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Orbital control of low‐latitude seasonality during the Eemian
Author(s) -
Winter Amos,
Paul André,
Nyberg Johan,
Oba Tadimichi,
Lundberg Joyce,
Schrag Dan,
Taggart Bruce
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl016275
Subject(s) - eemian , climatology , latitude , low latitude , milankovitch cycles , seasonality , environmental science , forcing (mathematics) , climate oscillation , insolation , range (aeronautics) , atmospheric sciences , paleoclimatology , orbital forcing , climate change , geology , glacial period , global warming , oceanography , interglacial , effects of global warming , ecology , materials science , geodesy , composite material , geomorphology , biology
We used Sr/Ca and stable isotope data from well dated and preserved corals from the northeastern Caribbean to determine the seasonal environmental conditions for four continuous years during the Eemian, the last time the Earth was in a prolonged warm phase. We determined that the seasonal range in SST during the Eemian was 25°–30° C. This is ∼1–2° larger than at present and caused primarily by winter cooling and, only to a small degree, by summer warming. As climate modeling studies indicate, the bias towards colder winters can be explained by changes in low latitude insolation induced by altered orbital parameters, modulated by atmospheric CO 2 levels that were lower than today. Milankovitch forcing at higher latitudes was probably less important.