Physics Commons^™

Cloud Microphysical Response To Entrainment And Mixing Is Locally Inhomogeneous And Globally Homogeneous: Evidence From The Lab, Jaemin Yeom, Ian Helman, Prasanth Prabhakaran, Jesse Anderson, Fan Yang, Raymond Shaw, Will Cantrell

Michigan Tech Research Data

The effects of entrainment-mixing on the cloud droplet size distribution are examined in the Pi cloud chamber that creates a turbulent supersaturated environment for cloud formation. The experiments are conducted with a temperature-controlled flange to mimic the entrainment-mixing process. The entrainment zone is created at the center of the top surface of the chamber, allowing dry air of controlled temperature (T_e) and flow rate (Q_e) to flow into the mixing cloud region. Due to the large-scale circulation, the downwind region is directly affected by entrained dry air from the flange, whereas the upwind region is representative …

Molecular Dynamics Simulation Data: Mw And Mlmw Water Model Ice Nucleation On A Hydrophilic Substrate With Negative Pressure, Will Cantrell, Tianshu Li, Issei Nakamura, Elise Rosky, Raymond Shaw

Michigan Tech Research Data

This dataset contains the data supporting Figures in the study by Rosky et al., "Molecular simulations reveal that heterogeneous ice nucleation occurs at higher temperatures in water under capillary tension", submitted for publication in Atmospheric Chemistry and Physics in February 2023. Input files for reproducing the molecular dynamics simulations are included.

The abstract from the paper reads: Using a molecular model of water freezing on a hydrophilic substrate, it is found that heterogeneous ice nucleation rates occur at higher temperatures in water that is under tension, in other words under negative pressure. For pressures ranging from from 1 atm to …

Data Supporting The Paper "Is The Water Vapor Supersaturation Distribution Gaussian?", Subin Thomas, Prasanth Prabhakaran, W. Cantrell, Raymond Shaw

Michigan Tech Research Data

The data in this file are from the MTU Pi Cloud Chamber and large eddy simulations. This work was supported by NSF grant AGS-1754244. Data are made available in support of the above publication by Thomas et al.. For any further use, e.g., for publication elsewhere, the authors should be contacted to ensure the appropriate use of the data and proper acknowledgment.

Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni

Michigan Tech Publications

Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after …

Data Supporting The Paper "Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations", Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn R. Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra Dubey, Allison Aiken, Rajan K. Chakrabarty, Hans Moosmüller, Timothy B. Onasch, Rahul A. Zaveri, Barbara Scarnato, Paolo Fialho, Claudio Mazzoleni

Department of Physics Publications

No abstract provided.

Data Supporting The Paper "Scaling Of An Atmospheric Model To Simulate Turbulence And Cloud Microphysics In The Pi Chamber", Subin Thomas, Mikhail S. Ovchinnikov, Fan Yang, Dennis Van Der Voort, Will Cantrell, Steven K. Krueger, Raymond Shaw

Department of Physics Publications

No abstract provided.

Fine-Scale Droplet Clustering In Atmospheric Clouds: 3d Radial Distribution Function From Airborne Digital Holography, Michael L. Larsen, Raymond Shaw, Alexander Kostinski, Susanne Glienke

Department of Physics Publications

The extent of droplet clustering in turbulent clouds has remained largely unquantified, and yet is of possible relevance to precipitation formation and radiative transfer. To that end, data gathered by an airborne holographic instrument are used to explore the three-dimensional spatial statistics of cloud droplet positions in homogeneous stratiform boundary-layer clouds. The three-dimensional radial distribution functions g(r) reveal unambiguous evidence of droplet clustering. Three key theoretical predictions are observed: the existence of positive correlations, onset of correlation in the turbulence dissipation range, and monotonic increase of g(r) with decreasing r. This implies that current theory captures the essential processes contributing …

Turbulence Induced Cloud Voids: Observation And Interpretation, Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Department of Physics Publications

The phenomenon of cloud voids, i.e., elongated volumes inside a cloud that are devoid of droplets, was observed with laser sheet photography in clouds at a mountain-top station. Two experimental cases, similar in turbulence conditions yet with diverse droplet size distributions and cloud void prevalence, are reported. A theoretical explanation is proposed based on the study of heavy inertial sedimenting particles inside a Burgers vortex. A general conclusion regarding void appearance is drawn from theoretical analysis. Numerical simulations of polydisperse droplet motion with realistic vortex parameters and Mie scattering visual effects accounted for can explain the presence of voids with …

Molecular And Physical Characteristics Of Aerosol At A Remote Free Troposphere Site: Implications For Atmospheric Aging, Simeon Schum, Bo Zhang, Katja Džepina, Paolo Fialho, Claudio Mazzoleni, Lynn Mazzoleni

Department of Chemistry Publications

Aerosol properties are transformed by atmospheric processes during long-range transport and play a key role in the Earth's radiative balance. To understand the molecular and physical characteristics of free tropospheric aerosol, we studied samples collected at the Pico Mountain Observatory in the North Atlantic. The observatory is located in the marine free troposphere at 2225m above sea level, on Pico Island in the Azores archipelago. The site is ideal for the study of long-range-transported free tropospheric aerosol with minimal local influence. Three aerosol samples with elevated organic carbon concentrations were selected for detailed analysis. FLEXPART retroplumes indicated that two of …

Data Supporting The Paper "Turbulence Induced Cloud Voids: Observation And Interpretation", Katarzyna Karpinska, Jonathan F. E. Bodenschatz, Szymon P. Malinowski, Jakub L. Nowak, Steffen Risius, Tina Schmeissner, Raymond Shaw, Holger Siebert, Hengdong Xi, Haitao Xu, Eberhard Bodenschatz

Department of Physics Publications

No abstract provided.

Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius, K. K. Chandrakar, Will Cantrell, A. Kostinski, Raymond Shaw

Department of Physics Publications

Cloud optical properties are determined not only by the number density n_d and mean radius ṝ of cloud droplets but also by the shape of the droplet size distribution. The change in cloud optical depth with changing n_d, due to the change in distribution shape, is known as the dispersion effect. Droplet relative dispersion is defined as d=σ_r / ṝ . For the first time, a commonly used effective radius parameterization is tested in a controlled laboratory environment by creating a turbulent cloud. Stochastic condensation growth suggests d independent of n_d for a nonprecipitating cloud, …

Data Supporting The Paper "Dispersion Aerosol Indirect Effect In Turbulent Clouds: Laboratory Measurements Of Effective Radius", K. K. Chandrakar, Will Cantrell, A. Kostinski, R. A. Shaw

Department of Physics Publications

No abstract provided.

Simulation Data Supporting The Paper "Optical Properties And Radiative Forcing Of Fractal-Like Tar Ball Aggregates From Biomass Burning", Janarjan Bhandari, Swarup China, Giulia Girotto, Barbara Scarnato, Kyle Gorkowski, Allison Aiken, Manvendra Dubey, C. Mazzoleni

Department of Physics Publications

Simulations data supporting the paper "Optical properties and radiative forcing of fractal-like tar ball aggregates from biomass burning," to be submitted to the Journal of Quantitative Spectroscopy and Radiative Transfer.

Measurement And Modeling Of The Multiwavelength Optical Properties Of Uncoated Flame-Generated Soot, Sara D. Forestieri, Taylor M. Helgestad, Andrew T. Lambe, Lindsay Renbaum-Wolff, Paulo Massoli, Eben S. Cross, Claudio Mazzoleni, Et. Al.

Michigan Tech Publications

Optical properties of flame-generated black carbon (BC) containing soot particles were quantified at multiple wavelengths for particles produced using two different flames: a methane diffusion flame and an ethylene premixed flame. Measurements were made for (i) nascent soot particles, (ii) thermally denuded nascent particles, and (iii) particles that were coated and then thermally denuded, leading to the collapse of the initially lacy, fractal-like morphology. The measured mass absorption coefficients (MACs) depended on soot maturity and generation but were similar between flames for similar conditions. For mature soot, here corresponding to particles with volume-equivalent diameters >∼160 nm, the MAC and absorption …

Observation Of A Link Between Energy Dissipation Rate And Oscillation Frequency Of The Large-Scale Circulation In Dry And Moist Rayleigh-Bénard Turbulence, Dennis Niedermeier, Kelken Chang, Will Cantrell, Kamal Kant Chandrakar, David Ciochetto, Raymond Shaw

Department of Physics Publications

In this study both the small- and large-scale flow properties of turbulent Rayleigh-Bénard convection are investigated. Experiments are carried out using the Π chamber (aspect ratio Γ=2) for Rayleigh number range Ra∼10⁸–10⁹ and Prandtl number Pr≈0.7. Furthermore, experiments are run for dry and wet conditions, i.e., top and bottom surfaces of the chamber are dry and wet, respectively. For wet conditions we further distinguish between conditions with and without the presence of sodium chloride aerosol particles which, if supersaturated conditions are achieved, lead to cloud droplet formation. We therefore refer to these conditions as moist and cloudy, …

Data Supporting The Paper "Influence Of Microphysical Variability On Stochastic Condensation In A Turbulent Laboratory Cloud", N. Desai, K. K. Chandrakar, K. Chang, Will Cantrell, Raymond Shaw

Department of Physics Publications

No abstract provided.

A Laboratory Facility To Study Gas-Aerosol-Cloud Interactions In A Turbulent Environment: The Π Chamber, K. Chang, J. Bench, M. Brege, Will Cantrell, K. Chandrakar, David Ciochetto, Claudio Mazzoleni, Lynn Mazzoleni, Dennis Niedermeier, R. A. Shaw

Department of Physics Publications

A detailed understanding of interactions of aerosols, cloud droplets/ice crystals, and trace gases within the atmosphere is of prime importance for an accurate understanding of Earth’s weather and climate. One aspect that remains especially vexing is that clouds are ubiquitously turbulent, and therefore thermodynamic and compositional variables, such as water vapor supersaturation, fluctuate in space and time. With these problems in mind, a multiphase, turbulent reaction chamber—called the Π chamber because of the internal volume of 3.14 m³ with the cylindrical insert installed—has been developed. It is capable of pressures ranging from 1,000 to –60 hPa and can sustain …