Title:
The importance of nitrogen fixation to the nitrogen budget of the North Atlantic Ocean

dc.contributor.author Hall, Madison
dc.contributor.department Biology
dc.date.accessioned 2009-06-08T19:18:11Z
dc.date.available 2009-06-08T19:18:11Z
dc.date.issued 2009-05-04
dc.description.abstract Samples of seawater and suspended particles in the mixed layer (top 100m) were collected on Seward Johnson cruises SJ9603, SJ9612, and SJ0005 to the tropical and subtropical North Atlantic Ocean. Deep-water nitrate has been proposed to provide most nitrogen to the upper water column of the North Atlantic Ocean. Recent evidence has shown that N2 fixation is plays a significant role in supplying nitrogen for new production. The ratio of 15N: 14N, referred to as δ15N, provides a useful tracer for identifying major sources to new nitrogen in the upper water column. Persistently low δ15N values coupled with high N* values imply a large contribution of N2 fixation, with 83 of 85 stations suggesting some contribution of N2 fixation. The highest levels of diazotrophic contribution were recorded in the southwestern tropical Atlantic Ocean, where a large bloom of the N2 fixing diatom/ cyanobacterial association Hemiaulus/ Richelia association in addition to the N2 fixing cyanobacterium Trichodesmium was previously recorded. The isotopic data, N* data, and diazotrophic contribution estimates show N2 fixation is making a significant contribution to the nitrogen budget of the nutrient-poor North Atlantic Ocean. en
dc.description.advisor Montoya, Joseph - Faculty Mentor ; Garton, David - Committee Member/Second Reader
dc.identifier.uri http://hdl.handle.net/1853/28175
dc.language.iso en_US en
dc.publisher Georgia Institute of Technology en
dc.subject North Atlantic Ocean en
dc.subject Marine nitrogen cycle en
dc.subject N* en
dc.subject Nitrogen fixation en
dc.title The importance of nitrogen fixation to the nitrogen budget of the North Atlantic Ocean en
dc.type Text
dc.type.genre Undergraduate Thesis
dspace.entity.type Publication
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Biological Sciences
local.contributor.corporatename Undergraduate Research Opportunities Program
local.relation.ispartofseries Undergraduate Research Option Theses
relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
relation.isOrgUnitOfPublication 0db885f5-939b-4de1-807b-f2ec73714200
relation.isSeriesOfPublication e1a827bd-cf25-4b83-ba24-70848b7036ac
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