On Sea Ice Predictability in the US Arctic Regional Seas
Source: LASG Viewed: time(s) Time: 2016-9-1
Dr. Wei Cheng
University of Washington, USA
10:30 am,1 September,2016
This study assesses sea ice predictability in the US Arctic regional (Bering, Chukchi, and Beaufort) seas to understand regional differences from the pan-Arctic perspective and how predictability might change under changing climate. Lagged correlation is derived using existing output from the CESM Large Ensemble (CESM-LE), Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), and NOAA Coupled Forecast System Reanalysis (CFSR) models. Each has similar lagged correlation for the pan-Arctic area, whereas the pan-Arctic ice thickness lagged correlation has more model diversity. On regional scales, CESM-LE ice area lagged correlations are strongly location- and season-dependent. Using CESM-LE, the pan-Arctic ice thickness correlation’s e-folding time scale is a few months to a year (depending on the initialization month); longer than that of ice area correlation. Contrasting CESM-LE pre- and post-2040 periods with early 20th century climate, the melt-to-freeze season ice area memory intensifies whereas the freeze-to-melt season memory weakens as climate warms.