Reevaluating the Little Ice Age: Novel insights from oceanic and terrestrial records on unexpected warm winters

This investigation into the Little Ice Age (LIA) climate discrepancies explores sea surface temperature (SST) anomalies in the South China Sea (SCS) using monthly resolved coral Sr/Ca proxies. Results show that, during the LIA, while overall summer and annual SSTs were cooler compared to the Medieval Climate Anomaly and the Current Warm Period, winters were unexpectedly warmer. This warming is corroborated by another coral-based study and aligns with terrestrial data from high-latitude regions reporting similar warmer winters during the LIA. The analysis suggests that these higher winter SSTs in the SCS were likely due to a weakened East Asian winter monsoon and stronger El Nino events. The presence of warmer winters in various regions contradicts the traditional view of a consistently cold LIA, indicating complex regional climate variations influenced by atmospheric and oceanic interactions. This work underscores the need to reassess our understanding of the LIA's heterogeneous climate impacts globally.