High‐ and Low‐Latitude Insolation Forcing Drives the Half‐Precession Cycle in Winter Arctic Sea Ice

Abstract The half‐precession cycle is a key climatic signal in global climate system, linking high‐ and low‐latitude climate variability and bridging orbital‐ and millennial‐scale climate changes. While it characterizes tropical insolation, its origin in high‐latitude climate records remains unclear. Based on a transient climate simulation spanning the past 800,000 years, here we find that in response to astronomical forcing, the eccentricity‐modulated half‐precession cycle emerges as an evident signal in the winter Arctic sea ice variability. It is driven by the combined influence of summer insolation at northern high latitudes and winter northward atmospheric heat transport, with the latter being primarily regulated by winter insolation at low latitudes. Moreover, the half‐precession cycle in winter Arctic sea ice leaves a distinct imprint on Arctic Ocean surface albedo as well as upward heat and moisture fluxes, which may serve as an important mechanism to explain the half‐precession signal observed in high latitudes.