{"id":{"repo_id":"woods-hole","oai_identifier":"oai:darchive.mblwhoilibrary.org:1912/5465"},"canonical_url":"https://search.dev.ndltd.org/etd/woods-hole/oai:darchive.mblwhoilibrary.org:1912/5465","repository":{"repo_id":"woods-hole","name":"Woods Hole Oceanographic Institute","base_url":"https://darchive.mblwhoilibrary.org/server/oai/request"},"display":{"title":"Circulations and water mass balances in the Brazil Basin","abstract":"Based on the Levitus atlas, we find that the application of the Montgomery streamfunction to the isopycnal surfaces induces an error which can not be ignored in some regions in the ocean. The error arises from the sloping effect of the specific volume anomaly along isopycnal surfaces. By including the major part of this effect, new streamfunctions, namely the pressure anomaly and main pressure streamfunctions, are suggested for the use in potential density coordinates. By using the newly proposed streamfunction and by including the variations of specific volume anomaly along isopycnal surfaces, the inverse model proposed by Hogg (1987) is modified for increasing accuracy and applied to the Brazil Basin to study the circulation, diffusion and water mass balances. The equations in the model, i.e. the dynamic equation, continuity equation, integrated vorticity equation, and conservation equations for heat, salt and oxygen (in which a consumption sink term is allowed), are written in centered finite difference form with lateral steps of 2 degree latitude and longitude and 8 levels in the vertical. This system of equations with constraints of positive diffusivities and oxygen consumption rates is solved by the inverse method. The results indicate that the circulation in the upper oceans is consistent with previous works, but that in the deep ocean is quite different. In the NADW region, we find a coincidence of the flows with the tongues of water properties. The diffusivities and diapycnal velocities seem stronger in the region near the equator than in the south, with reasonable values. Diffusion plays an important role in the water mass balance. Examples show that similar property fields may results from different processes.","abstract_html":"Based on the Levitus atlas, we find that the application of the Montgomery streamfunction to the isopycnal surfaces induces an error which can not be ignored in some regions in the ocean. The error arises from the sloping effect of the specific volume anomaly along isopycnal surfaces. By including the major part of this effect, new streamfunctions, namely the pressure anomaly and main pressure streamfunctions, are suggested for the use in potential density coordinates. By using the newly proposed streamfunction and by including the variations of specific volume anomaly along isopycnal surfaces, the inverse model proposed by Hogg (1987) is modified for increasing accuracy and applied to the Brazil Basin to study the circulation, diffusion and water mass balances. The equations in the model, i.e. the dynamic equation, continuity equation, integrated vorticity equation, and conservation equations for heat, salt and oxygen (in which a consumption sink term is allowed), are written in centered finite difference form with lateral steps of 2 degree latitude and longitude and 8 levels in the vertical. This system of equations with constraints of positive diffusivities and oxygen consumption rates is solved by the inverse method. The results indicate that the circulation in the upper oceans is consistent with previous works, but that in the deep ocean is quite different. In the NADW region, we find a coincidence of the flows with the tongues of water properties. The diffusivities and diapycnal velocities seem stronger in the region near the equator than in the south, with reasonable values. Diffusion plays an important role in the water mass balance. Examples show that similar property fields may results from different processes.","abstract_has_math":false,"creators":["Zhang, Huai-Min"],"institution":"Massachusetts Institute of Technology and Woods Hole Oceanographic Institution","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991-09","date_published":"1991-09","updated_at":"2026-07-27T22:05:12Z","subjects":["Ocean circulation","Oceanic mixing"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.1575/1912/5465"],"render_values":[{"text":"10.1575/1912/5465","href":"https://doi.org/10.1575/1912/5465","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/1912/5465","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Zhang, Huai-Min"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2012-10-17T18:38:36Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2012-10-17T18:38:36Z"]},{"key":"dc:date.issued","label":"Date","values":["1991-09"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology and Woods Hole Oceanographic Institution"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Ocean circulation","Oceanic mixing"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.1575/1912/5465"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/1912/5465"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1991"]},{"key":"dc:description.abstract","label":"Abstract","values":["Based on the Levitus atlas, we find that the application of the Montgomery streamfunction to the isopycnal surfaces induces an error which can not be ignored in some regions in the ocean. The error arises from the sloping effect of the specific volume anomaly along isopycnal surfaces. By including the major part of this effect, new streamfunctions, namely the pressure anomaly and main pressure streamfunctions, are suggested for the use in potential density coordinates. By using the newly proposed streamfunction and by including the variations of specific volume anomaly along isopycnal surfaces, the inverse model proposed by Hogg (1987) is modified for increasing accuracy and applied to the Brazil Basin to study the circulation, diffusion and water mass balances. The equations in the model, i.e. the dynamic equation, continuity equation, integrated vorticity equation, and conservation equations for heat, salt and oxygen (in which a consumption sink term is allowed), are written in centered finite difference form with lateral steps of 2 degree latitude and longitude and 8 levels in the vertical. This system of equations with constraints of positive diffusivities and oxygen consumption rates is solved by the inverse method. The results indicate that the circulation in the upper oceans is consistent with previous works, but that in the deep ocean is quite different. In the NADW region, we find a coincidence of the flows with the tongues of water properties. The diffusivities and diapycnal velocities seem stronger in the region near the equator than in the south, with reasonable values. Diffusion plays an important role in the water mass balance. Examples show that similar property fields may results from different processes."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Circulations and water mass balances in the Brazil Basin"]}]}],"canonical_facts":{"dc:creator":["Zhang, Huai-Min"],"dc:date.accessioned":["2012-10-17T18:38:36Z"],"dc:date.available":["2012-10-17T18:38:36Z"],"dc:date.issued":["1991-09"],"dc:description":["Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1991"],"dc:description.abstract":["Based on the Levitus atlas, we find that the application of the Montgomery streamfunction to the isopycnal surfaces induces an error which can not be ignored in some regions in the ocean. The error arises from the sloping effect of the specific volume anomaly along isopycnal surfaces. By including the major part of this effect, new streamfunctions, namely the pressure anomaly and main pressure streamfunctions, are suggested for the use in potential density coordinates. By using the newly proposed streamfunction and by including the variations of specific volume anomaly along isopycnal surfaces, the inverse model proposed by Hogg (1987) is modified for increasing accuracy and applied to the Brazil Basin to study the circulation, diffusion and water mass balances. The equations in the model, i.e. the dynamic equation, continuity equation, integrated vorticity equation, and conservation equations for heat, salt and oxygen (in which a consumption sink term is allowed), are written in centered finite difference form with lateral steps of 2 degree latitude and longitude and 8 levels in the vertical. This system of equations with constraints of positive diffusivities and oxygen consumption rates is solved by the inverse method. The results indicate that the circulation in the upper oceans is consistent with previous works, but that in the deep ocean is quite different. In the NADW region, we find a coincidence of the flows with the tongues of water properties. The diffusivities and diapycnal velocities seem stronger in the region near the equator than in the south, with reasonable values. Diffusion plays an important role in the water mass balance. Examples show that similar property fields may results from different processes."],"dc:format.mimetype":["application/pdf"],"dc:identifier.doi":["10.1575/1912/5465"],"dc:identifier.uri":["https://hdl.handle.net/1912/5465"],"dc:language.iso":["en_US"],"dc:publisher":["Massachusetts Institute of Technology and Woods Hole Oceanographic Institution"],"dc:subject":["Ocean circulation","Oceanic mixing"],"dc:title":["Circulations and water mass balances in the Brazil Basin"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T22:05:12Z"}