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  • AERODYNAMICS  (546)
  • METEOROLOGY AND CLIMATOLOGY
  • 2020-2020
  • 1985-1989  (876)
  • 1925-1929
  • 1988  (876)
  • 1984
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  • 2020-2020
  • 1985-1989  (876)
  • 1925-1929
  • 1980-1984  (981)
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  • 1
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    A model of stationary gravity wave breakdown with convective adjustment (1988)
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    Publication Date: 2011-08-19
    Description: A steady WKB model of gravity wave propagation including convective adjustment is used to investigate approximations used in various gravity-wave parameterization schemes. First, it is shown that estimates of the wave breaking height assuming a single horizontal wavenumber gravity wave can lead to errors if the topography is not sinusoidal. Second, the model results show that the assumption that wave growth ceases with the onset of convection or shear instability is an oversimplification. Since convection appears first over a very limited spatial region of the wave field, the wave is initially unaffected by turbulent mixing. However, when the convection zone spreads over a large portion of the wave field the amplitude is constrained. Estimates of the heat flux by breaking gravity waves are used to develop a simple parameterization of the vertical diffusion in terms of the Reynolds stress.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 980-992
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  • 2
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    A generalization of Petterssen's frontogenesis function and its relation to the forcing of vertical motion (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The classic Peterssen frontogenesis function, defined as the Lagrangian rate of change of the magnitude of the potential temperature gradient, is generalized to apply to the vector potential temperature gradient. The derivation of vector frontogenesis in natural coordinates is shown, and analytical examples of frontal evolution in nondivergent horizontal velocity fields are given which suggest that both the frontogenetic and rotational components of the vector frontogenesis function F may be comparable in developing frontal zones observed in nature. The relative importance of the magnitude and direction contributions to F is quantitatively investigated, and it is found that the Lagrangian rates of change of the magnitude and direction of the potential temperature gradient are comparable. The frontal circulation is found to be related to the magnitude component of the Q vector, whereas the background circulation is related to the direction component.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 762-780
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  • 3
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    Effects of using a posteriori methods for the conservation of integral invariants (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The nature and effect of using a posteriori adjustments to nonconservative finite-difference schemes to enforce integral invariants of the corresponding analytic system are examined. The method of a posteriori integral constraint restoration is analyzed for the case of linear advection, and the harmonic response associated with the a posteriori adjustments is examined in detail. The conservative properties of the shallow water system are reviewed, and the constraint restoration algorithm applied to the shallow water equations are described. A comparison is made between forecasts obtained using implicit and a posteriori methods for the conservation of mass, energy, and potential enstrophy in the complete nonlinear shallow-water system.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 525-545
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  • 4
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    Assessment of polar climate change using satellite technology (1988)
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    Publication Date: 2011-08-19
    Description: Using results of selected studies, this paper highlights some of the problems that exist in the remote sensing of snow and ice, and demonstrates the importance of remote sensing for the study of snow and ice in determining the effect of temperature increase, due to the atmospheric CO2 increase, on the cryospheric features. Evidence obtained from NOAA, Nimbus, and other satellites, that may already indicate a global or at least a regional warming, includes an increase in permafrost temperature in northern Alaska and the retreat of many of the world's small glaciers in the last 100 years. It is emphasized that remote sensing is of major importance as the method of obtaining data for monitoring future changes in cryospheric features.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Reviews of Geophysics (ISSN 8755-1209); 26; 26-39
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  • 5
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    A proposed tropical rainfall measuring mission (TRMM) satellite (1988)
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    Publication Date: 2011-08-19
    Description: The proposed Tropical Rainfall Measuring Mission (TRMM) satellite (presently in its third year of planning), is described. The TRMM satellite, planned for an operational duration of at least three years beginning in the mid-1990s, is intended to obtain high-quality measurements of tropical precipitation by means of information derived from a quantitative spaceborne radar, a multichannel passive microwave radiometer, and an AVHRR. The satellite's orbit will be low-altitude (320 km), for high resolution, and low-inclination (30 to 35 deg), for making it possible to visit each sampling area twice a day. Radar and passive microwave algorithms and rain-retrieval algorithms to be used in precipitation measurements are discussed together with cloud dynamical models designed to test these algorithms.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: American Meteorological Society, Bulletin (ISSN 0003-0007); 69; 278-295
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  • 6
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    A satellite infrared technique to estimate tropical convective and stratiform rainfall (1988)
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    Publication Date: 2011-08-19
    Description: A new method of estimating both convective and stratiform precipitation from satellite infrared data is described. This technique defines convective cores and assigns rain rate and rain area to these features based on the infrared brightness temperature and the cloud model approach of Adler and Mack (1984). The method was tested for four south Florida cases during the second Florida Area Cumulus Experiment, and the results are presented and compared with three other satellite rain estimation schemes.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Applied Meteorology (ISSN 0733-3021); 27; 30-51
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  • 7
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    Genesis of Atlantic Lows Experiment (GALE) - An overview (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The field phase of the Genesis of Atlantic Lows Experiment (GALE) was conducted from 15 January to 15 March 1986. The objectives of GALE were to study mesoscale and air-sea interaction processes in East Coast winter storms, with particular emphasis on their contributions to cyclogenesis. This project area, specail observing systems, and field operations are described. There were thirteen special observing periods during the field phase including eight cases of cyclogenesis. Meterological and oceanographic phenomena on which special observations were collected include: cyclogenesis, rainbands, cold fronts, coastal fronts, cold-air damming, jets streaks, tropopause folding, low-level jets, cold-air outbreaks, lightning and marine boundary layer interactions with Gulf Stream and mid-shelf oceanic fronts. Preliminary research findings and operational implications are presented. GALE data documents are listed. The GALE data set is open to all interested scientists.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: American Meteorological Society, Bulletin (ISSN 0003-0007); 69; 148-160
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  • 8
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    Diagnostic study of explosive cyclogenesis during FGGE (1988)
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    Publication Date: 2011-08-19
    Description: Two rapidly developing extratropical maritime cyclones (one, developed during January 13-15, 1979, along an intense frontal zone south of Japan, the other, of January 26-27, 1979, in a polar mass over the North Atlantic) were investigated using the FGGE data and ECMWF level IIIb analyses to describe the structure and dynamics of these events. Although the cyclones evolved from a strong low-level baroclinic zone without initial large midtropospheric vorticity advection, thus resembling the Petterssen type A development, rapid deepening occurred in both cases when an approaching upper tropospheric jet with appreciable shear vorticity advection became favorably superposed over the surface low. During the development period, stability decreased in the low troposphere, aiding in the rapid development of an intense mass-circulation and low tropospheric vorticity production by the divergence term. The results suggest that upper-level forcing plays a greater role in the initiation of explosive oceanic development than is suggested by the Petterssen and Smebye (1971) description.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 431-451
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  • 9
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    Medium range lagged average forecasts (1988)
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    Publication Date: 2011-08-19
    Description: In this work, the application of the lagged average forecasting (LAF) technique to operational forecasts of the ECMWF is reported. The ECMWF data consist of two 100-day samples of 10-day forecasts of 500-mb geopotential height for winter 1980/81 and summer 1981. the LAF ensemble includes the latest operational forecast, and also forecast for the same verification time started one or more days earlier than the latest one. The focus is on the following two issues: (1) does ensemble averaging improve forecast skill and (2) is the dispersion of the ensemble useful in predicting forecast skill. The LAF technique was used to produce 3, 5, 7, 8, and 9 day forecasts of the 500-mb height field. The results show that the statistically filtered LAF is a marked improvment upon the operational forecast after 5 days. It is found that on a global scale, forecast skill is weakly correlated with the dispersion of the ensemble, as measured by the rms difference between the operational forecast and the statistically filtered LAF.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 402-416
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  • 10
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    Design of a nonsingular Level 2.5 second-order closure model for the prediction of atmospheric turbulence (1988)
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    Publication Date: 2011-08-19
    Description: The suitability of applying the Mellor and Yamada (1974, 1982) Level 2.5 second-order turbulence closure model to general circulation models is investigated by examining not only the scheme's simulation of fully (or nearly fully) developed turbulence, but also its simulation of rapidly growing or strongly decaying turbulence. The behavior of the model is presented over its entire domain of definition, with special consideration given to the pathologies of the model. The model is then modified for the case of growing turbulence to rectify some of its physical shortcomings for that case, and to remove the pathologies that prohibit its use in a general circulation model. The performance of the modified Level 2.5 model is compared to the performance of various other modified versions through the numerical simulation for a growing convective PBL. The results show that the modified Level 2.5 model is a viable candidate for the prediction of turbulence and the simulation of the PBL in general circulation models.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 113-132
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  • 11
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    The relative utility of persistence and medium-range dynamical forecasts of monthly mean 700 mb heights (1988)
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    Publication Date: 2011-08-19
    Description: The proposal of Harnack et al. (1986) that monthly 700-mb height anomalies can be predicted using simulated medium-range numerical forecasts is tested with actual numerical forecasts produced under strict operational conditions. These conditions included nonavailability of long model forecast histories from which to develop estimates of drift, frequent model changes over the period of the experiment, a requirement that each monthly forecast be made four days before the beginning of the month, and the use of only data which are available on the day of the forecast. The overall results and month-by-month results confirm the hypothesis of the Harnack group.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 266-268
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  • 12
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    Force and pressure study of thick cambered/twisted 58 deg delta wings (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 69-75
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  • 13
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    Progress in analysis and prediction of dynamic stall (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 6-17
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  • 14
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    Thin cirrus clouds - Seasonal distribution over oceans deduced from Nimbus-4 IRIS (1988)
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    Publication Date: 2011-08-19
    Description: Spectral differences in the extinction of the 10.8- and 12.6-micron bands of the IR window region, due to optically thin clouds, were found in the measurements made by both an airborne broadband IR radiometer and the IR interferometer spectrometer (IRIS) aboard the Nimbus-4 satellite; the extinction at 12.6 microns was significantly larger than that at 10.8 microns; both water and ice particles in the clouds can account for such spectral difference in extinction. Multiple scattering radiative transfer calculations of IRIS data revealed this spectral feature about 100 to 20 km away from the high-altitude cold clouds; it is assumed that this feature is related to the spreading of cirrus clouds. Based on this assumption, mean seasonal maps of the distribution of thin cirrus clouds over the oceans were deduced from the IRIS data. The maps show that such clouds are often present over the convectively active areas, such as ITCZ, SPCZ, and the Bay of Bengal during the summer monsoon.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Applied Meteorology (ISSN 0894-8763); 27; 379-399
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  • 15
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    Evapotranspiration from nonuniform surfaces - A first approach for short-term numerical weather prediction (1988)
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    Publication Date: 2011-08-19
    Description: Observations of surface heterogeneity of soil moisture from scales of meters to hundreds of kilometers are discussed, and a relationship between grid element size and soil moisture variability is presented. An evapotranspiration model is presented which accounts for the variability of soil moisture, standing surface water, and vegetation internal and stomatal resistance to moisture flow from the soil. The mean values and standard deviations of these parameters are required as input to the model. Tests of this model against field observations are reported, and extensive sensitivity tests are presented which explore the importance of including subgrid-scale variability in an evapotranspiration model.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 600-621
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  • 16
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    On the accuracy of monthly mean wind speeds over the equatorial Pacific (1988)
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    Publication Date: 2011-08-19
    Description: In this paper, yearlong in situ wind measurements at a 3.8-m height, obtained at three sites along the Pacific equator (95, 110, and 152 deg W), were used to estimate the number of random observations required per month for monthly mean wind speeds accurate to 1.0 m/s and 0.5 m/s. Wind measurements were made with a vector-averaging wind recorder mounted on a surface-following toroid float, which measured speed continuously, and direction nearly continuously. For equatorial Pacific winds in the 95 to 152 deg W region, the typical numbers of random wind observations required per month were found to be about nine for a 1.0 m/s accuracy, and 35 for a 0.5 m/s accuracy. The corresponding number of ship winds would likely be greater. The number of random observations required increased westward and was highly correlated with monthly mean standard deviations.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Atmospheric and Oceanic Technology (ISSN 0739-0572); 5; 362-367
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  • 17
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    First-guess dependence of a physically based set of temperature-humidity retrievals from HIRS2/MSU data (1988)
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    Publication Date: 2011-08-19
    Description: The first-guess dependence of temperature and humidity fields retrieved from HIRS2/MSU data using the GLA (Goddard Laboratory for Atmospheres) physically based retrieval scheme is examined. Retrievals were performed over the ALPEX region for two successive synoptic periods, 1200 UTC March 4 and 00000 UTC March 5, 1982, using three different initial guesses for each period. Results show rather low first-guess dependence for the thickness fields and larger first-guess dependence for the precipitable water fields, especially close to the surface. The humidity retrieval algorithm used is described. The processing system has the property of maintaining the accuracy of a good guess and improving a poor one for both thickness and precipitable water at all levels.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Atmospheric and Oceanic Technology (ISSN 0739-0572); 5; 70-83
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  • 18
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    A vertically integrated snow/ice model over land/sea for climate models. I - Development. II - Impact on orbital change experiments (1988)
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    Publication Date: 2011-08-19
    Description: A vertically integrated formulation (VIF) model for sea ice/snow and land snow is discussed which can simulate the nonlinear effects of heat storage and transfer through the layers of snow and ice. The VIF demonstates the accuracy of the multilayer formulation, while benefitting from the computational flexibility of linear formulations. In the second part, the model is implemented in a seasonal dynamic zonally averaged climate model. It is found that, in response to a change between extreme high and low summer insolation orbits, the winter orbital change dominates over the opposite summer change for sea ice. For snow over land the shorter but more pronounced summer orbital change is shown to dominate.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 93; 3663-367
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  • 19
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    Vacillations in a coupled ocean-atmosphere model (1988)
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    Publication Date: 2011-08-19
    Description: Results are presented from a 35-year integration of a coupled ocean-atmosphere model. Both ocean and atmosphere are two-level, nonlinear primitive equation models. The global atmospheric model is forced by a steady, zonally symmetric Newtonian heating. The ocean model is solved in a rectangular tropical basin. Heat fluxes between ocean and atmosphere are linear in air-sea temperature differences, and the interfacial stress is proportional to lower-level atmospheric winds. The coupled models produce ENSO-like variability on time scales of 3 to 5 years. Since there is no external time-dependent forcing, these are self-sustained vacillations of the nonlinear system. It is argued that the energetics of the vacillations is that of unstable coupled modes and that the time scale is crucially dependent on the effects of ocean waves propagating in a closed basin.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 549-566
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  • 20
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    The GISS global climate-middle atmosphere model. I - Model structure and climatology (1988)
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    Publication Date: 2011-08-19
    Description: A coupled global climate/middle atmosphere model (GCMAM) is developed by extending the Hansen et al. (1983) GISS global climate model to include the middle atmosphere up to 85 km. The model includes numerical solutions of the primitive equations, calculations of the radiative and surface fluxes, and a complete hydrologic cycle with convective and cloud-cover parameterizations. In addition, a parameterized gravity wave drag cycle is incorporated, in which gravity-wave momentum fluxes due to flow over topography, wind shear, and convection are calculated at each grid box, using theoretical relationships between the grid-scale variables and expected source strengths. The results of the GCMAM demonstrate that the model produces a reasonable simulation of the stratosphere. It is shown that the improvements over the previous version were achieved largely through the incorporation of the parameterized gravity wave drag.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 329-370
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  • 21
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    The GISS global climate-middle atmosphere model. II - Model variability due to interactions between planetary waves, the mean circulation and gravity wave drag (1988)
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    Publication Date: 2011-08-19
    Description: The variability which arises in the GISS Global Climate-Middle Atmosphere Model on two time scales is reviewed: interannual standard deviations, derived from the five-year control run, and intraseasonal variability as exemplified by statospheric warnings. The model's extratropical variability for both mean fields and eddy statistics appears reasonable when compared with observations, while the tropical wind variability near the stratopause may be excessive possibly, due to inertial oscillations. Both wave 1 and wave 2 warmings develop, with connections to tropospheric forcing. Variability on both time scales results from a complex set of interactions among planetary waves, the mean circulation, and gravity wave drag. Specific examples of these interactions are presented, which imply that variability in gravity wave forcing and drag may be an important component of the variability of the middle atmosphere.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 371-386
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  • 22
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    Two-component LDV investigation of three-dimensional shock/turbulent boundary-layer interactions (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 52-56
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  • 23
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    Trace gas exchanges and convective transports over the Amazonian rain forest (1988)
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    Publication Date: 2011-08-19
    Description: The NASA Amazon Boundary Layer Experiment (ABLE 2A) based in Manaus, Brazil, in July and August 1985, is used to examine meteorological processes responsible for the vertical and horizontal transport of biogenic and anthropogenic trace gases generated over the Amazon basin. Direct sampling of the surrounding environment of deep convective clouds shows marked changes in the vertical distribution of the lower and midtroposphere concentration of O3 and such surface-derived species as CO, CO2, and NO. Thermodynamic observations, together with two-dimensional cloud model simulations, confirm vertical transports within the convection and provide a basis for an estimation of the magnitude and efficiency of cloud upward and downward exchanges. A distinction is drawn between local changes due to convective updrafts and downdrafts and convective overturning as a net result of the storm processes. Marked variability is seen in trace gas concentrations along horizontal flight paths in the vicinity of the convection. Interpretation of simultaneously measured thermodynamic quantities and trace gas concentrations provide the information to infer the presence and direction of atmospheric transports and/or the presence of anthropogenic influences.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 93; 1528-155
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  • 24
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    Airborne lidar observations of Arctic polar stratospheric clouds - Indications of two distinct growth stages (1988)
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    Publication Date: 2011-08-19
    Description: Airborne lidar observations of Arctic polar stratospheric clouds (PSCs) during January 1984 and January 1986 show contrast suggestive of two distinct PSC growth stages delineated by the frost-point temperature. Results obtained at temperatures 2-6 K above the frost point indicate a stage of significant, but limited, particle growth such as proposed in recent models of PSC formation by co-deposition of HNO3 and H2O vapors. Results obtained at a temperature near the frost point indicate the formation of somewhat larger crystalline particles.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Geophysical Research Letters (ISSN 0094-8276); 15; 21-23
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  • 25
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    The estimation of precipitation intensity in the presence of surface backscatter and the converse using a spaceborne radar (1988)
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    Publication Date: 2011-08-19
    Description: The 'rain-modified' surface backscattering coefficient and the rain intensity can be estimated simultaneously by analyzing the return echo waveforms obtained by a nonnadir pointing spaceborne radar. Preliminary simulation results, using system parameters for the TRMM rain mapping radar, indicate that path-averaged rain attenuation coefficient can be estimated to 20 percent by such technique.
    Keywords: METEOROLOGY AND CLIMATOLOGY
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  • 26
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    Could modern forecasting techniques have predicted the blizzard of 1888? (1988)
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    Publication Date: 2011-08-19
    Description: Surface meteorological data for March 1888, which were collected at 170 stations across the U.S. three times a day, are combined with ship reports to construct a surface weather analysis for the blizzard of 1888. Surface weather charts are constructed to determine the ability of current forecasting techniques to predict the blizzard. The evolution of the storm is described in detail and current methods for treating a storm of similar intensity are discussed.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Earth in Space (ISSN 1040-3124); 1; 5-9
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  • 27
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    On air motion trajectories in cold fronts (1988)
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    Publication Date: 2011-08-19
    Description: This paper examines air parcel trajectories in the two-dimensional model for a cold front by Reeder and Smith (1987). These are found to be in close agreement with trajectories deduced from analyses of summertime 'cool changes' in southeastern Australia, adding further support to the applicability of the numerical model to this kind of cold front. The favorable comparison points also to the dynamical consistency of the conceptual model for the cool change, which has evolved from the analysis of data from observational experiments.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 4005-400
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  • 28
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    A comparison of a GCM simulation of the seasonal cycle of the atmosphere with observation. I - Mean fields and the annual harmonic. II - Stationary waves and transient fluctuations (1988)
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    Publication Date: 2011-08-19
    Description: The seasonal cycle of a GCM is analyzed in terms of the behavior of the monthly and seasonal mean fields and the structure of the annual harmonic. The GCM is found to be successful in simulating the Northern Hemisphere sea-level pressure and 200-mb heights over eastern continents and oceans and in the entire Southern Hemisphere. Problems in the simulation include an anomalously deep Aleutian low and low values of the height over Europe in winter. The GCM fails to show the observed amplitude of the annual harmonic in 200-mb temperature over Antarctica. In the second section, the seasonal dependence of the stationary and transient eddies of the GCM are presented for a two-year annual cycle. The accuracy of the wave and eddy simulations is analyzed.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Atmosphere - Ocean (ISSN 0705-5900); 26; 541-607
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  • 29
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    Unsteady transonic flow simulation on a full-span-wing-body configuration (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 1450-145
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    A mesoscale gravity wave event observed during CCOPE. III - Wave environment and probable source mechanisms (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The multiscale environment of gravity wave events and the probable mechanisms of their origin are examined on the basis of observations taken during the Cooperative Convective Precipitation Experiment in extreme eastern Montana, during the period from 1200 UTC July 11, 1981, to 0500 UTC July 12. During this time, two distinct gravity wave episodes were diagnosed. The results of the analysis of the evolving structures in the subsynoptic-scale and mesoscale environments indicate that the observed mesoscale gravity waves were generated by geostrophic adjustment processes, with additional energy supplied through interaction with the critical level; their coherence was maintained through a ducting mechanism.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2570-259
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    Sampling error study for rainfall estimate by satellite using a stochastic model (1988)
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    Publication Date: 2011-08-19
    Description: In a parameter study of satellite orbits, sampling errors of area-time averaged rain rate due to temporal sampling by satellites were estimated. The sampling characteristics were studied by accounting for the varying visiting intervals and varying fractions of averaging area on each visit as a function of the latitude of the grid box for a range of satellite orbital parameters. The sampling errors were estimated by a simple model based on the first-order Markov process of the time series of area averaged rain rates. For a satellite of nominal Tropical Rainfall Measuring Mission (Thiele, 1987) carrying an ideal scanning microwave radiometer for precipitation measurements, it is found that sampling error would be about 8 to 12 pct of estimated monthly mean rates over a grid box of 5 X 5 degrees. It is suggested that an observation system based on a low inclination satellite combined with a sunsynchronous satellite simultaneously might be the best candidate for making precipitation measurements from space.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Applied Meteorology (ISSN 0894-8763); 27; 1218-123
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    A GCM simulation study of the influence of Saharan evapotranspiration and surface-albedo anomalies on July circulation and rainfall (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The influence of surface albedo and evapotranspiration anomalies that could result from the hypothetical semiarid vegetation over North Africa on its July circulation and rainfall is examined using the Goddard Laboratory for Atmospheres GCM. It is shown that increased soil moisture and its dependent evapotranspiration produces a cooler and moister PBL over North Africa that is able to support enhanced moist convection and rainfall in Sahel and southern Sahara. It is found that lower surface albedo yields even higher moist static energy in the PBL and enhances the local moist convection and rainfall. Modifying the rain-evaporation parameterization in the model produces changes in the hydrological cycle and rainfall anomalies in distant regions. The effects of different falling rain parameterizations are discussed.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2388-240
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    The roles of dry convection, cloud-radiation feedback processes and the influence of recent improvements in the parameterization of convection in the GLA GCM (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The Goddard Laboratory for Atmospheres GCM is used to study the sensitivity of the simulated July circulation to modifications in the parameterization of dry and moist convection, evaporation from falling raindrops, and cloud-radiation interaction. It is shown that the Arakawa-Schubert (1974) cumulus parameterization and a more realistic dry convective mixing calculation yielded a better intertropical convergence zone over North Africa than the previous convection scheme. It is found that the physical mechanism for the improvement was the upward mixing of PBL moisture by vigorous dry convective mixing. A modified rain-evaporation parameterization which accounts for raindrop size distribution, the atmospheric relative humidity, and a typical spatial rainfall intensity distribution for convective rain was developed and implemented. This scheme led to major improvements in the monthly mean vertical profiles of relative humidity and temperature, convective and large-scale cloudiness, rainfall distributions, and mean relative humidity in the PBL.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2366-238
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    A model-based diagnostic study of the rapid development phase of the Presidents' Day cyclone (1988)
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    Publication Date: 2011-08-19
    Description: A model simulation of the rapid development phaser of the Presidents' Day cyclone on February 19, 1979, is studied. Model trajectories and Eulerian analyses show that, during this phase, three airstreams converge into the cyclogenetic region. The evolution of the PJ-trough system and its associated tropopause fold is described, including the simulated surface low and the vertical profile of mass divergence which contributes to the decreasing sea-level pressure. The various terms of the vorticity equation are evaluated to identify the processes contributing to the increase in absolute vorticity. The nature and origin of airstreams entering the low-level circulation associated with rapid cyclogenesis are examined from a Lagrangian perspective.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2337-236
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    Satellite-observed characteristics of midwest severe thunderstorm anvils (1988)
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    Publication Date: 2011-08-19
    Description: The cloud top and anvil structure of severe thunderstorms observed by the GOES satellite are analyzed for five SESAME cases in 1979 and four non-SESAME cases in 1980-1982. The data is compared with previous models and hypotheses, paying particular attention to the V feature and thermal couplets in the IR observations. The characteristics of the cases are examined and related to the upper-level temperature and wind conditions. It is found that the warm points downwind of the cloud top are due to subsidence. The anaylsis suggests the presence of subsidence due to mountainlike waves. A model in which the close-in warm point is produced by both internal cloud air motions and stratospheric flow around and over the cloud top. It is suggested that the distant warm point is due to either a wave perturbation from air flowing over the cloud top, or air flowing horizonatlly around the elevated portion of the cloud top and anvil.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2200-222
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  • 36
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    One-level modeling for diagnosing surface winds over complex terrain. II - Applicability to short-range forecasting (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The Alpert and Getenio (1988) modification of the Mass and Dempsey (1985) one-level sigma-surface model was used to study four synoptic events that included two winter cases (a Cyprus low and a Siberian high) and two summer cases. Results of statistical verification showed that the model is not only capable of diagnosing many details of surface mesoscale flow, but might also be useful for various applications which require operative short-range prediction of the diurnal changes of high-resolution surface flow over complex terrain, for example, in locating wildland fires, determining the dispersion of air pollutants, and predicting changes in wind energy or of surface wind for low-level air flights.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 2047-206
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  • 37
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    On the movement and low-level structure of cold fronts (1988)
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    Publication Date: 2011-08-19
    Description: Factors that are pertinent to the cold-front motion were examined using the results from previous studies of the low-level structure of cold fronts. Observational studies indicate the existence of two different types of behavior for a cold front. These types of behavior were related to the results of recent theoretical studies, and the mechanism responsible for front propagation was elucidated. It is shown that a necessary requirement for propagation is the existence of an alongfront temperature gradient.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 1927-194
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  • 38
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    Unsteady transonic aerodynamics and aeroelastic calculations at low-supersonic freestreams (1988)
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    Publication Date: 2011-08-19
    Description: A computational procedure is presented to simulate transonic unsteady flows and corresponding aeroelasticity of wings at low-supersonic freestreams. The flow is modeled by using the transonic small-perturbation theory. The structural equations of motions are modeled using modal equations of motion directly coupled with aerodynamics. Supersonic freestreams are simulated by properly accounting for the boundary conditions based on pressure waves along the flow characteristics in streamwise planes. The flow equations are solved using the time-accurate, alternating-direction implicit finite-difference scheme. The coupled aeroelastic equations of motion are solved by an integration procedure based on the time-accurate, linear-acceleration method. The flow modeling is verified by comparing calculations with experiments for both steady and unsteady flows at supersonic freestreams. The unsteady computations are made for oscillating wings. Comparisons of computed results with experiments show good agreement. Aeroelastic responses are computed for a rectangular wing at Mach numbers ranging from subtransonic to upper-transonic (supersonic) freestreams. The extension of the transonic dip into the upper transonic regime is illustrated.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 955-961
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  • 39
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    Further comparisons of interactive boundary-layer and thin-layer Navier-Stokes procedures (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 897-903
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  • 40
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    Transonic Navier-Stokes solutions for a fighter-like configuration (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 875-881
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  • 41
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    Sensitivity of a global climate model to the specification of convective updraft and downdraft mass fluxes (1988)
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    Publication Date: 2011-08-19
    Description: The response of the GISS global climate model to different parameterizations of moist convective mass flux is studied. A control run with arbitrarily specified updraft mass flux is compared to experiments predicting cumulus mass fulx on the basis of low-level convergence, convergence plus surface evaporation, or convergence and evaporation modified by varying boundary layer height. Also, an experiment that includes a simple parameterization of saturated convective-scale downdrafts is discussed. It is found that the model correctly simulates the correlation between deep convection strength and tropical sea surface temperature in each experiment with the parameterization of cumulus mass flux having little effect. The implications of the experiments for cloud effects on climate sensitivity are examined.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 2641-266
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  • 42
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    Experimental aerodynamic characteristics of an NACA 0012 airfoil with simulated glaze ice (1988)
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    Publication Date: 2011-08-19
    Description: The effect of a simulated glaze-ice accretion on the aerodynamic performance of a NACA 0012 airfoil was studied experimentally. Two ice shapes were tested: one from an experimentally measured accretion, and one from an accretion predicted using a computer model given the same icing conditions. Lift, drag, and pitching moment were measured for the airfoil with both smooth and rough ice shapes. The ice shapes caused large lift and drag penalties, primarily due to large separation bubbles. Surface pressure distributions clearly showed the regions of separated flow. The aerodynamic performance of the two shapes compared well at positive, but not negative, angles of attack.
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 849-854
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  • 43
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    Grid generation and inviscid flow computation about a cranked-winged airplane geometry (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 820-826
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  • 44
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    The Nimbus-7 Global Cloud Climatology (1988)
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    Publication Date: 2011-08-19
    Description: The Nimbus-7 Global Cloud Climatology (N7GCC) has been produced from measurements made between April 1979 and March 1985 using the Temperature Humidity IR Radiometer and the Total Ozone Mapping Spectrometer on the Nimbus-7 satellite. The N7GCC gives, near local noon and midnight, the fractional area covered by high-level, middle-level, and low-altitude clouds, and the total fractional area covered by all clouds. Statistics for cirrus, deep convective, and warm low-altitude clouds and the cloud and clear-sky radiances with correlative surface temperatures are also included. The N7GCC is compared with other cloud data sets, including the International Satellite Cloud Climatology Project.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: American Meteorological Society, Bulletin (ISSN 0003-0007); 69; 743-752
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  • 45
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    Heating rates in tropical anvils (1988)
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    Publication Date: 2011-08-19
    Description: The interaction of infrared and solar radiation with tropical cirrus anvils is addressed. Optical properties of the anvils are inferred from satellite observations and from high-altitude aircraft measurements. An infrared multiple-scattering model is used to compute heating rates in tropical anvils. Layer-average heating rates in 2 km thick anvils were found to be on the order of 20 to 30 K/day. The difference between heating rates at cloud bottom and cloud top ranges from 30 to 200 K/day, leading to convective instability in the anvil. The calculations are most sensitive to the assumed ice water content, but also are affected by the vertical distribution of ice water content and by the anvil thickness. Solar heating in anvils is shown to be less important than infrared heating but not negligible. The dynamical implications of the computed heating rates are also explored and it is concluded that the heating may have important consequences for upward mass transport in the tropics. The potential impact of tropical cirrus on the tropical energy balance and cloud forcing are discussed.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of the Atmospheric Sciences (ISSN 0022-4928); 45; 1606-162
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  • 46
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    Comparison of high-altitude remote aircraft measurements with the radar structure of an Oklahoma thunderstorm - Implications for precipitation estimation from space (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The present NASA ER-2 aircraft observations of an isolated group of thunderstorms over Oklahoma, encompassing passive radiometry in the visible, IR, and microwave portions of the spectrum obtained above the storm top, is compared with coincident data from two Doppler radars as well as aircraft-gathered in situ cloud top particle data. Reflectivity cores are found to be nearly colocated with cold anomalies in the microwave brightness temperature field. Theoretical considerations suggesting that microwave frequencies are sensitive to the deeper layer of large ice particles in the storm's convective region are supported.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 1157-117
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  • 47
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    Effects of surface roughness on two Shuttle Orbiter models (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 349-354
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  • 48
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    Thermal environment of transatmospheric vehicles (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 355-363
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  • 49
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    Unsteady low-speed aerodynamic model for complete aircraft configurations (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 302-310
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  • 50
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    Passive venting system for modifying cavity flowfields at supersonic speeds (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: The drag of airfoils in transonic flow can be reduced through the use of a passive venting system that employs a porous plate for part of the airfoil upper surface with a vent chamber underneath the porous plate Attention is given to the results obtained with a wind tunnel model employing such a porous floor system. This passive venting system has been used to extend the length/height value before the onset of high drag-producing closed cavity flow at supersonic speeds.
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 374-376
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  • 51
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    Vortex shedding in high-speed compressor blade wakes (1988)
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    Publication Date: 2011-08-19
    Description: The wakes of highly loaded compressor blades are generally considered to be turbulent flows. Recent work has suggested that the blade wakes are dominated by a vortex streetlike structure. The experimental evidence supporting the wake vortex structure is reviewed. This structure is shown to redistribute thermal energy within the flowfield. The effect of the wake structure on conventional aerodynamic measurements of compressor performance is noted. A two-dimensional, time-accurate, viscous numerical simulation of the flow exhibits both vortex shedding in the wake and a lower-frequency flow instability that modulates the shedding. The numerical results are shown to agree quite well with the measurement from transonic compressor rotors.
    Keywords: AERODYNAMICS
    Type: Journal of Propulsion and Power (ISSN 0748-4658); 4; 236-244
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    Comparison of cloud amounts derived using GOES and Landsat data (1988)
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    Publication Date: 2011-08-19
    Description: A hybrid bispectral threshold method (HBTM) is presently used to compare cloud amounts derived from Landsat digital data over 22 regions having various cloud types with cloudiness information obtained from collocated, nearly-simultaneous 4 x 8-km GOES visible and IR data. A sensitivity analysis indicates that an rms underestimation of about 0.01 in clear sky reflectance by the HBTM increased the GOES cloud amount by 0.06, which is more than twice the decrese in cloud amount obtained by an equivalent increase in clear-sky reflectance. Landsat imagery and cloud properties derived from the Landsat data are used to explain how the partially cloud-filled GOES pixels were treated by the HBTM. It is found that the HBTM accounts for the effects of partially cloud-filled FOVs in most cases of the present study.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 93; 9385-940
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    Prediction of oscillating thick cambered aerofoil aerodynamics by a locally analytic method (1988)
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    Publication Date: 2011-08-19
    Description: The effects of mean-flow incidence, airfoil camber, and airfoil thickness on the incompressible aerodynamics of an oscillating airfoil are investigated theoretically, developing and applying a first-order FEM based on locally analytical solutions (LASs). Laplace equations are used to describe the steady and unsteady harmonic velocity potentials; a body-fitted computational grid is employed; grid-element solutions for both potentials are determined using a numerical LAS method; and the LASs are then assembled to obtain a complete solution. Results for a series of flat-plate and Joukowski airfoils are presented in extensive graphs and discussed in detail.
    Keywords: AERODYNAMICS
    Type: International Journal for Numerical Methods in Fluids (ISSN 0271-2091); 8; 913-931
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    Mesoscale spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical model simulations (1988)
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    Publication Date: 2011-08-19
    Description: It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation mesoscale model with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 1374-138
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    Fluctuation statistics of outgoing longwave radiation in a general circulation model and in satellite data (1988)
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    Publication Date: 2011-08-19
    Description: Fluctuation statistics of Northern-Hemisphere-winter outgoing longwave radiation (OLR) obtained from data collected by Nimbus 7 and NOAA AVHRR are compared with those computed by a general circulation model (GCM). It was found that the GCM OLR has more variance than does the satellite, but that the GCM clear-sky OLR has less variance than the satellite OLR. The variance of the GCM outgoing full-sky OLR was found to be forced by clouds. While the standard deviation of the GCM full OLR is larger than that of the satellite OLR, the geographical patterns of both are similar. The autocorrelations of the modeled and the observed OLR also display similar geographical distributions, and they are in turn correlated with the dynamics.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Monthly Weather Review (ISSN 0027-0644); 116; 1540-155
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  • 56
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    Multigrid solution of the two-dimensional Euler equations on unstructured triangular meshes (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 824-831
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  • 57
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    Comparison of LIMS temperatures and geostrophic winds with Berlin radiosonde temperature and wind measurements (1988)
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    Publication Date: 2011-08-19
    Description: The temperature and the derived winds obtained from the LIMS Map Archival Tape data for the period of October 25, 1978, to May 28, 1979, were compared with corresponding data from the Berin (Tempelhof) radiosonde station at several representative levels in the stratosphere, to assess the quality of the LIMS satellite data for use in dynamics and transport studies. It was found, on the basis of this single-station time series comparison, that the synoptically mapped LIMS temperature and wind analyses are of a sufficiently high quality for investigating large-scale dynamics in the stratosphere in conjunction with high-resolution radiosonde measurements.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Geophysical Research (ISSN 0148-0227); 93; 11217-11
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    Multigrid acceleration of the flux-split Euler equations (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 649-654
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  • 59
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    Vortical flow over an elliptical-body missile at high angles of attack (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Spacecraft and Rockets (ISSN 0022-4650); 25; 24-30
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  • 60
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    Lidar observations of the fine-scale variability of marine stratocumulus clouds (1988)
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    Publication Date: 2011-08-19
    Description: An Nd:YAG lidar system was flown aboard NASA's ER-2 high altitude aircraft. Observations of cloud top height were made with 70 m along-track and 7.5 m vertical-height resolution. The lidar data observed from an East Pacific stratocumulus cloud height deck revealed large cloud variability on 1-5 km scales. The cloud deck sloped upward from 700 to 1000 m in a northeast-southwest direction over a distance of 120 km. Vertical cloud top distributions were negatively skewed indicating flat-topped clouds. The dominant spectral peak of the cloud top variations was found at 4.5 km, which is 5 to 7 times the depth of the local boundary layer. No other peaks were significant in the average spectrum. The cloud layer was stable with respect to cloud top entrainment instability. The southwestern region of the study area was more prone to shear instability at cloud top than the northeastern region. The results of this study show that a lidar system is ideal to provide the topography of clouds and local boundary layer depth. This information is useful in the study of cloud top radiation and parameterization of clouds in numerical models.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Journal of Applied Meteorology (ISSN 0894-8763); 27; 797-810
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    Theory of idealized two-dimensional ballute in Newtonian hypersonic flow (1988)
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Spacecraft and Rockets (ISSN 0022-4650); 25; 217-224
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    The morphology and meteorology of Southern Hemisphere spring total ozone mini-holes (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: Two case studies of miniholes, rapid ozone decreases, noted in 1987 near the base of the Antarctic peninsula are studied using a digital filter. The results show a strong correlation of the total ozone minihole with a temperature minihole (a negative temperature perturbation), and a westward tilt with altitude of the temperature minihole. The ozone minihole is phase shifted both slightly to the east of a high in the geopotential height field and slightly to the west of a local low in the Ertel potential vorticity field.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Geophysical Research Letters (ISSN 0094-8276); 15; 923-926
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  • 63
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    Incompressible Navier-Stokes computations for a round-edged double-delta wing (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 675
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  • 64
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    Transonic characteristics of a humped airfoil (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 673
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  • 65
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    Prediction of incidence effects on oscillating airfoil aerodynamics by a locally analytical method (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: A complete mathematical model is formulated to analyze the effects of mean-flow incidence angle on the unsteady aerodynamics of an oscillating airfoil in an incompressible flow field. A velocity potential formulation is utilized. The steady flow is independent of the unsteady flow field but coupled to it through the boundary conditions on the oscillating airfoil. The numerical solution technique for both the steady and unsteady flow fields is based on a locally analytical method. The flow model and solution method are then verified through the excellent correlation obtained with the Theodorsen oscillating-flat-plate and Sears transverse-gust classical solutions. The effects of mean flow incidence on the steady and oscillating airfoil aerodynamics are then investigated.
    Keywords: AERODYNAMICS
    Type: International Journal for Numerical Methods in Engineering (ISSN 0029-5981); 26; 2227-223
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  • 66
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    Efficient algorithm for solution of the unsteady transonic small-disturbance equation (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: Journal of Aircraft (ISSN 0021-8669); 25; 598-605
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  • 67
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    Study of multibody aerodynamic interference at transonic Mach numbers (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 553-560
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  • 68
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    A thin-layer solution of the flow about a prolate spheroid (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: Computational results are presented for the transitional or turbulent flow about a prolate spheroid, at alpha = 10 deg or 30 deg, correspondingly, using an implicit, approximately factored, partially flux-split algorithm, based on the thin-layer equations. The computed flow field is in good agreement with available experimental data.
    Keywords: AERODYNAMICS
    Type: Zeitschrift fuer Flugwissenschaften und Weltraumforschung (ISSN 0342-068X); 12; 173-180
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  • 69
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    Turbulent viscous drag reduction with thin-element riblets (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: Thin-element riblets for aircraft aerodynamic surface turbulent viscous drag reduction are presently found to be as effective as symmetric V-grooves in this role, while possessing a greater range of admissible spacings. The thin-element geometry shows the qualitatively predictable influence of independent riblet height and spacing variations. The evidence for more than one drag-reduction mechanism in thin-element riblets is found to be inconclusive.
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 496-498
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  • 70
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    Rarefaction effects for hypersonic re-entry flow (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Keywords: AERODYNAMICS
    Type: AIAA Journal (ISSN 0001-1452); 26; 392
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  • 71
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    An overview of hypersonic aerothermodynamics (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: This paper briefly reviews some national studies and new programs concerning hypersonic flight. The flight environment that will be encountered by this new class of hypersonic vehicles is described, and the fluid-dynamic and chemical phenomena that occur in hypersonic flight are examined. Ground-based facilities are briefly described, and their use in helping to validate the codes is examined.
    Keywords: AERODYNAMICS
    Type: Communications in Applied Numerical Methods (ISSN 0748-8025); 4; 319-325
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  • 72
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    Entropy and vorticity corrections for transonic flows (1988)
    In:  Other Sources
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    Publication Date: 2011-08-19
    Description: Different models for inviscid transonic flows are examined. The common assumptions that the flow is isentropic and irrotational are critically evaluated. Entropy and vorticity correction procedures for potential and stream function formulations are presented, together with the details of the treatment of shocks and wakes, and drag and lift calculations. The non-uniqueness problem of the potential formulation is studied using different artificial viscosity forms. Numerical results are compared with Euler solutions.
    Keywords: AERODYNAMICS
    Type: International Journal for Numerical Methods in Fluids (ISSN 0271-2091); 8; 31-53
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  • 73
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    Drag measurements on a laminar flow body of revolution in Langley's 13 inch magnetic suspension and balance system (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Low-speed wind tunnel drag force measurements were taken on a laminar flow body of revolution free of support interference. This body was tested at zero incidence in the NASA Langley 13 inch Magnetic Suspension and Balance System (MSBS). The primary objective of these tests was to substantiate the drag force measuring capabilities of the 13 inch MSBS. A secondary objective was to obtain support interference free drag measurements on an axisymmetric body of interest. Both objectives were met. The drag force calibrations and wind-on repeatability data provide a means of assessing the drag force measuring capabilities of the 13 inch MSBS. The measured drag coefficients for this body are of interest to researchers actively involved in designing minimum drag fuselage shapes. Additional investigations included: the effects of fixing transition; the effects of fins installed in the tail; surface flow visualizations using both liquid crystals and oil flow; and base pressure measurements using a one-channel telemetry system. Two drag prediction codes were used to assess their usefulness in estimating overall body drag. These theoretical results did not compare well with the measured values because of the following: incorrect or non-existent modeling of a laminar separation bubble on the body and incorrect of non-existent estimates of base pressure drag.
    Keywords: AERODYNAMICS
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    Comparative verification between GEM model and official aviation terminal forecasts (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The Generalized Exponential Markov (GEM) model uses the local standard airways observation (SAO) to predict hour-by-hour the following elements: temperature, pressure, dew point depression, first and second cloud-layer height and amount, ceiling, total cloud amount, visibility, wind, and present weather conditions. GEM is superior to persistence at all projections for all elements in a large independent sample. A minute-by-minute GEM forecasting system utilizing the Automated Weather Observation System (AWOS) is under development.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 133-138
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  • 75
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    Aircraft/lidar turbulence comparison (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Very good agreement between remotely sensed winds using a ground-based Doppler lidar and in situ measurements with an instrumented aircraft is possible. Results show that turbulence intensities computed from time histories measured with the aircraft and time histories of the radial wind measured with lidar can be analyzed statistically to provide turbulence intensities and turbulence spectra which agree well with one another. The results further show that the second moment data, as presently compared with the NASA/MSFC algorithms, do not provide meaningful comparisons with turbulence intensities measured with the aircraft. This disagreement, however, must be investigated further in terms of the accuracy of the second moment data determined by both the lidar hardware and the algorithm for computing the second moment.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 103-113
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  • 76
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    National plans for aircraft icing and improved aircraft icing forecasts and associated warning services (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Recently, the United States has increased its activities related to aircraft icing in numerous fields: ice phobics, revised characterization of icing conditions, instrument development/evaluation, de-ice/anti-ice devices, simulated supercooled clouds, computer simulation and flight tests. The Federal Coordinator for Meteorology is involved in two efforts, one a National Plan on Aircraft Icing and the other a plan for Improved Aircraft Icing Forecasts and Associated Warning Services. These two plans will provide an approved structure for future U.S. activities related to aircraft icing. The recommended activities will significantly improve the position of government agencies to perform mandated activities and to enable U.S. manufacturers to be competitive in the world market.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 121-123
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  • 77
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    Objective detection and forecasting of Clear-Air Turbulence (CAT): A status report (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Clear-air turbulence has become the largest single cause of weather-related injuries occurring in commercial carriers at cruising altitudes. A technique for objective operational CAT detection (the SCATR index) has been formulated. Its physical basis ties CAT to total energy dissipation as a response to meso- and synoptic-scale dynamical processes associated with upper-level jet stream/frontal zones. Early case studies using properly analyzed routine RAOB rawinsonde sounding data have shown promise.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 125-132
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  • 78
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    Special observations (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The wind or temperature profiler is a new special observation device designed to supplement traditional atmospheric measurement and provide more accurate middle-range forecasts, including aviation and space applications. Radar is most useful in the short, nowcast time frame. Satellites and surface observations are also most useful for short-range forecasts but have less impact on the longer range. The radiosonde network, on the other hand, only starts to be very important after about six hours and has greatest impact at lead times of 12 hours or more. In the wind profiler, wind is measured by using clear-air Doppler radar principles, Two fixed beams, pointing 15 deg to the north and 15 deg to the east, sense the Doppler shift. The resulting wind vectors are then rotated to the horizontal and combined to give total wind. The temperature profiler measures temperature and humidity by using passive radiometers. Development on the profiler is 95 percent complete, and on the temperature profiler 75 percent complete.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 53-65
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  • 79
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    Automation of surface observations program (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: At present, surface weather observing methods are still largely manual and labor intensive. Through the nationwide implementation of Automated Surface Observing Systems (ASOS), this situation can be improved. Two ASOS capability levels are planned. The first is a basic-level system which will automatically observe the weather parameters essential for aviation operations and will operate either with or without supplemental contributions by an observer. The second is a more fully automated, stand-alone system which will observe and report the full range of weather parameters and will operate primarily in the unattended mode. Approximately 250 systems are planned by the end of the decade. When deployed, these systems will generate the standard hourly and special long-line transmitted weather observations, as well as provide continuous weather information direct to airport users. Specific ASOS configurations will vary depending upon whether the operation is unattended, minimally attended, or fully attended. The major functions of ASOS are data collection, data processing, product distribution, and system control. The program phases of development, demonstration, production system acquisition, and operational implementation are described.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 25-39
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  • 80
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    Optimization of slender wings for center-of-pressure shift due to change in Mach number (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: It is observed that the center of pressure on a wing shifts as the Mach number is changed. Such shifts are in general undesirable and are sometimes compensated for by actively shifting the center of gravity of the aircraft or by using active stability controls. To avoid this complication, it is desirable to design the wings of a high speed aircraft so as to minimize the extent of the center-of-pressure shifts. This, together with a desire to minimize the center-of-pressure shifts in missile control surfaces, provides the motivation for this project. There are many design parameters which affect center-of-pressure shifts, but it is expected that the largest effects are due to the wing planform. Thus, for the sake of simplicity, this study is confined to an investigation of thin, flat, (i.e., no camber or twist), relatively slender, pointed wings flying at a small angle of attack. Once the dependence of the center of pressure on planform and Mach number is understood, we can expect to investigate the sensitivity of the center-of-pressure shifts to various other parameters.
    Keywords: AERODYNAMICS
    Type: Hampton Inst., NASA/American Society for Engineering Educ; Hampton Inst., NASA(
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  • 81
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    Texture-based cloud classification (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The purpose of the 1988 ASEE Summer Program has been to broaden the application of texture-based cloud classification approaches to lower spatial resolution GOES imagery, and to design texture-based approaches for determining cloud cover over high albedo surfaces.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Hampton Inst., NASA/American Society for Engineering Ed; Hampton Inst., NASA(
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    Approaches to non-linear aerodynamic analysis and design (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Within the last two decades, there has been increasing emphasis on developing more sophisticated computational fluid dynamics (CFD) methods to handle a wide range of problems of interest to the aerospace community. The comprehensive picture of the status of CFD development and capability as well as an assessment of requirements and future directions are given. An independent review and assessment was also carried out by the author as part of the current assignment and the results are outlined herein.
    Keywords: AERODYNAMICS
    Type: Hampton Inst., NASA/American Society for Engineering Educ; Hampton Inst., NASA(
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  • 83
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    Rainfall on microwave return from the sea surface (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The long range goal remains unchanged; to conduct experiments and develop/test theoretical models to permit useful algorithms to be constructed for microwave systems that observe oceanic processes. This topic is relevant to altimeters, scatterometers, and rain rate measurements. The current focus is attention to scatterometer wind velocity measurement. One component of the laboratory efforts is an experiment conducted, in the wind wave tank at the GSFC/WFF, to quantify the effect of rain-generated surface wave brightening of radar cross section. Laboratory conditions can be characterized as light wind, functional rain rates, a single drop size, and a 36 GHz radar system at 30 degrees inclination.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Laboratory for Oceans; p 157-158
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  • 84
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    Water vapor profiling using microwave radiometry (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Water vapor is one of the most important constituents in the Earth's atmosphere. Its spatial and temporal variations affect a wide spectrum of meteorological phenomena ranging from the formation of clouds to the development of severe storms. The passive microwave technique offers an excellent means for water vapor measurements. It can provide both day and night coverage under most cloud conditions. Two water vapor absorption features, at 22 and 183 GHz, were explored in the past years. The line strengths of these features differ by nearly two orders of magnitude. As a consequence, the techniques and the final products of water vapor measurements are also quite different. The research effort in the past few years was to improve and extend the retrieval algorithm to the measurements of water vapor profiles under cloudy conditions. In addition, the retrieval of total precipitable water using 183 GHz measurements, but in a manner analogous to the use of 22 GHz measurements, to increase measurement sensitivity for atmospheres of very low moisture content was also explored.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Laboratory for Oceans; p 165-167
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    Tropical Rainfall Measurement Mission (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: It has long been noted that anomalies in the sea surface temperature (SST) in the tropics are strongly correlated with climate in the temperate latitudes on a seasonal time scale. The ability to measure the global SST and the atmospheric pressure/temperature patterns has made great progress. However, rainfall measurement, the putative connection between the two, is poorly accomplished. The Tropical Rainfall Measurement Mission (TRMM) was conceived to fill this gap. The TRMM spacecraft would fly in a low inclination, (about 35 deg), orbit which would concentrate the sampling in the very important tropical latitudes. The precession of such an orbit would enable observations at all times of the day over the span of a month which would permit corrections for the diurnal cycle of precipitation which is quite marked in parts of the tropics. The payload of the TRMM spacecraft is carefully designed to provide accurate measurements of rain. It consists of microwave radiometers, a microwave radar and visible/infrared radiometer. The two types of microwave instruments provide direct measurements of the hydrometeors, each having strengths which compensate for weaknesses of the other. The VIS/IR instrument provides a connection to the long time series of VIS/IR measurements from polar and Geosynchronous spacecraft which are currently the best available source of global rainfall estimates. The TRMM is currently in a phase A (feasibility) study.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Laboratory for Oceans; p 37-40
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    NASA follow-on on the Fiji South Pacific Severe Storm Warning System Project (SPSSD/WS) (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The follow-on agreement will implement needed systems enhancements of the satellite ground station installed under the previous SPSSD/WS project. These enhancements include the purchase and installation of an Uninterruptible Power Supply (UPS) and lightning protection unit, hardware modifications to provide system redundancy and increased data storage capacity, software modifications for the new Japanese GMS digital data, upgrades of the image processing software, and both hardware maintenance and tropical cyclone analysis training, and a non-renewable grant to provide emergency field repairs and replacement/spare parts. In March 1988, the UPS and lightning protection unit was installed at the Fiji Meteorological Service by NASA personnel. A tape recorder and demodulator was shipped to Fiji to record the new digital GMS data. Data tapes are not yet available from the Japanese Meteorological Service of the new digital format. This data is required to test the GMS digital software being developed for the Fiji SPSSD/WS facility.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Laboratory for Oceans; p 31-33
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    Computational unsteady aerodynamics for lifting surfaces (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Two dimensional problems are solved using numerical techniques. Navier-Stokes equations are studied both in the vorticity-stream function formulation which appears to be the optimal choice for two dimensional problems, using a storage approach, and in the velocity pressure formulation which minimizes the number of unknowns in three dimensional problems. Analysis shows that compact centered conservative second order schemes for the vorticity equation are the most robust for high Reynolds number flows. Serious difficulties remain in the choice of turbulent models, to keep reasonable CPU efficiency.
    Keywords: AERODYNAMICS
    Type: VKI, Unsteady Aerodynamics, Volume 2; 120 p
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  • 88
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    CFD application to supersonic/hypersonic inlet airframe integration (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Supersonic external compression inlets are introduced, and the computational fluid dynamics (CFD) codes and tests needed to study flow associated with these inlets are outlined. Normal shock wave turbulent boundary layer interaction is discussed. Boundary layer control is considered. Glancing sidewall shock interaction is treated. The CFD validation of hypersonic inlet configurations is explained. Scramjet inlet modules are shown.
    Keywords: AERODYNAMICS
    Type: VKI, Intake Aerodynamics, Volume 2; 62 p
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    CFD application to subsonic inlet airframe integration (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: The fluid dynamics of curved diffuser duct flows of military aircraft is discussed. Three-dimensional parabolized Navier-Stokes analysis, and experiment techniques are reviewed. Flow measurements and pressure distributions are shown. Velocity vectors, and the effects of vortex generators are considered.
    Keywords: AERODYNAMICS
    Type: VKI, Intake Aerodynamics, Volume 2; 59 p
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  • 90
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    Computational methods for inlet airframe integration (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Fundamental equations encountered in computational fluid dynamics (CFD), and analyses used for internal flow are introduced. Irrotational flow; Euler equations; boundary layers; parabolized Navier-Stokes equations; and time averaged Navier-Stokes equations are treated. Assumptions made and solution methods are outlined, with examples. The overall status of CFD in propulsion is indicated.
    Keywords: AERODYNAMICS
    Type: VKI, Intake Aerodynamics, Volume 2; 43 p
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  • 91
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    Use of the Terminal Area Simulation System (TASS) to study microburst wind shears (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Ground-based and airborne Doppler radar and LIDAR systems are being designed to alert pilots when a hazardous windshear is present. A key element in this design effort is understanding the microburst itself. This is accomplished by means of the TASS model which was developed for NASA by Proctor (1987a,b). The time-dependent TASS model has two vesions: a two-demensional high resolution axisymmetric model, and a three-demensional model. The model includes a sophisticated parameterization of cloud microphysics and a friction layer, both of which are essential to a realistic simulation of the microburst phenomenon. The TASS model has been successfully tested on well-observed convective events.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Hampton Inst., NASA/American Society for Engineering Educ; Hampton Inst., NASA(
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  • 92
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    Numerical investigation of a jet in ground effect using the fortified Navier-Stokes scheme (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: One of the flows inherent in VSTOL operations, the jet in ground effect with a crossflow, is studied using the Fortified Navier-Stokes (FNS) scheme. Through comparison of the simulation results and the experimental data, and through the variation of the flow parameters (in the simulation) a number of interesting characteristics of the flow have been observed. For example, it appears that the forward penetration of the ground vortex is a strong inverse function of the level of mixing in the ground vortex. Also, an effort has been made to isolate issues which require additional work in order to improve the numerical simulation of the jet in ground effect flow. The FNS approach simplifies the simulation of a single jet in ground effect, but it will be even more effective in applications to more complex topologies.
    Keywords: AERODYNAMICS
    Type: The 1987 Ground Vortex Workshop; p 191-206
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  • 93
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    F-15 SMTD low speed jet effects wind tunnel test results (1988)
    In:  CASI
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    Publication Date: 2013-08-31
    Description: Key results from low speed wind tunnel testing of the F-15 STOL and Maneuver Technology Demonstrator (SMDT) with thrust reversers are presented. Longitudinally, the largest induced increments in the stability and control occur at landing gear height. These generally reflect an induced lift loss and a nose-up pitching moment, and vary with sideslip. Directional stability is reduced at landing gear height with full reverse thrust. Nonlinearities in the horizontal tail effectiveness are found in free air and at landing gear height.
    Keywords: AERODYNAMICS
    Type: NASA, Ames Research Center, The 1987 Ground Vortex Workshop; p 91-119
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  • 94
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    An assessment of ground effects determined by static and dynamic testing techniques (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: A new testing technique was developed wherein the rate of descent can be included as a parameter in ground effects investigations. This technique simulates the rate of descent by horizontal motion of a model over an inclined ground board in the Langley Vortex Research Facility (VRF) During initial evaluations of the technique, dynamic ground effects data were obtained over the inclined ground board, steady state ground effects data were obtained over a flat portion of the ground board, and the results were compared to conventional static wind tunnel ground effect data both with and without a moving belt ground plane simulation. Initial testing and analysis led to the following conclusions: the moving belt ground plane had little effect on static ground effects for the configurations tested unless thrust reversers were employed; in general, rate-of-descent reduced ground effects to the point that for reversed thrust cases an expected loss of lift due to ground effects was eliminated at approach conditions; and, in general, the steady state results from the VRF matched static results obtained from the wind tunnel once the flow field stabilized over the flat portion of the ground board.
    Keywords: AERODYNAMICS
    Type: NASA, Ames Research Center, The 1987 Ground Vortex Workshop; p 121-146
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  • 95
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    Summary of an experimental investigation on the ground vortex (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The results of an experimental investigation into the position and characteristics of the ground vortex are summarized. A 48-inch wind tunnel was modified to create a testing environment suitable for the ground vortex study. Flow visualization was used to document the jet-crossflow interaction and a two-component Laser Doppler Velocimeter (LDV) was used to survey the flowfield in detail. Measurements of the ground vortex characteristics and location as a function of freestream-to-jet velocity ratio, jet height, pressure gradient and upstream boundary layer thickness were obtained.
    Keywords: AERODYNAMICS
    Type: NASA, Ames Research Center, The 1987 Ground Vortex Workshop; p 39-60
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  • 96
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    Ground vortex flow field investigation (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Flow field investigations were conducted at the NASA Ames-Dryden Flow Visualization Facility (water tunnel) to investigate the ground effect produced by the impingement of jets from aircraft nozzles on a ground board in a STOL operation. Effects on the overall flow field with both a stationary and a moving ground board were photographed and compared with similar data found in other references. Nozzle jet impingement angles, nozzle and inlet interaction, side-by-side nozzles, nozzles in tandem, and nozzles and inlets mounted on a flat plate model were investigated. Results show that the wall jet that generates the ground effect is unsteady and the boundary between the ground vortex flow field and the free-stream flow is unsteady. Additionally, the forward projection of the ground vortex flow field with a moving ground board is one-third less than that measured over a fixed ground board. Results also showed that inlets did not alter the ground vortex flow field.
    Keywords: AERODYNAMICS
    Type: The 1987 Ground Vortex Workshop; p 61-90
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  • 97
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    The characteristics of the ground vortex and its effect on the aerodynamics of the STOL configuration (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The interaction of the free stream velocity on the wall jet formed by the impingement of deflected engine thrust results in a rolled up vortex which exerts sizable forces on a short takeoff (STOL) airplane configuration. Some data suggest that the boundary layer under the free stream ahead of the configuration may be important in determining the extent of the travel of the wall jet into the oncoming stream. Here, early studies of the ground vortex are examined, and those results are compared to some later data obtained with moving a model over a fixed ground board. The effect of the ground vortex on the aerodynamic characteristics are discussed.
    Keywords: AERODYNAMICS
    Type: The 1987 Ground Vortex Workshop; p 1-38
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  • 98
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    Applications products of aviation forecast models (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: A service called the Optimum Path Aircraft Routing System (OPARS) supplies products based on output data from the Naval Oceanographic Global Atmospheric Prediction System (NOGAPS), a model run on a Cyber-205 computer. Temperatures and winds are extracted from the surface to 100 mb, approximately 55,000 ft. Forecast winds are available in six-hour time steps.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 67-77
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  • 99
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    Bracknell Meteorological Office (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The Bracknell (U.K.) Meteorological Office runs a global weather model twice a day, providing the following data: surface and radiosonde; aircraft reports; and satellite soundings and wind. A human forecast is made every six hours. The model runs on a 150 km grid with 15 levels, and takes about four minutes on a Cyber-205. The standard output from the global products are wind, temperature, height, tropopause, and maximum wind. Various experiments have been conducted to see if short-range forecasters could improve on the upper-wind forecasts over the numerical model; the numerical model remains of paramount importance. Small-scale models are being run in the U.S. and the U.K. A fine-mesh model covers Europe and the Atlantic. A mesoscale model is under development. A great deal of verification work is done to see how good the models are.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 41-51
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  • 100
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    General-aviation's view of progress in the aviation weather system (1988)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: For all its activity statistics, general-aviation is the most vulnerable to hazardous weather. Of concern to the general aviation industry are: (1) the slow pace of getting units of the Automated Weather Observation System (AWOS) to the field; (2) the efforts of the National Weather Service to withdraw from both the observation and dissemination roles of the aviation weather system; (3) the need for more observation points to improve the accuracy of terminal and area forecasts; (4) the need for improvements in all area forecasts, terminal forecasts, and winds aloft forecasts; (5) slow progress in cockpit weather displays; (6) the erosion of transcribed weather broadcasts (TWEB) and other deficiencies in weather information dissemination; (7) the need to push to make the Direct User Access Terminal (DUAT) a reality; and (7) the need to improve severe weather (thunderstorm) warning systems.
    Keywords: METEOROLOGY AND CLIMATOLOGY
    Type: Tennessee Univ. Space Inst., Tullahoma. Meteorological and Environmental Inputs to Aviation Systems; p 79-85
    Format: application/pdf
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