Basin-Wide Modification of Dynamical and Biogeochemical Processes by the Positive Phase of the Indian Ocean Dipole During the SeaWiFS Era

  1. Jerry D. Wiggert,
  2. Raleigh R. Hood,
  3. S.Wajih A. Naqvi,
  4. Kenneth H. Brink and
  5. Sharon L. Smith
  1. Jerry D. Wiggert1,
  2. Jéréme Vialard2 and
  3. Michael J. Behrenfeld3

Published Online: 19 MAR 2013

DOI: 10.1029/2008GM000776

Indian Ocean Biogeochemical Processes and Ecological Variability

Indian Ocean Biogeochemical Processes and Ecological Variability

How to Cite

Wiggert, J. D., Vialard, J. and Behrenfeld, M. J. (2009) Basin-Wide Modification of Dynamical and Biogeochemical Processes by the Positive Phase of the Indian Ocean Dipole During the SeaWiFS Era, in Indian Ocean Biogeochemical Processes and Ecological Variability (eds J. D. Wiggert, R. R. Hood, S.Wajih. A. Naqvi, K. H. Brink and S. L. Smith), American Geophysical Union, Washington, D. C.. doi: 10.1029/2008GM000776

Author Information

  1. 1

    Department of Marine Sciences, University of Southern Mississippi Stennis Space Center, Mississippi, USA

  2. 2

    Laboratoire D'Oc'Anographie: Expérimentation Et Approches Numériques, CNRS, UPMC, IRD Paris, France

  3. 3

    Department of Botany and Plant Pathology, Oregon State University Corvallis, Oregon, USA

Publication History

  1. Published Online: 19 MAR 2013
  2. Published Print: 1 JAN 2009

ISBN Information

Print ISBN: 9780875904757

Online ISBN: 9781118666364

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Keywords:

  • Chemical oceanography—Indian Ocean;
  • Marine chemical ecology—Indian Ocean;
  • Carbon cycle(Biogeochemistry)—India Ocean;
  • Monsoons—Indian Ocean;
  • Indian Ocean—Environmental conditions

Summary

Characterizing how the Indian Ocean dipole (IOD) modifies typical basin-wide dynamical variability has been vigorously pursued over the past decade. Along with this dynamic response, a clear biological impact has been revealed in the ocean color data acquired by remote sensing platforms such as Sea-viewing Wide Field-of-View Sensor (SeaWiFS). The signature feature illustrating IOD alteration of typical spatiotemporal chlorophyll variability is the phytoplankton bloom that first appears in September along the eastern boundary of the IO in tropical waters that are normally highly oligotrophic. Positive chlorophyll anomalies (CLa) are also apparent in the southeastern Bay of Bengal, while negative anomalies are observed over much of the Arabian Sea. Moreover, in situ measurements obtained by the R/V Suroit as part of the Cirene cruise during the 2006/2007 IOD reveal anomalous subsurface biochemical distributions in the southern tropical IO that are not reflected in SeaWiFS data. Despite the clear basin-wide influence of IOD events on biological variability, the accompanying influence on biogeochemical cycling that must occur has received little attention. Here, the dynamical signatures apparent in remote sensing fields for the two positive-phase IODs of the SeaWiFS era are used to illuminate how these events are similar or distinct. A corresponding comparison of IOD-engendered surface CLa is performed, with the dynamical fields providing the framework for interpreting the mechanisms underlying the biological response. Then, results from a newly developed net primary production algorithm are presented that provide the first characterization of how biogeochemical fluxes throughout the IO are altered by IOD occurrence