Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition
A global ocean biogeochemical model is used to quantify the sensitivity of marine biogeochemistry and air–sea CO2 exchange to variations in dust deposition over decadal timescales. Estimates of dust deposition generated under four climate states provide a large range in total deposition with spatial...
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ftcdlib:qt7vr7g4g3 2023-05-15T18:25:37+02:00 Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition Moore, J. Keith Doney, Scott C Lindsay, Keith Mahowald, Natalie Michaels, Anthony F 560 - 572 2006-11-01 application/pdf http://www.escholarship.org/uc/item/7vr7g4g3 english eng eScholarship, University of California qt7vr7g4g3 http://www.escholarship.org/uc/item/7vr7g4g3 Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ CC-BY Moore, J. Keith; Doney, Scott C; Lindsay, Keith; Mahowald, Natalie; & Michaels, Anthony F. (2006). Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition. Tellus B, 58(5), 560 - 572. doi:10.1111/j.1600-0889.2006.00209.x. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/7vr7g4g3 Physical Sciences and Mathematics model version-3 ccsm3 last glacial maximum southern-ocean carbon-cycle phytoplankton bloom iron fertilization ecosystem model climate-change pacific future article 2006 ftcdlib https://doi.org/10.1111/j.1600-0889.2006.00209.x 2016-04-02T18:36:22Z A global ocean biogeochemical model is used to quantify the sensitivity of marine biogeochemistry and air–sea CO2 exchange to variations in dust deposition over decadal timescales. Estimates of dust deposition generated under four climate states provide a large range in total deposition with spatially realistic patterns; transient ocean model experiments are conducted by applying a step-function change in deposition from a current climate control. Relative to current conditions, higher dust deposition increases diatom and export production, nitrogen fixation and oceanic net CO2 uptake from the atmosphere, while reduced dust deposition has the opposite effects. Over timescales less than a decade, dust modulation of marine productivity and export is dominated by direct effects in high-nutrient, low-chlorophyll regions, where iron is the primary limiting nutrient. On longer timescales, an indirect nitrogen fixation pathway has increased importance, significantly amplifying the ocean biogeochemical response. Because dust iron input decouples carbon cycling from subsurface macronutrient supply, the ratio of the change in net ocean CO2 uptake to change in export flux is large, 0.45–0.6. Decreasing dust deposition and reduced oceanic CO2 uptake over the next century could provide a positive feedback to global warming, distinct from feedbacks associated with changes in stratification and circulation. Article in Journal/Newspaper Southern Ocean University of California: eScholarship Pacific Southern Ocean Tellus B: Chemical and Physical Meteorology 58 5 560 572 |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Physical Sciences and Mathematics model version-3 ccsm3 last glacial maximum southern-ocean carbon-cycle phytoplankton bloom iron fertilization ecosystem model climate-change pacific future |
spellingShingle |
Physical Sciences and Mathematics model version-3 ccsm3 last glacial maximum southern-ocean carbon-cycle phytoplankton bloom iron fertilization ecosystem model climate-change pacific future Moore, J. Keith Doney, Scott C Lindsay, Keith Mahowald, Natalie Michaels, Anthony F Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
topic_facet |
Physical Sciences and Mathematics model version-3 ccsm3 last glacial maximum southern-ocean carbon-cycle phytoplankton bloom iron fertilization ecosystem model climate-change pacific future |
description |
A global ocean biogeochemical model is used to quantify the sensitivity of marine biogeochemistry and air–sea CO2 exchange to variations in dust deposition over decadal timescales. Estimates of dust deposition generated under four climate states provide a large range in total deposition with spatially realistic patterns; transient ocean model experiments are conducted by applying a step-function change in deposition from a current climate control. Relative to current conditions, higher dust deposition increases diatom and export production, nitrogen fixation and oceanic net CO2 uptake from the atmosphere, while reduced dust deposition has the opposite effects. Over timescales less than a decade, dust modulation of marine productivity and export is dominated by direct effects in high-nutrient, low-chlorophyll regions, where iron is the primary limiting nutrient. On longer timescales, an indirect nitrogen fixation pathway has increased importance, significantly amplifying the ocean biogeochemical response. Because dust iron input decouples carbon cycling from subsurface macronutrient supply, the ratio of the change in net ocean CO2 uptake to change in export flux is large, 0.45–0.6. Decreasing dust deposition and reduced oceanic CO2 uptake over the next century could provide a positive feedback to global warming, distinct from feedbacks associated with changes in stratification and circulation. |
format |
Article in Journal/Newspaper |
author |
Moore, J. Keith Doney, Scott C Lindsay, Keith Mahowald, Natalie Michaels, Anthony F |
author_facet |
Moore, J. Keith Doney, Scott C Lindsay, Keith Mahowald, Natalie Michaels, Anthony F |
author_sort |
Moore, J. Keith |
title |
Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
title_short |
Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
title_full |
Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
title_fullStr |
Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
title_full_unstemmed |
Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
title_sort |
nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition |
publisher |
eScholarship, University of California |
publishDate |
2006 |
url |
http://www.escholarship.org/uc/item/7vr7g4g3 |
op_coverage |
560 - 572 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Moore, J. Keith; Doney, Scott C; Lindsay, Keith; Mahowald, Natalie; & Michaels, Anthony F. (2006). Nitrogen fixation amplifies the ocean biogeochemical response to decadal timescale variations in mineral dust deposition. Tellus B, 58(5), 560 - 572. doi:10.1111/j.1600-0889.2006.00209.x. UC Irvine: Department of Earth System Science, UCI. Retrieved from: http://www.escholarship.org/uc/item/7vr7g4g3 |
op_relation |
qt7vr7g4g3 http://www.escholarship.org/uc/item/7vr7g4g3 |
op_rights |
Attribution (CC BY): http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1111/j.1600-0889.2006.00209.x |
container_title |
Tellus B: Chemical and Physical Meteorology |
container_volume |
58 |
container_issue |
5 |
container_start_page |
560 |
op_container_end_page |
572 |
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1766207180386598912 |