Earth's climate undergoes regular glacial-interglacial cycles with phases strongly linked to orbital variations known as the Milankovitch cycles â\u20ac\u201c eccentricity (100-kyr), obliquity (41-kyr), and precession (23-kyr). Although the Milankovitch cycles are well understood as modulating the amount and distribution of solar energy that reaches Earth (insolation), the mechanism by which they affect global climate remains poorly understood. We propose that Southern Hemisphere sea ice growth may be the main driver of glacial onset timing, due to geographic restraints on sea ice potential in the Arctic Circle. Thus, orbital conditions of low obliquity or June perihelion and high eccentricity--which decrease Southern Hemisphere summer energy, allowing for sea ice growth pace glacial onset. This solution addresses the dominant 40-kyr glacial cycle of the Early Pleistocene, as well as the 100-kyr glacial cycle of the past million years.
Chang, Andres,
"The impact of orbital configuration on earth's glaciation cycles"
(2015).
Summer Research Symposium.
Brown Digital Repository. Brown University Library.
https://doi.org/10.26300/bt5p-d295
Each year, Brown University showcases the research of its undergraduates at the Summer Research Symposium. More than half of the student-researchers are UTRA recipients, while others receive funding from a variety of Brown-administered and national programs and fellowships and go …
