[1] The effect of cloud droplet sedimentation on the entrainment rate and liquid water path of a nocturnal nondrizzling stratocumulus layer is examined using largeeddy simulations (LES) with bulk microphysics. In agreement with a prior study by Ackerman et al. (2004), sedimentation is found to decrease entrainment rate and thereby increase liquid water path. They suggested this is due to reduction of boundary-layer turbulence. Our simulations suggest otherwise. Instead, sedimentation reduces entrainment by removing liquid water from the entrainment zone. This inhibits two mechanisms that promote the sinking of entrained air into the cloud layerentrainment-induced evaporative cooling and longwave radiative cooling. A sensitivity study shows that the radiative effect is less important than the reduced evaporation. A possible parameterization of the effect of sedimentation on entrainment rate in a mixed layer model is proposed and tested. Since the droplet sedimentation rate is inversely related to cloud droplet (and presumably aerosol) concentration and nearly nondrizzling marine stratocumulus are widespread, sedimentation impacts on stratocumulus entrainment efficiency should be considered in climate model simulations of the aerosol indirect effect. Citation: Bretherton, C. S., P. N.Blossey, and J. Uchida (2007), Cloud droplet sedimentation, entrainment efficiency, and subtropical stratocumulus albedo, Geophys. Res. Lett., 34, L03813,

Since the discovery of the liquid-crystalline state in 1888, liquid crystal science has made great advances through fusion with various technologies and disciplines. Recently, new molecular design strategies and new self-assembled structures have been developed as a result of the progress made in synthetic procedures and characterization techniques. Since these liquid crystals exhibit new functions and properties derived from their nanostructures and alignment, a variety of new functions for liquid crystals, such as transport for energy applications, separation for environmental applications, chromism, sensing, electrooptical effects, actuation, and templating have been proposed. This Review presents recent advances of liquid crystals that should contribute to the next generation of materials.

In this study, a new method is proposed for the depiction of the atmospheric transportation of the 137 Cs. However, significant differences were found in some cases, and this suggests the need to improve the modeling of the emission scenario, plume height, wet deposition process, and plume propagation in the Abukuma Mountain region. The contributions of these error sources differ in the early and dissipating phases of each event, depending on the meteorological conditions.

In marine stratocumulus-capped boundary layers under strong inversions, the timescale for thermodynamic adjustment is roughly a day, much shorter than the multiday timescale for inversion height adjustment. Slow-manifold analysis is introduced to exploit this timescale separation when boundary layer air columns experience only slow changes in their boundary conditions. Its essence is that the thermodynamic structure of the boundary layer remains approximately slaved to its inversion height and the instantaneous boundary conditions; this slaved structure determines the entrainment rate and hence the slow evolution of the inversion height and can be regarded as a one-dimensional slow manifold. Slow-manifold analysis is applied to mixed-layer model and large-eddy simulations of an idealized nocturnal stratocumulus-capped boundary layer. Both models are found to have multiple equilibria; depending on the initial inversion height, the simulations slowly evolve toward a shallow thin-cloud boundary layer or a deep, well-mixed thick cloud boundary layer. In the mixed-layer model, this can be described using a single slow manifold bifurcated by an unstable equilibrium inversion height which separates a branch that evolves toward a deep steady state from a branch which shallows indefinitely. In the large-eddy simulations, there are two separate slow manifolds (one of which becomes unstable if cloud droplet concentration is reduced). On one, the boundary layer is well-mixed and deepens to a thick-cloud steady state. On the other, the boundary layer is decoupled and shallows to a thin-cloud steady state. If the initial inversion height supports an optically thick but nearly nondrizzling cloud, it evolves onto the wellmixed manifold; if the initial cloud layer is either too thin to efficiently radiatively cool, or thick enough to heavily drizzle, it evolves onto the decoupled manifold. Applications to analysis of stratocumulus observations and to pockets of open cells and ship tracks are proposed.

Liquid crystals have been intensively studied as functional materials. Recently, integration of various disciplines has led to new directions in the design of functional liquid‐crystalline materials in the fields of energy, water, photonics, actuation, sensing, and biotechnology. Here, recent advances in functional liquid crystals based on polymers, supramolecular complexes, gels, colloids, and inorganic‐based hybrids are reviewed, from design strategies to functionalization of these materials and interfaces. New insights into liquid crystals provided by significant progress in advanced measurements and computational simulations, which enhance new design and functionalization of liquid‐crystalline materials, are also discussed.

The design and functions of liquid-crystalline (LC) polymers with classifying them into conventional-, supramolecular-, dendriticand network-type LC polymers are described. LC polymers show new functions as new devices in the field of energy and environment by incorporating mesogenic moieties exhibiting photonic, electronic and ionic functions. Supramolecular LC polymers show dynamic and unique properties because the mesogenic moieties are built with non-covalent interactions. Dendritic-type LC polymers exhibit liquid crystallinity by nanosegregation of aromatic and aliphatic moieties. Dendritic fork-like mesogens have also been prepared. A variety of nonmesogeic functional building blocks including fullerene, π-conjugated moieties, catenane, rotaxane and others can be incorporated into LC phases by attaching these dendritic moieties. LC networks are constructed in situ polymerization of polymerizable nematic or nanostructured liquid crystals. The specific characteristics of the LC networks have generated new research trends to develop well-defined polymers that exhibit optical, transport and separation properties. In these materials, through suitable design of LC monomers, the preservation of smectic, columnar and bicontinuous cubic phases has been successfully used for the development of membranes with one-dimensional, two-dimensional and three-dimensional nanostructures.

[1] This study presents an intercomparison of single-column model simulations of a nocturnal heavily drizzling marine stratocumulus-topped boundary layer. Initial conditions and forcings are based on nocturnal flight observations off the coast of California during the DYCOMS-II field experiment. Differences in turbulent and microphysical parameterizations between models were isolated by slightly idealizing and standardizing the specification of surface and radiative fluxes. For most participating models, the case was run at both typical operational vertical resolution of about 100 m and also at high vertical resolution of about 10 m. As in prior stratocumulus intercomparisons, the simulations quickly develop considerable scatter in liquid water path (LWP) between models. However, the simulated dependence of cloud base drizzle fluxes on LWP in most models is broadly consistent with recent observations. Sensitivity tests with drizzle turned off show that drizzle substantially decreases LWP for many models. The sensitivity of entrainment rate to drizzle is more muted. Simulated LWP and entrainment are also sensitive to the inclusion of cloud droplet sedimentation. Many models underestimate the fraction of drizzle that evaporates below cloud base, which may distort the simulated feedbacks of drizzle on turbulence, entrainment, and LWP.

Supramolecular self-assembly of 24 forklike mesogenic ligands and 12 transition metal ions led to the formation of giant spherical coordination complexes that exhibit liquid-crystalline (LC) phases. Self-healing LC supramolecular gels were also obtained through the introduction of these LC nanostructured supramolecular giant spherical complexes into dynamic covalent networks formed by cross-linkers and bifunctional polymers. The giant spherical structures of the Pd complexes with 72 rodlike moieties on the periphery were characterized by NMR, diffusion-ordered NMR spectroscopy, and mass spectrometry. These complexes are stable and exhibit lyotropic LC behavior, while the mesogenic ligands show thermotropic LC properties. The self-assembled LC structures of the spherical complexes can be tuned by the length of the rodlike moieties.