Influence of Ocean Acidification and Climate Change on the Biogeochemistry in the Gulf of Alaska: A regional modeling study
Abstract
The biogeochemistry of the Gulf of Alaska is heavily influenced by hundreds of glacially fed rivers that enter into this pristine environment. Projected increased melting of glaciers and changes in precipitation may further change the biogeochemistry and accelerate the progression of ocean acidification. To get a better understanding of the physical and biogeochemical mechanisms that control pH, aragonite saturation state, oxygen and productivity, we have developed a new regional ROMS-Cobalt (Regional Ocean Modeling System - Carbon Ocean Biogeochemistry and Lower Trophics) model domain covering the Alaskan coastline along the Gulf of Alaska. Our new carbon based model is explicitly forced with coastal freshwater discharges, thereby not only affecting salinity, but also alkalinity, dissolved inorganic carbon and nutrient concentrations. The model's performance is carefully evaluated with in situ observations from the Northern Gulf of Alaska Long Term Ecological Research site. We explore the seasonal, interannual, and decadal variability of inorganic carbon, oxygen, and productivity, and detangle the complex interplay of underlying mechanisms. The 35 yearlong hindcast simulation also gives insights into how rising atmospheric CO2, increased freshwater discharges and other physical changes may have already affected the biogeochemistry of this highly productive and socio-economically important ecosystem.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMOS41B2009H
- Keywords:
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- 4805 Biogeochemical cycles;
- processes;
- and modeling;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICALDE: 4806 Carbon cycling;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICALDE: 4813 Ecological prediction;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICALDE: 4815 Ecosystems;
- structure;
- dynamics;
- and modeling;
- OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL