Oceanography and Atmospheric Sciences and Meteorology Commons^™

Understanding The Effects Of Water Vapor And Temperature On Aerosol Using Novel Measurement Methods, Tyler Jacob Capek

Dissertations, Master's Theses and Master's Reports

Aerosol and water are inexorably linked, and both are ubiquitous within our atmosphere and required components for cloud formation. Relative humidity (RH), a temperature dependent quantity, can have a significant influence on the size, shape, and ultimately, the optical properties of the aerosol. RH can vary substantially on small spatial and short temporal scales in turbulent conditions due to rapid fluctuations in temperature and water vapor mixing ratio. Accurate assessment of optical enhancements due to an increase in RH is key for determining the particles’ impact on the climate and visibility.

A humidity-controlled cavity attenuated phase-shift albedometer (H-CAPS-PM_SSA) …

Activation Scavenging Of Aerosol : Effect Of Turbulence And Aerosol-Composition, Abu Sayeed Md Shawon

Dissertations, Master's Theses and Master's Reports

The interaction of aerosol particles with solar radiation significantly contributes to the global radiation balance. The magnitude of this aerosol-radiation interaction, among other parameters, depends on different aerosol properties, including how readily these particles would act as cloud condensation nuclei (CCN). These properties are governed by the formation and scavenging processes of aerosol. This dissertation explores some of these scavenging processes.

Favorable humidity and preexisting aerosol particles acting as CCN are the sine qua non conditions to form cloud droplets in Earth’s atmosphere. Forming cloud droplets (known as activation), meanwhile, acts as a wet scavenging mechanism for those CCN. Given …

Modeling And Numerical Simulations Of The Michigan Tech Convection Cloud Chamber, Subin Thomas

Dissertations, Master's Theses and Master's Reports

Understanding atmospheric clouds is essential for human progress, ranging from short-term effects such as when and how much it rains to long-term effects such as how much temperatures would rise due to global climate change. Clouds vary globally and seasonally; also they have length scales ranging from a few nanometers to a few kilometers and timescales from a few nanoseconds to a few weeks. Knowledge gaps in aerosol-cloud-turbulence interactions and a lack of sufficient resolution in observations pose a challenge in understanding cloud systems.

Experimental facilities like the Michigan Tech Cloud Chamber can provide a suitable platform for studying aerosol-cloud …

Investigating Ice Nucleation At Negative Pressures Using Molecular Dynamics: A First Order Approximation Of The Dependence Of Ice Nucleation Rate On Pressure, Elise Rosky

Dissertations, Master's Theses and Master's Reports

Atmospheric scientists and climate modelers are faced with uncertainty around the process of ice production in clouds. While significant progress has been made in predicting homogeneous and heterogeneous ice nucleation rates as a function of temperature, recent experiments have shown that ice nucleation rates can be enhanced without decreasing temperature, through various mechanical agitations. One hypothesis for these findings is that mechanisms of stretching water and thereby inducing negative pressure in the liquid could lead to an increase in freezing rate. To better understand the viability of this concept, the effect of negative pressure on ice nucleation rates needs to …