Climate System Dynamics on Long Time Scales

长时间尺度的气候系统动力学

• 批准号: 0082131
• 负责人: Michael Ghil
• 金额: $ 135万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-10-01 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0082131&HistoricalAwards=false
• 关键词: Climate; System; Dynamics; Long; Time

AbstractATM-0082131Ghil, MichaelUniversity of California, Los AngelesThe research bears on the problems of internal and external causes of climatic change. It emphasizes the role of the atmosphere in climate variability from months to years, of the oceans in variability from years to decades, and of the coupled ocean-atmosphere-ice-sheet system from decades to millennia. The methodology uses tools from fluid dynamics, dynamical systems theory, scientific computing and nonparametric statistics. The dynamical tools will be applied to a hierarchy of atmospheric, oceanic and coupled models. These models range from the simplest models with a small number of variables, such as box models of the ocean, to fully coupled general circulation models (GCMs).The PIs will study coupling of climate subsystems across timescales using various mathematical and statistical techniques. On the intraseasonal time scale of 10-100 days, the PIs will consider two complementary descriptions of low-frequency atmospheric variability, episodic and periodic, i.e. multiple weather regimes and intraseasonal oscillations. On the subannual-to-interannual time scale of 100 days to 10 or more years, the research emphasizes internal variability of the mid-latitude oceans' wind-driven circulation. This circulation is studied for prescribed time-constant and seasonally varying wind stress acting on ocean-only models, as well as for fully coupled ocean-atmosphere models. On time scales of decades-to-centuries and longer, the PIs will use comprehensive coupled models such as CSM and IPSL. The simulations will be analyzed and compared with instrumental and paleo-records to determine and describe the relative importance of natural variability and anthropogenic climate change on these time scales. The work is important because it will increase understanding of climate variability across various time scales.

加州大学洛杉矶分校的ATM-0082131 Ghil的研究涉及气候变化的内因和外因问题。它强调大气在气候变化中从数月到数年的作用，海洋在气候变化中从数年到数十年的作用，以及耦合的海洋-大气-冰盖系统从数十年到数千年的作用。该方法使用的工具，从流体动力学，动力系统理论，科学计算和非参数统计。动力学工具将应用于大气、海洋和耦合模型的层次结构。这些模式从最简单的只有少量变量的模式（如海洋箱型模式）到完全耦合的大气环流模式（GCMs）都有，主要研究员将利用各种数学和统计技术研究跨时间尺度的气候子系统的耦合。在10-100天的季节内时间尺度上，PI将考虑对低频大气变率的两种互补描述，即偶发性和周期性，即多种天气状况和季节内振荡。在100天至10年或更长时间的亚年度至年际时间尺度上，研究强调中纬度海洋风驱动环流的内部变化。这种环流研究规定的时间常数和季节性变化的风应力作用于海洋唯一的模型，以及完全耦合的海洋-大气模型。 在数十年至数百年甚至更长的时间尺度上，PI将使用CSM和IPSL等综合耦合模型。将对模拟结果进行分析，并与仪器记录和古记录进行比较，以确定和描述自然变率和人为气候变化在这些时间尺度上的相对重要性。这项工作很重要，因为它将增加对不同时间尺度气候变化的理解。