Potential biological responses to basin-scale climate forcing in the Pacific are assessed based on temporal variations in phytoplankton community structure observed at Station ALOHA (1989-2002) and the output of a Regional Ocean Modeling System (ROMS) model. Phytoplankton populations were monitored monthly during this period using taxon-specific pigment analyses. These analyses revealed distinct temporal patterns, with highest pelagophyte abundance during the periods 1990-1993 and 1996-2002. For other key groups, such as the haptophytes and cyanobacteria, there appears to be a recent post-1996 enhancement in their biomass relative to the previous 7-year period of observation. An Ocean General Circulation Model, based on the terrain-following vertical coordinate primitive equation ROMS model, was used to simulate hydrographic dynamics at Station ALOHA. Preliminary analysis comparing the model simulation with TAO observations has shown that the model can realistically reproduce the low-frequency (seasonal-to-interannual) variability. The ROMS simulation during 1989-2002 will be first compared against the HOT physical measurements and then used to help interpret the observed changes in phytoplankton community structure at Station ALOHA.
Presenter:
Dr. Robert Bidigare
Professor
University of Hawaii, Manoa
Director
Center for Marine Microbial Ecology & Diversity (CMMED)
Friday
June 4, 2004
11:00 a.m.
Biomedical Sciences Building, B-103
The Pacific Research Center for Marine Biomedicine (PRCMB) is a newly established center at the University of Hawaii dedicated to trans-disciplinary research designed to gain new knowledge about the profound impacts of the ocean on human health. The Center is funded by the National Science Foundation and the National Institute of Environmental Health Sciences.
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