基于温度场和水分场控制方程的青藏高原冻土区气候演变特征研究

Research on Climate Evolution Characteristics of Frozen Soil Regions in the Qinghai-Xizang Plateau Based on Temperature Field and Water Content Field Control Equations

摘要: 青藏高原冻土区对全球气候变化具有高度敏感性，传统分析方法常忽略冻结/融化锋面的相变过程，直接对温度场和水分场进行简化处理，导致对气候演变特征的模拟存在不确定性。为改进这一问题，本文构建了考虑冻融相变的一维垂向水热耦合模型，该方法基于温度场和水分场的控制方程，更精确地描述青藏高原冻土区在大尺度气候变化下的不同梯度演变特征。WRF敏感性实验显示，考虑冻融相变后，模型在冷暖气候背景下对感热与潜热通量的响应更符合冻土–大气能量交换的物理机制，能够更合理地反映不同气候阶段冻土区的能量分配差异。

Abstract: The permafrost region of the Qinghai-Xizang Plateau exhibits high sensitivity to global climate change. Traditional analytical methods often neglect the phase transition process at freezing/melting fronts and directly simplify the temperature and water content fields, leading to uncertainties in simulating climate evolution characteristics. To address this issue, this study constructs a one-dimensional vertical soil water-heat coupled model that explicitly considers freeze-thaw phase transitions. Based on the governing equations of the temperature and water content fields, the model more accurately describes the evolution characteristics of different gradients in the permafrost region under large-scale climate change. WRF-based sensitivity experiments show that, after incorporating freeze-thaw phase transitions, the model’s responses of sensible and latent heat fluxes under cold and warm climatic backgrounds are more consistent with the physical mechanisms of land-atmosphere energy exchange, and can more reasonably reflect differences in energy partitioning across climatic stages.