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The influence of the condensation process, inert gas, gravitational field and superheating on the flow of vapour around an impermeable isothermal circular cylinder is predicted. It is shown that the increase of the condensation rate and the decrease of the concentration of the inert gas in mixture with the vapour cause the point of flow separation to move toward the back of the cylinder. The paper is a continuation of a previous work1,2 where the author studied the effects of inert gas, gravitational field and superheating on the heat transfer rate to a circular cylinder.

A method is presented for estimating the dispersion and dilution of jet aircraft exhaust from aircraft passage through times on the order of weeks thereafter. In the near wake of the aircraft, the solution is that for round turbulent jets in a parallel flow. More rapid dispersion due to atmospheric effects begins when the scale-dependent eddy viscosity becomes larger than the turbulent jet eddy viscosity. In the far wake region, the solution approaches that for scale-dependent dispersion from a point source moving with the aircraft. Calculations are presented for supersonic aircraft at high altitude flight conditions.

A self-consistent theoretical model of the dynamical processes occurring in the Earth's upper atmosphere has been developed based on magnetohydrodynamic concepts. The May 1967 geomagnetic storm data recorded at College, Alaska, have been used in the resulting set of non-linear, partial differential magnetohydrodynamic equations, to calculate variations due to the storm in the amount of Joule heating and the winds at an altitude of approximately 140 km as a function of time. It is assumed that initially (1) the vertical wind velocity is zero everywhere, and (2) the horizontal pressure gradient is balanced by the Coriolis force where the background vertical pressure gradient is computed using the 1964 Jacchia model atmosphere. A finite difference numerical integration scheme is used to obtain a numerical solution of the set of governing equations. Presented here are the vertical and horizontal wind speeds, and amount of Joule heating as a function of time during the period of the geomagnetic storm.

Experiments were carried out to investigate the propagation of a cw CO2 laser beam through an absorbing slightly supersonic flow. A 500‐W CO2 beam was propagated through a small blow‐down wind tunnel operating with an air/SF6 mixture in order to simulate a high‐power beam propagating through the atmosphere. A collinear schlieren system was used to observe the density gradients caused by the absorbed power. Large density gradients were observed at a Mach number of 1.17; however, they were not shock initiated and their magnitude was not inconsistent with a heat‐balance analysis. Under the conditions of the experiment no shock waves were observed, even though their occurrence was predicted by a simple one‐dimensional analysis. From this study it is concluded that shock waves will not occur under most conditions encountered by high‐power cw CO2 laser radiation in the atmosphere. The presence of subshock density gradients and their effect on the propagating beam require further study.

Ionospheric plasma vertical drifts measured by the Millstone Hill incoherent scatter radar are decomposed into estimates of meridional neutral particle motion by accounting for ion diffusion and semidiurnal electric fields. For two equinoctial days with relatively high F-region electron densities the resulting neutral circulation at 300 km is composed of equatorward winds of 100 to 150 m sec/sup -1/ at night and poleward winds of 25 to 50 m sec/sup -1/ during the day. Harmonic analysis of the wind pattern yields a diurnal northward component of 80 to 100 m sec/sup -1/ with a maximum near noon, a semidiurnal component of 35 m sec/sup -1/ at 0600 LT and a prevailing southward wind of about 20 m sec/sup -1/. The observations are compared with tidal theory predictions and are interpreted by means of a simplified integration of the horizontal equations of motion through which effects of zonal advection, ion drag, viscosity, and pressure gradients are studied. Although the observed wind pattern is consistent in general with that derived from global models based on satellite drag observations, various discrepancies concerning the amplitude and phase of the diurnal bulge are noted and discussed. (auth)

A statistical study of solar wind data from the Explorer 33 satellite shows that interplanetary magnetic field irregularities are enhanced in the interaction region where a fast solar wind stream overtakes a slower solar wind stream. Comparison with geomagnetic AE and ap indexes further shows that these interplanetary irregularities enhance the level of geomagnetic disturbances. Thus while substorm occurrence is highly correlated with the dawn-dusk component of the solar wind electric field, the amplitude of the substorms is an increasing function of the variance in the interplanetary field. This result can be interpreted as a capacitative effect of the magnetopause that allows a time-varying solar wind electric field to penetrate the magnetosphere more effectively than a static solar wind electric field.

The intensity of the polar vortex at 10 mb is used to calculate theoretical values of mean total ozone north of 40° latitude. A satisfactory fit is attained between the development in time of the theoretical ozone and that of the mean of the observed total ozone. The results lead to the conclusion, that a one-cell mean meridional motion relative to the polar night vortex is important for the transport of heat and ozone.

The proton magnetic resonance relaxation times of water adsorbed on porous glass of varying pore size has been measured as a function both of temperature in the range −91 to +92°C and of percentage relative humidity at 50 and 100%. Only the adsorbed water on the glass with the smallest pore size was amenable to a least squares fit of the Resing model for magnetic relaxation. The data indicate that the intracrystaline fluid at room temperature has about 10 times the average viscosity of bulk water but is four orders of magnitude less viscous than ice. With regard to mobility, the water in all the porous glasses studied behaved more like liquid than like ice but had a definite degree of ordering quite different from that of bulk water. A freezing phenomenon was only observed for the two larger pore-size glasses at about −16°C.

The quasi-geostrophic theory leads to a single nonlinear partial differential equation for a streamfunction giving geostrophic velocity fields presumed to resemble the synoptic scales of atmospheric motion. This article is concerned with demonstrating that the quasi-geostrophic problem is well-posed mathematically, in the sense that solutions exist, and that they are continuously dependent on the initial data. The model studied is comprised of the quasi-geostrophic equation subject to the severe boundary condition that an isentrope coincides with the earth's surface. The main technique is the use of the eigenfunctions of an elliptic operator appearing within the quasi-geostrophic equation. These eigenfunctions provide the basis for a spectral model, which can be truncated to include a finite number of scales. The convergence properties of the solutions to the truncated model allow the existence of solutions to the entire model to be inferred with the methods of functional analysis. Thus, the conc...

A persistent mid- to high-latitude heating phenomenon is observed in both hemispheres in data from the Ogo 6 quadrupole mass spectrometer. The phenomenon is evidenced by an increase in N2 density (indicative of a thermospheric temperature rise) and a depletion in helium (indicating an upwelling of air). The composition changes maximize near 0900 and 2100 UT, appear to corotate with the local magnetic pole, and are larger near equinox than near the summer solstice. The variation in latitude of the peak in the winter helium density (as a function of UT) is a specific manifestation of this general heating phenomenon.

A simplified model of plasma motion in the low-latitude nighttime E region is used to investigate the role of uniform horizontal neutral winds in the formation of sporadic E layers. Numerical results show that thick layers may be formed in the mid-E region by plasma compression at the altitude where ion-neutral collisions destroy the ability of horizontal winds to move ionization vertically. It is hypothesized that this mechanism accounts for the appearance of early morning sporadic E layers that are observed to form near 125 km at low latitudes following descents of the F layer.

HF and VHF backscatter measurements carried out in Northern Germany and Scandinavia (φ = 55°–70°) from 1963–1971 were analysed and are now presented comprehensively. The daily and seasonal frequency distributions of auroral backscatter echoes are derived as well as the correlation between auroral occurrences and geomagnetic disturbances and the dependence of the echo amplitude on geomagnetic latitude. By means of a calculated equivalent current system the relation between the backscatter occurrences at different stations and the extension and strength of the polar electrojet have been investigated. All observed events when combined in a synoptic graph as a function of time and geomagnetic latitude show a spiral type structure. In addition to auroral backscatter results the daily and seasonal variation of Es -scatter and 2 × F 2 ground backscatter events are presented.

In this letter, we present the results of a method that uses two Doppler radars to observe the three-dimensional wind field during light snowfall. These radars are designed to scan in a series of tilted planes, passing through the two radar positions. From the mean Doppler shifts in the frequency spectra we can determine average radial velocities within the pulse volumes. Since the two radars do not observe the same volume increments at the same time, spatial interpolation is needed before the radial velocities can be combined into a two-dimensional velocity field at a set of common coordinates within each plane. The estimated terminal fall velocity of the snow is subtracted from the particle velocity to obtain the true air motion in the plane. The air motion component normal to the plane is obtained by integrating the equation of continuity in cylindrical coordinates starting with the surface boundary condition at the plane of zero elevation. The velocity field in the common planes scanned by the radars is then transformed into a rectangular coordinate system with one axis oriented parallel to the average wind direction. After the mean wind field is removed from the results, a well organized “eddy” wind field is evident.

Given only the most general conditions present in the atmosphere, it is demonstrated by theoretical means that the circulation regime must be of the eddy type rather than being axisymmetric. This is done by showing that the mean meridional circulations cannot transport angular momentum across surfaces of constant mean absolute angular momentum. In the course of the development of the argument a quantity named the rotational Rossby number is defined, this nondimensional parameter being somewhat distinct from the conventional Rossby number. The kinematic part of the discussion is applicable to a variety of other specific quantities in addition to angular momentum. Mention is made of the possible application of the results to systems other than the terrestrial atmosphere. DOI: 10.1111/j.2153-3490.1974.tb01630.x

The steady-state yield curve is derived from the growth curve of biomass and shown to bend back toward the origin only if the relative growth rate of biomass is not a monotonically decreasing function of biomass. The bearing of this shape of the yield curve on the possibility of extinction of species is discussed.

The primitive equations are integrated with The model includes topography and is capable of respond- respect to the vertical coordinate, sigma. The resulting ing to diabatic heating. Experiments with and without equations contain vertical eddy terms arising from non- the continuity equation are carried out, and a comparison linearities. These eddies are parameterized using a is made with barotropic forecasts. Exclusion of the mass standard-atmosphere temperature distribution and a continuity condition results in superior forecasts, especially linear jet wind profile independent of horizontal position. I

Vertical wind profiles above dryland wheat fields were measured simultaneously in the open and at horizontal distances of 2H, 4H, and 8H (H = shelterbelt height) in the lee of a highly permeable tree shelterbelt. Two-dimensional wind reduction patterns in the lee of the shelterbelt are presented. The effects of measurement height and atmospheric stability on the horizontal wind profiles (wind reduction curves) are presented. The wind reduction curves were most consistent during neutral atmospheric conditions. Drag coefficients for the shelterbelt were calculated utilizing the wind reduction curve data in a model by Seginer and Sagi (1972). Shelterbelt drag, characterized by the integrated wind reduction curve or a drag coefficient, is suggested as a practical basis for comparison of the effectiveness of different field shelterbelts. Utilization of the drag coefficients showed the 4-year old highly permeable windbreak was already 1 3 as effective as a fully grown shelterbelt.

The error in horizontal wind field measurements as computed from the trajectory of balloons with linear and quadratic rise rates (as functions of altitude) has been derived. Balloon trajectories through light, moderate, and severe wind fields have been considered. Figures are presented which show the wind error vs altitude for various rise rates in each wind field, assuming linear smoothing of the trajectory data. The rise rate profile of the Jimsphere is analyzed as a special case. The results and figures presented are useful in determining the ultimate capability of rising balloon systems in general and for the Jimsphere system in particular for measuring wind from the surface to 18 km. Using the figures presented, it is possible to estimate the wind accuracy that can be achieved by any type of rising balloon by knowing only its rise rate behavior vs altitude. In addition, the results can be used in balloon design to determine what rise rate function is needed to achieve specified wind accuracies. A table is presented which shows the balloon radius for smooth and roughened spheres needed to achieve 2 to 20 m/sec rise rates at 10 and 14 km altitudes.

The effects of seasonal noise on regression estimates are considered as a type of errors-in-variables problem. The natures of asymptotic biases due to the presence of seasonal noise and to the nature of seasonal adjustment in regressions using adjusted and unadjusted data are explored. Methods for recognizing such biases and for attenuating their effects are suggested.

Decreases in ionospheric absorption at auroral latitudes are found to accompany some negative si's in the geomagnetic field. These decreases are found mainly on the morning side of the magnetosphere, but examples were noted in postmidnight as well as the afternoon hours. The reduction in solar wind pressure on the magnetosphere associated with negative si's apparently reduces the wave turbulence responsible for precipitation of electrons on the dayside and affects electrojet/precipitation regions on the nightside of the magnetosphere.

Measurements of electron content ( N T ) near the crest of the equatorial ionosphere anomaly in South America have been made and analysed to investigate N T variations with solar hour, solar rotation and geomagnetic storms. The annual mean of diurnal ratio, defined as the ratio of the maximum to the minimum electron content of the day is found to be 5.0. Anomalous increases in night time electron content are observed with maxima around 2100 LMT and 2300 LMT during summer and equinoctial months. These increases are found to be linked with vertical motion of the F -layer. Spatial resonance in equatorial F -layer plasma appears to be the possible cause of these increases.

An analysis of some Eulerian measurements of wind speed and direction and their fluctuations is presented. Horizontal anisotropy and the presence of horizontal fluxes of momentum is demonstrated. At the site investigated these latter appear to be due to irregularities in the local terrain, rather than shear of speed and or direction with height.

The effects of wave front curvature, wind, and temperature on the determination of the direction of propagation of thunder at an array of microphones is examined, and it is shown that the direction of propagation can be measured at the array with an error of less than ±1° under the following conditions: the wind velocity at the array should be measured with an accuracy of ±1 m/s, the temperature at the array with an accuracy of ±2°C, and the range to the source with an accuracy of ±20%. The positions of the source points on the lightning channel, which represent the total lightning event at that location, are mapped by acoustic ray tracing techniques; this procedure requires information on the temperature and wind velocity as a function of altitude; without this information and in adverse conditions, errors of 10% for high-altitude sources and 25% for sources near the horizon will occur. By using supportive data on wind and temperature profiles all error estimates can be reduced to 5%, which is more than sufficient to do comparative studies of lightning channel structures inside clouds with the macrophysical properties of the clouds.

While site testing for the establishment of a new solar observatory, measurements of the microthermal turbulence as a function of the height were performed over the island of Tenerife (Canary Islands). These measurements were carried out with balloon-borne radiosondes to obtain the vertical profile of the parameters CT2 and Cn2 in order to compute, by means of theory of atmospheric optics, the optical quality of the air mass over the site.

The entire earth-facing lunar surface has been mapped at a resolution of 2 km using the 3.8-cm radar of Haystack Observatory. The observations yield the distribution of relative radar backscattering efficiency with an accuracy of about 10% for both the polarized (primarily quasispecular or coherent) and depolarized (diffuse or incoherent) scattered components. The results show a variety of discrete radar features, many of which are correlated with craters or other features of optical photographs. Particular interest, however, attaches to those features with substantially different radio and optical contrasts. An anomaly near 63° is noted in the mean angular scattering law obtained from a summary of the radar data.

The annual average values of the solar wind velocity over the period 1962–1972 were investigated on the basis of data obtained from different space probes. The comparison of the pattern of the annual average solar wind velocities observed by the Vela and Pioneer 6 satellites indicates that the pattern presented by Gosling et al. (1971) is realistic. The long-range trend in the solar wind velocity during the 11-year cycle is governed by the number and intensity of irregularities occurring in the corona. These irregularities may represent motions of mass or some types of MHD shock waves and they are responsible for the increased heating of the corona which then in turn causes an increase in the values of the solar radar cross-section and of the solar wind velocity. A close relation is demonstrated between the monthly and annual average values of the solar wind velocity and of the cross-section.

Opinions differ on the nature of near-equatorial troughs and their associated weather. Two research aircraft traversed a South Indian Ocean near-equatorial trough on 2 February 1964. Their detailed observations support earlier, large-scale studies which postulated that trough lines above 5° latitude coincide with maximum sea-surface temperature and relatively fine weather.

A pulse-Doppler backscatter radar operating in the HF band was used to test the feasibility to measure ocean surface motions in the North Atlantic Ocean under a variety of environmental conditions. Using the ionosphere as a part of the propagation path, data were collected at ranges from 600 to 2200 nmi. Environmental conditions included a relatively small hurricane, a large storm, and a relatively calm ocean. The Doppler data were converted to wind vectors and compared with weather data taken at the same times and places. Preliminary results indicate that there is, in general, good agreement between wind directions as determined from the radar data and this is indicated on the weather chart at all ranges and under all of the environmental conditions encountered. The agreement in wind strengths is fair to good, but at present reliability is mainly limited to the first-hop data because of multiple propagation modes. Improvements in this technique can be expected from refinement in the theoretical models of scattering, and in developing radar operation methods that minimize multipath responses.

Cross-spectra between wind speeds on several masts in Lake Ontario have been analyzed. As previously predicted, coherence over water (small intensity of turbulence) between wind speeds measured on masts lined up with the wind appears to be larger than over land, and increases with decreasing Richardson numbers. As a result, in cold air over warm water, wind speed fluctuations are well predictable from upstream measurements. For large angles between the anemometer line and wind, the difference between coherence over land and water disappears. Furthermore, there is no significant difference in vertical coherence between water and land. When the wind is parallel to the anemometer line, small ‘eddies’ travel, in agreement with Taylor's hypothesis, with the local mean wind speed. Large eddies travel significantly faster. Vertical phase delay increases with increasing Richardson number.

A case of squall line generation in the National Severe Storms Laboratory (NSSL) network has been examined with the intention of capturing synoptic-scale influences. A telescopic analysis approach was used whereby observations from both synoptic and mesoscale networks were combined. The squall line formed in the warm air behind the surface position of the cold front. Large-scale circulation was responsible for creating a shallow layer (∼1-km thick) of convectively unstable air immediately above this front. Horizontal gradient of low-level moisture, pronounced low-level wind shear, and surface convergence were the large-scale factors that combined to produce the unstable region. Mesoscale analysis showed that vertical velocity in the low levels exhibited a persistent small-scale variation prior to convective activity. The horizontal variation in vertical velocity was ultimately responsible for creating a favored position within the mesonetwork. Conservation of potential temperature and specific hu...

The author explores the use of simple mathematical models in optimizing the design of fixed protection systems by testing the cost sensitivity of an aircraft hangar foam-water deluge system to variations in semi-arbitrarily fixed design parameters.

Nucleation events involving water and ice play a vital role in many atmospheric processes. This paper describes a molecular model for prenucleation water clusters. Results are presented for the formation of these clusters from the supersaturated vapor. The temperature dependence of the model is shown to agree with the classical (liquid drop) model and nucleation rates are calculated and compared with experiment. This model has the advantage of being readily extended to homogeneous and heterogeneous nucleation of ice as well as being applicable to the description of ion-hydration processes. We believe the information inherent in the model concerning interactions on a molecular level can be applied to nucleation phenomena in the atmosphere and can enhance understanding of these processes. This introductory paper describes the progress which has been made and the areas of extended application of these results.

Turbulent jets of water, issuing from a nozzle at Re above 7000, remain coherent for some distance. The surface of the jet is covered with protrusions which are caused by the eddies in the turbulent liquid. In pure water, if Re is not too high, the surface tension, acting over the curvature of each protrusion, balances the “dynamic thrust” of the eddies. At very high Re, however, the eddies have enough thrust to splash through the surface of the jet: droplets are then visible. When “Polyox” is present in the jet liquid, however, elastic forces are added to those of surface tension in restraining the eddies. Mass transfer of CO2 into the jet liquid is reduced at moderate Reynolds numbers, and at higher velocities the formation of droplets can be strongly inhibited. We interpret these results quantitatively in terms of the rates of stretching of the protrusions and the elongational viscosity (μel) of the non-Newtonian solutions.

The vertical distribution of turbulence in the planetary boundary layer at the time and place of an aircraft accident is examined. Estimates of the surface stress are determined by means of the boundary-layer resistance laws with a correction for baroclinity. The response of the aircraft to turbulence during its approach, and the exceedance characteristics of the turbulence are given for an empirical spectrum of vertical velocity. Also, a simulation is made of the vertical velocity along the approach path.

It is shown through the use of weighting functions that Jupiter's brightness temperature in the wavelength range 0.8–1.5 cm contains information on the thermal structure and abundance of ammonia in and above the tropopause in Jupiter's atmosphere. We present new data of Jupiter's brightness temperature in this wavelength range, and compare the results with theoretical spectra. The pressure in the Jovian atmosphere is estimated from these data to be 0.48 atm at 130K.

A three-dimensional, 11-level, primitive equation model has been constructed for a simulation study of tropical cyclones. The model has four levels in the boundary layer and its 70×70 variable grid mesh encloses a 4000-km square domain with a 20-km resolution near the center. Details of the model, including the parameterization scheme for the subgrid-scale diffusion and convection processes, are described. A weak vortex in the conditionally unstable tropical atmosphere is given as the initial state for a numerical integration from which a tropical cyclone develops in the model. During the integration period of one week, the sea surface temperature is fixed at 302K. The central surface pressure drops to about 940 mb, while a warm moist core is established. The azimuthal component of mean horizontal wind is maximum at about 60 km from the center at all levels. A strong in-flow is observed in the boundary layer. At upper levels, a secondary radial-vertical circulation develops in and around the regi...

The conditions for upstream flame propagation from a plane heat source were used for the calculation of the laminar burning velocity in a one-dimensional liquid fuel spray. Calculations were carried out for sprays where the burning was heterogeneously controlled through the transition to premixed gas behavior. The effect of fuel concentration, droplet size, and upstream temperature on the burning velocity were examined. Agreement was satisfactory between calculated results and existing experimental and theoretical data using tetralin sprays.

The thermal-convective instability of a stellar atmosphere is considered to include rotation, finite Larmor radius and Hall effects in the presence of a uniform vertical magnetic field. The criterion for monotonic instability is found to be the same even if the above effects are included.

HF radio waves backscattered from the ocean surface can be used to measure ocean surface currents. Measurements of the range-Doppler spectrum of these signals yield the wavenumber k and the frequency ω of an ocean surface wave and its phase velocityν = ω/κ relative to the radar. Subtraction of the phase velocity of the wave in still water, c = √(g/k), yields a measure of the average current from the surface to a depth of the order of (2k)−1. A measure of the current shear is obtained by observing at more than one radio frequency. To test these ideas, surface currents were measured using both a conventional and the HF technique, and reasonable agreement was found.

The new equation of raindrop-size distribution will be proposed in this paper. It may be represented by the normal distribution of liquid water content per unit volume of air with size. Almost of the conventional distribution (e.g. Marshall-Palmer, and Best equation) and the observed and computed stationary distribution (reported in Part 1 and Part 2 of this paper) are to obey to this rule. Some physical considerations on such a rule will be made and the characteristics of the derived rain parameters will be described for radar meteorology.

The thermal infrared maps of Venus published by Murray, Wildey, and Westphal (1963) and Westphal, Wildey, and Murray (1965) have been analyzed systematically in order to separate the observed intensity into a limb-darkening component and a solar-associated component representing fixed patterns of intensity corotating with the earth and sun, respectively. Interesting new results are obtained for the solar-associated component. Regions near the subsolar point and the poles are not covered in the original maps or in the analysis. The solar-associated pattern of intensity is very nearly symmetric about the equator. In both northern and southern hemispheres, an intensity minimum seems to occur near the morning terminator at middle to high latitudes, slightly beyond the limit of the maps. An intensity maximum occurs on the equator slightly to the east of the antisolar point. Three broad ridges of relatively high intensity radiate away from this point, one pointing to the west along the equator, the others pointing to the northeast and southeast, respectively. The eastward tilt of the latter two ridges may indicate that horizontal exchange is important in maintaining the equatorial maximum of zonal momentum which is associated with the 4-day circulation of the Venus atmosphere.

Measurements are made of the average and pulsation velocities, the energy spectra, and the coefficients of turbulent diffusion during the flow of submerged jets of water and solutions of polyethylene oxide, Na-CMC, and guar gum.

A method is set forth for calculating the coefficients of viscosity of gases of moderate density on the basis of allowance for dimerization and the use of an effective potential function of the intermolecular interaction. The example of water vapor and ammonia show that the method is fairly reliable.

The hydrodynamic interaction between simple ice plates, idealized as oblate spheroids of axis ratio 0.05, and water drops, assumed to be spherical, was numerically investigated for atmospheric conditions of −10C and 700 mb. The ice plates had semi-major axis length between 147 and 404 µm and the water drops had radii up to 53 µm. Since the ratio of the mass of the drop to the mass of the crystal was small, the superposition model was found to be satisfactory. The flow fields around drops were those of LeClair et al., and the flow fields around oblate spheroids were those of Pitter et al. From the trajectories of the water drops relative to the ice crystals, collision efficiencies were determined. The model predicts preferential riming of the drops at the edges of crystals under certain conditions, in agreement with field observations in atmospheric clouds.

In many aircraft-tracking systems the following problem is of importance in correlating radar returns with tracks: Given the aircraft position and velocity at time t − Δt and the limits on the ability of the aircraft to maneuver and/or change speed, what is the set of all possible aircraft positions at time t? We call this set the reachable set (or set of attainability) at time t. This paper uses the Pontryagin maximum principle to derive a set of equations for describing the reachable set.

Field observations are reported of the frontal structure found along the boundary of the Connecticut River plume in Long Island Sound. The hydrography and the horizontal current field were determined in the vicinity of the front. The front separates ambient saltwater on the surface from the light brackish water of the plume. Beneath the surface an inclined frontal layer is found where static stability is a maximum. Isopycnals forming the frontal layer slope upward from a typical depth of 1 m and intersect the sea surface on a horizontal scale of 50 m. A sharp transition in surface color appears in the frontal zone. The primary motion relative to the front is manifested by a vigorous surface convergence from both sides. Sinking motion at the front is locally intense. Saltwater approaching the front is pressed downward beneath the pool of brackish water. The motion parallel to the front is much weaker and independent of density structure. The structure of a section of the front is destroyed by mixing over a period of several hours.

Description of a method for deriving horizontal density fields at altitudes above 30 km directly from satellite radiation measurements. The method is applicable to radiation measurements from any instrument with suitable transmittance weighting functions. Data such as those acquired by the Satellite Infrared Spectrometers on satellites Nimbus 3 and 4 are employed for demonstrating the use of the method for estimating stratospheric-mesospheric density fields.

A simple method for determining the electrostatic charge on a monodisperse aerosol consists of measuring the transmission of the aerosol through the electric field of a parallel plate analyzer, using an optical counter. An improved method of data analysis is presented which allows the determination of the charge distribution. The method was applied to 0.357 μm polystyrene latex aerosol which had been neutralized with a radioactive source and good agreement obtained with the equilibrium Boltzmann distribution. The charge distribution was also determined for highly charged latex aerosol.

Quantitative measures are presented for the intensity of emission features in the spectra of 32 southern red variables.

The equatorial front in the eastern Pacific Ocean observed during 14 October–7 December, 1971, from R/V Yaquina of Oregon State University is discussed. The front is clearly defined at the sea surface by a large horizontal gradient of temperature, salinity, σt and nitrate. Equatorial upwelling, which is believed to be driven by the prevailing wind and the Equatorial Undercurrent, appears as the primary source of the cold water on the south side of the front in the region west of the Galapagos Islands. In vertical distributions of various properties of the water across the equator, equatorial upwelling is apparent over the equator in the region between the Galapagos Islands and the Ecuadorian coast. It is suggested that the equatorial front in this region is also associated with the equatorial upwelling.