Conference presentation
The responses of seawater carbonate chemistry and productivity to a simulated OMZ upwelling event in the coastal upwelling area off Peru
American Geophysical Union Fall Meeting, Vol.2018
American Geophysical Union
American Geophysical Union 2018 fall meeting (Washington, D.C. , 10/12/2018 - 14/12/2018)
12/2018
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Abstract
One of the major challenges of climate change is growing deoxygenation in the ocean due to global warming. The intensification and expansion of oxygen minimum zones (OMZs) may induce changes in marine habitats, nutrient and carbon cycling, biological productivity, and ecological responses. To investigate the potential impacts of growing deoxygenation on natural plankton communities in the Peruvian upwelling system, a large-scale mesocosm experiment was conducted in the coastal upwelling area off Callao, Peru in February 2017. Eight KOSMOS mesocosm units were deployed in the coastal area. The experiment simulated an upwelling event in the mesocosms by addition of OMZ-influenced deep water that was deficient in dissolved inorganic nitrogen and enriched in carbon dioxide (CO (sub 2) ) collected from the nearby coastal area. The enclosed water was monitored by daily sampling and measurements for ecological and biogeochemical parameters for a period of 10 weeks. Here we present data on carbonate system parameters (total alkalinity, dissolved inorganic carbon, and pH) and chl a concentration from the mesocosm experiment as well as surface Pacific. Our results show that the addition of OMZ water induced changes in nitrogen and carbon cycling and triggered phytoplankton blooms in the mesocosms. In addition, the upwelling of acidified water to the surface may contribute to a strong sea-to-air CO (sub 2) flux. In comparison to the mesocosms, the Pacific experienced more frequent and intense upwelling, which brought more nutrients and CO (sub 2) to the surface and occasionally created under-saturation with respect to aragonite below the surface. During the study, an unusual "coastal El Nino" event caused warm sea surface temperature, heavy rains and floods on land, and washed alkalinity-enriched water into the Pacific Ocean. Overall, the development of carbonate chemistry in the mesocosms and the Pacific was consistent with the changes in nutrients and chl a concentration. This dataset provides first insights into the response of biogeochemical cycling to the simulated upwelling event. More parameters are now being processed and will be made available, which will help to support our understanding on how the response of plankton communities to growing deoxygenation will influence sea surface carbonate chemistry in the upwelling system.
Details
- Title
- The responses of seawater carbonate chemistry and productivity to a simulated OMZ upwelling event in the coastal upwelling area off Peru
- Creators
- Selma Chen - Dalhousie University Halifax, NS CAN CanadaL. T Bach - University of TasmaniaKai Schulz - Southern Cross UniversityE von der Esch - Technical University MunichC Sforna - GEOMAR Helmholtz Centre for Ocean Research KielU Riebesell - GEOMAR Helmholtz Centre for Ocean Research
- Publication Details
- American Geophysical Union Fall Meeting, Vol.2018
- Conference
- American Geophysical Union 2018 fall meeting (Washington, D.C. , 10/12/2018 - 14/12/2018)
- Publisher
- American Geophysical Union
- Identifiers
- 991012978036802368
- Academic Unit
- Centre for Coastal Biogeochemistry; Faculty of Science and Engineering; Science
- Language
- English
- Resource Type
- Conference presentation