FN Archimer Export Format
PT J
TI Significant mixed layer nitrification in a natural iron-fertilized bloom of the Southern Ocean
BT 
AF FRIPIAT, F.
   ELSKENS, M.
   TRULL, T. W.
   BLAIN, S.
   CAVAGNA, A. -J.
   FERNANDEZ, C.
   FONSECA-BATISTA, D.
   PLANCHON, F.
   RAIMBAULT, P.
   ROUKAERTS, A.
   DEHAIRS, F.
AS 1:1;2:1;3:2,3;4:4;5:1;6:4;7:1;8:5;9:6;10:1;11:1;
FF 1:;2:;3:;4:;5:;6:;7:;8:;9:;10:;11:;
C1 Vrije Univ Brussel, Earth Sci Res Grp, Analyt Environm & Geochem, Brussels, Belgium.
   Univ Tasmania, Antarctic Climate & Ecosyst Cooperat Res Ctr, Hobart, Tas, Australia.
   CSIRO Oceans & Atmosphere Flagship, Hobart, Tas, Australia.
   Univ Paris 06, Univ Paris 04, CNRS, Lab Oceanog Microbienne,Observ Oceanol, Banyuls Sur Mer, France.
   Inst Europeen Mer, Lab Sci Environm Marin, Plouzane, France.
   Aix Marseille Univ, CNRS INSU, IRD, Mediterranean Inst Oceanog UMR 7294, Marseille, France.
C2 UNIV VRIJE BRUSSEL, BELGIUM
   UNIV TASMANIA, AUSTRALIA
   CSIRO, AUSTRALIA
   UNIV PARIS 06, FRANCE
   UBO, FRANCE
   UNIV AIX MARSEILLE, FRANCE
UM LEMAR
IF 4.495
TC 16
UR https://archimer.ifremer.fr/doc/00296/40704/39700.pdf
   https://archimer.ifremer.fr/doc/00296/40704/39701.doc
   https://archimer.ifremer.fr/doc/00296/40704/39702.docx
LA English
DT Article
CR MD 145 / KEOPS
   MD 188 / KEOPS 2
BO Marion Dufresne
AB Nitrification, the microbially mediated oxidation of ammonium into nitrate, is generally expected to be low in the Southern Ocean mixed layer. This paradigm assumes that nitrate is mainly provided through vertical mixing and assimilated during the vegetative season, supporting the concept that nitrate uptake is equivalent to the new primary production (i.e., primary production which is potentially available for export). Here we show that nitrification is significant (~40–80% of the seasonal nitrate uptake) in the naturally iron-fertilized bloom over the southeast Kerguelen Plateau. Hence, a large fraction of the nitrate-based primary production is regenerated, instead of being exported. It appears that nitrate assimilation (light dependent) and nitrification (partly light inhibited) are spatially separated between the upper and lower parts, respectively, of the deep surface mixed layers. These deep mixed layers, extending well below the euphotic layer, allow nitrifiers to compete with phytoplankton for the assimilation of ammonium. The high contributions of nitrification to nitrate uptake are in agreement with both low export efficiency (i.e., the percentage of primary production that is exported) and low seasonal nitrate drawdown despite high nitrate assimilation.
PY 2015
PD NOV
SO Global Biogeochemical Cycles
SN 0886-6236
PU Amer Geophysical Union
VL 29
IS 11
UT 000368907500005
BP 1929
EP 1943
DI 10.1002/2014GB005051
ID 40704
ER

EF