Collaborative Research: Climate Variability and Change in the U.S. GLOBEC Regions as Simulated by the IPCC Climate Models: Ecosystem Implications

大量的文献表明，生态系统动态受到大尺度气候变化的强烈影响。气候影响海洋生物过程的一个主要方式是通过风驱动的海洋环流变化，这种变化受到自然和人为引起的变化的影响。为支持政府间气候变化专门委员会（IPCC）评估报告4（AR 4），使用23个最先进的气候模式进行的模拟是审查气候变化的主要手段。IPCC-AR 4模拟包括采用固定外部（太阳、火山、温室气体）强迫的模拟（对照模拟），以及根据观测到的20世纪记录（20世纪模拟）或根据不同气候变化情景规定外部强迫的模拟。这些气候整合是全球性的，提供了关于大量变量的完整信息，包括每个模型网格点上与海洋生态系统有关的变量。IPCC-AR 4模拟的结果将用于研究GLOBEC三个区域（东北太平洋、西北大西洋和南大洋）的气候变率和变化，重点关注以下问题：1.在GLOBEC的三个研究区域中，目前这一代的气候模式是否显示了大尺度低频风强迫变化与海洋环流变化之间的联系，与人们认为存在于自然界中的联系相似？IPCC-AR 4多模式集合能否用于扩展观测记录，并以更大的统计置信度检验气候-环流联系的假设？2.根据最可靠的气候模式，在21世纪和22世纪，气候对区域过程的影响将发生多大程度的变化？3.是否可以制定和使用统计降尺度方法，将区域（生态系统）尺度的变化与大尺度气候强迫联系起来？能否确定更适合统计降尺度的特定参数？第一个问题将通过分析控制和20世纪世纪的模拟来解决，而在未来世纪的气候对区域过程的影响的预测将使用情景模拟进行检查。现有数据以及区域模式在不同分辨率下的输出将用于评估统计降尺度的可行性，这项研究将增进对大尺度气候强迫与对不同区域生态系统动态具有重要意义的物理过程之间联系的了解。气候模式的全球性使得能够以一致的方式在不同地理区域内部和之间建立联系。因此，从这项研究的结果支持泛区域综合阶段的GLOBEC program.The目前的研究有可能提高预测能力，由于自然和/或人为引起的气候变化的生态系统变化。该项目的研究结果可以支持区域生态系统研究，提供一个视角的大尺度强迫及其演变在变化的气候，以及边界条件和强迫场的区域模式。具体而言，该项目的一个关键方面将是提供IPPC模型模拟的输出，并指导如何使用该输出到通过GLOBEC计划的这一阶段资助的其他研究人员。这项研究的结果也将通过NOAA和研究者所在大学的外展计划提供给初中和高中学生。

A large body of literature has shown that ecosystem dynamics is strongly influenced by large scale climate variations. A primary way by which climate can affect marine biological processes is through wind-driven changes of the ocean circulation, which are influenced by both natural and anthropogenically-induced variability. Simulations performed with 23 state-of-the-art climate models in support of the Intergovermental Panel for Climate Change (IPCC) Assessment Report 4 (AR4) are the principle means for examining climate change. The IPCC-AR4 simulations include runs with fixed external (solar, volcanoes, greenhouse gases) forcing (control simulations), as well as simulations where external forcing is prescribed according to the observed 20th century record (20th century simulations) or according to different climate change scenarios. These climate integrations are global and provide complete information on a large number of variables, including those relevant for marine ecosystems, at each model grid point. The output from the IPCC-AR4 simulations will be used to examine climate variability and change in the three GLOBEC regions (northeast Pacific, northwest Atlantic, and Southern Ocean) focusing on the following questions:1. Does the present generation of climate models show connections between large-scale low-frequency wind forcing variations and ocean circulation changes in the three GLOBEC study areas similar to those that are believed to exist in nature? Can the IPCC-AR4 multi-model ensembles be used to extend the observational record and test hypotheses on the climate-circulation links with a larger statistical confidence?2. Based on the most reliable climate models, to what extent will the influence of climate upon regional processes change over the 21st and 22nd centuries?3. Can statistical downscaling methods be developed and used for relating variations at the regional (ecosystem) scale to large-scale climate forcing? Can specific parameters be identified that are more amenable to statistical downscaling?The first question will be addressed by analyzing the control and 20th century simulations, while projections of the influence of climate on regional processes in the next century will be examined using the scenario simulations. Available data, as well as output from a regional model at different resolutions will be used to assess the feasibility of statistical downscaling.This study will improve understanding of the links between large-scale climate forcing and physical processes important for ecosystem dynamics in different regions. The global nature of climate models enables a consistent means of establishing connections within and between different geographical regions. Thus, results from this study support the pan-regional synthesis phase of the GLOBEC program.The present study has the potential to enhance the ability to predict ecosystem changes due to natural and/or anthropogenically induced climate variations. Results from this project can support regional ecosystem studies by providing a perspective of the large-scale forcing and its evolution in a changing climate, as well as boundary condition and forcing fields for regional models. Specifically, a key aspect of this project will be to provide output from the IPPC model simulations and guidance in how to use the output to other researchers funded through this phase of the GLOBEC program. Results from this study will also be presented to middle and high school students through the outreach programs at NOAA and at the investigators' Universities.