Search

An exact formulation of the impulse approach (IA), or quantum- mechanical spectator model, is applied to atom-diatom collisions. Results are compared with previous work on the IA, which has always involved the peaking approximation (PA). The PA is seen to overestimate (underestimate) differential cross sections for processes involving projectile atom energy loss (gain). The internal consistency of the IA is explored by subjecting it to semidetailed balancing. For small scattering angles the IA is seen to be an inadequate theory, probably due to the neglect of double-and higher collision terms in the multiple-collision expansion of the three-body T matrix. For large scattering angles, where the IA does appear to describe the scattering process accurately, the exact calculation is shown to give the same results as when only the energy- conserving on-the-energy-shell two-body processes are considered. An accurate approximation method is also developed for rapid computation of inelastic differential cross sections., Published in Physical Review A, v43 n1 p189-203, 1 Jan 1991.

Hydroxyl radical (OH) plays a preeminent role in both the chemistry and photophysics of the earths atmosphere. Stratospheric OH takes part in a number of key reactions, including those which determine the concentration of the halogen-containing species involved in the catalytic destruction of ozone. OH also mediates the relative densities of the odd nitrogen oxides (NO and NO2) and nitric acid. Because the presence of OH is a signature of numerous chemical and photochemical processes, its altitude distribution is of fundamental interest, and substantial effort has been made to develop better remote sensing techniques for OH. The steady-state vibrational populations of hydroxyl in the upper atmosphere are determined by the rates of various processes, including the chemical reactions that form and destroy OH, IR fluorescence from OH, and collisional relaxation of OH by bath gas molecules. Reprints., Pub. in Jnl. of Chemical Physics, v92 n6 p3387-3393, 15 Mar 1990.

Production of trace nitrogen oxide species in air discharge plasmas was observed with a quadrupole mass spectrometer attached to a specially- designed, S-band waveguide. At pressures between 25 and 200 Torr in the waveguide, nitric oxide (NO) was the most concentrated trace species observed, reaching concentrations of greater than 2% at 200 Torr. Nitrogen dioxide (NO2) was also observed, but only after the discharge had been turned off. NO2 concentrations were slightly lower than NO. At pressures between 9 and 0.3 Torr, the only species observed was nitrous oxide (N2O), which reached a concentration of approximately 2% at the lower pressure. The experimental apparatus, data collection procedures, calibration procedures, data reduction, and results are described in detail. (JES)

Partial Contents: Focusing and Defocusing of Teleseismic P waves by Known 3-D Structure Beneath Pahute Mesa, Spherical Wave Propagation in Low Porosity Brittle Rocks; Propagation-Corrected Lg Spectra to Estimate Yields of Soviet Explosions and Isolation and Enhancement of Regional Phases for Earthquakes in the Eastern United States; Wave Propagation Modeling and Regional Discriminants; Seismic Attenuation and Yield Estimates: New Results using the Lg Phase, High Frequency Seismic Source Functions for Cavity Decoupled Underground Nuclear Explosions; The Damage Mechanics of Rock Under Explosion Induced Loads, A knowledge Based System for Analyzing Data from a Network of NORESS Type Arrays; Detection and Location Capability of Hypothetical Monitoring Networks in the Soviet Union; Wide Band Slowness Estimation using a Small Aperture Seismic Array, Spectral Determination of Regional and Teleseismic Lg Attenuation and Source Multiplicity in Explosions, and Frequency Variable Filters and Surface-Wave Amplitude Analysis, Symposia.

Contents: What's Needed for a Quantitative and Confident Specification of a Verifiable Low Threshold Test Ban Treaty; Wave Propagation Issues Associated with Explosive Sources; Current Research Issues in Nuclear Test Limitation Treaty Monitoring; Engineering Perspectives on Seismic Monitoring of the Soviet Union; Attenuation and Moduli from Hysteresis Loops at 0.1 Hz; Pattern Recognition for Earthquake Detection; Nonlinear Constitutive Relations at Moderate Strain - .001 to .000001 in Salt; Development of an Intelligent Seismic Facility; The Fine Structure of Pn and Pg; Effects of Depth of Burial and Tectonic Release on Explosion and Earthquake Regional Seismograms; Geophysical Structure at Pahute Mesa, Nevada; SEA - An Automated Event Analyzer for Seismic Arrays; Databases and Software Support at the Center for Seismic Studies; and Discrimination of NTS Explosions and Earthquakes Using High-Frequency regional Data.

The launch induced vibro-acoustic environments have been forecast for several Ground Support System structures at V23, the STS launch facility at Vandenberg, AFB. These forecasts are based on site particular vibration and pressure responses determined by an explosive sounding program conducted at V23. The responses are coupled with an STS acoustic pressure term established by measurement of STS launches at KSC. This report provides a summary of the results of this effort and provides the forecasts for the vibration environment in the PPR. Motion levels in the PPR are found to be substantially below all levels of concern. However, companion studies have shown that high accelerations can be anticipated in the OFS Room and the PCR. In addition, pounding could occur between PCR and PPR. Strong reverberations on acoustic records from V23 indicate that launch overpressures at V23 will be significantly altered from those at KSC for the shuttle at altitude and clear of the ground. Finally, the potential of pounding due to earthquake ground motions is discussed. Keyword: Motion forecasts.

A preliminary statistical analysis of the ATS-5 and ATS-6 geosynchronous plasma data has been carried out. Variations in the electron and ion currents and temperatures, as represented by the single Maxwellian component temperatures T(AVG) and T(RMS), are evaluated with respect to local time and geomagnetic activity. The potential on the satellites is similarly evaluated. Results indicate that the geosynchronous plasma cannot be adequately represented by a simple Maxwellian distribution and that, at the very least, a two component Maxwellian is necessary. The electron current and eclipse potential were found to vary strongly with K sub p while the temperatures only varied weakly. Local time variations in temperature and current were observed but these were outweighed by a significant local time variation in satellite potential which peaked near midnight. An explanation of these results is proposed in terms of a simple model of the time evolution of the plasma following an injection., See also Part 1, ADA053164.

The increasing complexity and sophistication of synchronous orbit satellites has resulted in a corresponding increase in their susceptibility to anomalous behavior and disruption. Many of these problems can be attributed to the buildup of large potentials on various surfaces of the satellites in response to the ambient space plasma. Such large potentials (as great as -20,000 V relative to the ambient plasma) can produce anomalies and disruptions by causing arcing between the surfaces. In this report, the question of the time rate of change of satellite potential is studied. Theory and observations are reviewed to give estimates of the time rate of change in potentials encountered at synchronous orbit. A clear need for future study is indicated. Plans for instrumentation being developed at AFGL to study the area are discussed.

A survey of data from the first year of the P78-2 SCATHA satellite operations showed that a highest level spacecraft frame charging (phi sub f) both in sunlight (-340 V) and in eclipse (> -8 kV) occurred on 24 April 1979. Analysis of the data indicates that if the sunlight charging environment had been present during eclipse, the vehicle would have charged in excess of 15 kV which is above any known charging level observed to date for the SCATHA satellite. Therefore, the environment at the peak of the sunlight charging at approx. 0650 UT 24 April 1979 was chosen for this worst case study. The environment at this time is characterized by an injection of high energy (30-335 keV) electron fluxes whose combined current correlates with phi sub f with a correlation coefficient of 0.95. The fluxes were highly anisotropic, maximizing perpendicular to the magnetic field. The low energy (< 4 keV) electron population had a density < 1/cc and the low energy ions were near background. The measured electron distribution functions, when fit to double Maxwellians by a least squares technique, show that throughout the sunlight charging the high and low temperatures remained nearly the same, while the density of the high energy component followed the charging levels. The injection occurred simultaneously with the rapid return of the magnetospheric magnetic field to a more dipole-like configuration.

These papers span the entire range of multi-disciplinary studies of transients propagating from the sun through the interplanetary medium and represent a current assessment of theoretical studies and analyses, computer simulation, and in situ measurements of these phenomena. This includes solar phenomena as the source of transient events propagating through the solar system, and theoretical and observational assessments of the dynamic processes involved as these transients propagate through the interplanetary medium. The subjects covered are solar physics, solar radio astronomy, interplanetary scintillation measurements, cometary studies, direct spacecraft observations from Venera 9, Venera 10, Helios 1 and Helios 2, energetic particle propagation in the interplanetary medium and shock-particle interactions. Also included are reports on coronal hole and solar wind studies during STIP Interval I (september-October 1975) and the dynamic solar-Terrestrial events that occurred during STIP Interval II (15 March-15 May 1976).

The responses of gridded spherical and planar electrostatic probes to plasmas with kappa type distribution functions are analyzed along lines developed by Mott-Smith and Langmuir. Specifically, consider a case that could be encountered when a satellite is in the outer reaches of the plasma-sphere. Practical rules are developed for calculating the plasma's spectral index (K), its mean thermal energy, and density. It is shown that treating the plasma as though it were Maxwellian, can lead to serious overestimates of the mean thermal energy but less serious overestimates of the electron density.

This chronology covers the entire history (1945-1985) of the Air Force Geophysics Laboratory and its three predecessor organizations. (The latter consist of the Cambridge Field Station, the Air Force Cambridge Research Center, and the Air Force Cambridge Research Laboratories.) The CHRONOLOGY lists major organizational developments and events relating to scientific programs. It also includes illustrations and appendices. The work is intended to provide a historical reference for staff at the Laboratory and at related government agencies. Keywords: Air Force research; Geophysics; Solar radiations; Space physics; Ionospheric physics; Aeronomy; Meteorology; Optical physics; Infrared technology; Seismology; Geodesy; Gravity; Balloon technology; Rocket instrumentation; Solid state sciences; and Electromagnetic propagation.

This is the fifth part of a planned Northern Hemisphere atlas of probabilities of cloud-free lines-of-sight between the earth and space. The probabilities are for the mid-season months: January, April, July, and October; four times of day: 0000-0200 LST, 0600-0800 LST, 1200-1400 LST, and 1800-2000 LST; and three elevation angles: 10, 30 and 90 deg. Parts 1, 2, 3, and 4 depicted cloud-free line-of-sight probabilities for Germany, the USSR, the USA, and Europe, respectively., See also Part 2, ADA040705.

A mobile, pulsed, coherent, Doppler CO2 lidar is being developed at Air Force Geophysics Lab. The system will be used to develop real-time techniques for determining wind field structures and evaluating aerosol backscatter measurements over path lengths of 1 km to 20 km range. Originator-supplied key words include: CO2 laser, Doppler lidar, Remote measurement of wind fields, Aerosol backscatter measurement, and Real-time analysis of lidar data., Presented at the Conference on 'Optical Remote Sensing of the Atmosphere', 15-18 Jan 1985 at Incline Village, NV.

Three computer/calculator programs were developed to solve tethered- balloon cable problems. The programs provide information on cable tension, geometry, and spacial positions from the balloon to the surface with a variable profile of wind speeds and azimuths. One program allows the holding of a constant cable length and the determination of a new balloon altitude and cable profile for any number of different wind fields. Both printed and plotted outputs are provided. Complete documentation including flow-charts is provided to permit the programs to be adapted to computers having different language than the Hewlett Packard 9810 used in their development.

A data set, first described in AFGL-TR-81-0275, Johnson (1981), which contains nearly 500 arrays representing measurements of sky and terrain radiance values, is reviewed and further illustrated with respect to naturally occurring radiance variations. The measurements were made using radiometer systems mounted on a C-130 aircraft during a series of European flights associated with the NATO Program OPAQUE, Fenn (1978) and Johnson et al. (1979). Radiance measurements throughout the 4 pi field surrounding the aircraft during seventeen separate flight episodes are presented and discussed with respect to their variability as a function of altitude, look angle, cloud cover and spectral band. The measurements were made in spectral bands having mean wavelengths of 478, 577, 664 and 765 nm, and under meteorological conditions ranging from fully overcast to clear and cloudfree. With appropriate caveats, examples of typical overcast, broken cloud and clear day radiance distributions are illustrated. Whereas these data illustrate substantial variations in the radiance distribution from day to day, there are determinable patterns that may provide boundary conditions for a very generalized attempt of classification. Thus, as were the data displayed in the earlier companion report, Johnson (1981), these data are appropriate for use in the development of operationally useful predictive models as illustrated in Hering (1981)., See also Rept. no. AFGL-TR-81-0275 dated Aug 1981, AD-A114 637.

Techniques for improved use of topside ionosphere observations within the Air Weather Service 4D ionosphere model system are investigated. Topside observations are available at the Air Force Global Weather Central from the Topside Ionospheric Plasma Monitor (SSIE) on the Block 5D DMSP satellites. The investigations cover three study areas: 1) improvements to the topside ionospheric electron density profile model used within the 4D model, 2) improvements to the ionospheric data preprocessors in the 4D model system, and 3) improvements to the 4D model. Results are presented for tasks completed during the second year of the project. A parametrization of the topside electron density profile was developed based on a two component diffusive equilibrium representation of the ionosphere. This topside model can use the entire data set from the SSIE sensor to specify the profile or, if some data are unavailable, it will use an empirical model of the height 0(+) to H(+) transition height to construct the profile. A method was developed for generating grids of the 840km electron density from observations along an orbit track, and a computer program was written to test the method. This program was also used to investigate joint analyses of N sub e (840) and Total Electron Content observations.

The Spacecraft Environmental Interactions Technology Conference was held at the U.S. Air Force Academy. Colorado Springs, Colorado, from October 4 to 6,1983. The fourth in a series of conferences jointly sponsored by NASA and the Air Force it summarized technology investigations concerning interactions between space systems and their orbital environments and presented information for use by designers of such systems. The series forms a part of the joint NASA/ Air Force technology programs and provides a forum for researchers, technologists, and engineers to exchange results and ideas. The conference was planned to provide an overview of both spaceflight and ground technology investigations directed toward understanding and controlling interactions of space systems with orbital environments. It focus included interactions between orbital environments and large, high-power space systems, including the shuttle, and astronaut extravehicular activity, as well as the earlier conferences in this series (in 1976, 1978, and 1980). This shift and expansion of focus reflects the changing areas of emphasis in the NASA/Air Force technology programs in the shuttle era.

Modern military communication, navigation, and surveillance systems depend on reliable, noise-free transionospheric radio frequency channels. They can be severely impacted by small scale electron density irregularities in the ionosphere which cause both phase and amplitude scintillation. Basic tools used in planning and mitigation schemes are climatological in nature and thus may greatly over- and under -estimate the effects of scintillation in a given scenario. This report describes the second year of an investigation into the feasibility of using in situ observations of the ionosphere from the USAF DMSP satellite to calculate estimates of irregularity parameters which could be used to update scintillation models in near real-time. Methods for processing DMSP scintillation Meter (SM) data and for calculating estimates of C sub K L from the SM data are described. Results of the analysis of DMSP SM data from a coordinated data-collection campaign run in January 1988 are presented. Keywords: Ionosphere; Ionospheric scintillation; Radiowave scintillation; Defense meteorology satellite program.

This report describes an algorithm for the accelerated computation of the convolution of a Lorentz line shape (pressure broadened) with spectral line data. A computational savings of approximately 10 has been achieved over conventional methods. The Lorentz function has been decomposed into three functions, each of which is convolved independently at optional sampling intervals. Criteria for the determination of the sampling interval of the Lorentz function for a resultant error of 0.1 percent is described. The report contains a listing of the computer program based on the algorithm and sample results in the spectral region 3550 to 3650/cm due to water and carbon dioxide.

In order to estimate the rate of vertical transport due to turbulence in the stratosphere, it is necessary to know the degree of mixing that takes place in 'Kelvin-Helmholtz billow events.' This is estimated by means of a discrete model and the results are compared with published experimental observations. From these considerations it is concluded that a very large degree of mixing probably takes place in such events, and that, therefore, one must use the relation between the bulk vertical eddy diffusivity and layer diffusivity originally proposed by Rosenberg and Dewan instead of the simple one usually employed.

This paper reviews the estimates to date of the vertical 'effective diffusion coefficient' for stratospheric small scale turbulence transport, KB. These estimates range (in order of magnitude) from 1.0 sq. meter/s to 0.01 sq. meter/s, that is to say from a value which would make turbulence a dominant factor in stratospheric transport to a value which would make it totally insignificant. Such a large range implies much ignorance in this subject. The various techniques are closely examined and the unanswered experimental questions are exhibited. The conclusion is reached that more experimental work needs to be done before one has a reliable estimate for KB.

A first principles scientific model for predicting the spectral radiance from the auroral thermosphere seen by an earthlimb observer is described. This model, and the resulting Auroral Atmospheric Radiance Code (AARC), describe the energy deposition in the thermosphere by primary auroral electrons and the ensuing effects. The latter include electron production and production of nonequilibrium concentrations of vibrationally and electronically excited states, by photochemical means, and by energy transfer. Relaxation of the states by collisions and radiation is described, and the transmission of the infrared radiation emitted from these states is treated. Currently, the model considers four radiators: the nitric oxide vibrational fundamental and first overtone at 2.8 and 5.3 micro the NO+ fundamental at 4.3 mirco, and the CO2 asymmetric- stretch (NU -3 mode) emission at 4.3 micro. The prompt optically optically thin emitters (NO and NO+) are treated in terms of stored, precalculated tables of efficiencies (photons per ion-pair). Infrared spectroscopy, Atmospheric emission, Aurora, Thermosphere, Energy deposition, Spectral radiance.

A self-consistent method of characterizing vertical turbulent transport by means of a diffusion parameter is demonstrated for the extremely inhomogeneous case of layered turbulence in a stratified fluid. Between the horizontal turbulent layers, horizontal laminar flow is assumed to occur, and molecular diffusion is ignored. The layers are assumed to occur at random heights with random thickness. An analogy is made between the process of random mixing layers and the finite difference representation of the diffusion equation. It is demonstrated by means of a series of digital computer experiments that, in the case where total mixing takes place within the turbulent layers, the diffusion parameter herein developed is the valid one to use (in contrast to 'eddy diffusivity'). The relation between this inhomogeneous diffusion parameter and practical experimental measurements is given. The motive behind this investigation involves vertical transport of pollution in the environment in general and in the stratosphere in particular.

A data set which contains nearly 500 arrays representing the measurements of visible spectrum sky and terrain radiance values first discussed in an earlier document has been organized into a readily transportable, machine readable library. A complementary data set including contemporary measurements of atmospheric volume scattering coefficients plus selected meteorological variables as a function of altitude has been included in a similar machine oriented format. The data base contents are described as are the storage tape formats and sample extraction procedures.

The Flight Model Discharge System (FMDS) Program has completed its fourth year. The FMDS is a spacecraft charge control system designed to overcome the problem of charge buildup on a space vehicle which occurs during periods of adverse space environmental conditions. An overview of the FMDS system is presented, followed by an in-depth treatment of the significant technical developments that have occurred during the past year. The major areas covered include the plasma generator and electrostatic analyzer testing. Keywords: Spacecraft charging, Charge control system, Automatic active discharge system, Flight model discharge system.

This report contains information in four areas: (1) Air-Launched Balloon System (ALBS); Programs, their Description, Flowcharts, and Documentations; (2) Balloon Tracking Using VOR; Description and Logic of Mathematical Development, and a Program Employing These Techniques (Including Flowchart and Documentation); (3) Tethered Balloon Experiment: Analysis and Recommendations; and (4) Balloon Flight Simulations Using Eglin AFB, Holloman, and White Sands Wind Data.

The Air Launched Balloon System (ALBS) development history is traced and the circumstances leading up to planned ALBS flight tests are described, including a report on successful tests of the cryogenic storage subsystem. The theoretical performance of a candidate parachute development system--35-ft (10. 67 m) diameter ring sail drogue, 64-ft (19.51 m) diameter flat circular main chute--is mathematically analyzed using a number of stated assumptions. Contingency arrangements (e.g., use of ballast) and their impact are discussed. Data indicate that the ALBS mid-air deployment concepts require experimental proof-of-concept testing to ensure optimum component selection. Parachute subsystem verification tests planned for the autumn of 1976 at El Centro, Calif. , are outlined along with plans for partial and complete ALBS system test drops from a carrier balloon in 1977 at White Sands Missile Range.

The circumstances leading to the second phase of the Air-Launched Balloon System Development Program are described, along with the governing design constraints. Individual component development efforts and system design modifications are described in turn: the procurement and testing of the new dewar, the qualification of the updated cryogenic unit, the redesign of the balloon/parachute interface, the solution of the extraction line recoil problem, and the development of a reliable cryogenic unit recovery system. The complicated command, control, and telemetry subsystem is also described in detail. The results of component tests and a system dress rehearsal system test are summarized. Preparations for two full-scale system tests conducted in 1981 are covered in considerable detail. The results of those tests are presented and the test data are analyzed. It is concluded that the system's air-launch and mid-air inflation techniques are acceptable. The balloon requires structural reinforcements, however, before the system can be said to be fully developed. (Author)

Aerosol models have been developed for the lower atmosphere. These models are representative of conditions found in rural, urban, and maritime air masses. The changes in the aerosol properties with variations in the relative humidity are discussed. To describe the aerosol optical properties in the extreme of 100 percent relative humidity, several fog models are presented. For each model the coefficients for extinction, scattering, and absorption, the angular scattering distribution, and other optical parameters have been computed for wavelengths between 0.2 and 40 microns. These aerosol models are presented together with a review of their experimental basis. The optical properties of these models are discussed and some comparisons of the model with experimental measurements are presented.

The requirements for the Air Launched Balloon System (ALBS) development program and the highlights of that program, prior to the flight test phase, are presented. The rationale behind an ambitious ALBS parachute subsystem test flight series, using C-130 aircraft, at the National Parachute Test Range is given, along with the initial system configuration chosen for that series. The test-demonstrated inadequacy of the 32-ft drogue chute is documented. The successes achieved subsequently in flights with a 28-ft drogue chute (in combination with the 42-ft main chute) are described, both for tests employing a dummy balloon and for later tests in which a real balloon was used. Attempts at partial balloon inflation at the NPTR are discussed. The unsolved parachute coning problem is also described, along with tests aimed at its solution. Planning and preflight preparations for the January 1978 balloon drop test over the White Sands Missile Range are covered in considerable detail. The abortive launch of that flight is related and an analysis of the reasons for the flight failure is presented. Five (5) appendices are included with supporting calculations.

Vertical transport in the stratosphere occurs by many processes and the question of the relative importance of stratified turbulence is considered in the context of a 'vertical stack model' described in a previous report. The 'vertical stack model' was designed to estimate the effect of intermittent turbulent layers (separated by essentially laminar flow) and it is here examined in some detail. In particular, a number of less obvious implications are discussed and a list of experimental tests of the model is suggested. It is concluded that the rate of turbulence for vertical transport in the stratosphere remains an open question.

The work performed under this contract consisted of: conducting balloon flight operations from selected sites; integrating government-furnished equipment instrumentation and flight safety equipment into balloon-borne payloads; providing engineering support for payload integration and integrity; fabricating, calibrating and repairing command control/telemetry equipment; analyzing data; and reporting flight results.

Five different instruments were used in multiple experiments to measure atmospheric turbulence in the form of the refractive structure constant, C sub n squared. These included UHF radar, optical scintillometer, modified radiosondes, AFGL thermosondes, and aircraft micro-thermal measurements. Described here are the radiosonde and thermosonde electronics and their calibrations. The data reduction scheme is described and a brief program description is given. Although the different instruments gave measurements somewhat separated in space and time, first results show good agreement between the radar, scintillometer, and thermosonde measurements.

A triaxial fluxgate magnometer has been successfully flown on a satellite of the Defense Meteorological Satellite Program. This instrument is sensitive enough to be used for scientific studies as well as for spacecraft operations. Unlike previous scientific-quality magnetometers in space, the sensor for this instrument is not mounted on a long boom but is mounted on the outer skin of the satellite, under the thermal blanket. While magnetic signals from the spacecraft are noticeable in the data, they do not significantly degrade the quality of the data. Algorithms are now available to process the magnetic field data in a quick format. This enables a researcher to locate in the data the signature of disturbances in the earth's magnetic field due to geophysical events. In particular, the signature of field-aligned currents associated with high-latitude phenomena such as aurora can be found in the data. Additional keywords: Ionospheres; Geomagnetic fields; F7 spacecraft.

This is the second part of a planned Northern Hemisphere atlas of probabilities of cloud-free lines-of-sight between the earth and space. The probabilities are for the mid-season months-January, April, July, and October; four times of the day-0000-0200 LST, 0600-0800 LST, 1200-1400 LST, and 1800-2000 LST; and three elevation angles-10,30, and 90 deg.

The results of a multicolor infrared survey conducted by the Air Force Geophysics Laboratory are reported. Observations, in one or more broad band colors at effective wavelengths of 4.2, 11.0, 19.8, and 27.4 micrometers are presented with positions for 2363 sources. Ninety percent of the celestial sphere has been surveyed at 11.0 micrometers and about two thirds of this area was covered more than once.

Positions and magnitude measurements at effective wavelengths of 4.2, 11.0, 19.8, and 27.4 micrometers are reported for an additional 2477 sources observed during the AFGL survey program. These sources were obtained by relaxing the stringent selection criteria used for the main catalog and subjectively selecting those that have associations and/or other characteristics which make them of interest for future investigation., See also Rept. no. AFGL-TR-76-0208 and Rept. no. AFGL-ERP- 576 dated 17 Sep 76, AD-A034 448.

The satellites of the Defense Meteorological Satellite Program (DMSP) are flown operationally to provide data for the specification of terrestrial weather and the near earth space environment. In support of space environment specification the satellites starting the F6, carry an improved set of electrostatic analyzers SSJ/4, designed to measure the flux of precipitating electrons and ions with energies between 30 eV and 30 keV. The data from these analyses are routinely processed at AFCL and are available to the scientific community. Both by itself, and in combination with other sensors on the satellite, the SSJ/4 detectors provide important data for the study of auroral processes. This report was prepared to facilitate the widespread use of the SSJ/4 data.

The 80 to 130 km altitude region is our old 'ionosphere' - the region of the atmosphere that no one seems to be interested in, and yet the critical region for shuttle entry and atmospheric braking. Comparison between the Air Force reference atmosphere and Shuttle IMU data shows large fluctuations at high latitudes. New data sources are available new, such as the Arecibo and Millstone Hill ionospheric scatter radars. (Author), Proceedings of a Workshop Held in Huntsville, AL on 19-21 Nov 85.

This report describes the 2nd phase of a study involving a surface-layer windflow model. The model produces a two-dimensional (x-y plane) variational analysis of windflow by employing Gauss' principle of least constraints to adjust an intial windfield to effects of topography, stability, momentum advection, and mass conservation. It used detailed terrain data (100 to 200 m horizontal resolution) to compensate for sparse meterological data availabl over the small areas for which the model is run (25 to 250 sq km). The first phase involved testing of the model to effects of stability and vegetation using terrain, vegetation, and climate for Ft. Polk, LA. The 2nd phase involves further model development, including changes in meteorological data input as well as changes in wind and stability initializations. Model experiments using artificially-produced terrain were conducted to test these changes. A two-part model validation was then performed using climate data and archived meteorological tower data from Vandenberg AFB, California. The area of interest is 11 x 12 km, and covers the South Vandenberg Launch Complex. Keywords: Complex terrain; Microclimate.

The particular features which must be considered when sensing arctic regions from space platforms include a generally dry atmosphere, thin and low water content clouds which often cover large areas, a highly reflective snow or ice background in the visible spectrum, and weak thermal contrast between snow and cloud in the thermal infrared spectrum. In recent years, more attention has been given to the problem of identifying clouds in arctic regions. An investigation of operational cloud analysis programs for arctic regions has been initiated; results from this study have shown that clouds are often specified in regions which turn out to be generally cloud-free and vice versa. Some possible reasons for this error will be presented. Results of discriminating clouds from a snow background using multi spectral visible and near Infrared sensors will also be given. A new Special Sensor Microwave/Imager (SSM/I) operating at four frequencies from 19 to 85 GHz is designed to provide estimates of several surface and atmospheric characteristics. Several parameters which will be estimated from SSM/I data are of particular interest to arctic regions. These include snow parameters, sea ice attributes, cloud amount over snow, cloud liquid water content, soil moisture, and land surface temperature. As an example of parameter retrieval from SSM/I data, the basis for estimating cloud amount over a snow surface will be discussed. Retrieval algorithms have been developed which lead to temperature profiles on a global scale. In addition, a microwave system operating in the 183 GHz water absorption band is being developed which will provide estimates of water vapor profiles., Presented at the DoD Symposium and Workshop on Arctic and Arctic-Related Environmental Sciences, p1-8 1986.

Calculations of the spacecraft interaction with the low earth orbit space plasma environment are presented, based on two computer codes, MACH and POLAR. MACH is an inside-out particle tracking code which treats spacecraft in a cylindrically symmetric grid, while POLAR is fully three dimensional. The methodology of MACH is more fundamental than that of POLAR, and MACH is used for validating the physics of POLAR in regimes where there are no comprehensive theoretical of experimental results. POLAR and MACH solutions for the wake of a charged disk in MACH 4, 5, and 8 flow are compared. Keywords: Computer simulation; Spacecraft interactions; Wake.

A stacked plot of 24-hour magnetograms from the AFGL Magnetometer Network is presented for each UT day of the year 1979. Each plot, on a single page, contains all 21 traces from the fluxgate magnetometers of the network (three components at seven stations). The data plotted are 2-min averages of the 1-min edited data set that has been provided to the World Data Center. To aid in comparisons between days, the magnetograms are plotted with a fixed amplitude scale that preserves a resolution of one or two nanoteslas. For the 10 percent of all days that are more active, the plots have been repeated at a reduced amplitude. These magnetograms serve to assess the general character of magnetic activity, identify events for scientific study, and indicate the coverage and quality of the data available from the World Data Center.

A number of mechanisms produce the convection necessary to initiate thunderstorms over mountainous terrain (that is, orographic lifting, channeling, wake effects, and leeside convergence zones). Mountain ranges are often poorly populated and instrumented, and forecasting severe mountain storms can be a problem. However, studies of satellite imagery of the Rockies of Colorado and northern New Mexico have emphasized the importance of certain topographic regions in producing convection. By tracing individual summer thunderstorms back through time to their initiation sits, it has been possible to identify specific mountainous areas that repeatedly serve as genesis regions for thunderstorms. The identification of these genesis regions and the terrain mechanisms at work. An understanding of the wind regimes and moisture fields is also necessary to recognize the conditions necessary to activate each region. This report is the culmination of a 3-year study of satellite imagery and thunderstorm initiation sites of the Rocky Mountains. (Author), Original contains color plates: All DTIC and NTIS reproductions will be in black and white.

Vertical profiles of temperature and density have been developed based on 1 and 10 percent warm and cold temperatures and 1 and 10 percent high and low densities occurring at the worst locations in the world (except Antarctica) during the worst month. The profiles, from the surface to 80 km, are based on extremes that occur at 5, 10, 20, 30, and 40 km. For example, one of the temperature profiles developed was based on a 10 percent warm temperature at an altitude of 20 km; thus, it represents meteorological conditions typically associated with this extreme. Ten such warm profiles (5 levels by 2 percentiles) and 10 cold profiles have been constructed from 14 years of rawinsonde and rocketsonde observations. Internally consistent hydrostatic profiles of density associated with these temperature profiles are provided. Twenty analogous density (and associated temperature) profiles also have been developed from extreme densities occurring at these altitudes. Thus, a set of realistic profiles (rather than envelopes) of temperature and density associated with extremes at specified levels in the troposphere and stratosphere are available for altitudes up to 80 km. Keywords: Atmospheric profiles; Extreme atmospheres; Temperature profiles; Density profiles; Thermodynamic properties.

The purpose of this atlas is to establish a global cloud climatology that details seasonal and diurnal variations. The Boehm Sawtooth Wave (BSW) simulation model is used to devise a method for describing the frequency distribution of total sky-cover. Two parameters, scale distance and mean sky-cover, permit the calculation of the sky cover distribution from clear to overcast. This is an efficient means of data storage, since two numbers define the entire frequency distribution. Hence, the frequency distribution of sky cover can be found for locations world-wide using the global analyses of mean sky cover and scale distance given in the atlas. Twenty maps are presented for each of these parameters - one set 4 times daily (0000-0200, 0600--0800, 1200-1400, 1800-2000 LST), for each midseason month (January, April, July, and October), and another set of monthly means for all hours for each midseason month.

A stacked plot of 24 hour magnetograms from the Magnetometer Network is presented for each UT day of the year 1980. Each plot, on a single page, contains all 21 traces from the fluxgate magnetometers of the network (three components at seven stations). The data plotted are 2-min averages of the 1 min edited data set that has been provided to the World Data Center. To aid in comparisons between the days the magnetograms are plotted with a fixed amplitude scale that preserves a resolution of one or two nanoteslas. For the 10 percent of all days that are more active, the plots have been repeated at a reduced amplitude. These magnetograms serve to assess the general character of magnetic activity, identify events for scientific study, and indicate the coverage and quality of the data available from the World Data Center. Keywords: Magnetograms; Magnetic fields; Network; Magnetic storms; Substorms; Ground measurement; Variations; Geomagnetism.

Experiments on a laser-produced oxygen plasma were observed by medium wavelength (MWIR) and long wavelength (LWIR) infrared emission. This research is part of a continuing series of LINUS (Laser Induced Nuclear Simulation) experiments starting in the short wavelength infrared (SWIR) and extended to longer wavelengths to continue studies on highly excited oxygen atom states produced by three-body recombination in a highly ionized, laser-produced plasma. The first observations of emission in the 5 to 8 micron region from a recombining oxygen plasma are reported, including the first experimental observation of 6h3,5 H to 5g3,5G subscript 0 oxygen atom emission. The observed linewidths of these MWIR emissions are discussed using a Stark lineshape analysis. Keywords: Infrared emission; Laser plasma; Rydberg states; Stark effect; Oxygen atoms; and Lineshape.

The AFGL Beam Emission Rocket Test-One (BERT-1) launched in June 1985, included in its instrumentation an Energetic Ion Retarding Mass Analyzer (EIRMA) to study the mass and energy distribution of positive ions in the return current to the spacecraft from which energetic ion and electron beams are emitted. The EIRMA is a quadrupole mass filter scannable over the 1 to 100 amu range with programmable resolution delta m/m to less than 1/15. The filter was biased by programs over a -100v to +4.5 kv range, allowing a retarding analysis of individual ion species in the return current. The report is a summary description of the instrument design, performance testing results and flight performance. Keywords: Retarding analyzer, Ion mass analyzer, Quadrupole mass filter, Energetic beams, Spacecraft charging.