 |
| Titel |
Summertime calcium carbonate undersaturation in shelf waters of the western Arctic Ocean – how biological processes exacerbate the impact of ocean acidification |
| VerfasserIn |
N. R. Bates, M. I. Orchowska, R. Garley, J. T. Mathis |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 8 ; Nr. 10, no. 8 (2013-08-06), S.5281-5309 |
| Datensatznummer |
250085285
|
| Publikation (Nr.) |
 copernicus.org/bg-10-5281-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Arctic Ocean accounts for only 4% of the global ocean area, but it
contributes significantly to the global carbon cycle. Recent observations of
seawater CO2-carbonate chemistry in shelf waters of the western Arctic
Ocean, primarily in the Chukchi Sea, from 2009 to 2011 indicate that bottom
waters are seasonally undersaturated with respect to calcium carbonate
(CaCO3) minerals, particularly aragonite. Nearly 40% of sampled
bottom waters on the shelf have saturation states less than one for aragonite
(i.e., Ωaragonite < 1.0), thereby exposing the benthos to
potentially corrosive water for CaCO3-secreting organisms, while 80%
of bottom waters present had Ωaragonite values less than
1.5. Our observations indicate seasonal reduction of saturation states
(Ω) for calcite (Ωcalcite) and aragonite
(Ωaragonite) in the subsurface in the western Arctic by as
much as 0.8 and 0.5, respectively. Such data indicate that bottom waters of
the western Arctic shelves were already potentially corrosive for biogenic
and sedimentary CaCO3 for several months each year. Seasonal changes in
Ω are imparted by a variety of factors such as phytoplankton
photosynthesis, respiration/remineralization of organic matter and air–sea
gas exchange of CO2. Combined, these processes either increase or enhance
in surface and subsurface waters, respectively. These seasonal physical and
biological processes also act to mitigate or enhance the impact of
Anthropocene ocean acidification (OA) on Ω in surface and subsurface
waters, respectively. Future monitoring of the western Arctic shelves is
warranted to assess the present and future impact of ocean acidification and
seasonal physico-biogeochemical processes on Ω values and Arctic
marine ecosystems. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|