Woods Hole Oceanographic Institution

Rachel Stanley

» Estuarine Production

» Arctic Primary Production

» High-Resolution Net Community Production

» Intercalibration Study

» Noble Gas Mass Spectrometer

» Carbon Cycle in the Equatorial Pacific

» Air-Sea Gas Exchange

» Biological Production in the Sargasso Sea

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This is the membrane inlet mass spectrometer used for continuous at-sea measurements of Ar and O2. (Rachel Stanley)

Towards a Mechanistic Understanding of Carbon Cycling in the Equatorial Pacific

Prof Michael Bender (Princeton University)
John Kirkpatrick (University of Washington)
Dr. Nicolas Cassar (Princeton University)
Bruce Barnett (Princeton University)
Prof Jim Murray (University of Washington)

The ocean plays a fundamental role in the natural cycle of CO2. Changes in the amount of marine net community production (NCP) influence atmospheric CO2 levels. Understanding the controls on NCP may therefore help us identify possible causes and effects of past climate variability and improve future climate projections. The equatorial Pacific, the largest natural oceanic source of CO2 to the atmosphere, is an ideal testing ground for theories of the controls of NCP in the ocean because many of the factors that have been proposed to control biological production (i.e. Fe, Si, major nutrients, physical instabilities) vary spatially and temporally throughout the region, making it a natural laboratory. Additionally, the equatorial Pacific is a high nutrient, low chlorophyll (HNLC) region, and processes there are representative of other such regions, including the Subarctic Pacific and the Southern Ocean. In the stratified mixed layer, the geochemical tracer O2/Ar reflects the balance between new community production (NCP) and gas exchange whereas the tracer D17O reflects the balance between gross primary production and gas exchange. We are using continuous measurements of O2/Ar from an underway membrane inlet mass spectrometer (MIMS), discrete measurements of D17O, and estimates of gas exchange in order to constrain NCP and gross production throughout a wide region in the Equatorial Pacific. The biological production rates estimated in this study are considered in relation to iron measurements and other factors that might be controlling biological production in this climatically important region. 

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