Causes and Impacts of Sea Ice Variability in the Sea of Okhotsk Using CESM-LE
Open Access
- Author:
- Williams, Matthew
- Graduate Program:
- Meteorology and Atmospheric Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- May 15, 2019
- Committee Members:
- Melissa Marie Gervais, Thesis Advisor/Co-Advisor
Chris Eliot Forest, Committee Member
Sukyoung Lee, Committee Member - Keywords:
- CESM
Okhotsk
sea ice
interannual variability
atmospheric dynamics
CESM-LE
thermodynamics - Abstract:
- This study investigates the mechanisms responsible for interannual variability in sea ice coverage in the Sea of Okhotsk, located in the northwestern North Pacific, as well as the potential atmospheric response to anomalous sea ice coverage in this region. We have performed this analysis using model output from the Community Earth System Model Large Ensemble (CESM-LE). We find that thermodynamic processes involving anomalous ocean-atmosphere heat fluxes as early as late autumn affect the timing of initial sea ice growth in the Sea of Okhotsk. Low-level wind anomalies in the winter affect the extent to which sea ice fully develops, both through advection of the sea ice itself and through changes in the transport of air masses over the Sea of Okhotsk. We also find evidence that anomalous ocean-atmosphere heat fluxes in the winter trigger an atmospheric response: locally, as a negative sea-level pressure anomaly; and remotely, as a Rossby wave that extends over North America. These results are consistent with previous observational studies on interannual variability in sea ice in the Sea of Okhotsk and atmosphere-only modeling studies on the atmospheric response to changes in Sea of Okhotsk sea ice. This work provides a new perspective on the coupled processes involved in generating and responding to interannual variability of sea ice in the Sea of Okhotsk, demonstrating the ability of the CESM to capture these processes in a fully-coupled modeling framework.