Collaborative Research: Decadal Coupled Ocean-Atmosphere Interactions in the North Pacific

OCE-0647994近年来的研究表明，西北太平洋黑潮-亲潮延伸体（KOE）周围大范围冬季海表温度（SST）的异常可以从北太平洋风应力的历史中预测。SST的这一可预测成分对北太平洋气候有意义，因为KOE是一个海气相互作用强烈的区域，与大尺度北太平洋/北美大气气候变率有关。在我们对与KOE地区相关的气候变化所涉及的机制的理解方面仍然存在重大差距。这些差距包括大气可能对KOE SST的可预测变化作出反应的方式;整个北太平洋/北美扇区大气对流层反应的详细性质;携带北太平洋可预测信号的行星波改变北太平洋SST、中尺度涡旋、水平速度和上升流的方式;以及中尺度海洋变化的重要性，它产生相关的地面风应力和热通量异常，在建立气候尺度KOE SST异常。智力优势：该项目的目的是澄清这些问题，通过缩小国家环境预测中心（NCEP）再分析领域的过去50年来在北太平洋使用高分辨率的区域耦合海洋大气模式（SCOAR），包括中尺度涡。通过这些耦合降尺度实验的集合，再加上非耦合海洋和非耦合大气模式后报的相关组合，将对结果进行诊断，并通过观测进行验证，以估计在十年反馈回路和气候可预测性的背景下与区域海洋-大气反馈相关的方差分数。分析将侧重于一系列复杂的过程，这些过程将KOE区域的区域海洋环流和SST异常与大气边界层和风暴轴联系起来，而风暴轴与控制北太平洋中部温跃层扰动激发和传播的流域尺度过程联系起来，这些温跃层扰动调节了KOE区域的环流和SST。更广泛的影响：这一研究项目的结果可能有重要的实际用途，在北太平洋（和北美下游）的年际时间尺度上改善大气气候预报。海表温度的可预测部分（以及相关的上层海洋温度、速度和上升流场）也令人感兴趣，因为该区域有商业上重要的渔业，这些渔业与KOE区域这种变异性所驱动的生态系统变化有关。该项目的结果可能有助于对北太平洋KOE区域的生态系统（包括渔业）进行新的预测。了解KOE区域海洋-大气耦合响应的物理学及其在强迫盆地尺度大气中的作用，对于试图利用年代际变率及其对北美气候、生态系统和渔业的下游影响之间的关系至关重要（包括阿拉斯加湾，白令海和加州海流）。该项目是对美国气候变化和可预测性（CLIVAR）计划的贡献。

OCE-0647994Recent work reveals that anomalies of wintertime Sea Surface Temperatures (SST) in a large area surrounding the Kuroshio-Oyashio Extension (KOE) in the northwest Pacific are predictable from the history of wind stress over North Pacific. This predictable component of SST is of interest for North Pacific climate because the KOE is a region of vigorous air-sea interaction, which is linked to large-scale North Pacific/North American atmospheric climate variability. Important gaps remain in our understanding of the mechanisms involved in the climate variations associated with the KOE region. These gaps include the ways that the atmosphere may respond to the predictable changes in the KOE SST; the detailed nature of the atmospheric tropospheric response across the North Pacific/North American sector; the means by which planetary waves, carrying the predictable signal in the North Pacific, change SST, mesoscale eddies, horizontal velocity and upwelling in the North Pacific; and the importance of mesoscale ocean variations, which create associated surface wind stress and heat flux anomalies, in establishing climate-scale KOE SST anomalies. Intellectual Merit: This project aims to clarify these issues by downscaling the National Center for Environmental Prediction (NCEP) reanalysis fields of the past 50 years over the North Pacific using a high-resolution regional coupled ocean atmosphere model (SCOAR) that includes mesoscale eddies. With an ensemble of these coupled downscaling experiments, combined with a related combination of uncoupled ocean and uncoupled atmospheric model hindcasts, the results will be diagnosed and validated with observations to estimate the fraction of variance associated with regional ocean-atmosphere feedbacks in the context of decadal feedback loops and climate predictability. The analysis will focus on the complicated sequence of processes that link regional ocean circulation and SST anomalies in the KOE region to the atmospheric boundary layer and the storm track with the basin-scale processes that govern the excitation and propagation of thermocline perturbations from the central North Pacific, which modulate the circulation and SST in the KOE region. Broader Impacts: The results of this research project may have important practical use in improving atmospheric climate forecasting on inter-annual timescales in the North Pacific (and downstream over North America). The predictable component of SST (and the associated upper-ocean temperature, velocity and upwelling fields) is also of interest because the region has commercially important fisheries that are linked to ecosystem changes driven by this variability of the KOE region. The results from this project may be useful for creating novel forecasts of the ecosystem (including fisheries) in the KOE region of the North Pacific. Understanding the physics of the coupled ocean-atmosphere response in the KOE region and its role in forcing the basin-scale atmospheric is paramount in attempting to exploit the relationships between decadal variability and its downstream effects on climate of North America, the ecosystem and fisheries (including those of the Gulf of Alaska, Bering Sea and California Current).This project is a contribution to the U.S. CLIVAR (CLImate VARiability and predictability) program.