The Evolution of Polar Climates: Forcings, Feedbacks, and Coupled Atmosphere-Ocean-Ice Dynamics

极地气候的演变：强迫、反馈和耦合的大气-海洋-冰动力学

• 批准号: RGPIN-2019-07211
• 负责人: Singh, Hansi
• 金额: $ 2.19万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750985
• 关键词: Evolution; Polar; Climates; Forcings; Feedbacks

The polar regions are among the most vulnerable to anthropogenic climate change, with observed warming over the Arctic nearly triple that over the rest of the globe. This phenomenon of rapid high--latitude climate change, polar amplification, is evident over the Arctic in nearly all climate model simulations, and has been attributed to local radiative feedbacks (associated with both sea ice loss and the stability of the polar atmosphere) and changes in energy convergence by the atmosphere and ocean. This rapid rate of climate change in the polar regions has implications for global sea level, marine ecosystems, and extrapolar atmospheric circulation patterns, with anticipated societal impacts on coastal habitability, fishery productivity, and extreme weather, among others. The polar regions release much more energy to space than what they absorb from the sun, in effect acting as cooling radiator fins for the planet. This functionality, in turn, is made possible by the large--scale transport of extrapolar energy by the atmosphere and oceans into the polar regions. In a changing climate, changes in the cooling efficiency of the polar radiator fins depend on radiative feedbacks and changes in energy transport, which also affect polar and extrapolar climatology. In the proposed research program, I will investigate the evolving relationship between top--of-atmosphere polar energy loss, polar radiative feedbacks, and changing (atmosphere and ocean) energy convergence into the polar regions over a variety of time scales. Using models, observations, and applied mathematical techniques, we focus on the following objectives: 1. To quantify the temporal evolution of polar top--of--atmosphere energy loss with greenhouse gas forcing, and co--evolving contributions from radiative feedbacks and energy transport changes. 2. To understand Bjerknes compensation of atmospheric and oceanic energy transport into the high latitudes by identifying dynamic mechanisms of coupled energy transport adjustment. 3. To assess the relationship between fluctuations in polar top-of-atmosphere energy loss with natural variability and with forced climatic change. 4. To quantify the predictive power of sea ice in determining the polar climate state, top-of--atmosphere energy loss, radiative feedbacks (other than ice--albedo), and energy transport adjustments. 5. To assess the extrapolar impacts of polar climate change through a framework of varying regional forcings, radiative feedbacks, and atmospheric and oceanic energy transport adjustments. This research program will expand upon my prior work polar climate change through a lens of interacting local feedback mechanisms alongside adjustments in large--scale atmosphere--ocean coupled dynamics. More broadly, it will establish a framework for greater understanding and prediction of polar and extrapolar climate change, with particular relevance for climate change impacts, adaptation, and mitigation in the Canadian Arctic.

极性区域是最容易受到人为气候变化的影响，观察到在北极几乎三倍的北极地区变暖。在几乎所有气候模型模拟中，北极地区的这种快速高纬度气候变化的现象是明显的，并且归因于局部辐射反馈（与海冰损失和极地气氛的稳定性相关）以及大气和海洋能量融合的变化。极地地区气候变化的迅速速度对全球海平面，海洋生态系统和外部大气环流模式产生了影响，对沿海可居住性，渔业生产力和极端天气等的社会影响产生了预期的影响。极地区域比从太阳中吸收的能量更大，实际上充当了地球的冷却散热器鳍。反过来，通过大气和海洋向极区域大规模运输的大规模运输，使该功能成为可能。在气候变化中，极性散热器鳍的冷却效率的变化取决于辐射反馈和能量传输的变化，这也影响了极性和外气候。在拟议的研究计划中，我将调查顶部 - 大气极性能量损失，极性辐射反馈以及（大气和海洋）能量在各种时间尺度上转向极性区域之间的不断发展的关系。使用模型，观察和应用数学技术，我们关注以下目标：1。量化极性顶部的时间演化，即大气能损失，而温室气体强迫和CO-从辐射反馈和能量运输变化中贡献了贡献。 2。通过确定耦合能量传输调节的动态机制，了解大气和海洋能量转运到高纬度的补偿。 3。评估极性大气顶能量损失的波动与自然变异性与强迫气候变化之间的关系。 4。为了量化海冰在确定极性气候状态的预测能力，大气能损失，辐射反馈（除了冰）和能量传输调整。 5。通过不同的区域强迫，辐射反馈以及大气和海洋能量运输调整的框架来评估极性气候变化的外影响。该研究计划将通过我先前的工作，通过各种相互作用的本地反馈机制以及大规模气氛的调整 - 近距离耦合动力学来扩展极性气候变化。更广泛地说，它将建立一个框架，以更深入地理解和预测极性气候变化，与气候变化的影响，适应和缓解措施特别相关。