Journal Article

Quantifying the Turbulent Entrainment‐Mixing Processes Based on Z‐LWC Relationships of Cloud Droplets

Lu, Chunsong, Zhu, Lei, Luo, Shi, Lv, Jingjing, Chen, Xuemin, Gao, Sinan, Xu, Xiaoqi, Zhang, Fengwei, Yang, Xinlin, Gu, Juan, Sun, Haining, Li, Junjun, He, Ying, Li, Haoran, He, Xin, Liu, Yangang

2025

Overview

Turbulent entrainment‐mixing processes profoundly influence the relationship between radar reflectivity factor and liquid water content (Z‐LWC) of cloud droplets. However, quantification of the entrainment‐mixing mechanisms based on the Z‐LWC relationship is still lacking. To address this gap, 12,218 entrainment‐mixing cases are simulated using the Explicit Mixing Parcel Model. We examine the variations of the parameters in the power‐law relationship Z = aLWCb, and the relationship between parameter b and homogeneous mixing degree (ψ), a measure quantifying entrainment‐mixing processes. The results indicate that parameter b distributes within the range of 1–2, with a positive correlation between parameter b and ψ. The b‐ψ relationship is fitted, which connects the Z‐LWC relationship for various entrainment‐mixing types. The results suggest the potential for employing a remote sensing approach to investigate the entrainment‐mixing mechanisms of non‐precipitating small cumulus/stratocumulus clouds, thereby overcoming the limitations of traditional observational studies that rely solely on aircraft observations. Plain Language Summary Clouds play a pivotal role in the Earth's weather and climate. Among the cloud‐related processes, the entrainment‐mixing process profoundly influences the relationship between radar reflectivity factor and liquid water content of cloud droplets. However, quantification of the entrainment‐mixing mechanisms based on the aforementioned relationship remains incomplete. The high‐resolution results quantify a robust connection between entrainment‐mixing processes and the relationship, indicating the potential for a remote sensing approach to study the entrainment‐mixing mechanisms of non‐precipitating small cumulus/stratocumulus clouds. This approach could overcome the limitations of traditional observational studies that rely solely on aircraft observations. Key Points The influence of the entrainment‐mixing process on the parameter b in the Z = aLWCb and the physical mechanisms are examined A robust relationship between the parameter b and the homogeneous mixing degree is established The result suggests a potential remote sensing approach for studying entrainment‐mixing mechanisms

• Publisher: John Wiley & Sons, Inc,American Geophysical Union (AGU),Wiley
• Subject: Aircraft / Aircraft observations / Cloud droplets / Clouds / Cumulus clouds / Droplets / Entrainment / Liquid water content / Mixing / Mixing processes / Moisture content / Observational studies / Parameters / Radar / Radar reflectivity / Reflectance / Remote sensing / Stratocumulus clouds / Turbulent entrainment / Water / Water content