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Test results and key principles are given for a radar altimeter designed for meteorological balloons. The instrument, which weighs 160 g and consumes 0.7 W, will fill a gap in meteorological, sensing using balloons-an area where pressure altitude was formerly the preveiling reference. The instrument is basically a delay-lock radar utilizing a superregenerative RF stage. Long-term absolute accuracy of ±10 m and short-term stability of better than- 2 m rms were measured at altitudes of 20 km.

Voyager 1 images of Titan, when normalized to remove limb darkening, reveal an axially symmetric brightness pattern with significant north-south asymmetry. This interhemispheric contrast seems to be a response to seasonal solar heating variations resulting from Titan's inclined spin axis. The contrast significantly lags the solar forcing, indicating that its production involves the atmosphere well below the unit optical depth level. The contrast has a significant effect on Titan's disk-integrated brightness as seen from earth, and probably accounts for most of the observed long term variation, with solar UV variations accounting for the remainder.

A powerful facility for meteorological analysis called the Man Computer Interactive Data Access System (McIDAS) was designed and implemented in the early 1970's at the Space Science and Engineering Center of the University of Wisconsin-Madison. Hardware and software experience gained via extensive use of that facility and its derivatives have led to a newer implementation of McIDAS on a larger computer with significant enhancements to the supporting McIDAS software. McIDAS allows remote and local access to a wide range of data from satellites and conventional observations, time lapse displays of imagery data, overlaid graphics, and current and past meteorological data. Available software allows one to perform analysis of a wide range of digital images as well as temperature and moisture sounding data obtained from satellites. McIDAS can generate multicolor composites of conventional and satellite weather data, radar and forecast data in a wide variety of two- and three-dimensional displays as well as time lapse movies of these analyses. These and other capabilities are described in this paper.

Results on cloud motions on Venus obtained over a period of 3.5 days from Mariner 10 television images are presented. The implied atmosphere flow is almost zonal everywhere on the visible disk, and is in the same retrograde sense as the solid planet. Objective analysis of motions suggests the presence of jet cores (-130 m/s) and organized atmospheric waves. The longitudinal mean meridional profile of the zonal component of motion of the ultraviolet features shows presence of a midlatitude jet stream (-110 m/s). The mean zonal component is -97 m/s at the equator. The mean meridional motion at most latitudes is directed toward the pole in either hemisphere and is at least an order of magnitude smaller so that the flow is nearly zonal. A tentative conclusion from the limited coverage available from Mariner 10 is that at the level of ultraviolet features mean meridional circulation is the dominant mode of poleward angular momentum transfer as opposed to the eddy circulation.

The pressure sensor for the Tropical Wind Energy conversion and Reference Level Experiment (TWERLE) is described. Key design features of the sensor are: capacitive coupling, reference at midrange, up-down counting, passive oven, storage at flight pressure and prelaunch calibration. Sensor specifications are given which are based on the production results of 440 units. Drift, as estimated from simulated life tests, is 1 mb per 6 months. The overall weight of the sensor, including thermal package, is 180 g.

Previous Voyager 1 and 2 Jovian circulation measurements exhibit a large positive correlation between eddy momentum transports and the meridional shear of the zonal wind component, implying a very large rate of conversion of eddy kinetic energy of the zonal jets. Examination of the vectors mainly responsible for the correlation in our recent Voyager 2 global measurements indicates that it is probably caused by a biased sampling of prominent cloud features associated with circulating eddies. Intensive diagnostic measurements with more nearly uniform spatial sampling show no significant correlation in regions where our original measurements showed strong correlations. If the sampling bias mechanism is fully accounted for in all Jovian circulation measurements, the estimated eddy-to-mean-flow kinetic energy conversion rate may be reduced significantly.

The overall objective of this experiment is exploratory reconnaissance of Jupiter, Saturn, their satellites, and Saturn's rings. Such reconnaissance, at resolutions and phase angles unobtainable from Earth, can be expected to provide much new data relevant to the atmospheric and/or surface properties of these bodies. The experiment also has the following specific objectives

The autodetachment lifetime of the long-lived parent negative ion of hexafluorobenzene (C6F6) has been calculated theoretically and found to decrease with increasing electron energy. A comparison of the calculated and the measured lifetimes of the C6F–*6 ion indicated that only ∼30 % of the possible modes of vibration effectively participate in the sharing of the ion's excess energy.

Voyager 2, during its encounter with the Jupiter system, provided images that both complement and supplement in important ways the Voyager 1 images. While many changes have been observed in Jupiter's visual appearance, few, yet significant, changes have been detected in the principal atmospheric currents. Jupiter's ring system is strongly forward scattering at visual wavelengths and consists of a narrow annulus of highest particle density, within which is a broader region in which the density is lower. On Io, changes are observed in eruptive activity, plume structure, and surface albedo patterns. Europa's surface retains little or no record of intense meteorite bombardment, but does reveal a complex and, as yet, little-understood system of overlapping bright and dark linear features. Ganymede is found to have at least one unit of heavily cratered terrain on a surface that otherwise suggests widespread tectonism. Except for two large ringed basins, Callisto's entire surface is heavily cratered.

Voyager 2 images provide a basis for detailed study of the morphology and circulation of Saturn's northern midlatitudes. Both Saturn's large-scale cloud bands and the distribution of its local cloud features have a characteristic zonal organization. The region between 30 N and 45 N contains two oppositely directed jets in close proximity, with many bright, active features in the westward jet, and an unusual ribbonlike wave feature encircling the planet in the eastward jet. Several of the smaller features within the westward jet do not remain at fixed latitudes and interact with each other. One group of v-shaped features is found to have periods of high activity correlated with the passage of a cyclonic bright spot. The ribbon wave was Fourier analyzed to determine its spectral composition. The greatest power is near wave number 9, with significant additional peaks appearing at planetary wave numbers 19, 25-27, 35-38, and 47-51. The phase velocity increases with wave number but is not well described by a Rossby-Haurwitz dispersion relation. The curvature of the mean wind profile obtained from cloud tracking indicates that the westward jet exceeds the standard barotropic instability condition, while the eastward jet marginally exceeds the deep-circulation instability condition of Ingersoll and Pollard (1982). The rms eddy velocities on Saturn are less than half as large as those observed on Jupiter.

The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto.

The Pioneer Venus Small-Probe Net Flux Radiometer temperature sensor and its calibration, the thermal model of the sensor head, the procedure for deriving atmospheric temperature from the sensor temperatures, and the new temperature results for each entry probe are reported. The new results are compared with those of the Small-Probe Atmospheric Structure experiment and with simple models of diurnal and latitudinal temperature contrasts. A dynamical inconsistency between these results and low-latitude measurements by the Sounder probe is described, and possible ways to resolve it are considered.

The University of Wisconsin net flux experiment on the Pioneer Venus mission investigated the distribution of radiative energy deposition and loss which drives atmospheric circulation on Venus. The instrument used an external sensor and a novel method of chopping to measure the net flux of solar and planetary radiation during descent through the thick Venus atmosphere. The sensor, consisting of a high temperature flux plate detector and protective diamond windows, was designed to make accurate flux measurements while exposed to the severe Venus environment.

New Venus temperature profiles, derived from engineering measurements of the Small Probe Net Flux Radiometer (SNFR) instruments generally confirm to high accuracy the vertical structure and horizontal temperature contrast results of Seiff et al. /1/.

Voyager 2 photography has complemented that of Voyager I in revealing many additional characteristics of Saturn and its satellites and rings. Saturn's atmosphere contains persistent oval cloud features reminiscent of features on Jupiter. Smaller irregular features track out a pattern of zonal winds that is symmetric about Saturn's equator and appears to extend to great depth. Winds are predominantly eastward and reach 500 meters per second at the equator. Titan has several haze layers with significantly varying optical properties and a northern polar "collar" that is dark at short wavelengths. Several satellites have been photographed at substantially improved resolution. Enceladus' surface ranges from old, densely cratered terrain to relatively young, uncratered plains crossed by grooves and faults. Tethys has a crater 400 kilometers in diameter whose floor has domed to match Tethys' surface curvature and a deep trench that extends at least 270 degrees around Tethys' circumference. Hyperion is cratered and irregular in shape. Iapetus' bright, trailing hemisphere includes several dark-floored craters, and Phoebe has a very low albedo and rotates in the direction opposite to that of its orbital revolution with a period of 9 hours. Within Saturn's rings, the "birth" of a spoke has been observed, and surprising azimuthal and time variability is found in the ringlet structure of the outer B ring. These observations lead to speculations about Saturn's internal structure and about the collisional and thermal history of the rings and satellites.

A few Mariner 10 images of Venus have been 'normalized' to a standard scattering geometry using the exact solution by Chandrasekhar (1950) involving his H functions. The most striking feature of the normalized images is the bright polar ring or cap beyond about 50 deg latitude circle and a narrower brightness frequency distribution. The brightness variation along a meridian shows substantial axial symmetry on a large scale, and small-scale brightness variations over the planet are no more than about 10%. Inferences regarding the polar cloud tops in light of available evidence are discussed. The variation of mean brightness and of the ratio of mean square deviation of brightness to average brightness is comparable to the performance limits of the vidicon camera for the image sequence lasting about a day, so that the variation in distribution of dark and bright features over the planet and the UV albedo of the planet over about a day is small.

Long-wave radiation loss maps, based on Explorer VII measurements of terrestrial radiation at night, are analyzed and compared with composite nephanalyses and frontal analyses. Results indicate a definite relationship between the radiation centers and their corresponding surface low and high pressure centers, their locations, 24-hour intensifications and movements, and the conformity of these movements to the 500-mb. geostrophic flow. Some of the potential applications to analysis and forecasting are noted.

The results of a direct synoptic measurement of infrared radiation flux obtained in a simultaneous ascent of fifteen radiometersondes are presented. The area covered is central and western United States. Vertical profiles of temperature, humidity, net radiation, and the divergence of net radiation provide patterns of tropospheric and stratospheric radiation. Conclusions as to the level of maximum radiation divergence, cooling effects of clouds, causes of atmospheric instability, principal radiators, importance of water vapor above the tropopause, and tentative conclusions on high-level ozone heating effects are discussed.

A tornado-forecast tool based on surface thermal patterns is presented. The procedures and results of an operational test of this forecast tool are presented. The results of this test are evaluated and suggestions made for using this additional simple tool in conjunction with existing tornado forecasting techniques.

A d-c motor integrator amplifier is described in which the motor speed is made proportional to the input signal; accumulated number of revolutions represents the integrated input. Application is made to integration of solar radiation, using an input from an Eppley pyrheliometer.

A net radiometer of moderate accuracy but of simple construction and very low cost is described. The value of net radiation is obtained from the difference of fourth power temperatures of the upper and lower radiating surfaces. Conduction losses are held to a low value by employing a good insulating material and ventilation losses above and below are kept to a low value by two layers of thin polyethylene film. Field tests, calibration data, and applications are described. DOI: 10.1111/j.2153-3490.1958.tb01996.x

Study of an imaging experiment planned for the 1973 Mariner Venus/Mercury flyby mission. Scientific objectives are presented together with mission constraints, analysis of alternative systems, and the rationale for the final choice. The final selection was a vidicon camera quite similar to that used for Mariner Mars 1971, but with the capability of real time transmission during the Venus and Mercury flybys. Systematic high resolution UV photography of Venus is planned after encounter in an attempt to understand the nature of the mysterious UV markings and their apparent 4- to 5-day rotation period.

Signal enhancement is advanced as a method for isolating selected features of ATS images. The discussion covers enhancement theory, limitations, and one important application, the isolation of deep convection within tropical cloud clusters. Comparisons of brightness contoured ATS images with radar images from BOMEX test the validity of associating deep convection with very bright clouds. The enhancement technique is then applied in a census of Atlantic cloud clusters, and in case studies of individual clusters. It is shown that in spite of difficulties involving control of the ATS signal, enhancement is an effective, precise tool for isolating selected features of ATS images. Comparisons of ATS and radar images establish a high correlation of bright areas on ATS with large radar echoes; therefore, enhanced ATS pictures emphasizing the upper levels of the brightness range effectively isolate deep convection. The brightness structure of convective clouds is such that they can be studied over a three-to four-hour period around local noon on pictures uncorrected for changes of incident and reflected radiation. A simple cosine law correction for incident radiation can appreciably extend this period. The census and case studies show that the eastern Atlantic was at least as convectively active as the western Atlantic during June and July, 1969, and had a significantly greater total area of cloud clusters in 1969 and 1970. Convective cores have a great range of size, spacing, and lifetime: nevertheless, an ordering invariably can be perceived. This most often is in the form of lines or bands; waves, spirals, or solitary cores are also observed. Lifetimes are a few minutes to several hours or more; large cores last longer. Displacement of cloud clusters is accomplished by a complex combination of band and cell movement and propagation. Structure, as evidenced by core behavior, is varied and complex.

Monte Carlo simulations of the transport of Doppler‐broadened resonance radiation in certain ideal geometries are described. The results corroborate the usual local thermodynamic equilibrium assumption. Spectral line shapes, quenching probabilities, and resonance defects are discussed, and simple empirical formulations are noted.

A simple photographic averaging technique using multiple exposures is applied to ESSA III and V computer produced mosaics. Several examples, showing the distribution of clouds, snow, ice and vegetation cover for typical half month periods are presented and discussed. Large scale cloud bands about equatorial dry regions as well as preferred storm tracks are revealed.

Reflection of sunlight to space and absorption by earth and atmosphere using radiometer data from earth satellites

This paper develops an objective technique for estimating the mass and energy exchange in convection systems corresponding to altocumulus cumulogenitus and cumulonimbus intensities using measurements of the area change of the cirrus outflow on a sequence of satellite cloud photographs obtained at geostationary altitude. The data clearly show that: (1) the technique is able to isolate vigorous and moderate convection regimes on the geostationary satellite cloud photos; and (2) the model-estimated mass and energy are consistent with ground-based measurements such as those of Braham and Brown.

This paper summarizes an extended time series of measurements of the earth's radiation budget from the first and second generation United States meteorological satellites. Values of planetary albedo, infrared radiant emittance, and the resulting net radiation budget are now available for 39 months during the period 1962–66. These measurements show a mean global albedo of 30%, and net radiation balance within measurement accuracy. The discussion treats global and zonally averaged values for the “mean annual” case, for “mean seasons,” and includes a comparison of measurements during the same seasons in different years. The role of these radiation budget measurements in the total global energy balance is noted.

An analysis of tropical radiosonde temperature measurements made during the Line Island Experiment suggests that conventional radiosonde preflight procedures are inadequate in a remote tropical environment. Temperatures computed from conventional and modified baseline techniques are compared at five pressure surfaces, 1000, 800, 600, 400 and 200 mb. Temperatures obtained from the two baseline techniques showed an average deviation at 1000 mb of 0.96C for 62 soundings. These comparisons indicate that a careful examination of radiosonde calibration techniques is needed before large investments are made in future global experiments.

This paper reports on a digital measurement (“chirp”) system which has application for a wide range of meteorological and earth satellite measurements. The system employs a simple concept in which a voltage pulse, proportional to a sensor voltage, is used to generate a burst of pulses from a voltage controlled oscillator (VCO). A count of the high frequency oscillations which make up the “chirp” provides the digital measurement. The system is adapted to multiple sensor use with a multiplexer. The system has the advantage in that one has the option of selecting an ac amplifier for low level signals in conjunction with a variety of multiplexers and VCO for the desired measurement. One particular combination of multiplexer and VCO was used to demonstrate its use as a digital radiosonde. A flight test of the digital radiosonde was obtained. Results clearly show fine structural detail in the temperature profile without any need for subjective interpretation by the operator. Numerous isothermal and inv...

Observations of the net vertical flux divergence of ir radiation is correlated with the outward flux at the top of the atmosphere

Study of time series of areal cloud coverage over the central Pacific to determine the large-scale variations of tropical disturbance activity for a four-month period in 1967. The persistent and fluctuating components are found to be more prevalent in regions of high and low mean cloudiness, respectively, with major longitudinal variations in activity most evident in the Southern Hemisphere. Normalized power spectra show that the transient activity occurring in the equatorial zone is dominated by shorter periods of about four days, while longer periods are dominant away from the equator. Coherency magnitudes and phases between different locations indicate that propagating cloud systems are most identifiable at lower frequencies in the Southern Hemisphere, and at somewhat higher frequencies in the Northern Hemisphere. Activity with periods in excess of five days consists largely of both westward and eastward propagation on the planetary wave scale. The shorter periods appear to consist of both synoptic-scale and planetary-scale modes, with westward propagation dominant near the equator.

An analog data reduction system for obtaining variance spectra of stationary time series is described and its accuracy is discussed. This equipment was developed to reduce data obtained with the sonic anemometer. The variance spectra of the vertical wind component observed with the sonic anemometer in 1953 at O'Neill, Nebraska, are presented in Table 1.

Following a short discussion of the limitations of the various types of balloon‐borne radiosondes when used to gather information in the stratosphere, an analysis of the reasons for these limitations and some means for circumventing them are presented. It is shown that the choice of sensing element, or transducer, for temperature measurement is rather arbitrary so long as the element possesses a small lag coefficient and a high albedo. For pressure measurement it is shown that a nonlinear transducer, such as the hypsometer, with a sensitivity which increases at low pressure, is essential. For humidity measurement, only the condensation (dew point) technique is capable of giving meaningful data at great heights. The balance of the paper describes in detail a complete sounding instrument consisting of a hypsometer, a fine‐wire thermo junction, and a fully automatic electronic dew‐point hygrometer, together with the necessary amplifier, radio telemetering equipment, and internal calibration standard. The tel...

In an experiment to verify the effect of convection and air conduction on the economical net radiometer, a flux plate type of radiometer, along with its required d-c amplifier, was designed, built, and flown with a radiosonde. Two such flights were made. The net radiation values given by the flux plate agreed well with the values given by the economical net radiometer, showing that convection does not occur in nighttime use of the economical radiometer and that the air conductivity function being used is valid. An estimate is given of the precision of radiative cooling values which can be obtained from economical radiometer data.

Recent developments in aerospace technology make it possible to probe all regions of the atmosphere. Suitable sensors for taking observations in all regions do not yet exist. Electronics scientists and engineers are usually not familiar with these problems but they have the knowhow needed to solve them technically. Meteorological rockets, special observations from satellites and indirect probes are discussed briefly as examples. Evidently more contact between electronic and atmospheric scientists could yield a significant increase in our understanding of the atmosphere.

An improved net-radiation instrument for measuring the net flux of radiant energy through a surface parallel to the earth's surface, which employs the principle of exposing a ventilated radiation-absorbing element to the radiation sources, is described. The importance of providing similar ventilation on both sides of the absorbing plate is pointed out, and the control features to insure this uniformity are described. A method of reducing the error due to the variation of the absorptivity of the blackened surface with wave-length is discussed. The performance of the instrument and the possible errors are described. It was found that the instrument is capable of giving net-radiation measurements accurate to within two per cent.

Thin layers of particulates or clouds in the high troposphere and lower stratosphere are generally not visible to an observer at the surface, even under the favorable viewing conditions at sunset. They are not easily detected by a television camera in a satellite from above. Yet these layers affect upwelling infrared flux. A flight program, employing balloon-borne radiometers and a jet aircraft from which visual observations of particle layers were made, was conducted to measure the attenuating effects of these layers on upwelling. terrestrial flux. An estimate of the error such attenuation can cause in surface temperatures deduced from the upward flux measurement was then made. The balloon-borne radiometers were launched from a desert area of California. During the ascents the presence of cirrus or particle layers could not he visually or photographically detected from the surface. They were, however, detected by the radiometer during ascent and by observers in a jet aircraft. The observations i...

Results and conclusions drawn from 50 radiometer-sonde ascents over Wisconsin are presented. Atmospheric infrared radiation flux is separated into upward, downward, and net components. Radiation divergence and resulting cooling are computed. Seasonal averages of these direct observations are compared.

Following a brief review of the assumptions involved in the usual (Laplacian) expression for the speed of sound waves, an instrument, the sonic thermometer, is described which utilizes this relationship to measure the air temperature. The advantages of the sonic thermometer are then discussed, the main advantages being the absence of radiational errors and extremely low lag—a result of the fact that the measured variable, the speed of sound, is independent of the properties of the measuring elements.

INTRODUCTION In teaching the calculus sequence one talks about centroids, moments of inertia and radii of gyration; volumes of revolution; pressure and total force on submerged planar areas; moments of force and the center of fluid pressure and perhaps even the products of inertia. These integrals are related to one another. Collected here together are several isolated results which do not appear, to my knowledge, in any one book and a new result about the center of fluid pressure coordinate other than the depth of the center of fluid pressure, which is the one usually discussed. It is assumed that the necessary definitions of centroids; moments of area, volume, force and inertia; radius of gyration; and the center of fluid pressure are the usual ones.(3 ) Suppose A is the area of one side of the enclosed region, R, lying wholly within the first quadrant, which is completely submerged in a fluid of uniform volume density, W. If the y-axis lies in the surface of the liquid and the positive x-axis is in the direction of gravity, then the fluid pressure per unit area at a depth x below the surface is given by Wx.(:) The following integrals are meaningful. (See Figure 1.)