The characteristics of the hrge-scale electrodynamic parameters, field-aligned currents (FACs), electric fields, and electron prec/pitation, which are associated with auroral substorm events in the nighttime sector, have been obtained through a unique analysis which places the ionospheric measurements of these parameters into the context of a generic substorm determined from global auroral images. A generic bulgetype auroral emission region has been deduced from auroral images taken by the Dynamics Explorer I (DE 1) satellite during a number of isolated substorms, and the form has been divided into six sectors, based on the peculiar emission characteristics in each sector: west of bulge, surge horn, surge, middle surge, eastern bulge, and east of bulge. By comparing the location of passes of the Dynamics Explorer 2 (DE 2) satellite to the simultaneously obtained auroral images, each pass is placed onto the generic aurora. The organization of DE 2 data in this way has systematically clarified peculiar characteristics in the electrodynamic parameters. An upward net current mainly appears in the surge, with litfie net current in the surge horn and the west of bulge. The downward net current/s distributed over wide longitudinal regions from the eastern bulge to the east of bulge. Near the poleward boundary of the expanding auroral bulge, a pair of oppositely directed FAC sheets is observed, with the downward FAC on the poleward side. This downward FAC and most of the upward FAC in the surge and the middle surge are associated with narrow, intense antisunward convection, corresponding to an equatorward d/rected spikelike electric field. This pair of currents decreases in amplitude and latitudinal width toward dusk in the surge and the west of bulge, and the region 1 and 2 FACs become embedded in the sunward convection region. The upward FAC region associated with the spikelike field on the poleward edge of the bulge coincides well with intense electron precipitation and aurora appearing in this western and poleward portion of the bulge. The convection reversal is sharp in the west of bulge and surge horn sectors, and near the high-latitude boundary of the upward region I FAC. In the surge, the convection reversal is near the low-latitude boundary of the upward region 1, with a near stagnation region often extending over a large interval of latitude. In the eastern bulge and east of bulge sectors, the region I and 2 FACs are located in the sunward convection region, while a spikelike electric field occasionally appears poleward of the aurora but usually not associated with a pair of FAC sheets. In the eastern bulge, magnetic field data show complicated FAC distributions which correspond to current segments and filamentary currents. INTRODUCTION Auroral substorms are defined by a systematic sequence of auroral motions and magnetic disturbances [Akasofu, 1964]. Since field-aligned currents (FACs), ionospheric electric fields or convection, charged particle precipitation, and resulting ionospheric conductivity are closely...

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Data from xplorer 45 (S 3 -A) instruments have revealed characteristics of magnetospheric storm or substorm time energetic particle enhancements in the inner magnetosphere (L •< 5). The properties of the ion 'nose' structure in the dusk hemisphere are examined in detail. A statistical study of the local time dependence of noses places the highest probability of occurrence around 2000 MLT, but they can be observed even near the noon meridian. It also appears that most noses are not isolated events but will appear on successive passes. A geoelectric field enhancement corresponding to a minimum value of AE of about 205 ¾ seems to be required to convect the particles within the apogee of Explorer 45. The dynamical behavior of the nose characteristics observed along successive orbits is then explained quantitatively by the time-dependent convection theory in a Volland-Stern type geoelectric field (¾ = 2). These calculations of adiabatic charged particle motions are also applied to explain the energy spectra and dispersion in penetration distances for both electrons and ions observed in the postmidnight to morning hours. Finally, useful descriptions are given of the dispersion properties of particles penetrating the inner magnetosphere at all local times as a function of time after a sudden enhancement of the geoelectric field. tions. Also the calculations of motion of charged particles drifting toward the morningside will be compared with observed enhancements of electrons and ions in the postmidnight to morning hours during the development of the main phase. Finally, useful graphs will be presented for all local times showing calculations of the time developing particle penetrations from the tail regions due to a sudden enhancement or modification of the convection electric field.A description of Explorer 45 is given by Longanecker and Hoffman [1973], and the following approximate initial parameters are useful for understanding the figures: apogee of 5.24 Re, orbital period of 7.8 hours, inclination of 3.6 ø , spin period

[1] Using global auroral images at ultraviolet wavelengths during 116 substorms, we have obtained quantitative measures of key features of the bulge aurora and oval aurora: their temporal variations, their locations, rates, and characteristics of gross expansion and decay, and the variability of these parameters. The expansion period identified solely from images varied primarily from 10 to 40 minutes, with an average of 30.9 minutes. To avoid mixing expansion data with recovery data, we normalized the time of each substorm to one unit from onset to maximum expansion. The average onset location was 22.6 magnetic local time (MLT) and 66.8°invariant latitude (ILat), in good agreement with previous analyses. We found that the bulge aurora rapidly expanded out of the onset location approximately equally to the west (surge) and to the east, so that the average center of the bulge remained close to the onset MLT. This is also the case for average location of the maximum expansion in latitude of the bulge. Thus the bulge is offset about 1 1/2 hours west of midnight. By half the expansion period the bulge has usually expanded poleward sufficiently to reveal a brightened portion of the original auroral oval. This brightening expands less than 1 hour MLT to the west, but rapidly to the east, farther than the east end of the bulge. Thus the two auroras are offset in MLT. The bulge expansion is fastest initially but slows for the second half of the expansion period. The ends of the bulge continue a small expansion poleward during early recovery when the center of the bulge slowly retreats. The large spreads of substorm expansion times, the onset locations and in the locations in ÁMLT and ÁILat of the key features of these auroras, argue strongly for the need to normalize the time of expansion and location of key features of the substorm for any kind of superposed epoch analysis to be meaningful.

The characteristic features of the initial enhancement of the storm time ring current particles in the evening hours are consistent with flow patterns resulting from a combination of inward convection, gradient drift, and corotation, which carries plasma sheet protons into low L values near midnight and the higher‐energy proton component into the plasmasphere and through the evening hours. Data from four magnetic storms during the early life of S³‐A (Explorer 45) when the local time of apogee was in the afternoon and evening hours show that protons with lower magnetic moments penetrate deeper into the magnetosphere until a lower limit, determined by the corotation and gradient drift forces, is reached. Such particle motions produce the stable energy‐dependent inner boundary of the ring current protons inside the plasmapause in the dusk sector and also provide the mechanism for energy injection into the ring current region. From the analyses of the pitch angle distributions it is evident that charge exchange and wave‐particle interactions are not the dominant causes of this inner boundary. Observations of plasma sheet protons and electrons at altitudes just beyond the measured plasmapause are also consistent with the resulting flow patterns.

A simple and rapid method for the determination of human T lymphocyte su lasses in buffy coat preparations or whole blood is described. This technique uses flow cytometry to distinguish lymphocytes from other feukocytes on the basis of their light-scattering properties. Lymphocyte subclasses were enumerated by cellular immunofluorescence; the immunofluorescent signals were produced by monoclonal, antibodies to surface differentiation antigens on T cells. Conventional techniques of enumerating T lymphocyte subclasses entail time-consuming (up to 2 days) density gradient and E rosette enrichment, and require at least 20 ml of blood. The method described here uses as little as 50 ;sI of whole blood for each antibody tested and produces results within 2 hr.

A flow cytometric assay was developed to detect rare cancer cells in blood and bone marrow. Multiple markers, each identified by a separate color of immunofluorescence (yellow and two shades of red), are used to reliably identify the cancer cells. Blood or bone marrow cells, which are not of interest but interfere in detecting the cancer cells, are identified by a panel of immunofluorescence markers, each of which has the same color (green). Thus, the rare cancer cells of interest are yellow and two different shades of red but not green. The requirement that the rare cancer cell be simultaneously positive for three separate colors (the specific markers) and negative for a fourth color (the exclusion color) allowed detection of as few as one cancer cell in 107 nucleated blood cells (a frequency of 10-7). To test this rare-event assay prior to clinical studies, a model study was performed in which the clinical sample was simulated by mixing small numbers of cells from the breast carcinoma line BT-20 with peripheral blood mononuclear cells. We detected statistically significant numbers of BT-20 cells at mixing frequencies of 10-5, 10-6, and 10-7. In control samples, no target events were observed when more than 108 cells were analyzed. For additional confirmation that the BT-20 cells in the model study were correctly identified and counted, the BT-20 cells (and only were covalently stained with a fifth fluorescent dye, 7-amino-4-chloromethylcoumarin (CMAC). CMAC fluorescence data were not used in the assay for detecting BT-20 cells. Only after the analysis using data from the specific and exclusion colors had been completed were the events identified as BT-20 cells checked for CMAC fluorescence. The putative BT-20 events were always found to be positive for CMAC fluorescence, which further increases confidence in the assay. Manual data analysis and an automated computer program were compared. Results were comparable with the manual and automated methods, but the automated "genetic algorithm" always found more

Although previous measurements have been made of proton distributions in the ring current region, especially those of low‐energy protons from 200 ev to 50 kev by Frank [1967] and of high‐energy protons with energies greater than 100 kev by Davis and Williamson [1966], S3‐A (Explorer 45) is providing the first total proton energy density measurements in the storm‐time ring current region. Detectors aboard S3‐A, which have been briefly described by Longanecker and Hoffman [1973], have yielded data on the proton energy density in the equatorial region of the earth's magnetosphere from L = 2.5 to 5.5. The results presented in this paper are derived from proton data taken during the geomagnetic storms of December 16–18, 1971, which occurred approximately one month after the satellite was launched. Cahill [1973] has presented the magnetometer measurements from S3‐A and has also shown some ground magnetograms describing the magnetic field variations during these storms. Both storms initiated with a sudden commencement and positive phase, but the main phase of the first storm did not fully develop. This letter will concentrate on the proton energy density distributions during the storms and will contrast the development of the ring current for the two events.