SODA4: ocean climate variability at mesoscale resolution

SODA4：中尺度分辨率的海洋气候变化

• 批准号: 1948952
• 负责人: James Carton
• 金额: $ 96.05万
• 依托单位: University of Maryland, College Park
• 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: 2020-03-15 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1948952&HistoricalAwards=false
• 关键词: SODA4; ocean; climate; variability; mesoscale

Oceanographic observations are sparse and not uniformly distributed over space or time. Since many analyses benefit from complete fields available over a regular grid, reanalysis products have been developed to fill this gap by constraining a numerical model with available observations. One of the most widely used ocean reanalysis products is the Simple Ocean Data Assimilation. Its current version (SODA3) does not have sufficient resolution to capture most of the eddies, especially in the high latitude regions. This may cause biases in regions where strong eddy activity or wind forcing and mixing are present. This project exploits the growth of computational power to make improved use of the limited historical observational record using a model that resolves the dominant smaller scales of motion in order to produce a mesoscale resolving global ocean/sea ice reanalysis called SODA4. The project also includes a focused examination of the role of mesoscale processes in the Arctic and in subpolar/Arctic exchanges. This work is directed toward understanding the role the ocean and sea ice systems play in regulating and modifying Earth’s weather and climate partly as a guide to improve forecasts of future changes. Improved understanding of historical ocean variability benefits the scientific enterprise by playing a crucial role as a guide to improve forecasts of coupled climate variability and by adding additional value to the historical observational record by reconstructing their basin-scale context. By supporting development and distribution of more realistic historical climate reanalysis spanning the past four decades this project can serve to integrate research activities across multiple areas and disciplines. The improved representation of smaller scales of motion and of regions of high human impact such as the nearshore environment should also help inform a broad community (coastal planners and engineers, wind farms, the fisheries community, etc.) regarding historical ocean variability and change. This research project also serves educational mission of University of Maryland College Park in several ways. Most directly it will support the dissertation research of a graduate student at the Department of Atmospheric and Oceanic Science. It will also involve a number of undergraduate research projects.Examination of SODA3 results shows that its resolution is insufficient where mesoscale variability and near-surface diapycnic processes play dominant roles. This project explores the additional improvements to representation of the state of the ocean/sea ice system that can be gained by more completely representing oceanic mesoscale processes even during decades when mesoscale-resolving observing systems were not available. One region which will benefit from enhanced resolution is the Arctic Ocean and its connection to the subpolar gyres. The subpolar North Atlantic is the major route by which water is exchanged with the Arctic Ocean and this connection is of particular interest for many reasons. First, the surface water of the Nordic Seas is warming rapidly and the winter ice is retreating. Second, strong decadal temperature variability is present with unknown consequences for the central Arctic. Third it is a key region of deepwater formation. This project thus includes a focused effort to improve representation and diagnosis of the dynamics of subpolar/Arctic exchanges and their connection to variable Arctic Ocean water masses.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.

由于许多分析受益于规则网格上可用的完整字段，海洋学观测结果稀疏且分布不均匀，因此开发了再分析产品，通过使用可用观测值约束数值模型来填补这一空白。海洋再分析产品是简单海洋数据同化，其当前版本（SODA3）没有足够的分辨率来捕获大部分涡流，特别是在高纬度地区，这可能会在涡流活动或风力强迫较强的地区造成偏差。该项目利用计算能力的增长，使用解决主要较小尺度运动的模型来更好地利用有限的历史观测记录，以产生称为 SODA4 的中尺度解决全球海洋/海冰再分析。还包括对北极和亚极地/北极交换中中尺度过程的作用的重点研究。这项工作旨在了解海洋和海冰系统在调节和改变地球天气和气候方面所发挥的作用。改进对未来变化的预测的指南对科学事业有好处，因为它可以作为改进耦合气候变率的预测的指南，并通过重建盆地规模为历史观测记录增加附加价值。通过支持过去四十年更现实的历史气候再分析的开发和分发，该项目可以整合多个领域和学科的研究活动，从而改进对较小尺度的运动和人类影响较大的区域的代表性。近岸环境也应该有助于为广大社区提供信息（沿海规划者和工程师、风电场、渔业界等）关于历史海洋变化和变化的研究项目还以多种方式服务于马里兰大学帕克分校的教育使命，最直接的是支持论文研究。它还将涉及一些本科生研究项目。SODA3 结果的检查表明，其分辨率不足，其中中尺度变化和近地表非渗透过程起主导作用。即使在没有中尺度分辨观测系统的几十年里，北冰洋和海冰系统也可以通过更完整地代表海洋中尺度过程来改善海洋/海冰系统状态的表示。它与副极地环流的联系是与北冰洋进行水交换的主要路线，这种联系由于多种原因而特别令人感兴趣，首先，北欧海洋的表层水正在迅速变暖，而且冬季。冰其次，存在着强烈的年代际温度变化，对北极中部产生了未知的影响。第三，它是深水形成的关键区域，因此该项目重点致力于改善副极地/北极交换和动态的表征和诊断。它们与变化的北冰洋水团的联系。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

RARE: The Regional Arctic Reanalysis

罕见：北极区域再分析

• DOI: 10.1175/jcli-d-22-0340.1
• 发表时间: 2023-04
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Carton, James A.;Chepurin, Gennady A.
• 通讯作者: Chepurin, Gennady A.