Ongoing transients in carbonate compensation

B.P. Boudreau; J.J. Middelburg; A.F. Hofmann; F.J.R. Meysman

doi:10.1029/2009GB003654

Ongoing transients in carbonate compensation

B.P. Boudreau, J.J. Middelburg, A.F. Hofmann, F.J.R. Meysman

Research output: Contribution to journal/periodical › Article › Scientific › peer-review

453 Downloads (Pure)

Abstract

Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a biogeochemical model of the oceanic carbonate system, we evaluate how these horizons will change with ongoing ocean acidification. Our model is an extended Havardton-Bear-type box model, which includes novel kinetic descriptions for carbonate dissolution above, between, and below these critical depths. In the preindustrial ocean, zsat and zcc are at 3939 and 4750 m, respectively. When forced with the IS92a CO2 emission scenario, the model forecasts (1) that zsat will rise rapidly (“runaway” conditions) so that all deep water becomes undersaturated, (2) that zcc will also rise and over 1000 years will pass before it will be stabilized by the dissolution of previously deposited CaCO3, and (3) that zsnow will respond slowly to acidification, rising by ∼1150 m during a 2000 year timeframe. A further simplified model that equates the compensation and saturation depths produces quantitatively different results. Finally, additional feedbacks due to acidification on calcification and increased atmospheric CO2 on organic matter productivity strongly affect the positions of the compensation horizons and their dynamics.

Original language	English
Article number	GB4010
Journal	Global Biogeochemical Cycles
Volume	24
Issue number	4
DOIs	https://doi.org/10.1029/2009GB003654
Publication status	Published - 2010

Access to Document

10.1029/2009GB003654Licence: Other

PDF
American Geophysical Union (AGU) -- Remove pre-print when submitting for publication (if not a personal or departmental web site)
Final published version, 1.02 MB

Fingerprint Dive into the research topics of 'Ongoing transients in carbonate compensation'. Together they form a unique fingerprint.

Cite this

@article{6ba32843e3db489c9d09760492f09176,

title = "Ongoing transients in carbonate compensation",

abstract = "Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a biogeochemical model of the oceanic carbonate system, we evaluate how these horizons will change with ongoing ocean acidification. Our model is an extended Havardton-Bear-type box model, which includes novel kinetic descriptions for carbonate dissolution above, between, and below these critical depths. In the preindustrial ocean, zsat and zcc are at 3939 and 4750 m, respectively. When forced with the IS92a CO2 emission scenario, the model forecasts (1) that zsat will rise rapidly (“runaway” conditions) so that all deep water becomes undersaturated, (2) that zcc will also rise and over 1000 years will pass before it will be stabilized by the dissolution of previously deposited CaCO3, and (3) that zsnow will respond slowly to acidification, rising by ∼1150 m during a 2000 year timeframe. A further simplified model that equates the compensation and saturation depths produces quantitatively different results. Finally, additional feedbacks due to acidification on calcification and increased atmospheric CO2 on organic matter productivity strongly affect the positions of the compensation horizons and their dynamics.",

author = "B.P. Boudreau and J.J. Middelburg and A.F. Hofmann and F.J.R. Meysman",

note = "Reporting year: 2010 Metis note: 4870;CEME; ES; file:///L:\EndnoteDatabases\NIOOPUB\pdfs\PDFS2010\Boudreau_ea_4870.pdf",

year = "2010",

doi = "10.1029/2009GB003654",

language = "English",

volume = "24",

journal = "Global Biogeochemical Cycles",

issn = "0886-6236",

publisher = "American Geophysical Union",

number = "4",

}

TY - JOUR

T1 - Ongoing transients in carbonate compensation

AU - Boudreau, B.P.

AU - Middelburg, J.J.

AU - Hofmann, A.F.

AU - Meysman, F.J.R.

N1 - Reporting year: 2010 Metis note: 4870;CEME; ES; file:///L:\EndnoteDatabases\NIOOPUB\pdfs\PDFS2010\Boudreau_ea_4870.pdf

PY - 2010

Y1 - 2010

N2 - Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a biogeochemical model of the oceanic carbonate system, we evaluate how these horizons will change with ongoing ocean acidification. Our model is an extended Havardton-Bear-type box model, which includes novel kinetic descriptions for carbonate dissolution above, between, and below these critical depths. In the preindustrial ocean, zsat and zcc are at 3939 and 4750 m, respectively. When forced with the IS92a CO2 emission scenario, the model forecasts (1) that zsat will rise rapidly (“runaway” conditions) so that all deep water becomes undersaturated, (2) that zcc will also rise and over 1000 years will pass before it will be stabilized by the dissolution of previously deposited CaCO3, and (3) that zsnow will respond slowly to acidification, rising by ∼1150 m during a 2000 year timeframe. A further simplified model that equates the compensation and saturation depths produces quantitatively different results. Finally, additional feedbacks due to acidification on calcification and increased atmospheric CO2 on organic matter productivity strongly affect the positions of the compensation horizons and their dynamics.

AB - Uptake of anthropogenic CO2 is acidifying the oceans. Over the next 2000 years, this will modify the dissolution and preservation of sedimentary carbonate. By coupling new formulas for the positions of the calcite saturation horizon, zsat, the compensation depth, zcc, and the snowline, zsnow, to a biogeochemical model of the oceanic carbonate system, we evaluate how these horizons will change with ongoing ocean acidification. Our model is an extended Havardton-Bear-type box model, which includes novel kinetic descriptions for carbonate dissolution above, between, and below these critical depths. In the preindustrial ocean, zsat and zcc are at 3939 and 4750 m, respectively. When forced with the IS92a CO2 emission scenario, the model forecasts (1) that zsat will rise rapidly (“runaway” conditions) so that all deep water becomes undersaturated, (2) that zcc will also rise and over 1000 years will pass before it will be stabilized by the dissolution of previously deposited CaCO3, and (3) that zsnow will respond slowly to acidification, rising by ∼1150 m during a 2000 year timeframe. A further simplified model that equates the compensation and saturation depths produces quantitatively different results. Finally, additional feedbacks due to acidification on calcification and increased atmospheric CO2 on organic matter productivity strongly affect the positions of the compensation horizons and their dynamics.

U2 - 10.1029/2009GB003654

DO - 10.1029/2009GB003654

M3 - Article

VL - 24

JO - Global Biogeochemical Cycles

JF - Global Biogeochemical Cycles

SN - 0886-6236

IS - 4

M1 - GB4010

ER -