OAP Projects in the NORTHEAST U.S.


Assessment of the Observing Network to Identify Processes Relevant to the Predictability of the Coastal Ocean of the Northeast on Centennial Time Scales

Samantha Siedlecki, University of Connecticut

Tuesday, March 3, 2020

Over the past 15 years, waters in the Gulf of Maine have taken up
CO2at a rate significantly slower than that observed in the open oceans due to a combination of
the extreme warming experienced in the region and an increased presence of well-buffered Gulf
Stream water [Salisbury and Johnson 2018]. The reduced uptake of CO2 by the shelves could
also alter local acidification rate, which differ from the global rates. The intrusion of
anthropogenic CO2is not the only mechanism that can reduce Ωarag within coastal surface waters.
Local processes like freshwater delivery, eutrophication, water column metabolism, and
sediment interactions that drive variability on regional scales can also modify spatial variability
in Ωarag [Cai et al. 2011; Siedlecki et al. 2017; Qi et al., 2017; Pilcher et al. 2018; Feely et al.
2008; 2018]. Global projections cannot resolve these local processes with resolution of a degree
or more. Some high-resolution global projections have been developed which perform well in
some coastal settings [Saba et al. 2016]. However, these simulations do not include regional
biogeochemical processes described above which can amplify or dampen these global changes,
particularly in coastal shelf regions. Our hypothesis is that a regionally downscaled projection
for the east coast of the US can be used to evaluate the ability of the existing observational
network to detect changes in ocean acidification relevant stressors for scallops and propose a
process-based strategy for the network moving forward.

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