Temperature signals of ice core and speleothem isotopic records from Asian monsoon region as indicated by precipitation δ18O

Ice cores and speleothem δ 18 O records from Asia have been widely used as a proxy to reconstruct paleoclimate changes. However, whether those δ 18 O records are a proxy of temperature or monsoon intensity has remained a great controversy. Generally, ice core δ 18 O records from non-monsoon and transition regions indicate temperature, but ice core and speleothem δ 18 O records from monsoon regions have been regarded as proxies for monsoon intensity or precipitation. Here, we address the controversy by showing three 20-yr long daily precipitation δ 18 O ( δ 18 Op) series and 120 monthly δ 18 Op series based on 17461 precipitation samples throughout Asia. We find that the δ 18 Op signals preserved in precipitation are consistent with those in ice cores, both in the non-monsoon and monsoon regions. The results confirm previous research that ice core δ 18 O records in the non-monsoon region provide reliable histories of surface temperature. However, ice core δ 18 O records can still directly indicate surface temperature in the monsoon domain if winter/spring precipitation is heavy. When winter/spring precipitation is sparse, inverted ice core records show good agreement with surface temperature records. This may be due to the effect of cloud-top temperatures (which differ from surface temperatures) on summer δ 18 Op values. Similarly, inverted speleothem δ 18 O records in the monsoon regions are similar to Greenland/Antarctic ice core δ 18 O/δD time series and other paleotemperature records. Our findings provide a reinterpretation of Asian ice core and speleothem δ 18 O records, and demonstrate that temperature signals have been preserved in those archives from the Asian monsoon region.