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A neural network is being trained to predict lightning at Cape Canaveral for periods up to two hours in advance. Inputs consists of ground based field mill data, meteorological tower data, lightning location data and radiosonde and rapid changes in the field mill data, offset in time, provide the 'forecasts' or 'desired output values' used to train the neural network through back propagation. Examples of input data are shown and an example of data compression using a hidden layer in the neural network is discussed. (kr), Prepared in collaboration with KTAADN, Inc., Newton, MA. Presented at the AIAA Aerospace Science Meeting (28th), Reno Nevada, 8-11 Jan 90.

Aircraft and radar weather data recorded for support of the Minuteman PVM-5 test are presented. The link-offset mode was used successfully to obtain radar data for correlation with the aircraft data. The correlation data were quite good, and provided usable relations of reflectivity factor (Z) and water content (M) on five of nine passes. Application of the Z-M relations to the reflectivity data recorded along the re-entry trajectories provided estimates of the water content profile and the weather severity index (WSI) for each of the trajectories., Air Force surveys in geophysics.

Cirriform clouds associated with a frontal system which passed through New Mexico on 4 and 5 April 1978 were sampled by a MC-130E which has been equipped with cloud physics instrumentation by AFGL. The clouds sampled were thin cirrus and cirrostratus layers in advance of the front on 4 April and behind the same front on 5 April. Particle sizes were small; maximum sizes on 4 April were approximately 700 microns. On 5 April, few clouds could be found, but one patch yielded particles as large as 1300 micron. Particle distribution curves are presented for three 5-min periods from the 4 April flight and one 5- min period from the 5 April flight. Additionally, consecutive 30-sec average distributions are presented for selected time periods from each of the flights. In addition to the visible cirrus clouds, particles were also found in clear air between the cirrus clouds. Some of the sub-visible cirrus particles seemed to come from clouds above the aircraft, but other instances of sub-visible cirrus occurred when there were no visible cirrus above the aircraft suggesting that the particles had developed in-situ., See also Part 1, AD-A061 485.

Published results of observations of crystal habits, particle sizes and numbers of ice particles in clouds are summarized and discussed. There are systematic variations with cloud type, and in some instances, with cloud age and location within a cloud system. However, the body of data available is insufficient to formulate a climatology of ice cloud microphysics. The several measurement techniques in current use are evaluated, as are some of the techniques now under consideration for future use. The particle enhancement observed on some occasions is discussed, and the various theories accounting for it presented. Finally, recommendations are made concerning future field programs and theoretical studies required before accurate predictions of the ice cloud microphysical environment can be made. (Author)

This is the fourth in a series of reports presenting particle distribution data acquired in cirrus clouds over the western U.S. The data herein were obtained 21 March 1978 by an instrumented MC-130E near Albuquerque, N.M. The area was under the influence of a slight upper level ridge, and the cirrus appeared related to jet stream winds. No significant surface weather was present at the time. Results include the following: (1) The largest particles measured were near 2500 micrometers, but there were only one or fewer of these per m3; (2) occasional particles as large as 1300 micrometers were recorded in what visually was cloud-free air; (3) few of the particles could be recognized in any known classification system but those most frequently recognized were bullet rosettes; (4) the PMS 2-D data revealed particle-type changes occurring in 5 sec or less of flight time; (5) a halo around the sun was periodically seen when mixed-type crystals containing bullet rosettes were recorded; (6) varying numbers of small particles (the difference between 1 to 28 micrometers) were recorded almost continually, even in clear air, while the aircraft was between 23,000 ft (7.0 km) and 27,300 ft (8.3 km) MSL; (7) computed ice water content values generally decreased with height and increased with temperature in the cirriform clouds sampled; (8) particle size spectra were seldom exponential for particles smaller than approximately 250 micrometers; and (9) bimodal peaks were frequent in the population distribution near 100 and 250 micrometers. (Author), See also Part 3, AD-A066 975.

Air Force requirements for in situ cloud physics measurements of crystal habit, particle size distribution and ice/water content values are reviewed. These areas of deficiency are noted. The first is in and just above the melting zone where there are large clusters of snow and mixed ice and snow. Two instruments developed for the Air Force are being tested to obtain total ice/water measurements throughh this region. The second deficiency exists in automatic instrumentation for the detection of the largest size particles. These data are needed for determining size spectra cut off. The third deficiency is in the area of measurements in tenuous clouds, and is essentially a sampling volume problem. (Author), Presented at Symposium on Meteorological Observations and Instrumentation (4th), Denver, CO, 10-14 Apr 78.

A WB-57F weather reconnaissance aircraft and a high-power radar (ALCOR) were used to document weather at Kwajalein Missile Range. Simultaneous measurements of cloud-reflectivity (Z) by radar, and water content (M) by aircraft were used to interpret measurements of reflectivity along the reentry trajectories close to the time of reentry. Techniques of obtaining and processing the data are described, and the results of the analysis for one mission are presented. These techniques permit the specification of the water content along the trajectory within a factor of 2, or plus or minus 3 dB. Observations from this case and from other days show the variability of the Z-M relation with altitude and cloud type. (Author), Presented at the Conference on Aerospace and Aeronautical Meterorology of the American Meteorological Society (6th) and the American Institute for the Aeronautics and Astronautics, El Paso, Tex., 12-15 Nov 74.

Weather scans taken by the Lincoln Laboratory ALCOR radar from Roi-Namur Island, Kwajalein Atoll, Marshall Islands, were used to obtain information on the ice water content (IWC) at altitudes above 10 km at tropical latitudes. Selected individual scans are presented, along with the envelopes of IWC vs height. Perusal of the information uncovered signficant biases in the manner in which the data were collected. (Author)

The microphysics of Large Scale Cloud Systems (LSCS) was investigated by in-situ measurements made from two specially instrumented aircraft, a United States Air Force MC-130E and a Learjet 36 Information was obtained on the distribution of liquid and ice water content, particle size distributions, crystal habits, and other meteorological variables. The morphologies of three storms were investigated in detail as the storms crossed the United States. (Author)

This report summarizes previous melting-layer research both within and outside AFGL and provides recommendations for future research in the melting layer. An extensive literature search provided a bibliography of previous research. This bibliography is included as an appendix. Several definitions of the top and bottom of the melting layer are presented and discussed. Aggregation and breakup appear to be the chief microphysical processes that determine the particle-size spectrum of snow and ice that enter the melting layer. Studies of the actual melting process and of the melting layer as seen by radar are presented. Microphysical and thermodynamic characteristics are discussed. Dynamic considerations are mentioned. Previously gathered aircraft data are reviewed, and recommendations are made for future aircraft and radar data-gathering efforts. (Author)

Columns of ions left by the passage of meteors through the 80- to 100-km altitude region are used as tracers to monitor the wind and density variations of the high atmosphere. Recent equipment development with pulse-interferometers operating in the 20- to 75-MHz band has made it possible to obtain more accurate information on the location of the reflection point on the ionized meteor trail. Analyses of the wind and density data obtained at AFCRL, at Stanford, California, Durham, New Hampshire, and Eglin AFB, Florida are reviewed. Rocket and meteor trail wind observations were obtained at Eglin AFB and, for a separation of 150 km, show reasonable comparisons within one hour. Poor comparisons at larger space and time separations are attributed to large-scale horizontal eddies (gravity waves). (Author Modified Abstract)

An advanced, inexpensive, transportable radar meteor trail set was developed and was recommended as an international standard by IUCSTP at the Moscow 1971 COSPAR meeting. The interferometer height-measuring technique, tested with the CRLH 001 Beacon in satellite OV1-17, was also recommended because of ground calibration capability and achieved accuracy. Computer programs for data reduction and advanced analysis were used to reduce and study wind and density data from AFCRL, Eglin AFB, Stanford University and the University of New Hampshire. Results were compared with other investigators' findings. (Author)

The Stanford University Mark II Radar Meteor Trail System was moved to Eglin AFB, Florida for field testing and to make comparison of winds obtained by the rocket, chemical release method and the radar meteor method. Recommendations for locating and maintaining meteor radar systems, as well as modifications for the Mark II system suggested by the aircraft and satellite calibrations and by operating experience, are given. (Author)

During the first seven days of April 1960 hourly rawinsonde runs were made at Bedford, Mass. This paper describes in detail the data-heights, temperatures, relative humidities and U, V components of the wind as given on IBM punch cards. The data is tabulated in two forms. In the first form thirty pressure levels from 1000 mb to 10 mb are used. In the second form, the position of the balloon is given for each minute of flight. Information on obtaining the IBM punch cards is included. (Author), See also AD-273 303.

A description of the data taken at AFCRL from 1964 through 1966 and the methods of analyzing the wind data are presented. A least squares fit to the mean, 24-hr, and 12-hr components of the wind was applied to the data, and the results are compared to those obtained by other investigators. (Author)

A review of all techniques for obtaining temperature soundings of the lower few kilometers of the atmosphere was undertaken in order to find suitable, reliable methods for obtaining comparison soundings and to educate ourselves concerning the accuracy and operating difficulties associated with these methods. The first section deals with measuring sensors which are imbedded in the atmosphere (mercury thermometers, thermistor rods, beads, etc.) to obtain the atmospheric temperature. Various means of placing these sensors in the atmosphere, such as balloons, towers, aircraft, rockets, kytoons, microwave levitation, etc. are discussed in the second section. The third section is concerned with other methods of obtaining temperature soundings; these methods can best be classified as indirect. (Author)