{"id":{"repo_id":"east-anglia","oai_identifier":"oai:ueaeprints.uea.ac.uk:42341"},"canonical_url":"https://search.dev.ndltd.org/etd/east-anglia/oai:ueaeprints.uea.ac.uk:42341","repository":{"repo_id":"east-anglia","name":"University of East Anglia","base_url":"https://ueaeprints.uea.ac.uk/cgi/oai2"},"display":{"title":"Triple oxygen isotopes and oxygen/argon ratio measurements to enhance coastal and open ocean production/respiration comparisons","abstract":"The accurate measurement of marine plankton production is required to constrain the global carbon balance. Traditional methods rely on bottle incubations, which are thought to underestimate plankton production. This study presents in situ measurements of gross oxygen production (G) derived from triple oxygen isotope analysis and of net community oxygen production (N) derived from O2/Ar ratios at station L4, which is part of the Western English Channel Observatory (WECO) and a latitudinal transect through the subtropical gyres in the Atlantic Ocean in October/November 2010. G and N were determined at weekly intervals between September 2009 and September 2010 at station L4. Annual N was positive (net autotrophic) at (0.88±0.24) mol m-2 a-1 O2. The triple oxygen isotope method overestimated G during winter months due to entrainment of waters from below the mixed layer. N of (3.8 ± 3.1) mmol m-2 a-1 O2 in the North Atlantic Gyre (NAG) and (2.9 ± 2.4) mmol m-2 a-1 O2 in the South Atlantic Gyre (SAG) show both gyres to be net autotrophic at the time of sampling. G values of (169±106) mmol m-2 a-1 O2 in the NAG and (250±130) mmol m-2 a-1 O2 in the SAG were higher than published results. Diapycnal mixing was found to contribute about 20% to apparent mixed layer N in both gyres and to G in the NAG. In order to achieve these results, a gas extraction line was built and tested. A method to halt biological activity in triple oxygen isotope and discrete O2/Ar samples was assessed. Benzalkonium chloride was found to be a less toxic alternative to mercuric chloride on short time scales of three days. Our results of N agree with previous in situ productivity measurements in these regions and highlight the importance of including physical effects in the estimates of G.","abstract_html":"The accurate measurement of marine plankton production is required to constrain the global carbon balance. Traditional methods rely on bottle incubations, which are thought to underestimate plankton production. This study presents in situ measurements of gross oxygen production (G) derived from triple oxygen isotope analysis and of net community oxygen production (N) derived from O2/Ar ratios at station L4, which is part of the Western English Channel Observatory (WECO) and a latitudinal transect through the subtropical gyres in the Atlantic Ocean in October/November 2010. G and N were determined at weekly intervals between September 2009 and September 2010 at station L4. Annual N was positive (net autotrophic) at (0.88±0.24) mol m-2 a-1 O2. The triple oxygen isotope method overestimated G during winter months due to entrainment of waters from below the mixed layer. N of (3.8 ± 3.1) mmol m-2 a-1 O2 in the North Atlantic Gyre (NAG) and (2.9 ± 2.4) mmol m-2 a-1 O2 in the South Atlantic Gyre (SAG) show both gyres to be net autotrophic at the time of sampling. G values of (169±106) mmol m-2 a-1 O2 in the NAG and (250±130) mmol m-2 a-1 O2 in the SAG were higher than published results. Diapycnal mixing was found to contribute about 20% to apparent mixed layer N in both gyres and to G in the NAG. In order to achieve these results, a gas extraction line was built and tested. A method to halt biological activity in triple oxygen isotope and discrete O2/Ar samples was assessed. Benzalkonium chloride was found to be a less toxic alternative to mercuric chloride on short time scales of three days. Our results of N agree with previous in situ productivity measurements in these regions and highlight the importance of including physical effects in the estimates of G.","abstract_has_math":false,"creators":["Gloel, Johanna"],"institution":"University of East Anglia","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-10","date_published":"2012-10","updated_at":"2026-07-24T02:11:51Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Gloel, Johanna"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-10"]},{"key":"dc:date.issued","label":"Date","values":["2012-10"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Schoolof Environmental Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of East Anglia"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://ueaeprints.uea.ac.uk/id/eprint/42341/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ueaeprints.uea.ac.uk/id/eprint/42341/1/2012GloelJPhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The accurate measurement of marine plankton production is required to constrain the global carbon balance. Traditional methods rely on bottle incubations, which are thought to underestimate plankton production. This study presents in situ measurements of gross oxygen production (G) derived from triple oxygen isotope analysis and of net community oxygen production (N) derived from O2/Ar ratios at station L4, which is part of the Western English Channel Observatory (WECO) and a latitudinal transect through the subtropical gyres in the Atlantic Ocean in October/November 2010. G and N were determined at weekly intervals between September 2009 and September 2010 at station L4. Annual N was positive (net autotrophic) at (0.88±0.24) mol m-2 a-1 O2. The triple oxygen isotope method overestimated G during winter months due to entrainment of waters from below the mixed layer. N of (3.8 ± 3.1) mmol m-2 a-1 O2 in the North Atlantic Gyre (NAG) and (2.9 ± 2.4) mmol m-2 a-1 O2 in the South Atlantic Gyre (SAG) show both gyres to be net autotrophic at the time of sampling. G values of (169±106) mmol m-2 a-1 O2 in the NAG and (250±130) mmol m-2 a-1 O2 in the SAG were higher than published results. Diapycnal mixing was found to contribute about 20% to apparent mixed layer N in both gyres and to G in the NAG. In order to achieve these results, a gas extraction line was built and tested. A method to halt biological activity in triple oxygen isotope and discrete O2/Ar samples was assessed. Benzalkonium chloride was found to be a less toxic alternative to mercuric chloride on short time scales of three days. Our results of N agree with previous in situ productivity measurements in these regions and highlight the importance of including physical effects in the estimates of G."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Triple oxygen isotopes and oxygen/argon ratio measurements to enhance coastal and open ocean production/respiration comparisons"]}]}],"canonical_facts":{"dc:creator":["Gloel, Johanna"],"dc:date":["2012-10"],"dc:date.issued":["2012-10"],"dc:description.abstract":["The accurate measurement of marine plankton production is required to constrain the global carbon balance. Traditional methods rely on bottle incubations, which are thought to underestimate plankton production. This study presents in situ measurements of gross oxygen production (G) derived from triple oxygen isotope analysis and of net community oxygen production (N) derived from O2/Ar ratios at station L4, which is part of the Western English Channel Observatory (WECO) and a latitudinal transect through the subtropical gyres in the Atlantic Ocean in October/November 2010. G and N were determined at weekly intervals between September 2009 and September 2010 at station L4. Annual N was positive (net autotrophic) at (0.88±0.24) mol m-2 a-1 O2. The triple oxygen isotope method overestimated G during winter months due to entrainment of waters from below the mixed layer. N of (3.8 ± 3.1) mmol m-2 a-1 O2 in the North Atlantic Gyre (NAG) and (2.9 ± 2.4) mmol m-2 a-1 O2 in the South Atlantic Gyre (SAG) show both gyres to be net autotrophic at the time of sampling. G values of (169±106) mmol m-2 a-1 O2 in the NAG and (250±130) mmol m-2 a-1 O2 in the SAG were higher than published results. Diapycnal mixing was found to contribute about 20% to apparent mixed layer N in both gyres and to G in the NAG. In order to achieve these results, a gas extraction line was built and tested. A method to halt biological activity in triple oxygen isotope and discrete O2/Ar samples was assessed. Benzalkonium chloride was found to be a less toxic alternative to mercuric chloride on short time scales of three days. Our results of N agree with previous in situ productivity measurements in these regions and highlight the importance of including physical effects in the estimates of G."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://ueaeprints.uea.ac.uk/id/eprint/42341/1/2012GloelJPhD.pdf"],"dc:language":["en"],"dc:publisher.department":["Schoolof Environmental Sciences"],"dc:publisher.institution":["University of East Anglia"],"dc:relation.isreferencedby":["https://ueaeprints.uea.ac.uk/id/eprint/42341/"],"dc:title":["Triple oxygen isotopes and oxygen/argon ratio measurements to enhance coastal and open ocean production/respiration comparisons"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T02:11:51Z"}