ADVANCE Fellows Award: Investigating the Origins of Orbitally Forced Paleoclimates: The Interplay of Climate Response, Geodynamics, Astrodynamics and Earth Noise

高级研究员奖：调查轨道强迫古气候的起源：气候响应、地球动力学、天体动力学和地球噪声的相互作用

• 批准号: 0137799
• 负责人: Linda Hinnov
• 金额: $ 40.07万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0137799&HistoricalAwards=false
• 关键词: ADVANCE; Fellows; Award; Investigating; Origins

Hinnov0137799This ADVANCE Fellows career-development plan centers on an investigation of orbitally forced paleoclimate signals as carriers of first order geodynamical and astrodynamical information. Geodynamical theory predicts that the Earth's tidal dissipation and dynamical ellipticity will perturb the Earth's axial precession rate and tilt. The perturbations should appear in paleoclimatically recorded orbital modes as phasing irregularities. Observation of these irregularities depends upon the accuracy of the timescale assigned to the paleoclimate record. This typically involves adjusting an interpreted orbital signal in the record to a "target" curve based upon an assumed climate response to orbital forcing. If the target is wrong, however, timing errors will corrupt the true phasing of the recorded orbital modes. Until this source of error can be effectively managed, no firm conclusions about the Earth's physical behavior should be drawn from the paleoclimate record. Astrodynamical theory indicates that long-period amplitude and frequency modulations in the Earth's orbital modes track planetary orbital motions; these should be detectable in very long paleoclimate signals. Some planetary orbits resonate, e.g., Earth and Mars; in the remote past, the orbits of Mars and Earth may have moved chaotically between two resonance states. Verification of this behavior using the paleoclimate record is therefore a top priority in astrodynamics. Complicating the extraction of this information, however, is low frequency "Earth noise" that can interfere with long paleoclimate signals. To unravel these problems, a multi-task computer model will be developed that calculates insolation at any geographical location over any timescale, and is linked to adjustable rotational-orbital parameters that include effects from the Earth's tidal dissipation and dynamical ellipticity. The model will be explored in a series of sensitivity experiments, then evaluated against paleoclimate records using advanced time series analysis.

HINNOV0137799 Thise Advance Fellows职业发展计划中心，将轨道强迫的古气候信号作为一阶地球动力学和天体动力学信息的载体进行调查。地球动力学理论预测，地球的潮汐耗散和动态椭圆将扰动地球的轴向进动率和倾斜。扰动应以古气候记录的轨道模式出现，作为阶段不规则。对这些不规则性的观察取决于分配给古气候记录的时间表的准确性。这通常涉及根据假定的气候对轨道强迫的气候响应，将记录中解释的轨道信号调整为“目标”曲线。但是，如果目标是错误的，则定时错误将损坏记录的轨道模式的真实分阶段。在有效管理这种错误源之前，不应从古气候记录中得出关于地球物理行为的确定结论。天体动力学理论表明，地球轨道模式中的长周期振幅和频率调制轨道轨道运动。这些应该在很长的古气候信号中检测到。一些行星轨道引起共鸣，例如地球和火星；在遥远的过去，火星和地球的轨道可能在两个共鸣状态之间混乱。因此，使用古气候记录对这种行为进行验证是天体动力学的首要任务。然而，使这些信息的提取复杂化是低频“土噪声”，可能会干扰长古气候信号。为了解散这些问题，将开发多任务计算机模型，该模型在任何时间尺度上都在任何地理位置计算可暴发，并与可调式旋转轨道参数有关，其中包括来自地球潮汐消散和动力椭圆形的影响。该模型将在一系列灵敏度实验中进行探讨，然后使用高级时间序列分析对古气候记录进行评估。