Northern Hemisphere sea ice variability in a transient CGCM simulation of the past 2.6 Ma.

ABSTRACT: The recent sea ice changes in the Northern Hemisphere (NH), necessitate elucidating the sea ice variability over the past 2.6 million years (Ma), when the Earth's glacial cycles transitioned from ∼41 to ∼100 kyr periodicity, following the Mid-Pleistocene Transition (MPT) period (0.7-1.2 Ma). Here, we analyze a coupled general circulation model (CGCM) simulation to understand how the NH sea ice responds to changes in the transient orbital, greenhouse gas (GHG), and ice-sheet forcings. We find that the Earth's axial tilt (obliquity) and axial wobble (precession) strongly influence the variability in high-latitude (>70° N) perennial sea ice and mid-latitude (35° N-70° N) seasonal sea ice, respectively, by modifying the net surface shortwave radiation. Meanwhile, the GHG forcing affects the gl

SUBMITTER: Mandal G 

PROVIDER: S-EPMC11695940 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature