FN Archimer Export Format
PT J
TI Physical mechanisms for biological carbon uptake during the onset of the spring phytoplankton bloom in the northwestern Mediterranean Sea
BT 
AF Merlivat, Liliane
   Hemming, Michael
   Boutin, Jacqueline
   Antoine, David
   Vellucci, Vincenzo
   Golbol, Melek
   Lee, Gareth A.
   Beaumont, Laurence
AS 1:1;2:2;3:1;4:3,4;5:5;6:5;7:6;8:7;
FF 1:;2:;3:;4:;5:;6:;7:;8:;
C1 Sorbonne Université, CNRS/IRD/MNHN, LOCEAN, IPSL, Paris, France
   Coastal and Regional Oceanography Lab, School of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales, Australia
   Remote Sensing and Satellite Research Group, School of Earth and Planetary Sciences, Curtin University, Perth, WA 6845, Australia
   Sorbonne Université, CNRS, Laboratoire d’Océanographie de Villefranche, Villefranche sur Mer 06230, France
   Sorbonne Université, CNRS, Institut de la Mer de Villefranche, Villefranche sur Mer 06230, France
   Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
   Division Technique INSU-CNRS, 92195 Meudon CEDEX, France
C2 UNIV SORBONNE, FRANCE
   UNIV NEW SOUTH WALES, AUSTRALIA
   UNIV CURTIN, AUSTRALIA
   UNIV SORBONNE, FRANCE
   UNIV SORBONNE, FRANCE
   UNIV E ANGLIA, UK
   INSU-CNRS, FRANCE
IN DOAJ
IF 4.9
TC 2
UR https://archimer.ifremer.fr/doc/00737/84858/89883.pdf
   https://archimer.ifremer.fr/doc/00737/84858/95969.pdf
LA English
DT Article
CR BOUSSOLE
   BOUSSOLE
AB Several trigger mechanisms have been proposed for the onset of the phytoplankton spring bloom. Among these is that phytoplankton cells begin to bloom when they experience higher average light levels in shallower mixed layers, a result of the surface net heat fluxes becoming positive and wind strength decreasing. We study the impact of these two forcings in the northwestern Mediterranean Sea. We take advantage of hourly measurements of oceanic and atmospheric parameters collected at two neighbouring moorings during the months of March and April in the years 2016 to 2019, combined with glider data in 2016. We identify the onset of the surface phytoplankton growth as concomitant with the start of significant biological activity detected by a sudden decrease in dissolved inorganic carbon derived from measurements in the upper 10 m of the water column. A rapid reduction in wind stress following high-wind events is observed at the same time. A resulting shallow mixing layer favours carbon uptake by phytoplankton lasting a few days. Simultaneously, the air–sea net heat flux switches from negative to positive, linked to changes in the latent air–sea heat flux, which is proportional to the wind speed. This results in an increased thermal stratification of the ocean's surface layers. In 2016, glider data show that the mixing layer is significantly shallower than the mixed layer at the onset of the surface phytoplankton bloom. We conclude that decreases in the mixing- and mixed-layer depths lead to the onset of the phytoplankton growth due to the relaxation of wind speed following storms. We estimate net daily community production in the mixing layer over periods of 3 d between 2016 and 2019 as between 38 and 191 mmol C m−2. These results have important implications, as biological processes play a major role in the seasonal evolution of surface pCO2 and thereby the rate of reduction in atmospheric CO2 by exchange at the air–sea interface. 
PY 2022
PD AUG
SO Biogeosciences
SN 1726-4170
PU Copernicus GmbH
VL 19
IS 16
UT 000847360400001
BP 3911
EP 3920
DI 10.5194/bg-19-3911-2022
ID 84858
ER

EF