论文标题
北极中海冰轨迹的概率预测：表面风和冰内不确定性的影响
Probabilistic forecasts of sea ice trajectories in the Arctic: impact of uncertainties in surface wind and ice cohesion
论文作者
论文摘要
我们研究了Lagrangian Sea Ice模型的Nextsim对海面风和海冰凝聚力的不确定性的响应。 Nextsim中的冰力学是基于脆性的流变框架。该研究考虑了2008年1月至4月的北极海冰的短期整体预测。通过分别和共同扰动风输入和冰凝聚场来产生合奏。概率预测的不确定性是根据模型中种子覆盖北极海洋并使用从搜索和救援文献中借用的指标对拉格朗日海冰轨迹的分析进行统计评估的。不同集团之间的比较表明，风扰动占据了预测不确定性，即集合的绝对扩散，而冰凝聚场中的不均匀性显着提高了扩散中各向异性的程度，即轨迹在不同方向上不同。我们建议，为了在具有脆性的流变学的海冰模型中获得完全不确定性的味道，以预测海冰漂移和轨迹，应该考虑使用基于合奏的模拟，在这些模拟中，风力强迫和海冰凝聚力都受到干扰。
We study the response of the Lagrangian sea ice model neXtSIM to the uncertainty in the sea surface wind and sea ice cohesion. The ice mechanics in neXtSIM is based on a brittle-like rheological framework. The study considers short-term ensemble forecasts of the Arctic sea ice from January to April 2008. Ensembles are generated by perturbing the wind inputs and ice cohesion field both separately and jointly. The resulting uncertainty in the probabilistic forecasts is evaluated statistically based on the analysis of Lagrangian sea ice trajectories as sampled by virtual drifters seeded in the model to cover the Arctic Ocean and using metrics borrowed from the search-and-rescue literature. The comparison among the different ensembles indicates that wind perturbations dominate the forecast uncertainty i.e. the absolute spread of the ensemble, while the inhomogeneities in the ice cohesion field significantly increase the degree of anisotropy in the spread i.e. trajectories drift differently in different directions. We suggest that in order to get a full flavor of uncertainties in a sea ice model with brittle-like rheologies, to predict sea ice drift and trajectories, one should consider using ensemble-based simulations where both wind forcing and sea ice cohesion are perturbed.
