The Memories of Soil Moisture and Soil Temperature Anomalies in Subsequent Soil Moisture and Soil Temperature in China

Abstract The memories of soil moisture (SM) and soil temperature (ST) modulate the effect of land surface on climate prediction on monthly and longer timescales. Based on a Lagrangian‐based understanding of SM and ST memories, this study explores the characteristics of SM and ST memories using ERA5‐Land reanalysis data, observations, land surface model and WRF model. The results show that SM and ST memories are longer in North China, Northeast China, Northwest China and Qinghai‐Tibet Plateau than in other regions of China, even exceeding 10 months. In the southern part of China, memories are short, approximately 0–6 months. SM memories have similar spatial distributions at different soil depths over 12 months, as do ST memories. The WRF‐simulated memories show generally consistent spatial patterns with ERA5‐Land but are lower in some regions. Moreover, SM and ST anomalies mainly persist in the form of subsequent SM and ST anomalies, respectively. The relationships between the memories and land surface fluxes exhibit distinct characteristics in arid and wet regions. The memories of SM anomalies are longer in frozen soil, non‐flood season and the arid‐humid transition zone. Additionally, SM and ST memories are characterized with clear monthly and decadal variations, which may be related to some oceanic and atmospheric patterns. This study advances the understanding of critical processes linking land conditions before a certain time to atmosphere thereafter.