Regional Coupled Ocean-Atmosphere Feedback Processes Affecting Climate Along the California Coast

智能优点：最近的卫星观测显示，中尺度海表面温度异常通过改变大气边界层的稳定性以及由此产生的动量和热量的垂直输送来扰乱大气边界层。然而，目前尚不清楚这些中尺度通量异常对大气和海洋中的平均和瞬变流动的影响有多大。为了更好地理解这些反馈的影响，需要使用一个现实的海洋-大气耦合模式进行长期模拟，该模式解析海洋中尺度、海洋驱动的表面通量以及相关的大气边界层和对流层响应。这项研究工作将使用耦合和非耦合模式结合观测来解决加州地区中尺度海洋-大气相互作用的几个关键问题：中尺度海洋-大气耦合对加州海岸云层和大气流动的局部影响是什么？中尺度海-气耦合对加利福尼亚沿海、中部山谷和内陆山区的细尺度大气环流、降雨模式、降雪模式和陆地表面过程的远程影响是什么？中尺度海-气耦合对加利福尼亚海岸沿岸上升流锋面结构演变的影响是什么？这些反馈效应将使用一个高分辨率的区域耦合海洋模式来研究，该模式将区域海洋模式系统与区域特殊模式相耦合。耦合和非耦合的下尺度大尺度大气再分析场将被并列比较，以评估中尺度表面通量异常对大气边界层、上覆对流层流动和海洋上升流锋流的影响。将采用一种新的策略，在耦合模式下运行耦合模式，但在空间上平滑中尺度SST变化，以去除耦合器中的海洋中尺度，以明确确定海洋中尺度对大气环流的影响。广泛的物理诊断和观测比较将进一步阐明将中尺度反馈与本地和远程大气和海洋响应联系起来的过程。更广泛的影响：更好地理解中尺度大气海洋耦合的影响，将为确定全球变暖对加州及其沿海海洋区域气候可能造成的变化奠定基础。这项研究的结果还将与气候可预测性、区域对全球变暖的反应、水资源使用、能源使用和海洋生态系统对气候变化的反应有关。一名研究生将接受海洋-大气耦合建模方面的培训。两名调查员都将继续他们的外联活动。诺里斯博士是加州大学圣迭戈分校一个项目的首席讲师，该项目为高中生提供为期一个月的实践科学学习体验，以鼓励他们主修工程或科学，该项目的结果将纳入他的指导中。米勒博士自愿在当地一所高中担任科学奥林匹克竞赛的教练。

Intellectual Merit: Recent satellite observations have revealed that mesoscale sea surface temperature (SST) anomalies perturb the atmospheric boundary layer by altering its stability and its consequent vertical transport of momentum and heat. It remains unclear, however, how strongly these mesoscale flux anomalies affect the mean and transient flows in both the atmosphere and ocean. Long-term simulations with a realistic coupled ocean-atmosphere model that resolves oceanic mesoscale, the ocean driven surface fluxes, and the associated atmospheric boundary layer and tropospheric response are needed to better understand the effects of these feedbacks. This research effort will use coupled and uncoupled model runs in conjunction with observations to address several key issues in mesoscale ocean-atmosphere interaction in the California Regional Sector: What are the local effects of mesoscale ocean-atmosphere coupling on the cloud cover and atmospheric flow along the California Coast? What are the remote effects of mesoscale ocean-atmosphere coupling on the fine-scale atmospheric circulation, rainfall patterns, snowfall patterns and land surface processes along the coastal, in the central valleys, and over the interior mountain regions of California? What are the effects of mesoscale ocean-atmosphere coupling on the evolution of coastal upwelling frontal structures along the California Coast?These feedback effects will be investigated using a high-resolution regional coupled ocean model that couples the Regional Ocean Modeling System to the Regional Special Model. Coupled and uncoupled runs of downscaled large-scale atmospheric reanalysis fields will be compared side-by-side to assess the effects of mesoscale surface flux anomalies on the atmospheric boundary layer, overlying tropospheric flows and oceanic upwelling frontal flows. A new strategy will be applied by running the coupled model in coupled mode, but with mesoscale SST variations spatially smoothed to remove ocean mesoscales in the coupler (only) to unambiguously identify the impact of the ocean mesoscale on the atmospheric circulation. Extensive physical diagnostics and observational comparisons will further elucidate the processes that link the mesoscale feedbacks to the local and remote atmospheric and oceanic responses.Broader Impacts: Improved understanding of the impacts of mesoscale atmosphere ocean coupling will form the foundation for determining likely changes induced by global warming on the regional climate of California and its coastal ocean. The results from this research will also be relevant to climate predictability, regional response to global warming, water resource usage, and energy usage and marine ecosystem response to climate variability. A graduate student will be trained in coupled ocean-atmosphere modeling. Both investigators will continue their outreach activities. Dr. Norris is a lead instructor in a UCSD program that provides a month-long hands-on science learning experience to high school students to encourage them to major in engineering or science, and the results of this project will be incorporated into his instruction. Dr. Miller volunteers as a Science Olympiad coach at a local high school.