Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic
The response of phytoplankton to various ecological forcings was examined in the upper waters of the NW Mediterranean (MED) and the subtropical North Atlantic (NA) from field observations, analysis of historical data sets and numerical simulations. Particular emphasis was given to the role played by...
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Universitat Politècnica de Catalunya
2011
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ftupcatalunya:oai:www.tdx.cat:10803/6381 2023-11-12T04:22:09+01:00 Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic Bahamon Rivera, Nixon Cruzado Alorda, Antonio Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental 2011-04-12T15:13:41Z application/pdf http://www.tdx.cat/TDX-1205102-113102 http://hdl.handle.net/10803/6381 eng eng Universitat Politècnica de Catalunya 8468807346 http://www.tdx.cat/TDX-1205102-113102 http://hdl.handle.net/10803/6381 B-4725-2003 ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs. info:eu-repo/semantics/openAccess TDX (Tesis Doctorals en Xarxa) modelos ecológicos fitoplàncton nitrogeno ecologia del plancton mar Mediterráneo noroccidental 2510. Oceanografia 504 574 info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion 2011 ftupcatalunya 2023-10-16T17:17:11Z The response of phytoplankton to various ecological forcings was examined in the upper waters of the NW Mediterranean (MED) and the subtropical North Atlantic (NA) from field observations, analysis of historical data sets and numerical simulations. Particular emphasis was given to the role played by the water column structure in controlling the nitrogen diffusion and new production. Using numerical simulations, the effects of different levels of heating of surface waters and nutrient concentrations in waters below the euphotic zone were examined. Spring microplankton metabolism of surface mixed waters in MED was studied. The system was heterotrophic explained by dark community respiration (DCR) rates higher than gross primary production (GPP) rates. The GPP to DCR ratio was ~0.53, indicating that the system was far from balance between carbon production (photosynthesis) and consumption (respiration), probably caused by organic matter accumulation in the mixed layer favouring respiration over production processes. Summer primary production and nitrogen fluxes in stratified water layers in NA were analysed. The nitrogen flux fuelling new primary production was closely linked to vertical turbulent diffusion at the nitracline rather than at the thermocline. Upward diffused nitrogen inducing new production explaining 21% of total primary production. The vertical turbulent diffusion model used to estimate new production did not explain new production in the Canary Current zone, where laterally advected nutrients from coastal upwelling areas altered the vertical nitrate gradients. A numerical ecological model of the pelagic domain was developed to assess the plankton response to different environmental pressures. The model represents the vertical dimension of the upper and intermediate water layers of the open ocean. A comparative study of the plankton functioning in MED and NA sites was carried out using the model. The nitrate entering the euphotic zone through the lower boundary explained the low but continuous ... Doctoral or Postdoctoral Thesis North Atlantic Universitat Politècnica de Catalunya (UPC): Theses and Dissertations Online (TDX) |
institution |
Open Polar |
collection |
Universitat Politècnica de Catalunya (UPC): Theses and Dissertations Online (TDX) |
op_collection_id |
ftupcatalunya |
language |
English |
topic |
modelos ecológicos fitoplàncton nitrogeno ecologia del plancton mar Mediterráneo noroccidental 2510. Oceanografia 504 574 |
spellingShingle |
modelos ecológicos fitoplàncton nitrogeno ecologia del plancton mar Mediterráneo noroccidental 2510. Oceanografia 504 574 Bahamon Rivera, Nixon Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
topic_facet |
modelos ecológicos fitoplàncton nitrogeno ecologia del plancton mar Mediterráneo noroccidental 2510. Oceanografia 504 574 |
description |
The response of phytoplankton to various ecological forcings was examined in the upper waters of the NW Mediterranean (MED) and the subtropical North Atlantic (NA) from field observations, analysis of historical data sets and numerical simulations. Particular emphasis was given to the role played by the water column structure in controlling the nitrogen diffusion and new production. Using numerical simulations, the effects of different levels of heating of surface waters and nutrient concentrations in waters below the euphotic zone were examined. Spring microplankton metabolism of surface mixed waters in MED was studied. The system was heterotrophic explained by dark community respiration (DCR) rates higher than gross primary production (GPP) rates. The GPP to DCR ratio was ~0.53, indicating that the system was far from balance between carbon production (photosynthesis) and consumption (respiration), probably caused by organic matter accumulation in the mixed layer favouring respiration over production processes. Summer primary production and nitrogen fluxes in stratified water layers in NA were analysed. The nitrogen flux fuelling new primary production was closely linked to vertical turbulent diffusion at the nitracline rather than at the thermocline. Upward diffused nitrogen inducing new production explaining 21% of total primary production. The vertical turbulent diffusion model used to estimate new production did not explain new production in the Canary Current zone, where laterally advected nutrients from coastal upwelling areas altered the vertical nitrate gradients. A numerical ecological model of the pelagic domain was developed to assess the plankton response to different environmental pressures. The model represents the vertical dimension of the upper and intermediate water layers of the open ocean. A comparative study of the plankton functioning in MED and NA sites was carried out using the model. The nitrate entering the euphotic zone through the lower boundary explained the low but continuous ... |
author2 |
Cruzado Alorda, Antonio Universitat Politècnica de Catalunya. Departament d'Enginyeria Hidràulica, Marítima i Ambiental |
format |
Doctoral or Postdoctoral Thesis |
author |
Bahamon Rivera, Nixon |
author_facet |
Bahamon Rivera, Nixon |
author_sort |
Bahamon Rivera, Nixon |
title |
Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
title_short |
Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
title_full |
Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
title_fullStr |
Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
title_full_unstemmed |
Dynamics of oligotrophic pelagic environments:North western Mediterranean sea and subtropical north Atlantic |
title_sort |
dynamics of oligotrophic pelagic environments:north western mediterranean sea and subtropical north atlantic |
publisher |
Universitat Politècnica de Catalunya |
publishDate |
2011 |
url |
http://www.tdx.cat/TDX-1205102-113102 http://hdl.handle.net/10803/6381 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
TDX (Tesis Doctorals en Xarxa) |
op_relation |
8468807346 http://www.tdx.cat/TDX-1205102-113102 http://hdl.handle.net/10803/6381 B-4725-2003 |
op_rights |
ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs. info:eu-repo/semantics/openAccess |
_version_ |
1782337286564741120 |