INVESTIGATORS:
Olivier Sulpis
- McGill University
Bernard P. Boudreau
- Dalhousie University; Institute of Oceanography
Alfonso Mucci
- GEOTOP and Department of Earth and Planetary Sciences, McGill University
Chris Jenkins
- INSTAAR, University of Colorado at Boulder
David S. Trossman
- Institute of Computational Engineering and Sciences, University of Texas-Austin
Brian K. Arbic
- Department of Earth and Environmental Sciences, University of Michigan
Robert M. Key
- Princeton University; Department of Geosciences; Program in Atmospheric and Ocean Sciences (AOS)
PACKAGE DESCRIPTION: This dataset consists of current CaCO3 dissolution at the seafloor caused by anthropogenic CO2 in the World Oceans. This dataset contains the main results from Sulpis et al. (PNAS, 2018). All the variables have a 1x1 degree resolution. It can be used to compute calcite dissolution at the seafloor for changing bottom-water chemistry, calcite rain rates or current speeds, for instance. Oceanic uptake of anthropogenic CO2 leads to decreased pH, carbonate ion concentration, and saturation state with respect to CaCO3 minerals, causing increased dissolution of these minerals at the deep seafloor. This additional dissolution will figure prominently in the neutralization of man-made CO2. Yet, there has been no concerted assessment of the current extent of anthropogenic CaCO3 dissolution at the deep seafloor. Here, recent databases of bottom-water chemistry, benthic currents, and CaCO3 content of deep-sea sediments are combined with a new rate model to derive the global distribution of benthic calcite dissolution rates and obtain primary confirmation of an anthropogenic component. By comparing pre-industrial with present-day rates, we determine that significant anthropogenic dissolution now occurs in the western North Atlantic, amounting to 40-100% of the total seafloor dissolution at its most intense locations. At these locations, the calcite compensation depth has risen ~300 m. Increased benthic dissolution was also revealed at various hot spots in the southern extent of the Atlantic, Indian and Pacific Oceans. Our findings place constraints on future predictions of ocean acidification, are consequential to the fate of benthic calcifiers, and indicate that a by-product of human activities is currently altering the geological record of the deep sea.
CITE AS: Sulpis, Olivier; Boudreau, Bernard P.; Mucci, Alfonso; Jenkins, Chris; Trossman, David S.; Arbic, Brian K.; Key, Robert M. (2018). Current calcite (CaCO3) dissolution at the seafloor caused by anthropogenic CO2 (NCEI Accession 0176672). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/kbqy-4v05. Accessed [date].
DATA PACKAGES RELATED TO THIS ONE:
IDENTIFICATION INFORMATION FOR THIS DATA PACKAGE:
NCEI ACCESSION: 0176672
NCEI DOI: https://doi.org/10.25921/kbqy-4v05
EXPOCODE: Various;
CRUISE ID: Various;
SECTION/LEG: Various;
TYPES OF STUDY: Data synthesis product;Discrete measurement;Profile;TEMPORAL COVERAGE:
START DATE: 1800-01-01
END DATE: 2002-12-31
SPATIAL COVERAGE:
GEOGRAPHIC NAMES:
Pacific Ocean;Atlantic Ocean;Indian Ocean;Southern Ocean;Arctic Ocean;
PLATFORMS: Various;
RESEARCH PROJECT(S):
none;
VARIABLES / PARAMETERS:
Calcite Compensation Depth (CCD) |
Abbreviation: |
Depth |
Unit: |
KM |
Observation type: |
depth at which the calcite rain rate equals its dissolution rate, see Sulpis et al. (PNAS, 2018) |
Preindustrial Calcite Compensation Depth (PI_CCD) |
Abbreviation: |
Depth |
Preindustrial calcite dissolution rate at the sediment-water interface (PI_r) |
Abbreviation: |
Calcite dissolution rate |
Unit: |
mol/m2/a |
Calcite dissolution rate at the sediment-water interface (r) |
Abbreviation: |
Calcite dissolution rate |
Unit: |
mol/m2/a |
Observation type: |
Current (2002) |
Botton current speed (u): |
Abbreviation: |
Botton current speed (u) |
Unit: |
m/s |
Observation type: |
inferred from an inline computation of the annually averaged kinetic energy field of a nominally 1/25th degree global configuration of the HYbrid Coordinate Ocean Model (HYCOM), see Trossman et al. (Ocean Modelling, 2016) |
Carbonate ion water-side mass transfer coefficient (beta) |
Abbreviation: |
Carbonate ion water-side mass transfer coefficient (beta) |
Unit: |
m/a |
Observation type: |
it is simply the free solution diffusion coefficient for carbonate ion divided by the thickness of the DBL, and is computed here as a function of seawater viscosity and bottom-current speed, as explained in Sulpis et al. (PNAS, 2018) |
Carbonate ion sediment-side mass transfer coefficient (ks) |
Abbreviation: |
Carbonate ion sediment-side mass transfer coefficient (ks) |
Unit: |
m/a |
Observation type: |
it depends on the CaCO3 content of the sediment and is temperature-corrected |
Carbonate ion overall mass transfer coefficient (kstar) |
Abbreviation: |
Carbonate ion overall mass transfer coefficient (kstar) |
Unit: |
m/a |
Observation type: |
non-linear combination of the water-side and sediment-side mass transfer coefficients |
Calcium carbonate solid fraction in surface sediments (Xc) |
Abbreviation: |
Calcium carbonate solid fraction in surface sediments (Xc) |
Unit: |
[no unit] |
Observation type: |
from the dbSEABED database compiled by Chris Jenkins at INSTAAR, see Jenkins (Sea Technol., 1997), Goff and Jenkins (Cont. Shelf. Reas., 2008) |
Diffusive boundary layer thickness (zDBL) |
Abbreviation: |
Diffusive boundary layer thickness (zDBL) |
Unit: |
micrometers |
Observation type: |
computed as explained in Sulpis et al. (PNAS, 2018) |
Longitude (lon) |
Abbreviation: |
Longitude (lon) |
Unit: |
in degrees N |
Latitude (lat) |
Abbreviation: |
Latitude (lat) |
Unit: |
in degrees E |
PUBLICATIONS DESCRIBING THIS DATASET: none;
ADDITIONAL INFORMATION: none;
FUNDING AGENCY: US National Science Foundation, NSERC Discovery Grants
PROJECT TITLE:
Current calcite (CaCO3) dissolution
PROJECT ID:
OCE-0960820 and PLR-1425989
SUBMITTED BY: Olivier Sulpis (olivier.sulpis@mail.mcgill.ca)
SUBMISSION DATE: 2018-10-09