Showing papers in "Atmospheric Research in 1994"

TL;DR: In this paper, a parameterization scheme is presented by which coagulation growth of drops is simulated, oriented at the common parameterization idea of partitioning the total water substance in a cloud water and a rainwater portion.

TL;DR: In this article, the authors measured the measured radiance to the theoretically calculated radiance from clouds having various microphysical properties, and estimated the likelihood for precipitation formation processes is then estimated and verified against actual observations of precipitation, using a weather radar.

TL;DR: In this article, a new optical sensor, PVM-100A, for aircraft cloud-microphysical measurements is described, which measures the liquid water content (LWC), the integrated particle surface area (PSA), and the effective droplet radius of cloud droplets.

TL;DR: In this paper, the authors used the geometric optics approximation to evaluate the scattering, absorption and polarization properties of hexagonal ice crystals whose sizes are much larger than the incident wavelength, and demonstrated that the radiative forcing at the top of the atmosphere involving most cirrus clouds is positive, implying that the IR greenhouse effect outweighs the solar albedo effect.

TL;DR: The relationship between Ka-band (0.86 cm) equivalent radar reflectivity factor Z e (mm 6 /m 3 ) and cirrus cloud ice content and ice crystal precipitation content IWC (mg/ m 3 ) are developed through regression analyses by utilizing a numerical scheme that combines the conjugate gradient and the fast Fourier transform method (CG-FFT) and the Rayleigh approximation, to calculate backscattering.

TL;DR: In this article, a three dimensional model for simulating the effect of enhanced cloud condensation nucleus (CCN) concentrations on stratocumulus clouds is presented, which is a large-scale simulation version of the Regional Atmospheric Modeling System (RAMS) with explicit representation of the CCN spectrum and cloud droplet spectrum.

TL;DR: In this paper, the authors investigated the characteristics of tropical high clouds based on the 1989 Stratospheric Aerosol and Gas Experiment (SAGE II) particulate extinction measurements and the National Meteorological Center (NMC) temperature data.

TL;DR: In this article, 11 flights of the C-130 of the Meteorological Research Flight, in several different cloud types and air masses, have been used to determine the ratio of the mass of ice to water in mixed phase clouds.

TL;DR: Several measuring methods using various properties of radar signals to estimate rainfall rate R are reviewed in this article, including measurements of the radar reflectivity factor Z at one or two polarizations, on measurements of attenuation A or on a combination of these two quantities.

TL;DR: In this paper, a preliminary analysis of the vertical distribution of clouds based on these observations is presented, and a mean cirrus thickness of just under 1 km has been observed with a mean altitude of about 80 percent of the tropopause height.

TL;DR: In this article, a 2D dynamic model including spectral microphysics and a detailed treatment of the scavenging and processing of (NH 4 ) 2 SO 4 and NaCl aerosol particles as well as SO 2, H 2 O 2, and O 3 has been evaluated for a warm precipitating convective cloud at Day 261 (September 18, 1974) of the GATE campaign.

TL;DR: A large-scale, long-term physical climatology of hailfalls is being installed in southwestern France, one of the severely hailed regions in the world as discussed by the authors, and the first five years of operation of this network have enabled the organization of a suitable standardization of the data.

TL;DR: In this paper, a satellite method for estimating precipitation using infrared and microwave data is proposed, which takes advantage of both, the good time and space resolution of infrared satellite images and the rain related information retrieved from microwave images.

TL;DR: In this paper, the results from a numerical simulation of a stratocumulus cloud-topped boundary layer (CTBL) based on a newly developed model that includes 3-D LES dynamical framework and explicit formulation of cloud microphysics are presented.

TL;DR: In this paper, the rapid initial precipitation growth and initial electrification of a convective cloud, growing as a new cell on the upshear side of a cloud system in Florida, is traced from radar data and aircraft penetrations at the −7°C to −10°C level.

TL;DR: In this article, a three-dimensional, time-dependent, non-hydrostatic model is used to simulate the microphysical processes in an intense supercell storm that passed through the Cooperative Convective Precipitation Experiment (CCOPE) network on 2 August 1981.

TL;DR: In this paper, the magnitude of correlation between measures of the same quantity by different processes is defined by an equation that accounts for standard errors of estimates, the range of values, and the density distribution function.

TL;DR: In this article, a three-dimensional radiative transfer model based on the discrete-ordinates method for application to atmospheric radiation and remote sensing is developed, which has the capabilities to address one-, two-and three dimensional rectangular parallelepiped geometries containing nonhomogeneous, absorbing, emitting, anisotropic scattering media.

TL;DR: In-situ measurements with the counterflow virtual impactor (CVI) during the ICE-89 campaign are presented in this paper, which include measurements of size distribution of ice crystal residues and independent measurements of crystal number concentration and cloud water content.

TL;DR: In this paper, simulated soft hail (graupel) particles are grown in a laboratory chamber and evaporated under controlled conditions of wind speed, temperature and under-substance.

TL;DR: In this article, the results of studying droplet size distributions in stratiform clouds (St, Sc, As, Ac, Ns) over the USSR obtained with a FSSP-100 (PMS).

TL;DR: In this article, a 2D cumulus ensemble model was used to simulate the trade cumulus boundary layer (TCBL) and the authors compared profiles of the apparent heat source and the apparent moisture sink with profiles obtained from BOMEX observations and found good agreement.

TL;DR: In this article, a calculation of cloud susceptibility, defined as the increase in albedo resulting from the addition of one cloud drop per cubic centimeter (as cloud liquid water content remains constant), is made through satellite remote sensing of cloud drop radius and optical thickness.

TL;DR: In this paper, the shape of cloud and precipitation hydrometeors observed with PMS 2D probes is analyzed using simple and easily generated geometric measures of individual hydrometeor images, combined over the observed population of images, to give new measures which can be related to the dominant hydrometer growth mode, crystal habit and size distribution of the population.

TL;DR: In this paper, the measurements of cloud condensation nuclei, CCN, concentration (both in cloud-free air mass and within clouds-interstitial CCN), cloud droplet size distribution and liquid water content are reported for three cloud episodes observed in Mount Mitchell (38°44'05″N, 82°17'15″W, 2038 m MSL - highest peak in eastern U.S.A.) State Park, North Carolina.

TL;DR: In this paper, an analytical solution to the collisional problem of atmospheric particles is presented based on the potential flow theory and takes into account the effects of the non-frictional flow outside the boundary layer.

TL;DR: In this paper, a mobile aerosol sampling facility was employed on the NCAR Sabreliner research aircraft to take aerosol samples from the vicinity of cirrus clouds over Colorado and Wyoming.

TL;DR: In this paper, the evolution of multicell convective clouds in a shear-free environment is investigated with a high-resolution explicit microphysical cloud model, where rotation is generated in the merging clouds without the agency of the Coriolis force or an ambient wind shear.

TL;DR: In this article, the authors show that under some conditions radiation and convection can interact nonlinearly to produce spontaneous temporal fluctuations on "large scales" and provide evidence that this can, indeed, happen.