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

最近的研究表明，西北太平洋黑潮-好潮延伸（KOE）周围大面积的冬季海面温度（SST）异常可以从北太平洋的风应力历史中预测。这种海温的可预测分量对北太平洋气候很有意义，因为东太平洋是一个强烈的海气相互作用区域，而海气相互作用与大尺度的北太平洋/北美大气气候变率有关。我们对与KOE区域相关的气候变化机制的理解仍然存在重大差距。这些差距包括大气可能对可预测的KOE海温变化作出反应的方式；北太平洋/北美地区大气对流层响应的详细性质；携带北太平洋可预测信号的行星波改变北太平洋海温、中尺度涡旋、水平速度和上升流的手段；以及中尺度海洋变化在建立气候尺度KOE海温异常中的重要性，海洋变化会产生相关的地面风应力和热通量异常。知识价值：该项目旨在通过使用包括中尺度涡旋在内的高分辨率区域海洋-大气耦合模式（SCOAR）缩小美国国家环境预测中心（NCEP）过去50年对北太平洋再分析领域的规模，从而澄清这些问题。利用这些耦合降尺度实验的集合，结合不耦合的海洋和不耦合的大气模式预测的相关组合，将对结果进行诊断，并通过观测结果进行验证，以估计在年代际反馈环和气候可预测性背景下与区域海洋-大气反馈相关的方差比例。分析将集中于将KOE区域的区域海洋环流和海温异常与大气边界层和风暴路径联系起来的复杂过程序列，以及控制来自北太平洋中部的温跃层扰动的激发和传播的盆地尺度过程，这些过程调节了KOE区域的环流和海温。更广泛的影响：本研究项目的结果可能在改善北太平洋（以及北美下游地区）年际时间尺度的大气气候预报方面具有重要的实际用途。海温的可预测成分（以及相关的上层海洋温度、速度和上升流场）也令人感兴趣，因为该地区具有重要的商业渔业，而这些渔业与KOE区域的这种变化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地区的生态系统（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特性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（包括阿拉斯加湾、白令海和加利福尼亚海流）的下游影响之间的关系至关重要。该项目是对美国CLIVAR（气候变率和可预测性）计划的贡献。

OCE-0647815Recent 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.