Data and scripts for: The role of timescale dependencies of the Soil moisture-temperature pathways in shaping extreme heats

Abstract: Intra-seasonal soil moisture-temperature coupling (STC) plays an essential role in regional climate extremes, whereas the multiscale mechanisms are poorly studied. This study examines multi-temporal scales of the soil moisture – temperature interactions over the Low‐Latitude Highlands and Indochina Peninsula(LLH-ICP). By using frequency-domain diagnostics on ERA5-Land, we disentangle the two coupling pathways at different time scales. At low frequencies (periods >40 days), the slow STC is controlled by land-driven forcing, with soil moisture(SM) anomalies leading 2m temperature(T) variations and the response becoming stronger during the spring-to-summer transition. On the other hand, at higher frequencies (15-20 days), STC displays an atmosphere-driven fast response where T variations are mainly controlled by atmospheric dynamics. These show that the couplings are dominant across distinct timescales. Under extreme conditions, such as during the 2019 heatwave, the enhancement of the slow pathway leads to a pre-conditioned dry state that significantly amplifies surface warming. These results provide a helpful schematic of how land-atmosphere interactions can amplify extreme heat across multiple time scales, contributing valuable insights into the predictability of intra-seasonal compound extremes over tropical-subtropical transition zones. Repository Structure: The files are organized into a hierarchical structure to facilitate navigation across different diagnostic stages: data/climatology/: Standardized daily anomalies (1979–2019), including pre-computed Empirical Orthogonal Function (EOF) results and filtered frequency components used for climatological diagnostics 。 data/2019/: Variables and filtered components specifically processed for the 2019 extreme heatwave natural experiment 。 data/shapefile/: National Large Scientific Facility shapefiles (e.g., gms.shp) used for precise regional masking and removing extraneous regional characteristics from the analysis. data/scripts/: The complete suite of analytical code: NCL Scripts (v6.6.2): For data preprocessing, EOF analysis, and Cross-Power Spectral Density (CPSD) calculations 。 Python Scripts (v3.12): For phase-space diagnostics, constructing hysteresis loops, and visualizing the cross-scale amplifier effect (nesting analysis) 。 README.md: Detailed instructions on software dependencies and step-by-step figure reproduction 。 Technical Acknowledgments: Computational support for the execution of these analysis workflows was provided by the National Large Scientific and Technological Infrastructure "Earth System Numerical Simulation Facility" (https://cstr.cn/31134.02.EL)。 Data Sources: Raw input data were sourced from the ERA5-Land reanalysis distributed by the Copernicus Climate Change Service (C3S) 。