<mods:mods xmlns:mods="http://www.loc.gov/mods/v3" xmlns:METS="http://www.loc.gov/METS/" xmlns:fits="http://hul.harvard.edu/ois/xml/ns/fits/fits_output" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:IR="http://dl.lib.brown.edu/md/irdata" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:rights="http://cosimo.stanford.edu/sdr/metsrights/" ID="etd295">
<mods:titleInfo>
<mods:title>A Data Assimilating Model of the Microbial Ecosystem in the Open Ocean</mods:title>
</mods:titleInfo>
<mods:name type="personal">
<mods:namePart>Luo, Yawei</mods:namePart>
<mods:role>
<mods:roleTerm type="text">creator</mods:roleTerm>
</mods:role>
</mods:name>
<mods:originInfo>
<mods:copyrightDate keyDate="yes" encoding="w3cdtf">2009</mods:copyrightDate>
</mods:originInfo>
<mods:physicalDescription>
<mods:extent>xiv, 310 p.</mods:extent>
<mods:digitalOrigin>born digital</mods:digitalOrigin>
</mods:physicalDescription>
<mods:note>Thesis (Ph.D.) -- Brown University (2010)</mods:note>
<mods:name type="personal">
<mods:namePart>Ducklow, Hugh</mods:namePart>
<mods:role>
<mods:roleTerm type="text">director</mods:roleTerm>
</mods:role>
</mods:name>
<mods:name type="personal">
<mods:namePart>Friedrichs, Marjorie</mods:namePart>
<mods:role>
<mods:roleTerm type="text">reader</mods:roleTerm>
</mods:role>
</mods:name>
<mods:name type="personal">
<mods:namePart>Prell, Warren</mods:namePart>
<mods:role>
<mods:roleTerm type="text">reader</mods:roleTerm>
</mods:role>
</mods:name>
<mods:name type="personal">
<mods:namePart>Vallino, Joseph</mods:namePart>
<mods:role>
<mods:roleTerm type="text">reader</mods:roleTerm>
</mods:role>
</mods:name>
<mods:name type="corporate">
<mods:namePart>Brown University. Division of Biology and Medicine. Ecological and Evolutionary Biology</mods:namePart>
<mods:role>
<mods:roleTerm type="text">sponsor</mods:roleTerm>
</mods:role>
</mods:name>
<mods:genre authority="aat">theses</mods:genre>
<mods:abstract>Prokaryotic microbes, commonly termed bacteria, are essential components of the ecosystem in the open ocean. They are major primary producers, major diazotrophs that fix dinitrogen
(N2) into new bio-available nitrogen, and are major consumers of dissolved organic matter (DOM). An ocean ecosystem model was constructed for the open ocean focusing on bacterial dynamics. A
data assimilation technology was adapted to integrate the model with observations by objectively optimizing model parameters and minimizing the differences between the model results and
observations. As up to 17 types of major biogeochemical observations, usually in seasonal or monthly profiles, were assimilated, the model was constrained and tested rigorously to fit different
aspects of the ecosystem simultaneously. The 1-dimensional model was applied to three open ocean sites: the Arabian Sea, Equatorial Pacific and Hawaii Ocean Time-series (HOT). Good fitness to
most of the observations supported the robustness of the model and reliability of the results. The results indicated the importance of heterotrophic bacteria in carbon cycling and nutrient
regeneration in all the three sites. Semilabile DOM was identified as a stabilizing resource for heterotrophic bacteria. The model also indicated refractory DOM could be an important form of
export from the upper ocean. Heterotrophic bacterial production (BP) observations improved the model by strengthening constraints on the model parameters. Despite uncertainties related to
estimating BP, the model supported current estimates of BP as 5 ? 25% of primary production and the commonly-used conversion factors for BP measurements as 0.7 ? 3.1 kg C/mol leucine
incorporation. A 15-year modeling experiment at HOT successfully simulated the observed interannual increase of primary production. The model suggested three mechanisms for this increase: (1)
the deepening mixed layer and increased physical nitrate supply from the deep ocean, (2) enhanced nitrogen recycling as part of N2 fixation was replaced with physical nitrate supply, and (3) new
nitrogen supply from semilabile DOM. The last two mechanisms only applied to the surface 20 m.</mods:abstract>
<mods:subject authority="local">
<mods:topic>Data assimilation</mods:topic>
</mods:subject>
<mods:subject authority="local">
<mods:topic>Marine Ecosystem</mods:topic>
</mods:subject>
<mods:subject authority="local">
<mods:topic>Model</mods:topic>
</mods:subject>
<mods:subject authority="local">
<mods:topic>Dissolved organic matter</mods:topic>
</mods:subject>
<mods:subject authority="local">
<mods:topic>Primary production</mods:topic>
</mods:subject>
<mods:subject authority="local">
<mods:topic>Dinitrogen fixation</mods:topic>
</mods:subject>
<mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1753801"><mods:topic>Heterotrophic bacteria</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1766441"><mods:topic>Water--Organic compound content</mods:topic></mods:subject><mods:subject authority="FAST" authorityURI="http://id.worldcat.org/fast" valueURI="http://id.worldcat.org/fast/1038049"><mods:topic>Nitrogen--Fixation</mods:topic></mods:subject><mods:recordInfo>
<mods:recordContentSource authority="marcorg">RPB</mods:recordContentSource>
<mods:recordCreationDate encoding="iso8601">20091218</mods:recordCreationDate>
</mods:recordInfo>
<mods:language><mods:languageTerm type="code" authority="iso639-2b">eng</mods:languageTerm><mods:languageTerm type="text">English</mods:languageTerm></mods:language><mods:identifier type="doi">10.7301/Z07W69GG</mods:identifier><mods:accessCondition type="rights statement" xlink:href="http://rightsstatements.org/vocab/InC/1.0/">In Copyright</mods:accessCondition><mods:accessCondition type="restriction on access">Collection is open for research.</mods:accessCondition><mods:typeOfResource authority="primo">dissertations</mods:typeOfResource></mods:mods>