3.2. Treatment and analysis of samples
4. Results and discussion
　4.1. Dynamics of DSi, NOx, and PO4
　4.2. δ³⁰Si of surface water
　4.3. Estimation of silicon isotope fractionation
　4.4. Comparison with other data
　4.5. Implications for the interpretation of Si isotopes in sediment cores
Acknowledgments
References