Seasonal-to-Decadal Predictability of Arctic Sea Ice

北极海冰的季节到十年的可预测性

• 批准号: RGPIN-2018-04838
• 负责人: Tremblay, Bruno
• 金额: $ 3.13万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=713291
• 关键词: Seasonal; Decadal; Predictability; Arctic; Sea

With the opening of the summer pack ice in 2007, there has been an increased interest in short-term, seasonal and decadal forecasting or projections of sea ice conditions. Methods used in the community to study the predictability of the system on these time scales include coupled ice-ocean models forced with atmospheric fields from reanalyses (with or without data assimilation), fully coupled General Circulation Models with initial conditions derived from observations, or statistical models and heuristic or mixed approaches. For short-term forecasting (1-2 days), thermodynamic effects are less important and fully coupled models are not necessary. In this case, forecasting skill relies on the specification of accurate initial conditions, surface atmospheric stresses and an accurate representation of sea ice and surface ocean physics. For seasonal forecasting, accurate initial conditions are again crucial along with a good representation of ice-ocean-atmosphere physics and feedbacks. For decadal projections, the sensitivity to initial conditions is lost, and predictive skill relies on an accurate representation of the ice-ocean-atmosphere physics, as well as accurate representation of internal variability and external forcing such as CO2, ozone, aerosol, solar irradiance at the top-of-the-atmosphere, etc. The long-term objectives of this research program are to improve short-term to decadal forecasts or projections of sea ice in the Arctic Ocean. The specific objectives of the proposal are to improve sea ice physics (drift and deformation); to quantify potential predictability from observed quantities and reanalysis data (ice speed, concentration, thickness and lower/upper atmospheric circulation); to identify key metrics responsible for predictability in observations and assess whether those metrics are correctly simulated in Global Climate Models (pointing to area of model improvements and improved forecasts); to quantify potential improvements in predictability associated with ocean heat flux (both lateral in the Bering Strait and Barents Sea Opening and vertical via convection and Ekman dynamics). The completion of this work will lead to a better understanding of forecast skill and potential predictability. The novelty in this work is that it assesses predictability directly from observations. This is crucial given that small biases in the simulated mean state of models can lead to significant loss of predictability. This research program will place Canada in a unique position to improve sea ice forecasts for local populations and industry, allowing for safer operations in an Arctic, that is becoming increasingly accessible to navigation. It will also reduce uncertainties in the timeline for when these changes are more likely to occur.

随着2007年夏季包冰的开放，对短期，季节性和十年预测或海冰状况预测的兴趣增加了。社区中用于研究系统在这些时间尺度上的可预测性的方法包括耦合的冰山模型与重新分析的大气场（有或没有数据同化），完全耦合的一般循环模型，其初始条件具有从观察结果或统计模型和启发式模型或混合方法中得出的初始条件。对于短期预测（1-2天），热力学效应不太重要，无需完全耦合模型。在这种情况下，预测技能依赖于准确的初始条件，表面大气应力以及海冰和表面海洋物理物理的准确表示。对于季节性预测，准确的初始条件再次至关重要，并且良好地表示冰山 - 大气物理和反馈。 For decadal projections, the sensitivity to initial conditions is lost, and predictive skill relies on an accurate representation of the ice-ocean-atmosphere physics, as well as accurate representation of internal variability and external forcing such as CO2, ozone, aerosol, solar irradiance at the top-of-the-atmosphere, etc. The long-term objectives of this research program are to improve short-term to decadal forecasts or projections of sea ice in北极海。该提案的具体目标是改善海冰物理学（漂移和变形）；从观察到的数量和重新分析数据（冰速度，浓度，厚度和下部大气循环）中量化潜在的可预测性；确定负责观察中可预测性的关键指标，并评估这些指标是否在全球气候模型中正确模拟（指向模型改进的领域并改善了预测）；为了量化与海洋热通量相关的可预测性的潜在改善（在白令海峡的侧面和巴伦特海洋开口和通过对流和ekman动力学）。这项工作的完成将导致对预测技能和潜在可预测性有更好的了解。这项工作的新颖性是它直接从观察结果中评估可预测性。鉴于模拟平均模型状态的小偏差可能会导致可预测性的显着丧失，这至关重要。该研究计划将使加拿大处于一个独特的位置，以改善当地人口和行业的海冰预测，从而使北极行动更加安全，这在航行中变得越来越易于​​使用。它还将减少时间表中的不确定性，以便在更可能发生这些变化时。