Open AccessWater isotopologues as a quantitative paleosalinity proxy
Author(s) -
LeGrande Allegra N.,
Schmidt Gavin A.
Publication year - 2011
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/2010pa002043
Subject(s) - isotopologue , salinity , geology , holocene , proxy (statistics) , climatology , δ18o , paleoceanography , general circulation model , climate change , oceanography , stable isotope ratio , chemistry , physics , organic chemistry , quantum mechanics , machine learning , molecule , computer science
Paleosalinity reconstructions are a goal of paleoceanographic study because of their potential to provide insight into past ocean circulation. While temperature reconstructions have been assessed by using multiple independent proxies, the skill of existing salinity reconstructions remains poorly quantified. We examine the applicability of two different approaches using a set of coupled water isotope–enabled general circulation model experiments as a numerical analog for the real climate system. These simulations for the Holocene, at roughly 1000 year time steps, explicitly track variability in both the water isotopologues and salinity. Our simulations suggest that quantitative reconstructions of past salinity variability based solely on inferred δ 18 O sw variability have very large errors and uncertainties. However, we find that paired δ 18 O sw and δ D variability (from combining biomarker and calcite proxies) holds promise for providing better quantitative estimates of salinity variability.