Critical Soil Moisture Estimates and Regime Properties

This repository provides the datasets, processing workflows, and analysis codes used to estimate critical soil moisture thresholds (θ*) at the global scale and to characterize hydrological regime dynamics and land–atmosphere interactions. The framework derives θ* using three independent proxy pathways that represent complementary physical processes governing land surface feedbacks: diurnal soil temperature range (dTsoil), evaporative fraction (EF), and the temporal rate of soil moisture drying (dθ/dt). In addition to θ* estimates, the repository includes a suite of derived regime diagnostics designed to quantify hydrological stability and transition behavior. These include persistence (γ), defined as the fraction of time spent in the water-limited regime; tipping potential (τ), representing the probability of regime switching; and binary regime classification accuracy (π), which measures the level of agreement among independent critical threshold estimation methods. The persistence (γ) and tipping potential (τ) metrics are computed separately for EF-, dTsoil-, and dθ/dt-based thresholds, whereas the classification accuracy (π) metric is evaluated between dTsoil–EF and dTsoil–dθ/dt method pairs to assess cross-proxy consistency. The repository further provides estimates of land–atmosphere coupling strength (Ω), a diagnostic metric that describes the sensitivity of surface energy partitioning to soil moisture variability and enables the identification of regions with strong soil moisture–atmosphere feedbacks (“coupling hotspots”). The Ω metric is derived consistently across all three methods.<b>References</b>: For detailed methodological descriptions, definitions of θ* thresholds, and full explanations of derived regime metrics, users are referred to the original article: https://doi.org/10.1029/2025EF006194. See the latest version of this repository at: https://doi.org/10.6084/m9.figshare.28498622<b>Connect</b>: For questions, technical clarifications, or collaboration inquiries, please contact the repository author at: [e-mail] | https://sites.google.com/view/sandipan-paul?usp=sharing本数据集仓库提供了用于全球尺度临界土壤湿度阈值（θ*，critical soil moisture thresholds）估算、水文情势动态特征刻画以及陆气相互作用分析所需的数据集、处理流程与分析代码。本研究框架依托三类独立的替代指标路径推导θ*，这三类路径分别对应调控陆面反馈的互补物理过程：日间土壤温度极差（dTsoil，diurnal soil temperature range）、蒸发比（EF，evaporative fraction）以及土壤湿度干燥的时间变化率（dθ/dt，temporal rate of soil moisture drying）。除θ*估算结果外，本仓库还包含一套衍生的情势诊断工具集，用于量化水文系统的稳定性与状态转换行为。其中包括：持续度（γ，persistence），定义为系统处于水分限制情势的时间占比；临界转换潜力（τ，tipping potential），即水文情势发生切换的概率；以及二元情势分类准确率（π，binary regime classification accuracy），用于衡量不同独立临界阈值估算方法间的一致性水平。持续度（γ）与临界转换潜力（τ）指标分别基于EF、dTsoil及dθ/dt三类阈值独立计算，而二元情势分类准确率（π）则通过dTsoil-EF与dTsoil-dθ/dt两组方法对的比对进行评估，以检验不同替代指标路径间的一致性。本仓库还进一步提供了陆气耦合强度（Ω，land–atmosphere coupling strength）的估算结果：该诊断指标用于描述地表能量分配对土壤湿度变异性的敏感性，可识别出存在强土壤湿度-大气反馈的区域（即“耦合热点区域”）。三类方法下的Ω指标推导逻辑保持一致。<b>参考文献</b>：若需了解详细的方法学描述、θ*阈值的定义以及衍生情势指标的完整解释，请参阅原文：https://doi.org/10.1029/2025EF006194。本仓库的最新版本可通过以下链接获取：https://doi.org/10.6084/m9.figshare.28498622<b>联系</b>：若有疑问、技术澄清或合作意向，请通过以下方式联系仓库作者：[e-mail] | https://sites.google.com/view/sandipan-paul?usp=sharing