The East Coast of the USA

[See also: OAPS for the Caribbean Sea and Gulf of Mexico]

Scientists of the ACCRETE (Acidification, Climate, and Coral Reef Ecosystems Team) Lab and Ocean Carbon Group of AOML’s Ocean Chemistry and Ecosystems Division (OCED) have constructed a tool to view ocean acidification on the east coast of the USA. This tool utilizes satellite data and a data-assimilative hybrid model to map the components of the carbonate system of surface water.

Algorithms are derived to determine the partial pressure of CO2 (pCO2) in surface water for five different regions on the east coast. These algorithms use optimally interpolated sea surface temperature (SST) products that merge multiple satellites, sea surface salinity (SSS) and chlorophyll-a. The algorithms are described in Signorini SR, et al. (2013).

The TA-SSS-SST (Total Alkalinity / Sea Surface Salinity / Sea Surface Temperature) relationships are SSS dependent:

SSS < 32.45
TA = (42.6 * SSS) + 815.9

SSS >= 32.45
TA = (61.9 * SSS) + 190.0

These linear relationships are based on coastal cruises GOMECC 1 and 2 data and account for non-zero alkalinity from riverine outflows for the low salinity algorithm (Wang et al. 2017).

Using the computed pCO2 and TA all other variables were computed using standard CO2SYS algorithms.

Data Sources 2014-2017:

Data Sources 2018 to present:


The following animations show the monthly progression of pH, surface pressure of CO2, total alkalinity, aragonite saturation state (Ωarag) and calcite saturation state (Ωcalc) in 2020. Clicking any animation will load it in its original, full-sized format.

The monthly progression of pH in 2020

The monthly progression of surface pressure of CO2 in 2020

The monthly progression of total alkalinity in 2020

The monthly progression of aragonite saturation state (Ωarag) in 2020

The monthly progression of calcite saturation state (Ωcalc) in 2020

For each of the variables, a netCDF file can be downloaded that has 12 monthly values on a grid with 151 cells latitude, 187 cells longitude. The domain is bounded by 24°N to 47°N, 82°W to 54°W. The variables that can be downloaded (by clicking the desired data year in the list below) are:

For further details about this product, contact Dr. Ruben van Hooidonk. The development and maintenance of this product is supported by the NOAA Ocean Acidification Program.

Signorini, S. R., A. Mannino, R. G. Najjar, Jr., M. A. M. Friedrichs, W.-J. Cai, J. Salisbury, Z. Al-eck Wang, H. Thomas, and E. Shadwick (2013), Surface ocean pCO2 seasonality and sea-air CO2 flux estimates for the North American east coast, J. Geophys. Res. Oceans, 118, 5439–5460, doi:10.1002/jgrc.20369.

Wang, Z. A., G. L. Lawson, C. H. Pilskaln, and A. E. Maas (2017), Seasonal controls of aragonite saturation states in the Gulf of Maine, J. Geophys. Res. Oceans, 122, doi:10.1002/2016JC012373.