Current Research & Project

(Participate)

The Antarctic region is being influenced by climate change most severely. Physical changes such as seasonal sea ice melting will influence the carbon cycling in this region. The change in carbon cycling, in turn, will affect the future climate change through feedback mechanisms. Understanding the cause of the change in carbon cycling of this region will provide information to enhance the model performance for future climate projection. 

West Antarctic region is experiencing a rapid decrease of ice shelf thickness. This region has recently attracted international research interests to understand the current status and the cause of melting of the ice shelf. In this sense, it is necessary and timely to perform a multi-prong, interdisciplinary, and multi-year research project to study the Amundsen Sea in the West Antarctic related to the carbon cycling.

As part of this large project, operated by KOPRI, we focused  on understanding the POC (particulate organic carbon) cycling in the Amundsen Sea. Also we aim to reveal the water circulation using radiocarbon of the DIC (dissolved inorganic carbon) in the Amundsen Sea.

​

I joined in three times of the Amundsen Sea cruises through this program. 

​

Following are the investigated sets of paper-unit studies:

1. 1-year sinking particles in sea ice covered region (SIZ) had been obtained and compared to the one obtained inside the ASP and suggested that POC flux at both sites in summer were comparable despite the considerable difference in primary productivity (Kim et al., 2015).

2. We examined the recent history of sedimentary organic carbon (SOC) accumulation on the western Amundsen Shelf, to help characterize the biological carbon pump in the Amundsen Sea. At the center of the polynya, a sudden change in SOC accumulation rate was observed at about 16 cm depth, corresponding to 4.7 kyr BP, implying that changes (during this time period) in physical environments greatly affected primary production, SOC burial and/or supply of allochthonous particles to this site (Kim et al., 2016).

3. We use radiocarbon isotope signature from dissolved inorganic carbon to examine how rapidly atmospheric CO2 is absorbed into the Amundsen Sea Polynya and how long the water should stay in the western Amundsen Shelf to have the observed radiocarbon isotope signature (B, Kim et al., 2018).

4. Temporally expanded two-year data covering three summers were obtained in the perennial SIZ. Sea ice evolution and POC export and their relationship in perennial SIZ was examined, too. Spatial comparisons among the sinking particles obtained in perennial SIZ, inside the ASP and in front of DIS were also made (Kim et al., 2019).

5. Collection of large benthic invertebrates including juvenile scallops, a sea urchin, and long and slender worms in sediment traps for 2 years at three locations in the Amundsen Shelf also have been reported. Plausible source region and transport mechanisms of these benthic organisms and the impacts on Antarctic biology, as a disturbance to benthic ecosystems, a dispersal mechanism for benthic invertebrates, and an energy supply to the deeper benthic ecosystems were investigated   (Kim et al., 2019).

6. Sediment samples collected by gravity core were used to investigate recent and Holocene organic carbon cycling in this region. High resolution radiocarbon ages in depth for the cores were analyzed. History of the ASP formation and sedimentation characteristics were examined from three gravity cores recovered in the shelf break, inside the polynya, and near the Dotson Ice Shelf Gravity core-temporally expanded (Kim et al., in prep).

7. Box core samples from various locations of different surface water conditions in the western Amundsen Shelf were investigated to complement the spatial limitation of gravity cores. Radiocarbon, biomarkers representing phytoplankton communities and paleoproductivity (brassicasterol, cholesterol, and dinosterol), and grain size were analyzed for a high spatial-resolution of SOC accumulation characteristics on the Amundsen Shelf Sterols, high resolution spatial understanding (Kim et al., in prep).