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Title: Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model

Abstract

Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a fact that is often omitted from biogeochemical ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observational data coverage and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C : N : P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model (CESM) and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolvedmore » organic C, N, and P below 100 m was found to be 2.28 Pg C yr -1 (143 Tmol C yr -1, 16.4 Tmol N yr -1, and 1 Tmol P yr -1, respectively, with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. Dissolved organic carbon (DOC) export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less

Authors:
 [1];  [1];  [1];  [1]
  1. Univ. of California, Irvine, CA (United States)
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Science Foundation (NSF)
OSTI Identifier:
1198058
Grant/Contract Number:  
ER65358
Resource Type:
Journal Article: Published Article
Journal Name:
Biogeosciences (Online)
Additional Journal Information:
Journal Name: Biogeosciences (Online) Journal Volume: 12 Journal Issue: 1; Journal ID: ISSN 1726-4189
Publisher:
European Geosciences Union
Country of Publication:
Germany
Language:
English

Citation Formats

Letscher, R. T., Moore, J. K., Teng, Y. -C., and Primeau, F. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model. Germany: N. p., 2015. Web. doi:10.5194/bg-12-209-2015.
Letscher, R. T., Moore, J. K., Teng, Y. -C., & Primeau, F. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model. Germany. doi:10.5194/bg-12-209-2015.
Letscher, R. T., Moore, J. K., Teng, Y. -C., and Primeau, F. Mon . "Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model". Germany. doi:10.5194/bg-12-209-2015.
@article{osti_1198058,
title = {Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model},
author = {Letscher, R. T. and Moore, J. K. and Teng, Y. -C. and Primeau, F.},
abstractNote = {Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a fact that is often omitted from biogeochemical ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observational data coverage and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C : N : P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model (CESM) and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr-1 (143 Tmol C yr-1, 16.4 Tmol N yr-1, and 1 Tmol P yr-1, respectively, with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. Dissolved organic carbon (DOC) export contributed ~ 25% of the combined organic C export to depths greater than 100 m.},
doi = {10.5194/bg-12-209-2015},
journal = {Biogeosciences (Online)},
number = 1,
volume = 12,
place = {Germany},
year = {Mon Jan 12 00:00:00 EST 2015},
month = {Mon Jan 12 00:00:00 EST 2015}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.5194/bg-12-209-2015

Citation Metrics:
Cited by: 15 works
Citation information provided by
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