Date of Award
2017
Document Type
Open Access Master's Thesis
Degree Name
Master of Science in Applied Physics (MS)
Administrative Home Department
Department of Physics
Advisor 1
Will Cantrell
Committee Member 1
Raymond Shaw
Committee Member 2
Mark Kulie
Abstract
The water vapor concentration plays an important role for many atmospheric processes. The mean concentration is key to understand water vapor's effect on the climate as a greenhouse gas. The fluctuations about the mean are important to understand heat fluxes between Earth's surface and the boundary layer. These fluctuations are linked to turbulence that is present in the boundary layer. Turbulent conditions are simulated in Michigan Tech’s multiphase, turbulent reaction chamber, the π chamber. Measurements for temperature and water vapor concentration were recorded under forced Rayleigh- Bénard convection at several turbulent intensities. These were used to calculate the saturation ratio, often referred to as the relative humidity. The fluctuations in the water vapor concentration were found to be the more important than the temperature for the variability of the saturation ratio. The fluctuations in the saturation ratio result in some cloud droplets experiencing a higher supersaturation than other cloud droplets, causing those "lucky" droplets to grow at a faster rate than other droplets. This difference in growth rates could contribute to a broadening of the size distribution of cloud droplets, resulting in the enhancement of collision-coalescence. These fluctuations become more pronounced with more intense turbulence.
Recommended Citation
Anderson, Jesse, "The Intrinsic Variability of the Water Vapor Saturation Ratio Due to Mixing", Open Access Master's Thesis, Michigan Technological University, 2017.