Community Talk: Elio Campitelli (Monash University)
First Impressions of ACCESS-S2 Antarctic Sea Ice Forecast
Abstract
ACCESS-S2, the Australian Bureau of Meteorology’s current operational seasonal forecast system, generates initial conditions by assimilating oceanic and atmospheric data. Unlike its predecessor ACCESS-S1, it does not incorporate sea ice concentration observations. Hence, the sea ice initial state is formed by the ocean initial conditions.
Our study evaluates ACCESS-S2’s performance in forecasting sea ice concentration in polar regions, with a focus on Antarctica. Using hindcast and reanalysis data from 1981 to 2018, we assess the system’s skill and investigate sources of error. Results indicate that ACCESS-S2 generally exhibits low skill in forecasting sea ice extent and concentration anomalies when compared to a simple persistence forecast. The system also displays high biases, particularly during summer months.
Analysis reveals that a significant portion of forecast errors stems from inaccuracies in initial conditions. This suggests that incorporating sea ice concentration data into the forecasting system could potentially reduce these errors, thereby improving overall forecast accuracy. Our findings highlight the importance of sea ice data assimilation in enhancing polar region predictions and provide valuable insights for future improvements to the ACCESS-S2 system.
Please use this thread for further discussion on this talk.
Slides are available here: slides
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I was wondering if it is worthwhile looking at the CAFE system output? It’s low resolution but uses the ENKF-C assimilation and may give you a better sea ice initialisation. @ChrisC28 might be able to tell you if that data is accessible.
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Thanks! I’ll look into it.