Open AccessAntarctic meltwater-induced dynamical changes in phytoplankton in the Southern Ocean
Author(s) -
JiHoon Oh,
Kyung Min Noh,
HyungGyu Lim,
Emilia Kyung Jin,
SangYoon Jun,
JongSeong Kug
Publication year - 2022
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/ac444e
Subject(s) - meltwater , upwelling , nitrate , oceanography , phytoplankton , environmental science , surface water , seawater , stratification (seeds) , antarctic bottom water , geology , bottom water , nutrient , glacial period , ecology , geomorphology , biology , environmental engineering , seed dormancy , botany , germination , dormancy
It has been suggested that the freshwater flux due to the recent melting of the Antarctic ice-sheet/shelf will suppress ventilation in the Southern Ocean (SO). In this study, we performed idealized earth-system simulations to examine the impacts of Antarctic meltwater on the biomass of surface phytoplankton in the Antarctic Ocean. The enhanced stratification due to the meltwater leads to a decrease in surface nitrate concentration, but an increase in the surface concentration of dissolved iron. These changes are associated with the reduced upwelling of nitrate-rich deep water and the trapped iron exported from terrestrial sediment. Because of the limited iron availability in the SO, the trapped iron in surface water enhances the chlorophyll concentration in the open ocean. However, in the marginal sea along the Antarctic coastline where the iron is relatively sufficient, a nitrate reduction induces a chlorophyll decrease, indicating a regime shift from iron-limited to nitrate-limited conditions.