Master of Science (MS)
Meteorology and Climate Science
Clouds have a large impact on Earth’s radiation budget, and although there is aconsiderable amount of research on them, there are still uncertainties concerning how thermodynamics, dynamics, and aerosol indirect effects impact their microphysical properties. The lack of observational analysis on cirrus and mixed-phase cloud controlling factors, i.e., temperature, relative humidity, vertical velocity, and aerosol number concentrations, limits our understanding of how these properties impact their microphysical properties and, therefore, complicates how they are simulated within climate models. With seven flight campaigns funded by the National Science Foundation (NSF) and five funded by the National Aeronautics and Space Administration (NASA), we categorize cirrus clouds into five evolution phases. We then compare the NSF dataset to simulated data from the National Center for Atmospheric Research (NCAR) Community Atmosphere Model 6 (CAM6). We find that the evolution phases demonstrate clear differences between one another indicating that it is important to take them into account when analyzing the aerosol indirect effects on cirrus clouds. Additionally, we present a new method to separate mixed-phase clouds into four transition phases which allows us to represent their macrophysical properties. Using this method and comparing it to a derived dataset that defines phases per particle reveals that there is a correlation between the macrophysical and microphysical properties of mixedphase clouds.
Maciel, Flor Vanessa, "The Influence of Aerosols on Ice and Mixed-Phase Clouds Based on In-Situ Observations and Cam6 Simulations" (2022). Master's Theses. 5318.