资源环境科技发展态势分析平台

Coupled subseasonal forecast systems with dynamical sea ice have the potential of providing important predictive information in polar regions. Here, we evaluate the ability of operational ensemble prediction systems to predict the location of the sea ice edge in Antarctica. Compared to the Arctic, Antarctica shows on average a 30% lower skill, with only one system remaining more skillful than a climatological benchmark up to -30 days ahead. Skill tends to be highest in the west Antarctic sector during the early freezing season. Most of the systems tend to overestimate the sea ice edge extent and fail to capture the onset of the melting season. All the forecast systems exhibit large initial errors. We conclude that subseasonal sea ice predictions could provide marginal support for decision-making only in selected seasons and regions of the Southern Ocean. However, major progress is possible through investments in model development, forecast initialization and calibration.

Plain Language Summary Being able to predict the evolution of the ice edge location from weeks to months in advance is crucial to ensure the safety and effectiveness of human activities in polar regions. This study evaluates the ability of six operational forecasting systems in predicting the evolution of the sea ice edge around the Antarctic continent. We find that only one system produces potentially useful forecast up to 1 month ahead. The dynamical forecasts are relatively more skillful in the west Antarctic sector, where the skill of statistical forecasts based on observational records tends to be reduced due to higher variability. Furthermore, our results show that forecasts initialized around the date of minimum sea ice extent exhibit low errors at the beginning of the freezing season. Overall, errors associated with current subseasonal Antarctic sea ice forecasts seem to be too large for the forecasts to be employed operationally for navigation purposes, although they might be useful already in selected seasons and regions around Antarctica. We expect that major progress is possible through future investments from the operational centers into model development, initialization, and calibration.