Carbonate ion concentrations, ocean carbon storage, and atmospheric CO2

Reconstructing past ocean [CO32−] allows the paleodepth of the chemical lysocline to be constrained, an important control on past atmospheric CO2. However, the causal mechanisms responsible for observed spatial and temporal variations in [CO32−] are difficult to quantify because of the complicated carbonate chemistry system. Here spatial and temporal variations in [CO32−] are quantitatively and concisely related to variations in ocean carbon storage due to different processes. The spatial variation in [CO32−] is given by Δ[CO32−] = γCsoft + ΔCdis+ (∂Csat/∂TT − ΔCcarb), where Csoft and Ccarb are the dissolved inorganic carbon (DIC) from remineralization of marine soft tissue and CaCO3, respectively, T is seawater temperature, (∂Csat/∂T) is the temperature-solubility sensitivity of DIC, Cdis is the DIC from air-sea disequilibrium, and γ is a carbonate chemistry coefficient. A similar quantitative function for temporal variation in global mean ocean [CO32−] is derived in terms of atmospheric CO2, CaCO3 precipitation and dissolution, and carbon exchanges of terrestrial or fossil fuel origin. Comparing published [CO32−] reconstructions at the Last Glacial Maximum (LGM) and the late Holocene, the quantitative relationships reveal how the spatial distribution of ocean carbon storage was altered. Relative to the Intermediate North Atlantic, the rest of the ocean saw Csoft + Cdis + (∂Csat/∂T)T − Ccarb increase by an extra 570–970 Pg C during the LGM. Assuming that the Intermediate North Atlantic Csoft + Cdis + (∂Csat/∂T)T − Ccarb did not decrease during the LGM, this 570–970 Pg C increase in the rest of the ocean is enough to explain 40%–70% of the observed glacial decrease in atmospheric CO2.

Goodwin P. & Lauderdale J. M., 2013. Carbonate ion concentrations, ocean carbon storage, and atmospheric CO2. Global Biogeochemical Cycles 27:882-893. Article.

0 Responses to “Carbonate ion concentrations, ocean carbon storage, and atmospheric CO2”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,266,082 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book