Persistence of Soil Enthalpy Drives the Winter and Summer Climate Connection in the Tibetan Plateau

Although some outcomes have been reported, our knowledge of the Tibetan Plateau (TP) climate and its prediction remains unclear due to land surface complexity and observational uncertainty. Here, long-term observations and reanalysis data revealed a significant positive relationship between winter and the subsequent summer surface air temperatures (SATs) over the TP, in which we highlighted the role of the persistence of soil enthalpy (SE) process. The winter SE can memorize the winter SAT anomaly, and the signal decays with depth gradually, but the consistency with spring SE increases substantially. This persistence of the SE process facilitates the winter SAT signals to be preserved for months until summer, resulting in homogeneous SAT anomalies in summer. The atmospheric response to the SAT anomaly further demonstrates the significant effect of winter thermal conditions on the subsequent summer climate over the TP. Hence, this work brings a new perspective for understanding the TP climate.

Automated summary

This study reveals a significant positive relationship between winter and subsequent summer surface air temperatures (SATs) over the Tibetan Plateau (TP). The persistence of the soil enthalpy (SE) process plays a crucial role in preserving winter SAT signals until summer, resulting in homogeneous SAT anomalies in summer. This research provides a new perspective for understanding the TP climate.