Stable isotopes of fossil teeth corroborate key general circulation model predictions for the Last Glacial Maximum in North America

[1] Oxygen isotope data provide a key test of general circulation models (GCMs) for the Last Glacial Maximum (LGM) in North America, which have otherwise proved difficult to validate. High dO pedogenic carbonates in central Wyoming have been interpreted to indicate increased summer precipitation sourced from the Gulf of Mexico. Here we show that tooth enamel dO of large mammals, which is strongly correlated with local water and precipitation dO, is lower during the LGM in Wyoming, not higher. Similar data from Texas, California, Florida and Arizona indicate higher dO values than in the Holocene, which is also predicted by GCMs. Tooth enamel data closely validate some recent models of atmospheric circulation and precipitation dO, including an increase in the proportion of winter precipitation for central North America, and summer precipitation in the southern US, but suggest aridity can bias pedogenic carbonate dO values significantly. Citation: Kohn, M. J., and M. McKay (2010), Stable isotopes of fossil teeth corroborate key general circulation model predictions for the Last Glacial Maximum in North America, Geophys. Res. Lett., 37, L22702, doi:10.1029/2010GL045404.