precession forcing depends upon eccentricity. However, there also exists a relationship between eccentricity and the frequency of precession such that orbital tuning generates eccentricity‐like amplitude modulation in filtered signals, regardless of the accuracy of the chronology or the actual presence of precession. This

2015年11月21日 · The present study focuses on the evaluation of records with relatively strong precession and eccentricity signals, but it is simple to adapt the approach to evaluate the expected long-eccentricity (405 ka) modulation of short eccentricity amplitude, and also the long-period amplitude modulation of obliquity.

climate model is used to show that the climatic effect of precession is muted in global isotope records due to two different mechanisms, with each dominating as a function of eccentricity. At low eccentricities (e0.019), the time-integrated summer insolation and number of positive degree-days impacting ice sheets varies at precessional periods, but

2010年12月23日 · When the eccentricity of Earth's orbit is small, the frequency of climatic precession undergoes large variations and less precession energy is passed through a narrow-band filter. Furthermore, eccentricity-like amplitude modulation is routinely obtained from pure noise records that are orbitally tuned to precession and then filtered.

2015年8月4日 · Earth’s astronomical parameters control the seasonal and lati-tudinal distribution of solar radiation entering the Earth’s atmo-sphere, following the periodicities of axial precession (c. 20 kyr), axial obliquity (c. 40 kyr) and orbital eccentricity (95–124 and 405 kyr; e.g., Berger et al., 1993; Laskar et al., 1993).

2016年5月15日 · Here we demonstrate that interference patterns accompanying frequency modulation (FM) of short eccentricity provide a robust basis for identifying the phase of long eccentricity forcing in stratigraphic data. One- and two-dimensional models of sedimentary distortion of the astronomical signal are used to evaluate the veracity of the FM method ...

2010年12月1日 · When the eccentricity of Earth's orbit is small, the frequency of climatic precession undergoes large variations and less precession energy is passed through a narrow-band filter. Furthermore, eccentricity-like amplitude modulation is routinely obtained from pure noise records that are orbitally tuned to precession and then filtered.

2010年12月1日 · When the eccentricity of Earth's orbit is small, the frequency of climatic precession undergoes large variations and less precession energy is passed through a narrow-band filter....

3 天之前 · Thus, these precession-driven precipitation changes, modulated by eccentricity, may have influenced high-latitude ice-sheet build-up during MIS 2-4 and MIS 12 which featured the most intense ...

2025年1月16日 · We present a novel approach to estimating the eccentricity waveform from geological time series by targeted modifications to the Astronomical Component Estimation model (ACEv.1). We show that analyzing individual precession components is highly beneficial in understanding the impact of perturbation on the estimator.