skip to main content


Search for: All records

Award ID contains: 1851900

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Abstract

    Upwelling deep waters in the Southern Ocean release biologically sequestered carbon into the atmosphere, contributing to the relatively high atmospheric CO2levels during interglacial climate periods. Paleoceanographic evidence suggests this “CO2leak” was lessened during the last glacial maximum (LGM), potentially due to increased stratification, weaker and equatorward‐shifted winds, and/or enhanced biological carbon export. The collective influences of these mechanisms on the ocean's biological pump efficiency and amount of atmospheric CO2can be quantified by determining preformed phosphate of deep waters. We quantify preformed PO4(Ppre,AOU) and preformed() of LGM bottom waters using a compilation of published paleo‐temperature, nutrient and oxygen estimates from benthic foraminifera. Our results show that preformed phosphate of the Pacific and Indian deep oceans was reduced by about −0.53 ± 0.13 μM and suggest that much (64 ± 28 ppmv) of the Glacial‐Interglacial CO2drawdown resulted from changes in the ocean's biological pump efficiency. Once carbonate compensation is accounted for, this can explain the entire CO2drawdown (87 ± 40 ppmv). Preformedshows similar results. The reconstructed LGM Ppre,AOUand oxygen are qualitatively consistent with the changes produced by a suite of numerical sensitivity experiments that roughly simulate three proposed mechanisms for an increase in LGM biological pump efficiency: an increase in biological activity, a decrease in wind‐driven upwelling, and an increase in stratification in the Southern Ocean.

     
    more » « less
  2. This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Climate Reconstruction. The data include parameters of paleoceanography with a geographic location of North Atlantic Ocean. The time period coverage is from 1930 to -52 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data. 
    more » « less