Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean
P. J. Vidya
S. Prasanna Kumar
M. Gauns
A. Verenkar
Daniela Unger
V. Ramaswamy
Abstract
Seasonal cycle of biogenic fluxes obtained fromsediment trap at two locations 5◦24′N, 86◦46′E (southernBay of Bengal trap; SBBT) and 3◦34′N, 77◦46′E (equato-rial Indian Ocean trap; EIOT) within the equatorial IndianOcean (EIO) were examined to understand the factors thatcontrol them. The sediment trap data at SBBT was collectedfor ten years from November 1987 while that at EIOT wasfor a one year period from January 1996. The characteris-tic of biogenic flux at SBBT was the strong seasonality withpeak flux in August, while lack of seasonality characterisedthe flux at EIOT. The high chlorophyll biomass at the SBBTduring the summer monsoon was supported by a combina-tion of processes such as wind-mixing and advection, bothof which supplied new nitrogen to the upper ocean. In con-trast, the elevated chlorophyll at EIOT during summer mon-soon was supported only by wind mixing. High cell counts ofphytoplankton (> 5 μm) at SBBT dominated by diatoms sug-gest the operation of classical food web and high carbon ex-port. On the contrary, dominance of pico-phytoplankton andone-and-a-half time higher magnitude of micro-zooplanktonbiomass along with 2-fold lesser meso-zooplankton at EIOTindicated the importance of microbial loop. The substantialdecrease in the carbon export at EIOT indicated faster rem-ineralization of photosynthetically produced organic matter.
Vidya P.J., Prasanna Kumar S., Gauns M., Verenkar A., Unger D. and Ramaswamy V. (2013) Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean. Biogeosciences Discussions 10(2): 2889-2936. 10.5194/bg-10-7493-2013
@article{Vidya2013,
Title = {Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean},
Author = {Vidya, P. J. and Prasanna Kumar, S. and Gauns, M. and Verenkar, A. and Unger, Daniela and Ramaswamy, V.},
Editor = {},
Journal = {Biogeosciences Discussions},
Year = {2013},
Pages = {2889-2936},
Volume = {10},
Doi = {10.5194/bg-10-7493-2013},
Abstract = {Seasonal cycle of biogenic fluxes obtained fromsediment trap at two locations 5◦24′N, 86◦46′E (southernBay of Bengal trap; SBBT) and 3◦34′N, 77◦46′E (equato-rial Indian Ocean trap; EIOT) within the equatorial IndianOcean (EIO) were examined to understand the factors thatcontrol them. The sediment trap data at SBBT was collectedfor ten years from November 1987 while that at EIOT wasfor a one year period from January 1996. The characteris-tic of biogenic flux at SBBT was the strong seasonality withpeak flux in August, while lack of seasonality characterisedthe flux at EIOT. The high chlorophyll biomass at the SBBTduring the summer monsoon was supported by a combina-tion of processes such as wind-mixing and advection, bothof which supplied new nitrogen to the upper ocean. In con-trast, the elevated chlorophyll at EIOT during summer mon-soon was supported only by wind mixing. High cell counts ofphytoplankton (> 5 μm) at SBBT dominated by diatoms sug-gest the operation of classical food web and high carbon ex-port. On the contrary, dominance of pico-phytoplankton andone-and-a-half time higher magnitude of micro-zooplanktonbiomass along with 2-fold lesser meso-zooplankton at EIOTindicated the importance of microbial loop. The substantialdecrease in the carbon export at EIOT indicated faster rem-ineralization of photosynthetically produced organic matter.},
}
TY - JOUR
AU - Vidya, P. J.
AU - Prasanna Kumar, S.
AU - Gauns, M.
AU - Verenkar, A.
AU - Unger, Daniela
AU - Ramaswamy, V.
TI - Influence of physical and biological processes on the seasonal cycle of biogenic flux in the equatorial Indian Ocean
T2 - Biogeosciences Discussions
PY - 2013
SP - 2889-2936
VL - 10
DO - 10.5194/bg-10-7493-2013
AB - Seasonal cycle of biogenic fluxes obtained fromsediment trap at two locations 5◦24′N, 86◦46′E (southernBay of Bengal trap; SBBT) and 3◦34′N, 77◦46′E (equato-rial Indian Ocean trap; EIOT) within the equatorial IndianOcean (EIO) were examined to understand the factors thatcontrol them. The sediment trap data at SBBT was collectedfor ten years from November 1987 while that at EIOT wasfor a one year period from January 1996. The characteris-tic of biogenic flux at SBBT was the strong seasonality withpeak flux in August, while lack of seasonality characterisedthe flux at EIOT. The high chlorophyll biomass at the SBBTduring the summer monsoon was supported by a combina-tion of processes such as wind-mixing and advection, bothof which supplied new nitrogen to the upper ocean. In con-trast, the elevated chlorophyll at EIOT during summer mon-soon was supported only by wind mixing. High cell counts ofphytoplankton (> 5 μm) at SBBT dominated by diatoms sug-gest the operation of classical food web and high carbon ex-port. On the contrary, dominance of pico-phytoplankton andone-and-a-half time higher magnitude of micro-zooplanktonbiomass along with 2-fold lesser meso-zooplankton at EIOTindicated the importance of microbial loop. The substantialdecrease in the carbon export at EIOT indicated faster rem-ineralization of photosynthetically produced organic matter.
ER -
