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这个高级研究员职业发展计划的中心是研究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。地球动力学理论预测，地球的潮汐耗散和动力椭圆度将扰动地球的轴向进动速率和倾斜。在古气候记录的轨道模式中，这些扰动应该表现为相位不规则。对这些不规则现象的观察取决于分配给古气候记录的时间尺度的准确性。这通常涉及根据假定的气候对轨道强迫的响应，将记录中解释的轨道信号调整为“目标”曲线。然而，如果目标是错误的，计时误差将破坏记录的轨道模式的真实相位。在这个误差源得到有效控制之前，不应该从古气候记录中得出关于地球物理行为的确凿结论。天体动力学理论表明，地球轨道模式中的长周期幅度和频率调制跟踪行星轨道运动；这些应该可以在非常长的古气候信号中检测到。一些行星轨道发生共振，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振状态之间混乱地移动。因此，利用古气候记录验证这一行为是天体动力学的首要任务。然而，使这一信息的提取复杂化的是可能干扰长时间古气候信号的低频“地球噪声”。为了解决这些问题，将开发一个多任务计算机模型，该模型计算任何地理位置在任何时间尺度上的日照，并与可调整的旋转轨道参数相关联，其中包括地球潮汐耗散和动态椭圆度的影响。该模型将在一系列敏感性实验中进行探索，然后利用先进的时间序列分析对照古气候记录进行评估。