History and future of coastal upwelling modes and biological responses in the California Current

气候变率是影响加州洋流生态系统（CCE）结构、功能和生产力的重要因素。然而，尽管有许多长期和综合的研究，对气候对上升流和生物过程的影响的详细了解仍然缺乏，这损害了我们评估生态系统“健康”和“恢复力”等重要概念的能力。为了解决CCE中北部的这些问题，pi最近整理和分析了有关上涌变变性的岩鱼和鲑鱼生长和海鸟繁殖成功的记录（NSF奖#0929017）。这些不同的、多年代际的时间序列揭示了冬季上升流对生态系统结构和功能的重要性，尽管上升流是CCE生产力的主要驱动力，在很大程度上是一个夏季过程。这项研究导致了一个意想不到的发现，冬季和夏季上升流以不同的季节“模式”相互独立地变化，其中一些生物过程受冬季模式影响，另一些受夏季模式影响。这很重要，因为夏季模态显示出长期的增加（尽管有年代际变化），而冬季模态则没有。智力优势：在这个新项目中，pi将测试一个总体假设，即上升流模式是由不同的大气-海洋学过程所驱动的，表现出不同的低频率和高频变化模式，并将受到全球气候变化的不同影响，并对生物产生相应的影响。为了解决这一假设，pi提出了一个三层方法来更好地理解季节性上升流模式及其对CCE生物学的差异影响。首先，他们将研究一套全新的物种对上升流模式的反应，包括太平洋沙丁鱼（招募），黑岩鱼（生长），犀牛小海雀和勃兰特鸬鹚（生存），以及银鲑（生存）。以前，在这些分析中使用了粗略分解的上升流指数，但现在pi将整合当地浮标数据中的风和温度，以便更好地捕捉更精细时间尺度上的气候变化。其次，他们将获得对季节性上升流模式的更机械的理解，并将这些信息与全球气候模式结合起来，预测各种气候变化情景下的上升流响应。第三，初步结果表明，树木年轮数据与鱼类和海鸟共同变化，并且对冬季上升流的驱动因素北方振荡指数（NOI）同样敏感。pi将使用树木年轮数据提供300-400年冬季NOI的重建，以评估上升流平均值和方差的历史变异性范围。这项研究将揭示过去，现在的强迫，和潜在的未来上升流和它的生物后果在加利福尼亚洋流。更广泛的影响：本研究将探索独立的季节性气候模式的历史、未来和生物影响及其对关键物种的影响。在此过程中，pi将形成对耦合气候-生态系统变化的理解，这将有助于州、国家和国际政策制定者，包括加州气候适应合作小组（CO-CAT）和IPCC评估报告5。pi将开发和测试加州当前生态系统生产力的生物和物理指标，并将这些信息提供给管理部门，特别是渔业资源和综合生态系统评估。该项目将为物理海洋学、海洋生态学、定量技能、传播学以及项目、财务管理和筹资等科学业务领域的2名博士后研究员、2名其他青年科学家和1名本科生提供交叉培训。

Climate variability on multiple temporal scales is increasingly recognized as a major factor influencing the structure, functioning, and productivity of the California Current Ecosystem (CCE). Yet, despite many long-term and integrative studies, a detailed understanding of climatic impacts on upwelling and biological processes is still lacking, compromising our abilities to assess important concepts such as ecosystem "health" and "resilience." To address these issues in the central-northern CCE, the PIs have recently collated and analyzed records of rockfish and salmon growth and seabird reproductive success with respect to upwelling variability (NSF award #0929017). These diverse, multi-decadal time series revealed the importance of wintertime upwelling on ecosystem structure and function, even though upwelling, a principal driver of productivity in the CCE, is largely a summertime process. This research led to an unexpected discovery that winter and summer upwelling vary independently of one another in distinct seasonal "modes", with some biological processes affected by the winter mode and others by the summer mode. This is of significance because the summer mode shows a long-term increase (despite inter-decadal variability) while the winter mode does not. Intellectual Merit: In this new project, the PIs will test the overarching hypothesis that upwelling modes are forced by contrasting atmospheric-oceanographic processes, exhibit contrasting patterns of low- and high-frequency variability, and will be differentially impacted by global climate change with corresponding impacts on biology. To address this hypothesis the PIs propose a three-tiered approach to better understand seasonal upwelling modes and their differential impacts on biology of the CCE. First, they will examine the responses of an entirely new suite of species to upwelling modes, including Pacific sardine (recruitment), black rockfish (growth), rhinoceros auklet and Brandt's cormorant (survival), and coho salmon (survival). Previously, coarsely resolved upwelling indices were used in these analyses, but the PIs now will integrate winds and temperatures from local buoy data to better capture climate variability on finer timescales. Second, they will derive a more mechanistic understanding of seasonal upwelling modes and use this information in combination with global climate models to forecast upwelling responses under various climate-change scenarios. Third, preliminary results indicate that tree-ring data co-vary with the fish and seabirds and are similarly sensitive to a driver of winter upwelling, the Northern Oscillation Index (NOI). The PIs will use tree-ring data to provide a 300-400 year reconstruction of the winter NOI to assess the historical range of variability in upwelling mean and variance. This study will reveal the past, present forcing, and potential future of upwelling and its biological consequences in the California Current.Broader Impacts: This study will explore the history, future, and biological impacts of independent, seasonal climate modes and their impacts on key species. In so doing, the PIs will develop an understanding of coupled climate-ecosystem change that will be contributed to state, national, and international policy-makers, including the California Cooperative Climate Adaptation Team (CO-CAT)and the IPCC Assessment Report 5. The PIs will develop and test biological and physical indicators of California Current ecosystem productivity and will make this information available for management, specifically fisheries stock and integrated ecosystem assessments. The project will provide cross-training for 2 post-doctoral research associates, 2 other young scientists, and 1 undergraduate in physical oceanography, marine ecology, quantitative skills, communication, as well as the business of science, such as project and fiscal management and fund-raising.