Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION)
Mechanistic understanding of factors governing pH is essential, given growing concern about ocean acidi cation. The classical approach to carbonate chemistry and pH calculations is centred around the alkalinity concept. In this publication, the classical approach is taken one step further: the in ue...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/44315 2023-07-23T04:21:11+02:00 Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) Hofmann, A.F. Middelburg, J.J. Soetaert, K. Wolf-Gladrow, D.A. Meysman, F.J.R. 2009 text/plain https://dspace.library.uu.nl/handle/1874/44315 en eng https://dspace.library.uu.nl/handle/1874/44315 info:eu-repo/semantics/ClosedAccess Part of book or chapter of book 2009 ftunivutrecht 2023-07-01T23:43:32Z Mechanistic understanding of factors governing pH is essential, given growing concern about ocean acidi cation. The classical approach to carbonate chemistry and pH calculations is centred around the alkalinity concept. In this publication, the classical approach is taken one step further: the in uences of biogeochemical and physical processes on the pH are calculated directly, without the detour of alkalinity. The in uence of a given process on pH is expressed by its process rate, modulated by a sensitivity factor. Here, we provide the necessary tools and procedures to calculate this sensitivity factor analytically for an arbitry process. Moreover, we show that the sensitivity can be decomposed as the ratio of a particular stoichiometric coe cient of protons over a bu er factor. The stoichiometric coe cient can be derived by describing the process using a fractional reaction equation at ambient pH and it represents the protons that are released by the process without accounting for re-equilibration. The presented approach thus provides a chemical interpretation of the mechanisms underlying pH changes in aquatic systems. Applying the concept of bu er capacity and pH sensitivities to an averaged global ocean shows that towards the end of the century the ocean will be around four times less bu ered than it is today. This demonstrates how the concepts and tools presented here can make a complementary contribution to the existing modelling approaches of ocean acidification. Book Part Ocean acidification Utrecht University Repository Detour ENVELOPE(-63.913,-63.913,-65.021,-65.021) The Detour ENVELOPE(-134.704,-134.704,62.733,62.733) |
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Open Polar |
collection |
Utrecht University Repository |
op_collection_id |
ftunivutrecht |
language |
English |
description |
Mechanistic understanding of factors governing pH is essential, given growing concern about ocean acidi cation. The classical approach to carbonate chemistry and pH calculations is centred around the alkalinity concept. In this publication, the classical approach is taken one step further: the in uences of biogeochemical and physical processes on the pH are calculated directly, without the detour of alkalinity. The in uence of a given process on pH is expressed by its process rate, modulated by a sensitivity factor. Here, we provide the necessary tools and procedures to calculate this sensitivity factor analytically for an arbitry process. Moreover, we show that the sensitivity can be decomposed as the ratio of a particular stoichiometric coe cient of protons over a bu er factor. The stoichiometric coe cient can be derived by describing the process using a fractional reaction equation at ambient pH and it represents the protons that are released by the process without accounting for re-equilibration. The presented approach thus provides a chemical interpretation of the mechanisms underlying pH changes in aquatic systems. Applying the concept of bu er capacity and pH sensitivities to an averaged global ocean shows that towards the end of the century the ocean will be around four times less bu ered than it is today. This demonstrates how the concepts and tools presented here can make a complementary contribution to the existing modelling approaches of ocean acidification. |
format |
Book Part |
author |
Hofmann, A.F. Middelburg, J.J. Soetaert, K. Wolf-Gladrow, D.A. Meysman, F.J.R. |
spellingShingle |
Hofmann, A.F. Middelburg, J.J. Soetaert, K. Wolf-Gladrow, D.A. Meysman, F.J.R. Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
author_facet |
Hofmann, A.F. Middelburg, J.J. Soetaert, K. Wolf-Gladrow, D.A. Meysman, F.J.R. |
author_sort |
Hofmann, A.F. |
title |
Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
title_short |
Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
title_full |
Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
title_fullStr |
Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
title_full_unstemmed |
Buffering, stoichiometry, and the sensitivity of pH to biogeochemical and physical processes: a proton-based model perspective (THESIS VERSION) |
title_sort |
buffering, stoichiometry, and the sensitivity of ph to biogeochemical and physical processes: a proton-based model perspective (thesis version) |
publishDate |
2009 |
url |
https://dspace.library.uu.nl/handle/1874/44315 |
long_lat |
ENVELOPE(-63.913,-63.913,-65.021,-65.021) ENVELOPE(-134.704,-134.704,62.733,62.733) |
geographic |
Detour The Detour |
geographic_facet |
Detour The Detour |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
https://dspace.library.uu.nl/handle/1874/44315 |
op_rights |
info:eu-repo/semantics/ClosedAccess |
_version_ |
1772186469887115264 |