Characteristics of the horizontal and vertical distributions of dimethyl sulfide throughout the Amundsen Sea Polynya.
We investigated horizontal and vertical distributions of DMS in the upper water column of the Amundsen Sea Polynya and Pine Island Polynya during the austral summer (January-February) of 2016 using a membrane inlet mass spectrometer (MIMS) onboard the Korean icebreaker R/V Araon. The surface water concentrations of DMS varied from <1 to 400nM. The highest DMS (up to 300nM) were observed in sea ice-polynya transition zones and near the Getz ice shelf, where both the first local ice melting and high plankton productivity were observed. In other regions, high DMS concentration was generally accompanied by higher chlorophyll and ΔO2/Ar. The large spatial variability of DMS and primary productivity in the surface water of the Amundsen Sea seems to be attributed to melting conditions of sea ice, relative dominance of Phaeocystis Antarctica as a DMS producer, and timing differences between bloom and subsequent DMS productions. The depth profiles of DMS and ΔO2/Ar were consistent with the horizontal surface data, showing noticeable spatial variability. However, despite the large spatial variability, in contrast to the previous results from 2009, DMS concentrations and ΔO2/Ar in the surface water were indistinct between the two major domains: the sea ice zone and polynya region. The discrepancy may be associated with inter-annual variations of phytoplankton assemblages superimposed on differences in sea-ice conditions, blooming period, and spatial coverage along the vast surface area of the Amundsen Sea.
Marine Radionuclide Research Center, Korea Institute of Ocean Science and Technology, Ansan 15627, South Korea.
Intae
I
Kim
Department of Oceanography, Pusan National University, Busan 46241, South Korea. Electronic address: hahm@pusan.ac.kr.
Doshik
D
Hahm
Division of Polar Ocean Sciences, Korea Polar Research Institute, Incheon 21990, South Korea. Electronic address: keyhongpark@kopri.re.kr.
Keyhong
K
Park
Division of Polar Ocean Sciences, Korea Polar Research Institute, Incheon 21990, South Korea.
Youngju
Y
Lee
Division of Polar Ocean Sciences, Korea Polar Research Institute, Incheon 21990, South Korea.
Jung-Ok
JO
Choi
Key Laboratory of Global Change and Marine-Atmospheric Chemistry, Third Institute of Oceanography, Xiamen 361005, PR China.
Miming
M
Zhang
Key Laboratory of Global Change and Marine-Atmospheric Chemistry, Third Institute of Oceanography, Xiamen 361005, PR China.
Liqi
L
Chen
Unit of Arctic Sea-Ice Prediction, Korea Polar Research Institute, Incheon 21990, South Korea.
Hyun-Cheol
HC
Kim
Division of Polar Ocean Sciences, Korea Polar Research Institute, Incheon 21990, South Korea.
SangHoon
S
Lee
Amundsen Sea; Antarctic polynya; Dimethyl sulfide; Membrane inlet mass spectrometer; Southern Ocean