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Full-Text Articles in Physics
Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw
Designing A Convection-Cloud Chamber For Collision-Coalescence Using Large-Eddy Simulation With Bin Microphysics, Aaron Wang, Mikhail Ovchinnikov, Fan Yang, Silvio Schmalfuss, Raymond A. Shaw
Michigan Tech Publications, Part 2
Collisional growth of cloud droplets is an essential yet uncertain process for drizzle and precipitation formation. To improve the quantitative understanding of this key component of cloud-aerosol-turbulence interactions, observational studies of collision-coalescence in a controlled laboratory environment are needed. In an existing convection-cloud chamber (the Pi Chamber), collisional growth is limited by low liquid water content and short droplet residence times. In this work, we use numerical simulations to explore various configurations of a convection-cloud chamber that may intensify collision-coalescence. We employ a large-eddy simulation (LES) model with a size-resolved (bin) cloud microphysics scheme to explore how cloud properties and …
An Intercomparison Of Large-Eddy Simulations Of A Convection Cloud Chamber Using Haze-Capable Bin And Lagrangian Cloud Microphysics Schemes, Fan Yang, Fabian Hoffmann, Raymond Shaw, Mikhail Ovchinnikov, Andrew M. Vogelmann
An Intercomparison Of Large-Eddy Simulations Of A Convection Cloud Chamber Using Haze-Capable Bin And Lagrangian Cloud Microphysics Schemes, Fan Yang, Fabian Hoffmann, Raymond Shaw, Mikhail Ovchinnikov, Andrew M. Vogelmann
Michigan Tech Publications
Recent in situ observations show that haze particles exist in a convection cloud chamber. The microphysics schemes previously used for large-eddy simulations of the cloud chamber could not fully resolve haze particles and the associated processes, including their activation and deactivation. Specifically, cloud droplet activation was modeled based on Twomey-type parameterizations, wherein cloud droplets were formed when a critical supersaturation for the available cloud condensation nuclei (CCN) was exceeded and haze particles were not explicitly resolved. Here, we develop and adapt haze-capable bin and Lagrangian microphysics schemes to properly resolve the activation and deactivation processes. Results are compared with the …
Scaling Of Turbulence And Microphysics In A Convection–Cloud Chamber Of Varying Height, Subin Thomas, Fan Yang, Mikhail Ovchinnikov, Will Cantrell, Raymond Shaw
Scaling Of Turbulence And Microphysics In A Convection–Cloud Chamber Of Varying Height, Subin Thomas, Fan Yang, Mikhail Ovchinnikov, Will Cantrell, Raymond Shaw
Michigan Tech Publications
The convection–cloud chamber enables measurement of aerosol and cloud microphysics, as well as their interactions, within a turbulent environment under steady-state conditions. Increasing the size of a convection–cloud chamber, while holding the imposed temperature difference constant, leads to increased Rayleigh, Reynolds and Nusselt numbers. Large–eddy simulation coupled with a bin microphysics model allows the influence of increased velocity, time, and spatial scales on cloud microphysical properties to be explored. Simulations of a convection–cloud chamber, with fixed aspect ratio and increasing heights of H = 1, 2, 4, and (for dry conditions only) 8 m are performed. The key findings are: …
Large-Eddy Simulations Of A Convection Cloud Chamber: Sensitivity To Bin Microphysics And Advection, Fan Yang, Mikhail Ovchinnikov, Subin Thomas, Alexander Khain, Robert Mcgraw, Raymond Shaw, Andrew M. Vogelmann
Large-Eddy Simulations Of A Convection Cloud Chamber: Sensitivity To Bin Microphysics And Advection, Fan Yang, Mikhail Ovchinnikov, Subin Thomas, Alexander Khain, Robert Mcgraw, Raymond Shaw, Andrew M. Vogelmann
Michigan Tech Publications
Bin microphysics schemes are useful tools for cloud simulations and are often considered to provide a benchmark for model intercomparison. However, they may experience issues with numerical diffusion, which are not well quantified, and the transport of hydrometeors depends on the choice of advection scheme, which can also change cloud simulation results. Here, an atmospheric large-eddy simulation model is adapted to simulate a statistically steady-state cloud in a convection cloud chamber under well-constrained conditions. Two bin microphysics schemes, a spectral bin method and the method of moments, as well as several advection methods for the transport of the microphysical variables …