On the importance of temperature and precipitation changes for glacial ice sheet stability

Abstract

Ice sheets undergo periodic advances and retreats, resulting in glacial-interglacial cycles. The Last Glacial Period is widely believed as involving a long-time buildup phase followed by a rapid termination over approximately 100 thousand years (kyr), resulting in a characteristic sawtooth pattern. This pattern aligns with the dominant 100-kyr cycle observed over the past million years. While there is a consensus on the significance of temperature and moisture contents as crucial factors in initiating and terminating glaciations, the precise role of these factors in governing glacial inceptions and terminations remains largely elusive. In this study, we assess the relative significance of temperature and precipitation anomalies during key glacial periods. We find as glacial severity intensifies, precipitation anomalies gain significance, yet temperature anomalies remain the primary influencer of Surface Mass Balance (SMB) variations. Our findings suggest that temperature anomalies may play a pivotal role in both glaciation inception and termination. However, it is important to note that this conclusion is drawn from the present day-LGM anomaly of a single climate model. If the magnitude difference between temperature anomalies (◦C) and precipitation anomalies (mm/day) is less pronounced, the influence of precipitation could become more prominent.