Omega Oracle: forecasting estuarine carbonate weather

There are serious concerns about ecological, social, and economic impacts in the Pacific Northwest due to Ocean Acidification (OA). We built a system to predict aragonite saturation state (Ω) of seawater in Netarts Bay, Oregon based on large scale forcing parameters. An artificial neural network – t...

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Bibliographic Details
Main Authors: Allen, Cameron, Waldbusser, George G., Hales, Burke
Format: Text
Language:English
Published: Western CEDAR 2018
Subjects:
Online Access:https://cedar.wwu.edu/ssec/2018ssec/allsessions/350
https://cedar.wwu.edu/cgi/viewcontent.cgi?article=2785&context=ssec
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Summary:There are serious concerns about ecological, social, and economic impacts in the Pacific Northwest due to Ocean Acidification (OA). We built a system to predict aragonite saturation state (Ω) of seawater in Netarts Bay, Oregon based on large scale forcing parameters. An artificial neural network – trained against a continuous, multiyear monitoring record of carbonate chemistry – learns a regression estimate of Ω based on seasonality, tides, and wind conditions. This approach is agnostic to the details of the underlying chemical and biological processes offering a distinct modelling perspective. The result is a conceptually simpler and more strictly empirical parameterization and a model that is flexible in application due to dependence on only easily obtainable parameters. Forecast validation by a cross validation method indicates good prediction performance, particularly for the high frequency content of the Ω time series, over periods of stable wind forecasting. Our forecast model demonstrates that the complex temporal dynamics of carbonate chemistry within an estuary can emerge from forcing operating on longer timescales. This further elucidates the management and commercial value of this model; experimental work with calcifiers suggests the details of these high frequency chemical dynamics are critical to the magnitude of stress imposed. Lastly, these forecasts, deployed as a web application, can facilitate OA mitigation strategies by providing aquaculturists with real-time predictions for consideration in operational decisions. Numerous sites, including on the Salish Sea, are poised to soon have viable training data for application of this method. Broader deployment promises to enable comparison between sites and expansion of direct aquaculture and management applications. Expansion to other sites is expected to require altered explanatory variables but this exercise may itself yield insight. Relatedly, we note the potential of this approach to help constrain timescales and sources (natural and ...