FN Archimer Export Format
PT J
TI The fate of a southwest Pacific bloom: gauging the impact of submesoscale vs. mesoscale circulation on biological gradients in the subtropics
BT 
AF DE VERNEIL, Alain
   ROUSSELET, Louise
   DOGLIOLI, Andrea M.
   PETRENKO, Anne A.
   MOUTIN, Thierry
AS 1:1;2:1;3:1;4:1;5:1;
FF 1:;2:;3:;4:;5:;
C1 Univ Toulon & Var, Aix Marseille Univ, CNRS, IRD,MIO,UM 110, F-13288 Marseille 09, France.
C2 UNIV TOULON, FRANCE
IN DOAJ
IF 3.441
TC 22
UR https://archimer.ifremer.fr/doc/00420/53124/54077.pdf
   https://archimer.ifremer.fr/doc/00420/53124/54092.zip
LA English
DT Article
CR OUTPACE
BO L'Atalante
AB The temporal evolution of a surface chlorophyll a bloom sampled in the western tropical South Pacific during the 2015 Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise is examined. This region is usually characterized by largely oligotrophic conditions, i.e. low concentrations of inorganic nutrients at the surface and deep chlorophyll a maxima. Therefore, the presence of a surface bloom represents a significant perturbation from the mean ecological state. Combining in situ and remote sensing datasets, we characterize both the bloom's biogeochemical properties and the physical circulation responsible for structuring it. Biogeochemical observations of the bloom document the bloom itself, a subsequent decrease of surface chlorophyll a, significantly reduced surface phosphate concentrations relative to subtropical gyre water farther east, and a physical decoupling of chlorophyll a from a deep nitracline. All these characteristics are consistent with nitrogen fixation occurring within the bloom. The physical data suggest surface mesoscale circulation is the primary mechanism driving the bloom's advection, whereas balanced motions expected at submesoscales provide little contribution to observed flow. Together, the data provide a narrative where subtropical gyre water can produce significant chlorophyll a concentrations at the surface that is stirred, deformed, and transported great distances by the mesoscale circulation. In this case, for the time period considered, the transport is in an easterly direction, contrary to both the large-scale and mean mesoscale flow. As a result, future studies concerning surface production in the region need to take into account the role complex mesoscale structures play in redistributing subtropical gyre water. 
PY 2017
PD JUN
SO Biogeosciences
SN 1726-4170
PU Copernicus Gesellschaft Mbh
VL 14
IS 14
UT 000406265000001
BP 3471
EP 3486
DI 10.5194/bg-14-3471-2017
ID 53124
ER

EF