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Articles 31 - 60 of 283
Full-Text Articles in Physics
Determining Cloud Cover With Machine Learning, Sarah Sesek
Determining Cloud Cover With Machine Learning, Sarah Sesek
Undergraduate Research Posters 2018
The cloud cover provided by boundary layer cumulus clouds is one of the greatest uncertainties in climate and weather prediction models. It is difficult with current technology to cheaply and accurately collect cloud cover data. The TSI (Total Sky Imager) provides a hemispheric field of view in order to maximize the area it can see. The farther away from the center of the image, the more angled the view of the the cloud is. Therefore, more of the side of the cloud is captured in addition to the cloud base. Machine learning is well suited to seeing through this bias. …
Construction And Applications Of An Inexpensive Muon Detector, Nicholas Knyszek
Construction And Applications Of An Inexpensive Muon Detector, Nicholas Knyszek
Undergraduate Research Posters 2018
Muons are important due to the abundance of them on earth. Muons that are on earth originate from the Sun and enter Earth’s atmosphere as decaying cosmic rays. Muons are somewhat unstable, with a lifespan of roughly 2.2 microseconds. Muons decay into electrons and two types of neutrinos. Since Muons travel near the speed of light they can still go thousands of meters into the Earth’s crust before stopping. Muons account for most of the cosmic radiation at sea level. Muons are harmless to humans. In this study, we built detectors and measured muon counts at different elevations. This research …
Methodology Development For The Implementation Ofmicrofluidic Mixers, Tahir Butt, Gautam Mahajan
Methodology Development For The Implementation Ofmicrofluidic Mixers, Tahir Butt, Gautam Mahajan
Undergraduate Research Posters 2018
Microfluidic platforms have been widely regarded as defining technologies for the development of chemical and biological synthesis and analysis systems, due to benefits associated with reduced reactant consumption, increases by orders of magnitude of the surface-to-volume ratios, and greatly enhanced control over reactions variables such as temperature and pressure. However, one of the bottlenecks for their wide application is the difficulty in achieving mixing, given the typical laminar flows in these systems. In this work we implement experimentally, various strategies using geometrical features to control the fluid motion and induce stirring flows. The mixers are fabricated using soft-lithography in PDMS …
Erosion In Extruder Flows: Analytical And Numerical Study, Miron Kaufman, Petru S. Fodor
Erosion In Extruder Flows: Analytical And Numerical Study, Miron Kaufman, Petru S. Fodor
Physics Faculty Publications
© 2017 Author(s). We consider the erosion of particles (e.g. carbonblack agglomerates) advected by the polymeric flow in a single screw extruder. We assume a particle to be made of primary fragments bound together. In the erosion process a primary fragment breaks out of a given particle. Particles disperse because of the shear stresses imparted by the fluid. The time evolution of the numbers of particles of different sizes is described by the Bateman coupled differential equations developed a century ago to model radioactivity. Using the particle size distribution we compute an entropic fragmentation index which varies from 0 for …
Endothelial Nitric Oxide Synthase Oxygenase On Lipid Nanodiscs: A Nano-Assembly Reflecting Native-Like Function Of Enos, Ghaith Altawallbeh, Mohammad M. Haque, Kiril A. Streletzky, Dennis J. Stuehr, Mekki Bayachou
Endothelial Nitric Oxide Synthase Oxygenase On Lipid Nanodiscs: A Nano-Assembly Reflecting Native-Like Function Of Enos, Ghaith Altawallbeh, Mohammad M. Haque, Kiril A. Streletzky, Dennis J. Stuehr, Mekki Bayachou
Physics Faculty Publications
© 2017 Elsevier Inc. Endothelial nitric oxide synthase (eNOS) is a membrane-anchored enzyme. To highlight the potential role and effect of membrane phospholipids on the structure and activity of eNOS, we have incorporated the recombinant oxygenase subunit of eNOS into lipid nanodiscs. Two different size distribution modes were detected by multi-angle dynamic light scattering both for empty nanodiscs, and nanodiscs-bound eNOSoxy. The calculated hydrodynamic diameter for mode 1 species was 9.0 nm for empty nanodiscs and 9.8 nm for nanodisc bound eNOSoxy. Spectroscopic Griess assay was used to measure the enzymatic activity. Remarkably, the specific activity of nanodisc-bound eNOSoxy is …
Stabilization Of Hypoxia Inducible Factor By Cobalt Chloride Can Alter Renal Epithelial Transport, Subhra Nag, Andrew Resnick
Stabilization Of Hypoxia Inducible Factor By Cobalt Chloride Can Alter Renal Epithelial Transport, Subhra Nag, Andrew Resnick
Physics Faculty Publications
© 2017 The Authors. Given the importance of the transcriptional regulator hypoxia-inducible factor-1 (HIF-1) for adaptive hypoxia responses, we examined the effect of stabilized HIF-1α on renal epithelial permeability and directed sodium transport. This study was motivated by histological analysis of cystic kidneys showing increased expression levels of HIF-1α and HIF-2α. We hypothesize that compression induced localized ischemia-hypoxia of normal epithelia near a cyst leads to local stabilization of HIF-1α, leading to altered transepithelial transport that encourages cyst expansion. We found that stabilized HIF-1α alters both transcellular and paracellular transport through renal epithelial monolayers in a manner consistent with secretory …
Evaluation Of Wrf Scm Simulations Of Stratocumulus-Topped Marine And Coastal Boundary Layers And Improvements To Turbulence And Entrainment Parameterizations, Mohamed S. Ghonima, Handa Yang, Chang Ki Kim, Thijs Heus, Jan Kleissl
Evaluation Of Wrf Scm Simulations Of Stratocumulus-Topped Marine And Coastal Boundary Layers And Improvements To Turbulence And Entrainment Parameterizations, Mohamed S. Ghonima, Handa Yang, Chang Ki Kim, Thijs Heus, Jan Kleissl
Physics Faculty Publications
© 2017. The Authors. Stratocumulus-topped boundary layers (STBLs) are notoriously difficult to parameterize in single-column models due to the strong inversion layer across which entrainment mixing plays an important role in modulating the boundary layer mass, energy, and moisture balances. We compare three different WRF planetary boundary layer (PBL) schemes (Yonsei University, YSU; Asymmetric Convective Model version 2, ACM2; Mellor-Yamada-Nakanishi-Niino, MYNN) against large eddy simulations (LES) to find out that they underestimate entrainment flux in stratocumulus over both ocean and coastal land. Hence, the PBL schemes produce a cooler, moister STBL with higher liquid water content. In order to improve …
Microhh 1.0: A Computational Fluid Dynamics Code For Direct Numerical Simulation And Large-Eddy Simulation Of Atmospheric Boundary Layer Flows, Chiel C. Van Heerwaarden, Bart J.H. Van Stratum, Thijs Heus, Jeremy A. Gibbs, Evgeni Fedorovich, Juan Pedro Mellado
Microhh 1.0: A Computational Fluid Dynamics Code For Direct Numerical Simulation And Large-Eddy Simulation Of Atmospheric Boundary Layer Flows, Chiel C. Van Heerwaarden, Bart J.H. Van Stratum, Thijs Heus, Jeremy A. Gibbs, Evgeni Fedorovich, Juan Pedro Mellado
Physics Faculty Publications
© 2017 Author(s). This paper describes MicroHH 1.0, a new and open-source (www.microhh.org) computational fluid dynamics code for the simulation of turbulent flows in the atmosphere. It is primarily made for direct numerical simulation but also supports large-eddy simulation (LES). The paper covers the description of the governing equations, their numerical implementation, and the parameterizations included in the code. Furthermore, the paper presents the validation of the dynamical core in the form of convergence and conservation tests, and comparison of simulations of channel flows and slope flows against well-established test cases. The full numerical model, including the associated parameterizations for …
P1: Synthesis Optimization And Characterization Of Polymeric Microgels, Samantha Tietjen, Samantha Hudson
P1: Synthesis Optimization And Characterization Of Polymeric Microgels, Samantha Tietjen, Samantha Hudson
Undergraduate Research Posters 2017
Microgels are spherical particles suspended in solution, comprised of crosslinked polymer chains. Due to the amphiphilic property of the parent polymer, microgels display a temperature dependent de-swelling property, and therefore have the potential to be used for drug delivery. In this case, microgels were synthesized using hydroxypropyl cellulose (HPC) polymer and divinyl sulfone (DVS) cross-linker, as well as dodecyltrimethylammonium bromide (DTAB) surfactant to decrease particle size and promote microgel monodispersity. Synthesized particles were then characterized using dynamic light scattering (DLS) for both temperature and angle dependence to determine hydrodynamic radius, Rh, at a range of temperatures showing a transition from …
Fabricating Non-Close Packed Colloidal Monolayers For Ion Irradiation Templates, Nandini Padaraju
Fabricating Non-Close Packed Colloidal Monolayers For Ion Irradiation Templates, Nandini Padaraju
Undergraduate Research Posters 2017
Due to their unique properties, anisotropic nanoparticles are desirable components for future applications yet there are few processes capable of fabricating nanoparticle impregnated coatings for the manufacturing environment. Our work seeks to develop new masking techniques for the production of the templated substrates that will induce ordered nanoparticle films. Specifically, we are fabricating non-close packed colloidal monolayers onto silicon substrates, which then serve as the template for ion irradiation. The first steps to creating this monolayer are obtaining a spin-coated poly(vinyl alcohol) (PVA) thin film of ~200 nm and a close-packed colloidal monolayer using a peltier heater. We achieved a …
Electrostatics At The Molecular Level, Ulrich Zurcher
Electrostatics At The Molecular Level, Ulrich Zurcher
Physics Faculty Publications
In molecular systems, positive and negative charges are separated, making them ideal systems to examine electrostatic interactions. The attractive force between positive and negative charges is balanced by repulsive ‘forces’ that are quantum-mechanical in origin. We introduce an ‘effective’ potential energy that captures the repulsion; it allows us to obtain fairly accurate estimates of the bonding properties of molecular systems. We use units (e.g., kcal mol–1 for energy) that emphasize the relevance of electrostatics to macroscopic behavior.
Achieving Atomically Smooth Surfaces And Ultra Sharp Platinum-Iridium Tips For Deposition Of Organic Molecules, William Myers
Achieving Atomically Smooth Surfaces And Ultra Sharp Platinum-Iridium Tips For Deposition Of Organic Molecules, William Myers
Undergraduate Research Posters 2017
Organic materials are used in traditional solar cells and in flexible electronics. Unfortunately, the conductivities of organic semiconductors are significantly lower than their inorganic counterparts. This project examines the crucial first steps to enhancing the conductivities of these organic materials by crystallization via surface reconstructions. For this, the surface must be not only atomically smooth, but also atomically clean because there must be both enough room for the molecule to lie on and no possible adsorbates for the deposited material to react with. In this work, we looked at two substrates, gold and silicon. For the gold, we examined two …
P3: What Determines The Shape Of A Cloud?, William Calabrase
P3: What Determines The Shape Of A Cloud?, William Calabrase
Undergraduate Research Posters 2017
Current climate models and weather forecasts suffer due to an uncertainty associated with the behavior of clouds, which directly impact the energy exchange between the earth and the Sun. This impact is determined in part by the shape of the clouds, thereby making the study of what affects cloud shape an area of interest. To characterize the shape of cumulus clouds we study the behavior of the cloud overlap ratio, or the ratio between the average cloud fraction and projected cloud cover. In this study, we used a high resolution computer model to 1) determine how the cloud overlap ratio …
P2: Reconciling Linear Measurements Of Fractal Cloud Structures, Nicholas Barron
P2: Reconciling Linear Measurements Of Fractal Cloud Structures, Nicholas Barron
Undergraduate Research Posters 2017
Clouds are a large unknown in meteorological predictions. Most of the issue can be derived from the odd shape of clouds. So, in order to correct the measurements of clouds, a thorough investigation of fractal cloud structures must be performed. Using the results from this study, a reconciliation method can then be constructed and applied to linear measurements of clouds.
P1: How High Does The Lower Atmosphere Go?, Vladimir Sworski, Justin Flaherty
P1: How High Does The Lower Atmosphere Go?, Vladimir Sworski, Justin Flaherty
Undergraduate Research Posters 2017
The Atmospheric Boundary Layer (ABL), consisting of the bottom few kilometers of the troposphere, is a region with strong mixing of moisture and winds. This region's activity has a large impact on weather and climate models. In this study, we use a high resolution computer model: Large Eddy Simulation (LES). Statistics produced require a strong understanding of the height of the ABL. The purpose of this study was to create a method for determining this height accurately and consistently, as previous models demonstrated significant error.
P1: Using Modified Dean Flow Designs To Increase Mixing Performance, Joshua Clark
P1: Using Modified Dean Flow Designs To Increase Mixing Performance, Joshua Clark
Undergraduate Research Posters 2017
We are using numerical solutions for the Navier-Stokes equations and the concentration - diffusion equation to model fluid flow and reactant distribution in serpentine type channels for micromixers/microreactors development. These mixers exploit centripetal forces on the fluid to induce cross-sectional fluid mixing, aka Dean flows. Various modifications are used to increase the mixing character of these crosssectional flows. We found that the performance of these mixers exceeds that of unmodified channels and we currently assess their performance relative to other state of the art methodologies used to induce mixing on the microscale.
P2: Implementation Of Groove Based Designs For Engineering Fluid Flow In Micromixers, Tahir Butt
P2: Implementation Of Groove Based Designs For Engineering Fluid Flow In Micromixers, Tahir Butt
Undergraduate Research Posters 2017
Mixing on microscale is important for the development of miniaturized chemical reactors that use small quantities of reactants and allow better control over the reaction conditions and products. Nevertheless, achieving rapid mixing in this type of micro-reactors is challenging due to the lack of turbulence and slow diffusion on the microscale. In this work we implement micromixers designs based on surface groove/ridge patterns targeted at inducing cross-sectional flows that both extend the interface between the different reactants, as well as induce chaotic advection. We discuss the fabrication of these structures using soft-lithography in PDMS employing a mold and their optical …
P2: Developing Methodologies For Wet-Sample Electron Microscopy Imaging, Daniel Terrano, Petru Fodor
P2: Developing Methodologies For Wet-Sample Electron Microscopy Imaging, Daniel Terrano, Petru Fodor
Undergraduate Research Posters 2017
Scanning Electron Microscopy (SEM) is widely used to analyze the size, shape, and composition of material systems. However, using this tool for analyzing systems such as particles suspended in solution requires drastic sample alterations, such as precipitation and fixation. Besides altering their environment, this exposes the particles to the harsh conditions within an electron microscope, such as high vacuum and electron beam exposure. To this end, the first goal of this study was to develop methodologies for imaging wet samples using electron microscopy. This is realized by creating a sandwich structure containing the solution of interest between a partially electron …
Purification And Crystallization Trials Of The Dihydroorotase From Methanococcus Jannaschii, Amy K. Dadisman
Purification And Crystallization Trials Of The Dihydroorotase From Methanococcus Jannaschii, Amy K. Dadisman
Undergraduate Research Posters 2017
Dihydroorotase is the enzyme that catalyzes the third step of the de novo biosynthesis of pyrimidines. M. jannaschii is a hyperthermophillic archaeon that can serve as a model organism for research purposes. This experiment is a first step toward elucidating the structure of the dihydroorotase in M. jannaschii. The enzyme was purified by salting out and heating the solution and then putting the supernatant through cation exchange chromatography and hydrophobic interaction chromatography. Twenty-four conditions were tested to determine if a crystal of dihydroorotase could be formed. Two of these conditions led to preliminary crystal formation. These findings can be utilized …
Cgils Phase 2 Les Intercomparison Of Response Of Subtropical Marine Low Cloud Regimes To Co2 Quadrupling And A Cmip3 Composite Forcing Change, Peter N. Blossey, Christopher S. Bretherton, Anning Cheng, Satoshi Endo, Thijs Heus, Adrian P. Lock, Johan J. Van Der Dussen
Cgils Phase 2 Les Intercomparison Of Response Of Subtropical Marine Low Cloud Regimes To Co2 Quadrupling And A Cmip3 Composite Forcing Change, Peter N. Blossey, Christopher S. Bretherton, Anning Cheng, Satoshi Endo, Thijs Heus, Adrian P. Lock, Johan J. Van Der Dussen
Physics Faculty Publications
© 2016. The Authors. Phase 1 of the CGILS large-eddy simulation (LES) intercomparison is extended to understand if subtropical marine boundary-layer clouds respond to idealized climate perturbations consistently in six LES models. Here the responses to quadrupled carbon dioxide (“fast adjustment”) and to a composite climate perturbation representative of CMIP3 multimodel mean 2×CO2 near-equilibrium conditions are analyzed. As in Phase 1, the LES is run to equilibrium using specified steady summertime forcings representative of three locations in the Northeast Pacific Ocean in shallow well-mixed stratocumulus, decoupled stratocumulus, and shallow cumulus cloud regimes. The results are generally consistent with a single-LES …
What Determines The Fate Of Rising Parcels In A Heterogeneous Environment?, Maren Brast, Roel A.J. Neggers, Thijs Heus
What Determines The Fate Of Rising Parcels In A Heterogeneous Environment?, Maren Brast, Roel A.J. Neggers, Thijs Heus
Physics Faculty Publications
© 2016. The Authors. We investigate the potential impact of the local environment on rising parcels in a convective boundary layer. To this end, we use data from an LES simulation of a shallow convective cloud field to feed a parcel model with a range of different local environments, representative of the heterogeneous environment inside a shallow cumulus cloud layer. With this method we can study the statistics of an ensemble of rising parcels, but also the behavior of individual parcels. Through the use of a heterogeneous environment, the interactions between different parcels are indirectly represented. The method, despite its …
Hif Stabilization Weakens Primary Cilia, Andrew Resnick
Hif Stabilization Weakens Primary Cilia, Andrew Resnick
Physics Faculty Publications
© 2016 Andrew Resnick. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Although solitary or sensory cilia are present in most cells of the body and their existence has been known since the sixties, very little is known about their functions. One suspected function is fluid flow sensing-physical bending of cilia produces an influx of Ca++, which can then result in a variety of activated signaling pathways. Defective cilia and ciliary-associated proteins have been …
Factors Controlling Stratocumulus Cloud Lifetime Over Coastal Land, Mohamed S. Ghonima, Thijs Heus, Joel R. Norris, Jan Kleissl
Factors Controlling Stratocumulus Cloud Lifetime Over Coastal Land, Mohamed S. Ghonima, Thijs Heus, Joel R. Norris, Jan Kleissl
Physics Faculty Publications
The breakup of stratocumulus clouds over coastal land areas is studied using a combination of large-eddy simulations (LESs) and mixed-layer models (MLMs) with a focus on mechanisms regulating the timing of the breakup. In contrast with stratocumulus over ocean, strong sensible heat flux over land prevents the cloud layer from decoupling during day. As the cloud thins during day, turbulence generated by surface flux becomes larger than turbulence generated by longwave cooling across the cloud layer. To capture this shift in turbulence generation in the MLM, an existing entrainment parameterization is extended. The MLM is able to mimic cloud evolution …
Consequences Of The Angular Spectrum Decomposition Of A Focused Beam, Including Slower Than C Beam Propagation, Gérard Gouesbet, James A. Lock
Consequences Of The Angular Spectrum Decomposition Of A Focused Beam, Including Slower Than C Beam Propagation, Gérard Gouesbet, James A. Lock
Physics Faculty Publications
When dealing with light scattering and propagation of an electromagnetic beam, there are essentially two kinds of expansions which have been used to describe the incident beam (i) a discrete expansion involving beam shape coefficients and (ii) a continuous expansion in terms of an angular spectrum of plane waves. In this paper, we demonstrate that the angular spectrum decomposition readily leads to two important consequences, (i) laser light beams travel in free space with an effective velocity that is smaller than the speed of light c, and (ii) the optical theorem does not hold for arbitrary shaped beams, both …
First-Principles Definition And Measurement Of Planetary Electromagnetic-Energy Budget, Michael I. Mishchenko, James A. Lock, Andrew A. Lacis, Larry D. Travis, Brian Cairns
First-Principles Definition And Measurement Of Planetary Electromagnetic-Energy Budget, Michael I. Mishchenko, James A. Lock, Andrew A. Lacis, Larry D. Travis, Brian Cairns
Physics Faculty Publications
The imperative to quantify the Earths electromagnetic-energy budget with an extremely high accuracy has been widely recognized but has never been formulated in the framework of fundamental physics. In this paper we give a first-principles definition of the planetary electromagnetic-energy budget using the Poynting- vector formalism and discuss how it can, in principle, be measured. Our derivation is based on an absolute minimum of theoretical assumptions, is free of outdated notions of phenomenological radiometry, and naturally leads to the conceptual formulation of an instrument called the double hemispherical cavity radiometer (DHCR). The practical measurement of the planetary energy budget would …
Large-Eddy Simulation Of The Transient And Near-Equilibrium Behavior Of Precipitating Shallow Convection, Axel Seifert, Thijs Heus, Robert Pincus, Bjorn Stevens
Large-Eddy Simulation Of The Transient And Near-Equilibrium Behavior Of Precipitating Shallow Convection, Axel Seifert, Thijs Heus, Robert Pincus, Bjorn Stevens
Physics Faculty Publications
Large-eddy simulation is used to study the sensitivity of trade wind cumulus clouds to perturbations in cloud droplet number concentrations. We find that the trade wind cumulus system approaches a radiative-convective equilibrium state, modified by net warming and drying from imposed large-scale advective forcing. The system requires several days to reach equilibrium when cooling rates are specified but much less time, and with less sensitivity to cloud droplet number density, when radiation depends realistically on the vertical distribution of water vapor. The transient behavior and the properties of the near-equilibrium cloud field depend on the microphysical state and therefore on …
Overlap Statistics Of Shallow Boundary Layer Clouds: Comparing Ground-Based Observations With Large-Eddy Simulations, G. Corbetta, E. Orlandi, Thijs Heus, Roel Neggers, S. Crewell
Overlap Statistics Of Shallow Boundary Layer Clouds: Comparing Ground-Based Observations With Large-Eddy Simulations, G. Corbetta, E. Orlandi, Thijs Heus, Roel Neggers, S. Crewell
Physics Faculty Publications
High-resolution ground-based measurements are used to assess the realism of fine-scale numerical simulations of shallow cumulus cloud fields. The overlap statistics of cumuli as produced by large-eddy simulations (LES) are confronted with Cloudnet data sets at the Jülich Observatory for Cloud Evolution. The Cloudnet pixel is small enough to detect cumuliform cloud overlap. Cloud fraction masks are derived for five different cases, using gridded time-height data sets at various temporal and vertical resolutions. The overlap ratio (R), i.e., the ratio between cloud fraction by volume and by area, is studied as a function of the vertical resolution. Good agreement is …
Mechanical Properties Of A Primary Cilium As Measured By Resonant Oscillation, Andrew Resnick
Mechanical Properties Of A Primary Cilium As Measured By Resonant Oscillation, Andrew Resnick
Physics Faculty Publications
Primary cilia are ubiquitous mammalian cellular substructures implicated in an ever-increasing number of regulatory pathways. The well-established ciliary hypothesis states that physical bending of the cilium (for example, due to fluid flow) initiates signaling cascades, yet the mechanical properties of the cilium remain incompletely measured, resulting in confusion regarding the biological significance of flow-induced ciliary mechanotransduction. In this work we measure the mechanical properties of a primary cilium by using an optical trap to induce resonant oscillation of the structure. Our data indicate 1) the primary cilium is not a simple cantilevered beam; 2) the base of the cilium may …
A Model For The Force Exerted On A Primary Cilium By An Optical Trap And The Resulting Deformation, Ian Lofgren, Andrew Resnick
A Model For The Force Exerted On A Primary Cilium By An Optical Trap And The Resulting Deformation, Ian Lofgren, Andrew Resnick
Physics Faculty Publications
Cilia are slender flexible structures extending from the cell body; genetically similar to flagella. Although their existence has been long known, the mechanical and functional properties of non-motile (“primary”) cilia are largely unknown. Optical traps are a non-contact method of applying a localized force to microscopic objects and an ideal tool for the study of ciliary mechanics. We present a method to measure the mechanical properties of a cilium using an analytic model of a flexible, anchored cylinder held within an optical trap. The force density is found using the discrete-dipole approximation. Utilizing Euler-Bernoulli beam theory, we then integrate this …
Reconciling And Validating The Cloud Thickness And Liquid Water Path Tendencies, Mohamed S. Ghonima, Joel R. Norris, Thijs Heus, Jan Kleissl
Reconciling And Validating The Cloud Thickness And Liquid Water Path Tendencies, Mohamed S. Ghonima, Joel R. Norris, Thijs Heus, Jan Kleissl
Physics Faculty Publications
A detailed derivation of stratocumulus cloud thickness and liquid water path tendencies as a function of the well-mixed boundary layer mass, heat, and moisture budget equations is presented. The derivation corrects an error in the cloud thickness tendency equation derived by R. Wood to make it consistent with the liquid water path tendency equation derived by J. J. van der Dussen et al. The validity of the tendency equations is then tested against the output of large-eddy simulations of a typical stratocumulus-topped boundary layer case and is found to be in good agreement.