Advancing Cloud Science: Exploring the Lifetime of Indiviual Cloud Droplets through Aerosol Optical Tweezers and Raman Spectroscopy

The lifetime of clouds has an important influence on radiation balance, atmospheric matter cycling, and global precipitation patterns. However, current assessments of cloud lifetime rely on statistical methods, underscoring the need for effective observational techniques. Moreover, existing research predominantly centers on precipitation removal, neglecting the process of cloud dissipation.Utilizing optical tweezers-Raman spectroscopy technology and CCD real-time imaging, this study conducts experiments on the evaporation of individual suspended droplets with a series of concentration gradients. We establish a method for quantifying the evaporation time of microdroplets, and characterize their evaporation dynamics through the temporal variation of OH-stretching Raman peak. Our research reveals the substantial influence of droplet solute concentration on evaporation time, indicating that even minute variations in solute concentration within cloud droplets can induce profound disparities in their lifetime.Furthermore, alterations in environmental relative humidity also have an impact on the dissipation of cloud droplets. These findings hold critical scientific significance, enhancing our understanding of cloud lifetime and providing a scientific foundation for accurately simulating cloud generation and dissipation processes in numerical models.