Sinking particle flux in the sea ice zone of the Amundsen Shelf, Antarctica

TitleSinking particle flux in the sea ice zone of the Amundsen Shelf, Antarctica
Publication TypeJournal Article
Year of Publication2015
AuthorsKim, M, Hwang, J, Kim, HJ, Kim, D, Yang, EJ, Ducklow, HW, La Hyoung, S, Lee, SH, Park, J, Lee, SH
JournalDeep Sea Research Part I: Oceanographic Research Papers
Volume101
Pagination110-117
Date PublishedJul
ISSN0967-0637
Accession NumberWOS:000356210100010
Abstract

We have examined the flux, biogenic composition, and isotopic values of sinking particles collected by a time-series sediment trap deployed in the sea ice zone (SIZ) of the Amundsen Sea from January 2011 for 1 year. The major portion of the particle flux occurred during the austral summer in January and February when sea ice concentration was reduced to 30 %) and a low bio-Si/POC ratio (<0.5) during the austral winter. CaCO3 content and its contribution to total particle flux was low (~6 %) throughout the study period. Aged POC likely supplied from sediment resuspension accounted for a considerable fraction only from October to December, which was evidenced by a low radiocarbon content and relatively high (30–50 %) content of the non-biogenic components. When compared with POC flux inside the Amundsen Sea polynya obtained by the US Amundsen Sea Polynya International Research Expedition (ASPIRE), the POC flux integrated over the austral summer in the SIZ was virtually identical, although the maximum POC flux was approximately half that inside the Amundsen Sea polynya. This comparatively high POC flux integrated over the austral summer in the SIZ may be caused by phytoplankton blooms persisting over a longer periods and more efficient export of organic matter potentially owing to the diatom-dominant plankton community. If this observation is a general phenomenon on the Amundsen Shelf, the role of the SIZ, compared with the polynyas, need to be examined more carefully when trying to characterize the POC export in this region.

DOI10.1016/j.dsr.2015.04.002