Collaborative Research: Coupled Ocean-Atmosphere Feedbacks Affecting California Coastal Climate: Current Conditions and Future Projections

加利福尼亚的沿海气候深受海洋的影响，海洋缓和了其炎热的夏季，并为其急需的冬季降雨提供了水分。海温（SST）异常和海流异常，从冷海岸上升流的中尺度到锋面尺度，到海洋热浪的区域到盆地尺度，都与大气有着内在的耦合关系。本文的研究重点是影响沿海气候、天气和上升流的基本海洋-大气耦合反馈过程。该项目将使用海洋-大气耦合系统的数值模型来提高对海洋-大气相互作用的理解，包括与加利福尼亚沿海地区的陆地和山脉的相互作用。此外，它还将研究预计未来温室气体强迫变化对加州沿海气候的影响。该项目将使用一系列区域高分辨率海洋-大气耦合模式模拟，包括全面的海洋-大气耦合和良好的地形和陆海分布，量化海洋-大气边界层耦合对加利福尼亚沿海地区的影响。这些将包括由观测到的当前气候和预估的未来气候边界条件所强迫的10年长期运行的集合，以及在观测到的海洋热浪条件下初始化的运行的集合。模式运行将用于研究大气和海洋上升流场的日、季内和年际变化统计数据如何受到与涡旋、锋和极端海温异常相关的海洋-大气异常条件的影响，并评估它们如何受到与全球变暖相关的大尺度大气和海洋驱动因素变化的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The coastal climate of California is profoundly affected by the ocean, which moderates its hot summers and provides moisture for much-needed winter rains. Sea surface temperature (SST) anomalies and ocean surface current anomalies, ranging from the meso-to-frontal scales of cool coastal upwelling to the regional-to-basin scales of the marine heat waves, are inherently coupled with the atmosphere. This study focuses on the fundamental coupled ocean-atmosphere feedback processes that affect the climate, weather, and upwelling along the coast. The project will use numerical models of the coupled ocean-atmosphere system to improve understanding of the ocean-atmosphere interactions, including with land and mountains, for coastal California. In addition, it will examine the effects on climate of coastal California under projected future greenhouse-gas-forced changes.This project will quantify the effects of ocean-atmosphere boundary layer coupling on California coastal regions using a series of regional high-resolution coupled ocean-atmosphere model simulations, including full ocean-atmosphere coupling and well-resolved orography and land-sea distribution. These will include ensembles of 10-year long runs forced by observed current climate and projected future climate boundary conditions, as well as ensembles of runs initialized under observed marine heat wave conditions. The model runs will be used to study how the statistics of daily, intraseasonal and interannual variability in the atmosphere and the oceanic upwelling field, are affected by the anomalous ocean-atmosphere conditions associated with eddies, fronts, and extreme SST anomalies, and assess how they may be altered by changes in large-scale atmospheric and oceanic drivers associated with global warming.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.