Evolution of Lunar Orbit under Climate Dynamics since the Last Glacial Cycle

Abstract Understanding the long-term evolution of lunar orbit is an essential task in astronomy and astrophysics because lunar and planetary ephemerides are indispensable in many important applications, such as spacecraft navigation and reference frame transformations. Recently, it has been suggested that climate dynamics, particularly sea level change due to melting of polar ice sheets, can subtly modulate ocean tides, thus altering the tidal dissipation and lunar recession rate by ∼2.6% in the 21st century. In our study, we provide a correction to standard models of lunar orbital evolution relevant for astrophysical applications. We use the reconstructed history of ice thickness, paleotopography, and sea level change since the last glacial cycle (∼122,000 yr ago) and adopt a revised tidal dissipation model to argue that the climate-induced changes in the lunar orbit might not be negligible and have likely altered the Earth–Moon distance by variable rates as large as ∼0.9 mm yr −1 , which occur on top of the background trend of ∼38.3 mm yr −1 . However, this is currently absent from dynamical models of lunar evolution. Our results suggest that lunar orbit ephemerides might need to be revised by at least ∼1.5%–2.3% in order to obtain a more accurate representation of the tidal dynamics and orbital motions. The model proposed in this paper might also be relevant for other astrophysical bodies, such as exoplanetary satellites.