Spatial Inorganic carbon timeseries

With funding from the Exxon Valdez Oil Spill Trustee Council, we collect and analyze discrete pH, total alkalinity, and dissolved inorganic carbon seawater samples in a collaborative effort with the Northern Gulf of Alaska - Long Term Ecological Research (NGA-LTER) grid. These observations, as well as our model output, informed NOAA's Gulf of Alaska Ecosystem Status Report 2023.

Maps of fall 2022 (Sept., Oct., and Nov.) of bottom pH (A) and aragonite saturation state (Ωarag, B). The faded area shows portions of the domain deeper than 500 m where the model vertical resolution decreases. The time series shows the modeled temporal evolution of pH (C) at the bottom of Seward Line stations GAK 5 (gray line) and GAK 9 (black line) between 1993 and 2022 (bottom depth of 170 m for GAK 5 and 280 m for GAK 9). The red circles show observations near the bottom of station GAK 9 and the blue squares show in situ observations at stationGAK 5 between 2018 and 2023. The dotted line shows the linear regression for each time series (GAK5,-0.0023 per year, R =-0.33, p-value < 0.01 and GAK 9,-0.001 per year, R =-0.37, p-value < 0.01). From NOAA GOA Ecosystem Status Report.