63 Gulf of Maine Weekly pCO2 and Omega-a
Description: The presented data are weekly averages of the partial pressure of carbon dioxide (pCO2) and the saturation state of calcium carbonate as aragonite (Omega-a), measured by the Gulf of Maine coastal buoy cooperatively operated by NOAA’s Pacific Marine Ecological Laboratory (PMEL) and the University of New Hampshire’s Ocean Process Analysis Laboratory. The buoy is located at 43.02 degrees North and 70.54 degrees West. pCO2 was measured directly, while Omega-a was calculated from observed pCO2, water temperature, salinity, and total alkalinity (modeled from temperature, salinity and month, similar to McGarry et al. 2021). The weekly averages from 2024 are depicted against the climatological bounds from observations at this site between 2006-2023.
Indicator family:
Contributor(s): Hunt, Christopher W; Vandemark, Douglas; Sutton, Adrienne
Affiliations: UNH
63.1 Introduction to Indicator
The pCO2 represents the partial pressure of carbon dioxide resulting from the combination of water mass mixing, air-sea exchange, and biogeochemical processes. Omega-a represents the saturation of calcium carbonate, an important mineral for many shell-building marine species and commonly-sed indicator of ocean acidification condition.
63.2 Key Results and Visualizations
In 2024, pCO2 followed the general pattern of elevated levels in the fall and winter and reduced levels in the spring and early summer. Omega-a reflected this pattern, with lower levels in the fall and winter and elevated levels in spring and early summer. This pattern is generally due to a combination of seasonal temperature shifts and the cyclical spring phytoplankton bloom. However, the levels of pCO2 at the beginning and end of 2024 were near or above the upper climatological bounds, and Omega-a was similarly low. This is presumably due to abnormally low salinity in the region, which is associated with high pCO2 and low Omega-a.
63.3 Indicator statistics
Spatial scale: coastal Gulf of Maine, fixed mooring
Temporal scale: Annual
Synthesis Theme:
63.4 Implications
Ocean acidification conditions were pronounced for extended periods early and late in 2024, but otherwise followed typical seasonal patterns with some periods of distinct variability.
63.5 Get the data
Point of contact: Christopher W. Hunt {chunt@unh.edu)){.email}
ecodata name: No dataset
Variable definitions
- pCO2; Definition: partial pressure of carbon dioxide; Units: microatmospheres 2)Omega-a; Definition: Saturation state of calcium carbonate as aragonite; Units: unitless
No Data
Indicator Category: