skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: A mapped dataset of surface ocean acidification indicators in large marine ecosystems of the United States
Abstract Mapped monthly data products of surface ocean acidification indicators from 1998 to 2022 on a 0.25° by 0.25° spatial grid have been developed for eleven U.S. large marine ecosystems (LMEs). The data products were constructed using observations from the Surface Ocean CO2Atlas, co-located surface ocean properties, and two types of machine learning algorithms: Gaussian mixture models to organize LMEs into clusters of similar environmental variability and random forest regressions (RFRs) that were trained and applied within each cluster to spatiotemporally interpolate the observational data. The data products, called RFR-LMEs, have been averaged into regional timeseries to summarize the status of ocean acidification in U.S. coastal waters, showing a domain-wide carbon dioxide partial pressure increase of 1.4 ± 0.4 μatm yr−1and pH decrease of 0.0014 ± 0.0004 yr−1. RFR-LMEs have been evaluated via comparisons to discrete shipboard data, fixed timeseries, and other mapped surface ocean carbon chemistry data products. Regionally averaged timeseries of RFR-LME indicators are provided online through the NOAA National Marine Ecosystem Status web portal.  more » « less
Award ID(s):
2023545
PAR ID:
10573600
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Nature
Date Published:
Journal Name:
Scientific Data
Volume:
11
Issue:
1
ISSN:
2052-4463
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Journal of Geophysical Research: Oceans)
    Abstract The California Current Ecosystem (CCE) is a natural laboratory for studying the chemical and ecological impacts of ocean acidification. Biogeochemical variability in the region is due primarily to wind‐driven near‐shore upwelling of cold waters that are rich in re‐mineralized carbon and poor in oxygen. The coastal regions are exposed to surface waters with increasing concentrations of anthropogenic CO2(Canth) from exchanges with the atmosphere and the shoreward transport and mixing of upwelled water. The upwelling drives intense cycling of organic matter that is created through photosynthesis in the surface ocean and degraded through biological respiration in subsurface habitats. We used an extended multiple linear‐regression approach to determine the spatial and temporal concentrations of Canthand respired carbon (Cbio) in the CCE based on cruise data from 2007, 2011, 2012, 2013, 2016, and 2021. Over the region, the Canthaccumulation rate increased from 0.8 ± 0.1 μmol kg−1 yr−1in the northern latitudes to 1.1 ± 0.1 μmol kg−1 yr−1further south. The rates decreased to values of about ∼0.3 μmol kg−1 yr−1at depths near 300 m. These accumulation rates at the surface correspond to total pH decreases that averaged about 0.002 yr‐1; whereas, decreases in aragonite saturation state ranged from 0.006 to 0.011 yr‐1. The impact of the Canthuptake was to decrease the amount of oxygen consumption required to cross critical biological thresholds (i.e., calcification, dissolution) for marine calcifiers and are significantly lower in the recent cruises than in the pre‐industrial period because of the addition of Canth. 
    more » « less
  2. ; ; (, Geophysical Research Letters)
    Abstract The ocean carbon reservoir controls atmospheric carbon dioxide (CO2) on millennial timescales. Radiocarbon (14C) anomalies in eastern North Pacific sediments suggest a significant release of geologic14C‐free carbon at the end of the last ice age but without evidence of ocean acidification. Using inverse carbon cycle modeling optimized with reconstructed atmospheric CO2and14C/C, we develop first‐order constraints on geologic carbon and alkalinity release over the last 17.5 thousand years. We construct scenarios allowing the release of 850–2,400 Pg C, with a maximum release rate of 1.3 Pg C yr−1, all of which require an approximate equimolar alkalinity release. These neutralized carbon addition scenarios have minimal impacts on the simulated marine carbon cycle and atmospheric CO2, thereby demonstrating safe and effective ocean carbon storage. This deglacial phenomenon could serve as a natural analog to the successful implementation of gigaton‐scale ocean alkalinity enhancement, a promising marine carbon dioxide removal method. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, Global Biogeochemical Cycles)
    Abstract This contribution to the RECCAP2 (REgional Carbon Cycle Assessment and Processes) assessment analyzes the processes that determine the global ocean carbon sink, and its trends and variability over the period 1985–2018, using a combination of models and observation‐based products. The mean sea‐air CO2flux from 1985 to 2018 is −1.6 ± 0.2 PgC yr−1based on an ensemble of reconstructions of the history of sea surface pCO2(pCO2products). Models indicate that the dominant component of this flux is the net oceanic uptake of anthropogenic CO2, which is estimated at −2.1 ± 0.3 PgC yr−1by an ensemble of ocean biogeochemical models, and −2.4 ± 0.1 PgC yr−1by two ocean circulation inverse models. The ocean also degasses about 0.65 ± 0.3 PgC yr−1of terrestrially derived CO2, but this process is not fully resolved by any of the models used here. From 2001 to 2018, the pCO2products reconstruct a trend in the ocean carbon sink of −0.61 ± 0.12 PgC yr−1 decade−1, while biogeochemical models and inverse models diagnose an anthropogenic CO2‐driven trend of −0.34 ± 0.06 and −0.41 ± 0.03 PgC yr−1 decade−1, respectively. This implies a climate‐forced acceleration of the ocean carbon sink in recent decades, but there are still large uncertainties on the magnitude and cause of this trend. The interannual to decadal variability of the global carbon sink is mainly driven by climate variability, with the climate‐driven variability exceeding the CO2‐forced variability by 2–3 times. These results suggest that anthropogenic CO2dominates the ocean CO2sink, while climate‐driven variability is potentially large but highly uncertain and not consistently captured across different methods. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, Global Biogeochemical Cycles)
    Abstract We assess the Southern Ocean CO2uptake (1985–2018) using data sets gathered in the REgional Carbon Cycle Assessment and Processes Project Phase 2. The Southern Ocean acted as a sink for CO2with close agreement between simulation results from global ocean biogeochemistry models (GOBMs, 0.75 ± 0.28 PgC yr−1) andpCO2‐observation‐based products (0.73 ± 0.07 PgC yr−1). This sink is only half that reported by RECCAP1 for the same region and timeframe. The present‐day net uptake is to first order a response to rising atmospheric CO2, driving large amounts of anthropogenic CO2(Cant) into the ocean, thereby overcompensating the loss of natural CO2to the atmosphere. An apparent knowledge gap is the increase of the sink since 2000, withpCO2‐products suggesting a growth that is more than twice as strong and uncertain as that of GOBMs (0.26 ± 0.06 and 0.11 ± 0.03 Pg C yr−1 decade−1, respectively). This is despite nearly identicalpCO2trends in GOBMs andpCO2‐products when both products are compared only at the locations wherepCO2was measured. Seasonal analyses revealed agreement in driving processes in winter with uncertainty in the magnitude of outgassing, whereas discrepancies are more fundamental in summer, when GOBMs exhibit difficulties in simulating the effects of the non‐thermal processes of biology and mixing/circulation. Ocean interior accumulation of Cantpoints to an underestimate of Cantuptake and storage in GOBMs. Future work needs to link surface fluxes and interior ocean transport, build long overdue systematic observation networks and push toward better process understanding of drivers of the carbon cycle. 
    more » « less
  5. ; ; ; ; (, Communications Earth & Environment)
    Abstract Long-term ocean time series have proven to be the most robust approach for direct observation of climate change processes such as Ocean Acidification. The California Cooperative Oceanic Fisheries Investigations (CalCOFI) program has collected quarterly samples for seawater inorganic carbon since 1983. The longest time series is at CalCOFI line 90 station 90 from 1984–present, with a gap from 2002 to 2008. Here we present the first analysis of this 37- year time series, the oldest in the Pacific. Station 90.90 exhibits an unambiguous acidification signal in agreement with the global surface ocean (decrease in pH of −0.0015 ± 0.0001 yr−1), with a distinct seasonal cycle driven by temperature and total dissolved inorganic carbon. This provides direct evidence that the unique carbon chemistry signature (compared to other long standing time series) results in a reduced uptake rate of carbon dioxide (CO2) due to proximity to a mid-latitude eastern boundary current upwelling zone. Comparison to an independent empirical model estimate and climatology at the same location reveals regional differences not captured in the existing models. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email