The HNBody output of Zeebe & Lourens (2019) after some pre-processing using
prepare_solution(). The wikipedia page on Orbital elements describes what the
components relate to in order to uniquely specify an orbital plane. The
function asks to download the files to the user's cache directory so that
they can be accessed more quickly in the future.
Format
get_solution("full-ZB18a")
A data frame with 250,001 rows and 20 columns:
- t
Time \(t\) (days).
- time
Time in thousands of years (kyr).
- aa
Semimajor axis \(a\) in astronomical units (au).
- ee
Eccentricity \(e\) (unitless).
- inc
Inclination \(I\) (degrees).
- lph
Longitude of perihelion \(\varpi\) (degrees).
- lan
Longitude of the ascending node \(\Omega\) (degrees).
- arp
Argument of perihelion \(\omega\) (degrees).
- mna
Mean anomaly \(M\) (degrees).
The following columns were computed from the above input with prepare_solution():
- lphu
Unwrapped longitude of perihelion \(\varpi\) (degrees without jumps).
- lanu
Unwrapped longitude of the ascending node \(\Omega\) (degrees without jumps).
- hh
Variable: \(e\sin(\varpi)\).
- kk
Variable: \(e\cos(\varpi)\).
- pp
Variable: \(2\sin(0.5I)\sin(\Omega)\).
Variable: \(2\sin(0.5I)\cos(\Omega)\).
- cc
Helper: \(\cos(I)\).
- dd
Helper: \(\cos(I)/2\).
- nnx, nny, nnz
The \(x\), \(y\), and \(z\)-components of the Eart's orbit unit normal vector \(\vec{n}\), normal to Earth's instantaneous orbital plane.
Source
All astronomical solutions by Zeebe can be found on http://www.soest.hawaii.edu/oceanography/faculty/zeebe_files/Astro.html.
They can be loaded into R quickly, using get_solution().
References
Zeebe, R. E., & Lourens, L. J. (2019). Solar System chaos and the Paleocene–Eocene boundary age constrained by geology and astronomy. Science, 365(6456), 926–929. doi:10.1126/science.aax0612 .
Zeebe, R. E. and Lourens, L. J. (2022). A deep-time dating tool for paleo-applications utilizing obliquity and precession cycles: The role of dynamical ellipticity and tidal dissipation. Paleoceanography and Paleoclimatology. doi:10.1029/2021PA004349