A ten-year time series from Monterey Bay,
California: Seasonal, interannual and long-term patterns
Results are taken from a ten-year time series of ship occupations of five major
stations in Monterey Bay that began in 1989 and includes data from the 1992-93 and 1997-98
El Niņos. The ship observations are supplemented by moored observations of currents
and winds. Satellite observations of temperature and ocean color provide spatial coverage.
Our primary focus is phytoplankton, the organisms that form the base of the oceanic
ecosystem. We report the seasonal mean fields and use these fields to quantitatively
assess the consequences of El Niņo as well as long term trends.
There is clear physical-biological coupling in the time series, starting with the
seasonal cycle. There appears a maximum in nutrients, centric diatoms, chlorophyll and
primary production associated with the upwelling season. The so-called oceanic and winter
seasons also have characteristic physics and biology. During the warmer El Niņo years
chlorophyll levels dropped (-19% in 1992 and -21% in 1997), and during colder years levels
have risen (+19% in 1991 and +11% in 1994). Results indicate sea surface temperature has
gradually risen over the course of the ten-year study, while chlorophyll, primary
production and subsurface nitrate levels are decreasing.
Next: Seasonal Cycle
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welcome to contact us through our group's webmaster, reiko at mbari.org.