Ice-atmosphere interactions and sea ice predictability at multiple resolutions in the Community Earth System Model

Thesis (Master's)--University of Washington, 2016-06

This work introduces a high resolution (0.1° ocean), slab ocean version of the Community Earth System Model (CESM1(CAM5)). This model is used to investigate ice/atmosphere interactions through comparison with a standard resolution (1° ocean) control run. Differences in the mean ice fields are dominated by differences in the model climates. The high resolution model is warmer and slightly favors thinner ice and lower ice concentrations. The atmospheric boundary layer responds to these changes, with larger boundary layer heights and weaker inversions over winter ice in the high resolution model. A kernel feedback analysis shows that despite some effects on the atmospheric structure, resolution does not appear to change climate feedbacks. Finally, the new slab ocean model is compared with the CESM Large Ensemble control runs and the PetaApps runs to investigate the effects of resolution and ocean model on monthly sea ice predictability from persistence. Resolution does not have a large effect. The dynamical ocean models generally have better predictability in ice area than slab ocean models in the Arctic. The effects of ocean dynamics are more complicated in the Antarctic.