FN Archimer Export Format
PT J
TI The Biological Pump and Seasonal Variability of pCO(2) in the Southern Ocean: Exploring the Role of Diatom Adaptation to Low Iron
BT 
AF PERSON, Roland
   AUMONT, Olivier
   LEVY, M.
AS 1:1;2:1;3:1;
FF 1:;2:;3:;
C1 Univ Paris 06, Sorbonne Univ, CNRS,LOCEAN IPSL, UPMC,IRD,MNHN,MR 7159, F-75252 Paris, France.
C2 UNIV PARIS 06, FRANCE
IF 3.235
TC 15
UR https://archimer.ifremer.fr/doc/00673/78490/80817.pdf
LA English
DT Article
CR OISO - OCÉAN INDIEN SERVICE D'OBSERVATION
DE ;Southern Ocean;diatoms;physiological adaptation;biological pump;pCO(2);seasonal variability
AB Iron is known to limit primary production in the Southern Ocean (SO). To cope with the lack of this micronutrient, diatoms, a dominant phytoplankton group in this oceanic region, have been shown in cultures to have developed an original adaptation strategy to maintain efficient growth rates despite very low cellular iron quotas, even in low light conditions. Using a global ocean biogeochemical model, we explored the consequences of this physiological adaptation for the biological pump and the seasonal variability of both surface chlorophyll concentrations and surface partial pressure of carbon dioxide (pCO(2)) in this key region for global climate. In the model, we implemented a low intracellular Fe:C requirement in the SO for diatoms uniquely. This results in an increase of 10% in the relative contribution of diatoms to total SO primary production. The biological pump is also strengthened, which increases the biological contribution to the seasonal evolution of pCO(2) relative to the thermodynamic component. Therefore, the seasonal evolution of both surface chlorophyll and surface pCO(2) is significantly impacted, with a marked improvement, in our model, in the SO polar zone compared to the observations. Our model study underscores the potentially important consequences that this adaptive physiological behavior of diatoms could have on marine biogeochemistry in the SO. It is thus critical to improve our understanding of the physiology of this key phytoplankton group, in particular in the SO. 
PY 2018
PD MAY
SO Journal Of Geophysical Research-oceans
SN 2169-9275
PU Amer Geophysical Union
VL 123
IS 5
UT 000436111400005
BP 3204
EP 3226
DI 10.1029/2018JC013775
ID 78490
ER

EF