Frequency of Synoptic‐Scale Precipitation Events Recorded by Daily Resolved δ18O of Land Snail Shells

Abstract Land snails exhibit the potential for capturing synoptic‐scale precipitation events through the δ18O records of their shells (δ18Oshell), but the application is hindered by the absence of a practical methodology for tracking these events. Here, we developed a statistical methodology to track the synoptic‐scale precipitation events from daily resolved snail body fluid δ18O (δ18OBF) record. We further tested and verified our approach using daily resolved δ18Oshell records of modern Cathaica fasciola from the Chinese Loess Plateau (CLP). The reconstructed 3‐day‐timescale precipitation events frequencies using first derivations of δ18OBF and δ18Oshell shows strong agreement with instrumental data (>85% detection accuracy). The strong correlation between precipitation days in snail‐growing‐season and annual precipitation amounts across the CLP also permits the reconstruction of synoptical precipitation frequency for investigating the interannual variability of precipitation. Our study paves the avenue in paleoweather study, enabling quantitative reconstructions of past synoptic‐scale precipitation events.