Showing papers in "Atmospheric Research in 1998"

TL;DR: A comparative evaluation of the different de-icing techniques, already developed and in development, which could be applied to the conductors and wires of electric power lines, based on energy efficiency and practicability suggests to favor the mechanical techniques over thermal methods that have been developed, but require more energy.

TL;DR: In this paper, the authors evaluated the existing widely used models of power line icing in freezing precipitation and pointed out that none of the models is both correct and complete in predicting design glaze ice loads.

TL;DR: In this paper, a new microphysical scheme that uses lognormal basis functions to represent cloud and drizzle. drop spectra is presented and incorporated in a two-dimensional 2D eddy-resolving model and applied to the simulation of a stratocumulus cloud deck based on a sounding from the Atlantic StratocUMulus Transition Experiment.

TL;DR: In this article, a simple ice load model that can be used to make conservative back-of-the-envelope calculations of ice loads based on the precipitation rate and wind speed is presented.

TL;DR: In this article, the explicit mixing parcel model (EMPM) is extended to explicitly account for individual droplet growth, and the model provides a 1D representation of physical properties within a cloud parcel and incorporates the rising of the cloud parcel, entrainment of environmental air into the parcel, finite-rate turbulent mixing parameterized by Kolmogorov inertial range scalings, and droplet growing.

TL;DR: In this paper, the authors used a Counterflow Virtual Impactor (CVA) to sample residual particles from evaporated ice crystals in both contrails and cirrus clouds and compared with interstitial aerosols found in natural cirrus.

TL;DR: In this article, the size distribution of polycyclic aromatic hydrocarbons (PAHs) in aerosol samples collected with a Berner-type nine-stage cascade impactor was determined.

TL;DR: In this paper, the authors compare and discuss the validation of rainfall estimates from five methods, at various space and time scales, at the Sahelian Africa region, where a network of about 580 raingauges is available and a small region covering Burkina-Faso where the Raingauge network is denser, with 58 RAGs in a 2.5°×3° area.

TL;DR: In this article, a nonlinear finite element analysis software (ADINA) was used to calculate the static and dynamic effects of ice-shedding on a two-span line section and a total of 21 ice shedding scenarios with variables including: ice thickness, span length, difference in elevation between end and suspension points, number of spans per line section, presence of unequal spans and partial ice shedding on sub-spans.

TL;DR: In this paper, the relationship between radar echoes aloft and precipitation at ground level is investigated and a three-step procedure for extracting information from the radar image in real time is presented.

TL;DR: In this paper, the average ice crystal size, defined as the ratio of total volume to the total projected area, can wellcharacterize the effect of various size distributions in determining the bulk radiative properties of cirrus clouds.

TL;DR: In this article, three observed cases of convection are simulated each with different precipitation production mechanisms, as deduced by the multiparameter radar at Chilbolton, and four simulations are carried out of each case, using different representations of precipitation.

TL;DR: In this article, the kinematic and microphysical aspects of precipitation formation are revisited and a conceptual model introduced that provides a basis for an improved understanding of differences observed in convective and stratiform rainfall.

TL;DR: In this paper, a variable timestep version of the kinetic solver (QSSA) was proposed to solve the problem of mass transfer in a real kinetic form, and the modified version was revealed to be more accurate than the basic version of QSSA.

TL;DR: In this paper, the effect of torsional vibration on the lift force of a two-dimensional cylindrical cylinder was investigated. But the effect was not considered for thin ice accretions.

TL;DR: In this article, the results of a widely used bulk treatment and five versions of a detailed microphysical model are presented to investigate the effect of bulk parametrization, ice initiation technique, CCN concentration and collision efficiency of rimed ice crystal-drop collision.

TL;DR: In this paper, a theory of the formation of water droplets on aerosol particles consisting of soluble inorganic salts and organic (soluble, insoluble and surface active) substances has been developed.

TL;DR: In this paper, the formation of relative velocities between low-density ice particles and the surrounding air within a turbulent medium is analyzed, and it is shown that an increase in relative velocity between particles leads to an increase of the swept volume and the collision kernel.

TL;DR: In this paper, the results from simultaneous collection and chemical analysis (including F−, Cl−, NO3−, SO42−, HCOO−, CH3COO+, Na+, NH4+, K+, Ca2+, Mg2+, pH) of spring rain, mold rain and typhoon rain during 1990 and 1991 in the region of Xiamen, Quanzhou, Zhangzhou and Tongan, which is called ''Minnan Golden Triangle'' and is a rapidly growing urban area in the southeastern Coast of China.

TL;DR: In this article, surface observations of freezing precipitation and pilot reports of severe in-flight aircraft icing for the continental United States are compared to the location of surface weather features, including airmasses of different origin and position relative to fronts, low-pressure centers and troughs.

TL;DR: In this article, a critique of one-dimensional models of boundary layer turbulence is presented, and it is shown that existing methods of coupling bin-microphysical models to the turbulence model omit important terms involving covariances of perturbation quantities.

TL;DR: In this paper, the authors describe a two-dimensional kinematic framework designed to test warm rain microphysical models based on a case study from the Hawaiian Rainband Project (1990).

TL;DR: In this paper, a new digital holographic camera is compared with PMS 2D-C measurements during the Canadian Freezing Drizzle Experiment, showing that the digital camera does not see the artificial tail.

TL;DR: In this paper, an optical spectrometer within the melting layer of stratiform precipitation was used to measure the number flux density of snowflakes and raindrops, and strong evidence was found for aggregation of hydrometeors within the upper part of a melting layer and breakup within the lower part.

TL;DR: In this paper, two procedures of conversion (and conversion errors) are considered in this paper assuming the steady state of charge distribution, and the comparison of results shows a promising agreement between the measured and calculated size spectra in the common size range.

TL;DR: In this article, the authors present data about the concentration and size distribution of ions in atmospheric aerosol under slightly polluted urban conditions in Hungary for 8 particle size range between 0.0625 and 16 μm.

TL;DR: In this article, the satellite data from the Stratospheric Aerosol and Gas Experiment (SAGE) II was used to study cloud vertical distribution, including thickness and multilayer structure, and to estimate cloud optical depth.

TL;DR: In this article, the authors analyzed the motion of water drops and graupel particles within a turbulent medium, where the turbulence is assumed to be homogeneous and isotropic.

TL;DR: In this article, the chemical conversion of emitted SO 2 and SO 3 to gaseous H 2 SO 4 in nascent aircraft exhaust plumes and subsequent adsorption of the fully oxidized sulfur species on the surfaces of emitted combustion aerosols (soot) is investigated.