U.S.
JGOFS
Synthesis & Modeling Project |
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Tsung-Hung Peng
Jia-Zhong Zhang Yuan-Hui Li |
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Re-evaluation of Redfield
ratios using OACES and DOE/WOCE/JGOFS CO2 survey data
NOAA/DOE OACES, 36 months |
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PROJECT DESCRIPTION: | The stoichiometric ratios (or Redfield ratios) of
P:N:C:O2 during photosynthesis, respiration, and remineralization
processes are fundamental for our understanding biogeochemistry in the
ocean. The separation of anthropogenic CO2 from the large
background variability of dissolved inorganic carbon in the ocean in the
C* calculation (Gruber et al., 1996) depends on how well we know these
stoichiometric ratios. To improve the estimate of anthropogenic CO2
in the ocean using NOAA/DOE global CO2 survey data, we must
first improve the estimates of Redfield ratios by using the available data
including those obtained during the NOAA/DOE global CO2 survey
cruises. We propose to re-evaluate the Redfield ratios based on these
new data sets by carrying out the new method of two-end-member and three-end-member
mixing models of Li et al. (1998) using the vertical profile data set,
as well as using the interpolated data to desired isopycnal surfaces corresponding
to various depth as in the traditional two-end-member mixing model.
Close collaboration with the Princeton group led by Dr. Key will be maintained.
This group focuses on evaluation of Redfield ratios with the isopycnal
two-end-member method. Results of our estimates will be compared
with theirs and both results will be evaluated to obtain the best possible
Redfield ratios. We also propose to analyze NOAA/DOE nutrient data
to examine specifically the N/P remineralization ratio and effects of nitrification
and denitrification on this ratio in the global oceans.
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DATA: | Redfield ratios based on WOCE and GEOSECS sections in Atlantic, Indian, and Pacific Oceans, via SMP Data collection. | |
PUBLICATIONS: | Li, Y-H and T-H Peng. submitted. Latitudinal change of remineralization ratios in the oceans and its implication for nutrient cycles. | |
RELATED PROJECTS: | Barber; Chai; Dugdale; Wilkerson; Peng "New
and export productivity regulation by Si and Fe in the equatorial Pacific
Ocean"
Key; Gordon; Sabine; Gruber; Mordy "Determination of the Redfield remineralization ratios based on neutral surface analysis of the new global data set" Sabine; Key; Feely; Millero; Wanninkhof; Kozyr "Synthesis and interpretation of the NOAA/DOE Global CO2 survey data"
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INVESTIGATOR
INFORMATION: |
Dr. Tsung-Hung
Peng
NOAA/AOML 4301 Rickenbacker Causeway Miami, FL 33149-1026 tel: (305) 361-4399 fax: (305) 361-4392 tsung-hung.peng@noaa.gov http://www.aoml.noaa.gov/ocd/people/peng/ Dr. Jia-Zhong Zhang
Dr. Yuan-Hui Li
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