Collaborative Research: Midlatitude Marine Heatwaves in a changing climate: Variability, Predictability, and Projections

合作研究：气候变化中的中纬度海洋热浪：变化性、可预测性和预测

• 批准号: 2022874
• 负责人: LuAnne Thompson
• 金额: $ 48.09万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2022874&HistoricalAwards=false
• 关键词: Collaborative; Research; Midlatitude; Marine; Heatwaves

Marine heatwaves (MHWs) are devastating periods of extreme sea surface temperatures (SST) that disrupt marine ecosystems and the fishing industries that rely on them. Their effects include increased economic tension between nations and an unprecedented harmful algal bloom that threatened public health. These events have been observed throughout the global ocean, with several large scale persistent events occurring in the mid-latitudes over the last decade. Climate model simulations suggest that under continued global warming we can expect MHWs to become longer lasting, more frequent and intense, pushing ecological systems beyond their thermal coping limit, leading to irreversible impacts to the environment. While the satellite record of SST over the last 40 years allows characterization of past MHWs, the number of these devastating midlatitude events is limited, making it difficult to assess how unusual the events are. Event based analysis of the causes and consequences of individual events has given insight into important processes that control these particular events, but whether these processes remain important in the future is unclear. This research will make use of an extensive set of existing model simulations, including both different model configurations and ensembles or multiple realizations of similar runs for better statistical convergence. The analysis will yield insights into both the fidelity of the simulations in critical parts of the ocean and the predictability of heat waves. The impacts of MHWs are profound to both human and natural systems, and quantifying both the impact of climate change on their properties as well as an examination of the predictability of these events will ultimately help to mitigate and prepare for potential impacts in the future. Two graduate students will be trained to use the National Center for Atmospheric Research (NCAR) analysis tools, as well as work with NCAR scientists in developing new tools in Python for use in future analyses of extreme ocean events. The research team will also work with the Northwest Association of the Networked Ocean Observing Systems (NANOOS), hosted at the University of Washington, and the North Carolina Nature Conservancy office to write short articles about the results of this research. Results of this research will also be incorporated into undergraduate courses in coastal oceanography and climate at the University of Washington and the University of Wisconsin.This project will take advantage of a suite of model simulations performed using the CESM (Community Earth System Model) including forced and coupled simulations at both low and high resolutions. An assessment of statistics of MHWs will be performed using a 40-member large ensemble of the climate from 1920 to 2100 allowing statistical robustness of event characteristics. Additional analysis of high resolution forced and coupled simulations will allow assessment of the fidelity of the representation of MHWs in boundary current regions where large biases are known to exist in low resolution simulation. In addition, a decadal prediction system using the same model version as the large ensemble will allow exploration of the role of ocean initialization in the predictability of these dangerous events. Typical analysis of MHW properties has used pointwise metrics, or metrics defined as area averages over fixed boxes. New integrated metrics for MHW characterization will be created that allow for MHWs that change shape and position over time, and will take into account heat stored below the surface. The role of climate variability in controlling MHWs will be assessed using the large ensemble, while comparison of high and low resolution models will allow for assessment of the robustness of the results from low resolution models. The focus on midlatitude events will include assessment of how ocean heat storage and re-emergence affect properties of MHWs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海洋热浪（MHW）是破坏海洋生态系统和依靠它们的捕鱼行业的极端海面温度（SST）的毁灭性时期。它们的影响包括国际之间的经济紧张局势和前所未有的有害藻华，威胁到公共卫生。这些事件已经在整个全球海洋中观察到，在过去十年中，在中期发生了一些大规模的持续事件。气候模型模拟表明，在持续的全球变暖下，我们可以期望MHW会变得更长，更频繁，更激烈，将生态系统推向其热应对极限，从而导致对环境的不可逆转影响。尽管过去40年中SST的卫星记录允许表征过去的MHW，但这些毁灭性的中纬度事件的数量受到限制，因此很难评估事件的异常情况。基于事件的个人事件的原因和后果的分析使人们对控制这些特定事件的重要过程有深入的了解，但是这些过程在将来是否仍然很重要。这项研究将利用一组广泛的现有模型模拟，包括不同的模型配置和合奏或类似运行的多个实现，以获得更好的统计收敛。该分析将对海洋临界部位的模拟的保真度和热浪的可预测性产生见解。 MHW的影响对人类和自然系统都是深远的，并量化气候变化对其性质的影响以及对这些事件的可预测性的检查最终将有助于减轻并准备将来的潜在影响。将对两名研究生进行培训，以使用国家大气研究中心（NCAR）分析工具，并与NCAR科学家合作开发Python的新工具，以在未来的极端海洋事件分析中使用。研究小组还将与西北网络海洋观测系统协会（NANOOS）合作，在华盛顿大学和北卡罗来纳州自然保护局举办，撰写有关这项研究结果的简短文章。这项研究的结果还将在华盛顿大学和威斯康星大学的沿海海洋学和气候的本科课程中纳入本科课程。该项目将利用使用CESM（社区地球系统模型）进行的一套模型模拟。从1920年到2100年，将对MHW的统计数据进行评估，从而允许统计事件特征稳健性。对高分辨率强制和耦合模拟的进一步分析将允许评估MHW在边界电流区域的表示的保真度，在低分辨率模拟中已知存在较大的偏见。此外，使用与大型合奏相同的模型版本的际预测系统​​将允许探索海洋初始化在这些危险事件的可预测性中的作用。对MHW属性的典型分析使用了指标，或定义为固定框上的面积平均值的指标。将创建用于MHW表征的新的集成指标，以允许随着时间的推移改变形状和位置的MHW，并考虑在表面下方存储的热量。气候变异性在控制MHW中的作用将使用大型合奏进行评估，而对高分辨率模型的比较将允许评估低分辨率模型的结果的鲁棒性。对中纬度事件的重点将包括评估海洋热量存储和重新出现如何影响MHW的特性。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，认为值得通过评估来获得支持。