ALBERT

Description: This paper presents the results of a series of total and spectral solar irradiance measurements made at ground surface (Table Mountain Facility, Calif., altitude 2.18 km). The spectral irradiance data are presented for the 0.3-3.0-micron spectral region for air mass 1.5.

Description: A proposal for a multi-institutional investigation of the processes involved in the growth and maintenance of high level extended clouds is presented. Mapping of variability of the cloud and of its radiative characteristics in terms of the meteorological environment of the cloud; performance of case studies involving observation of the cloud microphysics and radiation characteristics; and investigation of the processes responsible for the generation, maintenance, and dissipation of the cloud system are recommended. Both modeling and monitoring activities are considered. The specific research projects which the author proposes to carry out are described. Suggestions for the administrative organization of the total effort are presented.

Description: The interplay of the various physical processes involved in the formation, maintenance, and decay of middle and upper tropospheric stratiform clouds is discussed. Ice phase fair weather cloud forms are considered. Simulations of cirriform clouds which attempt to incorporate the physical processes in an interactive manner were performed. A two dimensional time dependent Eulerian numerical model, which incorporates all of the important physical processes in a simplified way, is employed to investigate the role of these processes in the evolution of a cloud in an isolated atmospheric layer. Physical parameters considered are the eddy viscosity and the thermal, water vapor, and ice water eddy diffusivities.

Description: The geostationary and polar satellites comprising the current operational system are discussed. The data acquisition capabilities of both satellite types and their complementary functions are reviewed. The advanced very high resolution radiometer on the TIROS N satellites is particularly addressed along with the imaging and atmospheric sounding instrumentation aboard the GOES satellites. The dissemination of the satellite data to the prospective users is also discussed.

Description: Stratospheric limb radiance profiles versus altitude of closest approach of the line of sight to the Earth's surface have been measured before and after the Mount St. Helens eruptions by means of photographs taken from a Sun-oriented balloon gondola floating above 35 km altitude over France. Preliminary data were reported for flights in October 1979 and in May and June 1980. The radiance integrated along the line of sight as in-situ radiance (R) can be derived taking into account absorption by ozone and air. The onion peeling inversion method was used to derive the vertical radiance (R) profiles respectively. The values of R were determined in the solar azimuth. The solar elevation angles are chosen larger for the backscattering observation than for the forward scattering observation to deal with as similar illumination conditions as possible despite the Earth's sphericity.

Description: Microscopical investigation of volcanic ash collected from ground stations during Mount St. Helens eruptions reveal a distinctive bimodel size distribution with high concentrations of particle ranges at (1) 200-100 microns and (2) 20-0.1 microns. Close examination of individual particles shows that most larger ones are solidified magma particles of porous pumice with numerous gas bubbles in the interior and the smaller ones are all glassy fragments without any detectable gas bubbles. Elemental analysis demonstrates that the fine fragments all have a composition similar to that of the larger pumice particles. Laboratory experiments suggest that the formation of the fine fragments is by bursting of glassy bubbles from a partially solidified surface of a crystallizing molten magma particle. The production of gas bubbles is due to the release of absorbed gases in molten magma particles when solubility decreases during phase transition. Diffusion cloud chamber experiments strongly indicate that sub-micron volcanic fragments are highly hygroscopic and extremely active as cloud condensation nuclei. Ice crystals also are evidently formed on those fragments in a supercooled (-20 C) cloud chamber. It has been reported that charge generation from ocean volcanic eruptions is due to contact of molten lava with sea water. This seems to be insufficient to explain the observed rapid and intense lightning activities over Mount St. Helens eruptions. Therefore, a hypothesis is presented here that highly electrically charged fine solid fragments are ejected by bursting of gas bubbles from the surface of a crystallizing molten magma particles.

Description: The direct solar radiation transmission record at Mauna Loa, dating from 1958 to the present, revealed with remarkable precision the presence of stratospheric aerosol from volcanic activity. This record can be used to quantify the intensity of the stratospheric volcanic aerosol perturbation following a significant eruption in reference to the Agung event in 1963. The Mount St. Helens' stratospheric cloud was first detected by lidar at 18 km over Mauna Loa on 17 July. The atmospheric transmission was seen to decrease slightly after that time, but only a few tenths of 1 percent. Although it is still fairly early to draw a definite conclusion on the ultimate magnitude of the Mount St. Helens stratospheric aerosol from the Mauna Loa results, it can be stated that the stratospheric aerosol optical depth presently observed is comparable with that observed from Fuego which erupted in 1974. At Boulder, Colorado, the atmospheric debris from Mount St. Helens was observed by lidar on a number of occasions. Also, observations of the diffuse, total and direct transmission of solar radiation were made on June 3 and 4. The latter set of observations is useful for deriving information on the scattering properties of the volcanic cloud. The lidar and solar radiation data are presented and some of their special features are discussed.

Description: Samples of stratospheric aerosols collected with U-2 aircraft for several months following the first three major eruptions of Mount St. Helens were analyzed for ash and liquid acid content. Ash grain sizes and compositions vary depending on collection altitude, location within the drifting cloud, and days following their injection. s computers Size distributions of ash particles vary with altitude. Generally small particles are depleted more rapidly at low altitudes (12 km) than at higher altitudes (17-18 km). Although samples collected 1 day after the first eruption of May 18, 1980, were dry, flow marks on the aircraft indicated parts of the cloud contained heavy acid concentrations. Indeed, all other samples obtained within 1 to 4 days after later eruptions (May 25 and June 12, 1980) were covered with copious amounts of liquid acid. Proportions of liquid to ash varied considerably depending on sampling location and cloud age. Because the acid-coated ash globules were large, they rapidly fell from the stratosphere until, by late June 1980, only a residue of acid droplets remained. Size distributions and concentrations of these droplets varied considerably.

Description: Programs for the development and operation of meteorological satellites from the TIROS 1 satellite and the establishment of NASA through the 1960's are described. The technical problems confronted in the development of the early satellite systems are discussed in addition to issues in international involvement and program support. The TIROS and Nimbus series satellites are primarily addressed.

Description: By using the most complete available records of direct beam radiation and volcanic eruptions, an historical analysis of the role of the latter in modulating the former was made. A very simple fallout and dispersion model was applied to the historical chronology of explosive eruptions. The resulting time series explains about 77 percent of the radiation variance, as well as suggests that tropical and subpolar eruptions are more important than mid-latitude eruptions in their impact on the stratospheric aerosol optical depth. The simpler climatic models indicate that past hemispheric temperature can be stimulated very well with volcanic and CO2 inputs and suggest that climate forecasting will also require volcano forecasting. There is some evidence that this is possible some years in advance.

Description: Visible and infrared pictures from two Geostationary Operational Environmental Satellite Systems satellites, in circular orbits at about 19,000 nautical miles, are available continuously at approximately 30 minute intervals. Still pictures and film loops from this system vividly depict the events associated with the May 18, 1980 eruption of Mount St. Helens. The initial explosion, shock wave, and visible horizontal dust distribution during the following week are readily apparent. Meteorological wind and height fields permit the inference of the vertical distribution of volcanic dust as well as explain the atmospheric behavior which caused the visible and nonvisible dust distribution.

Description: Examples of the use of geostationary satellites in meteorology are given. Studies of the rate of change of cumulus clouds and cloud systems and wind parameter determination from cloud motions are reviewed. Computer processed imagery products are also discussed.

Description: The Defense Meteorological Satellite Program is described with particular emphasis on the military applications of METSAT data. Satellite operational support, data processing and image quality requirements are discussed.

Description: A historical overview of the pioneer projects for the development of meteorological satellites is given. In addition, the parallel development of the responsible space agencies and panels is addressed. The Vanguard 2 satellite, the first Earth radiation experiment, and the vidicon equipped TIROS-1 satellite are discussed.

Description: A brief review of the effects of climate and weather on the 1980 Mount St. Helens eruptions and the subsequent dispersion of ash and gases and the reciprocal influences of the eruptions on climate and climatology is presented. The effects of mesoscale destruction of snow fields and vegetation, a revised mountain profile, and ash deposits are addressed along with impacts on hemispheric climate and disruption of normal climatological observations, in the areas directly affected by the explosions and ashfall. Environmental and economic consequences are also considered.

Description: Geographic coverage frequency and geographic shot density for a satellite borne Doppler lidar wind velocity measuring system are measured. The equations of motion of the light path on the ground were derived and a computer program devised to compute shot density and coverage frequency by latitude-longitude sections. The equations for the coverage boundaries were derived and a computer program developed to plot these boundaries, thus making it possible, after an application of a map coloring algorithm, to actually see the areas of multiple coverage. A theoretical cross-swath shot density function that gives close approximations in certain cases was also derived. This information should aid in the design of an efficient data-processing system for the Doppler lidar.

Description: Calculation of eletric field vectors within and near an isolated thundercloud (which has a given volume charge distribution) is envisaged. The maximum field strength within the thundercloud is calculated. The effects of screening layers, both above and below the thundercloud may be investigated, as well time-dependent potential problem. The study can lead to a better understanding of the charge distributions in a thundercloud, which in turn may shed some light on the actual mechanism of charging of a thundercloud.

Description: Future developments in satellite meteorology are proposed and examined in the light of policy and funding changes.

Description: Atmospheric and surface fields produced from the TIROS N high resolution infrared sounder/microwave sounding unit data are discussed. The data were analyzed by direct physical inversion of the multispectral radiative transfer equation. Sea ice mapping and sea surface temperature determination are addressed.

Description: Some of the research opportunities that are available from geostationary satellite data, especially from MONEX during the Global Weather Experiment are described. In addition, the International Cloud Climatology Program is described and the use of satellite imagery in studying mesoscale convection complexes is discussed. Finally, information derived from satellite data on ocean winds is examined.

Description: Nineteen stratospheric samples from the eruption plumes of Mount St. Helens were collected in five flight experiments. The plume samples were collected at various altitudes from 13.1 to 20.7 km by using the Ames cryogenic sampling system on board the NASA U-2 aircraft. The enriched, cryogenically collected samples were analyzed by chromatography. The concentrations of aerosols precursor gases (OCS, SO2, and CS2), CH3Cl, N2O, CF2Cl2, and CFCl3 were measured by gas chromatography. Large enhancement of the mixing ratio of SO2 and moderate enhancement of CS2 and OCS were found in the plume samples compared with similar measurement under pre-volcanic conditions. A fast decay rate of the SO2 mixing ratio in the plume was observed. Measurement of Cl(-), SO2(2-), and NO3(-) by ion chromatography was also carried out on water solutions prepared from the plume samples. The results obtained with this technique imply large mixing ratios of HCl, (NO + NO2 + HNO3), and SO2, in which these constituents are the respective sources of the anions. Measurement of the Rn222 concentration in the plume was made. Other stratospheric constituents in the plume samples, such as H2O, CO2, CH4, and CO, were also observed.

Description: Mount St. Helens erupted somewhat less than 0.5 cu km of magma (dense rock equivalent) on May 18, 1980. The May 18 event was usually violent. As much 35% of the volume of the airfall material fell outside of the 2.5 mm isopach, which encloses about 88,000 sq km. This extraordinary dispersive power was transmitted by an eruption column which reached heights of more than 20 km. There was a lateral blast (or surge) of unusually large dimensions associated with the onset of the eruption. The magma is dacitic in composition and had a low ( 500 ppm) sulfur content. Distal ashes contain much nonmagmatic (lithic) material, but smaller ( 50 microns m) particles are mostly finely divided magmatic dacite. The grain size distributions of the ash are multimodal, frequently with peaks at 90, 25, and 10 microns. The finer populations fell out faster than their terminal velocities as simple particles would suggest. It is inferred that large proportions of the fine ash fell out as composite particles. This condition greatly reduces the atmospheric burden of silicate particles. Some of the unusual aspects (violence, intense surges, multimodal grain size distributions, lithic content of the ashes) of the eruption may be due to its phreatomagmatic character. The hydrothermal system above the magma may have infiltrated the magma body at the onset of the eruption. An "overprint" of the geochemistry of this hydrothermal system on the geochemistry of the magmatic gas system is likely. One important feature is that reduced gas species may be much more abundant than in many eruptions. Another is that fine ash may form aggregates more readily.

Description: The evidence that volcanic eruptions affect climate is reviewed. Single explosive volcanic eruptions cool the surface by about 0.3 C and warm the stratosphere by several degrees. Although these changes are of small magnitude, there have been several years in which these hemispheric average temperature changes were accompanied by severely abnormal weather. An example is 1816, the "year without summer" which followed the 1815 eruption of Tambora. In addition to statistical correlations between volcanoes and climate, a good theoretical understanding exists. The magnitude of the climatic changes anticipated following volcanic explosions agrees well with the observations. Volcanoes affect climate because volcanic particles in the atmosphere upset the balance between solar energy absorbed by the Earth and infrared energy emitted by the Earth. These interactions can be observed. The most important ejecta from volcanoes is not volcanic ash but sulfur dioxide which converts into sulfuric acid droplets in the stratosphere. For an eruption with its explosive magnitude, Mount St. Helens injected surprisingly little sulfur into the stratosphere. The amount of sulfuric acid formed is much smaller than that observed following significant eruptions and is too small to create major climatic shifts. However, the Mount St. Helens eruption has provided an opportunity to measure many properties of volcanic debris not previously measured and has therefore been of significant value in improving our knowledge of the relations between volcanic activity and climate.

Description: The goals of map/wind (winter in Northern Europe) are to better understand: (1) the interaction of planetary waves of tropospheric origin; (2) the temporal and spatial development of sudden stratospheric warmings; (3) the temporal and spatial development of mesospheric cooling events in conjunction with stratospheric warmings; (4) the vertical and horizontal transport of minor constituents; (5) the effects on the chemistry of neutral and charged species of the large temperature changes occurring during stratospheric warmings and mesospheric cooling; (6) sources of turbulent energy; (7) the temporal and spatial development of turbulent layers; and (8) the contributions of dynamical processes to the heating and cooling of the mesospheric and turbopause region.

Description: Three general areas of study were identified: stratospheric composition; mesospheric and lower ionospheric structure and composition; and middle atmospheric dynamics. The role of chemical reactions and spectroscope in the study of the middle atmosphere is discussed.

Description: Organizations in the United States which are interested in MAP participation were surveyed. Satellites, rockets, balloons, and ground support systems are listed with available experimentation.

Description: The plans for India's participation in the middle Atmosphere Program are outlined.

Description: Several hundred topside ionograms were used to study simulated wave-particle interactions in the ionosphere. The study combined the benefits of high-frequency-resolution Alouette 2 analog sounder data with advanced digital graphics techniques. The study shows that the sounder phase can cause significant plasma heating when the plasma parameter is confined to specific ranges. The observations support the Harris instability generation process and the nonlinear Landau damping maintaining process for long-duration diffuse resonances. The observations also suggest that the so-called Q resonances have characteristics which imply that generation processes in a sounder-stimulated plasma turbulence may be involved.

Description: A simplified, time-dependent energy balance climate model is run at the latitude belt 40-50 deg N. The model solves for the temperatures of the land, air, and 12 vertical oceanic layers, and it includes a wind stirred mixed layer. A change in model ocean optical turbidity from relatively clear (Jerlov 1) to particle rich (Jerlov III) conditions decreases the effective thickness of the oceanic layer in which heat is stored seasonally and increases the seasonal variation of sea surface temperature by 2-3 C. A decrease in the liquid water content of clouds by a factor of 4 warms the model climate and increases the seasonal variation of sea surface temperatures by 2-3 C. A 2-3 C change in the seasonal variation of sea surface temperature is also obtained by varying oceanic mixing through a factor of 2 change in the surface wind speed.

Description: Empirical Orthogonal Functions (EOF's), eigenvectors of the spatial cross-covariance matrix of a meteorological field, are reviewed with special attention given to the necessary weighting factors for gridded data and the sampling errors incurred when too small a sample is available. The geographical shape of an EOF shows large intersample variability when its associated eigenvalue is 'close' to a neighboring one. A rule of thumb indicating when an EOF is likely to be subject to large sampling fluctuations is presented. An explicit example, based on the statistics of the 500 mb geopotential height field, displays large intersample variability in the EOF's for sample sizes of a few hundred independent realizations, a size seldom exceeded by meteorological data sets.

Description: A study has been conducted to determine the cause of a major synoptic difference in the 72 h GLAS model forecasts from 0000 GMT 19 February 1976 that resulted from the inclusion of satellite data. The prognostic differences that resulted in diverging cyclone paths between the forecast that included satellite temperature soundings (SAT) and the forecast that excluded satellite sounding data (NOSAT) have been traced to initial state differences in the upper level wind and temperature patterns. These modifications enhanced the variation of thermal vorticity and thermal advection across the cyclone center and in the SAT case, gave a greater initial rate of movement of the upper-level vorticity maximum associated with the surface cyclone.

Description: Storms on 20 May 1977 generated a vast cirrus deck. Disturbed areas at storm top had equivalent black-body temperatures (T sub BB) much lower than the tropopause temperature, indicative of overshooting tops. The area of T sub BB not greater than -71 C represents the area of convective activity penetrating 2 km above the tropopause. This area was relatively large after cloud tops and radar reflectivities reached their maximum heights. It became much smaller during tornadoes when reflectivities were decreasing. T sub BB was at a minimum at the time of mesocyclone formation. The Del City storm had two periods of growth, as indicated both by reflectivities and the T sub BB areas. The mesocyclone was first detected during the second less intense period of growth; the tornado occurred during decreasing reflectivities. The maintenance of large areas of relatively low T sub BB after tornado dissipation is ascribed to continued convection on the flanks of the storm and to residual updrafts in a thick anvil cloud.

Description: The effect of horizontal model resolution on satellite data impact has been studied for two versions of the GLAS second-order general circulation model: the C-model with a 4-deg latitude by 5-deg longitude resolution and the F-model with a 2.5-deg latitude and 3-deg longitude resolution. It is found that the 48-72 h forecast skill of the GLAS model was significantly improved by the increased resolution. Initial state differences between the SAT and NOSAT cycles using the F-model were on the average smaller than the corresponding differences with the C-model. However, the F-model cycle differences exhibited a smaller scale structure and, in some cases, larger gradients.

Description: Estimates are made showing that, as a consequence of rocket activity in the earth's upper atmosphere in the Shuttle era, average ice nuclei concentrations in the upper atmosphere could increase by a factor of two, and that an aluminum dust layer weighing up to 1000 tons might eventually form in the lower atmosphere. The concentrations of Space Shuttle ice nuclei (SSIN) in the upper troposphere and lower stratosphere were estimated by taking into account the composition of the particles, the extent of surface poisoning, and the size of the particles. Calculated stratospheric size distributions at 20 km with Space Shuttle particulate injection, calculated SSIN concentrations at 10 and 20 km altitude corresponding to different water vapor/ice supersaturations, and predicted SSIN concentrations in the lower stratosphere and upper troposphere are shown.

Description: Digital time series data at 16 heights within two storms were collected at vertical incidence with a 10-cm Doppler radar. On several occasions during data collection, lightning echoes were observed as increased reflectivity on an oscilloscope display. Simultaneously, lightning signals from nearby electric field change antennas were recorded on an analog recorder together with the radar echoes. Reflectivity, mean velocity, and Doppler spectra were examined by means of time series analysis for times during and after lightning discharges. Spectra from locations where lightning occurred show peaks, due to the motion of the lightning channel at the air speed. These peaks are considerably narrower than the ones due to precipitation. Besides indicating the vertical air velocity that can then be used to estimate hydrometeor-size distribution, the lightning spectra provide a convenient means to estimate the radar cross section of the channel. Subsequent to one discharge, we deduce that a rapid change in the orientation of hydrometeors occurred within the resolution volume.

Description: The influence of the geographical distribution and the number of the surface stations in the ozone detecting network on changes in global ozone inferred from the surface measurements is investigated by comparison with information obtained from satellite backscattered UV observations on the Nimbus 4 with nearly complete global coverage for the period 1970-1972. Results show that the geographical distribution of the stations does not properly represent different latitudes. While the number of stations in the north temperate zone appears adequate to represent monthly ozone averages to within 0.5% except during the early phase of the Northern Hemisphere spring maximum, the resultant error in the derived change in north temperature zone ozone between 1970-1972 is 0.5%. In the tropical and south temperate zones the smaller number of stations reduces precision, and the ozone averages for use in deriving seasonal variability and trends are uncertain by about 1%. However, in the south temperature zone, the average from the sample may differ as much as 5% in some months from the averages derived from the full set. It is concluded that the resulting uncertainty in the global averages is comparable in size to typical yearly changes.

Description: The effects of the earth's atmosphere on the Thematic Mapper (TM) measurements are studied with two radiative transfer models. A doubling model is used to compute the effective reflectance of the earth-atmosphere system, as measured by the TM for the reflective bands. An emission-transmission model is used to compute the satellite-received radiance for the thermal band. The influences of the aerosol loading, the amount of water vapor, and the solar illumination angle on the effective reflectance are investigated. The effect of varying atmospheric water vapor on the measurements of the thermal band is studied. The scattering and absorption effects on TM bands are compared with those on Multispectral Scanner System (MSS) bands. While the changes in the aerosol loading introduce comparable variation of the effective reflectance for both sensors, the changes in the water vapor amount give less impact on TM4 than MSS7.

Description: Solar ultraviolet flux data obtained within the atmosphere by using Fastie-Ebert double monochromators carried on a balloon-borne gondola and a rocket payload are analyzed. Both the direct and scattered components of the solar ultraviolet flux at wavelengths from 190 to 320 nm are measured at the balloon float altitude of 40 km. The nearly identical spectrometer carried on the rocket flight measures the direct solar flux from 60 to 38 km during a parachute descent. The ozone column content above 40 km and the temperature profile and ozone density below 40 km are deduced using the scattered and direct solar flux components. It is shown that the Nimbus 7 solar flux data are consistent with the present data and with the ozone absorption cross sections of Inn and Tanake (1959). The calculated and measured values of the scattered solar flux are found to agree fairly closely.

Description: The influence of the choice of the Lagrange multiplier on constrained linear inversions is explored, with reference made to applications in inferring the columnar aerosol size distributions from spectral aerosol optical depth measurements. A range of the Lagrange multiplier is examined to find all positive solutions for the solution vector, which represents modifying factors to the assumed form of the size distribution. An iterative method is devised to constrain the calculations to consideration of only positive quantities and a requirement that the regression fit to data be consistent with measurement errors. The determination of the variances and covariances is formulated and applied to existing data sets for optical depth. Variances in the solution are found to be large for particle radii when the information content of the data is small.

Description: To investigate the possibility that significant amounts of tropical tropospheric air may be convectively introduced into the stratosphere, aerosol samplings over Panama were made at various altitudes using a wire impactor collector. The percentage of particle sizes less than the mean mode decreases with height above the tropopause, suggesting depletion of small particles, possibly due to coagulation. Larger aerosols (greater than 0.3 micron in diam.) are more abundant farther above the tropopause, indicating growth, mainly by condensation. The total particle concentration decreases with increasing height above the tropopause, and also with increasing temperature. Aerosols containing smaller-size particles are thus found closer to the tropopause, and larger-size, more-evolved aerosols occur at higher altitudes. These data indicate that convective activity at the Intertropical Convergence Zone may be a source mechanism for stratospheric aerosols.

Description: Although mean circulations are generally credited with dehydration of the earth's stratosphere, convective instability in the tropics converts mean circulations to small residuals of local convective circulations. The effects of large cumulonimbus which penetrate the stratosphere and form huge anvils in the lower stratosphere are discussed with respect to hydration and dehydration of the stratosphere. Radiative heating at anvil base combined with cooling at anvil top drives a dehydration engine considered essential to explain the dry stratosphere. Seasonal and longitudinal variations in dehydration potentials are examined with maximum potential attributed to Micronesian area during winter and early spring.

Description: New line assignments in the spectrum of the stratospheric submillimeter emission, measured with unapodized resolution of 0.0033/cm, have been made. Positive evidence for the presence of symmetric and asymmetric ozone isotopes, water vapor excited to the (010) level, and HCN is given.

Description: The sensitivity of a Goddard Laboratory for Atmospheric Sciences global objective analysis cycle to the addition of FGGE level II-b data is assessed. The GOAS system comprises a predictive continuity provided by a model first-guess forecast integrated from a previous forecast and updated by data gathered in the interim. FGGE data originated in the Jan.-Mar. 1979 period and were acquired by rawinsondes, pilot balloons, surface stations, satellites, ships, and drifting buoys deployed during SOP-1. Focussing on 2-5 and 8-day forecasts, comparisons were made of the 6 hr forecast error at the 300 mb height in three experiments using all, no-satellite (NOSAT), and without rawinsondes or pilot balloons modes. Larger errors occurred in the case of NOSAT, while significant corrections to the GOAS predictions were noted using all the FGGE data. It was concluded that all forecasts were improved by inclusion of full FGGE data sets, including forecasting beyond one week.

Description: During its April 1979 eruption series, Soufriere Volcano produced two major stratospheric plumes that the SAGE (Stratospheric Aerosol and Gas Experiment) satellite system tracked to West Africa and the North Atlantic Ocean. The total mass of these plumes, whose movement and dispersion are in agreement with those deduced from meteorological data and dispersion theory, was less than 0.5 percent of the global stratospheric aerosol burden; no significant temperature or climate perturbation is therefore expected.

Description: At the time of the Soufriere, St. Vincent, volcanic eruption of April 17, 1979, a NASA P-3 aircraft with an uplooking lidar (light detection and ranging) system onboard was airborne 130 kilometers east of the island. Lidar measurements of the fresh volcanic ash were made approximately 2 hours after the eruption, 120 kilometers to the northeast and east. On the evening of April 18, the airborne lidar, on a southerly flight track, detected significant amounts of stratospheric material in layers at 16, 17, 18, and 19.5 kilometers. These data, and measurements to the north on April 19, indicate that the volcanic plume penetrated the stratosphere to an altitude of about 20 kilometers and moved south during the first 48 hours after the eruption.

Description: Observations of increases of stratospheric condensation nuclei suggest a photo-initiated sulphuric acid vapour formation process in spring in polar regions. It is proposed that the sulphuric acid rapidly forms condensation nuclei through attachment to negatively charged multi-ion complexes and that the process may be modulated through variations in solar activity.

Description: Orographically-induced lee-wave clouds were observed over New Mexico by a multichannel scanning radiometer on Skylab during December 1973. Channels centered at 0.83, 1.61 and 2.125 microns were used to determine the cloud optical thickness, thermodynamic phase and effective particle size. An additional channel centered at 11.4 microns was used to determine cloud-top temperature, which was corroborated through comparison with the stereographically determined cloud top altitudes and conventional temperature soundings. Analysis of the measured near-infrared reflection functions at 1.61 and 2.125 microns are most easily interpreted as indicating the presence of liquid-phase water droplets. This interpretation is not conclusive even after considerable effort to understand possible sources for misinterpretation. However, if accepted the resulting phase determination is considered anomalous due to the inferred cloud-top temperatures being in the -32 to -47 C range. Theory for the homogeneous nucleation of pure supercooled liquid water droplets predicts very short lifetimes for the liquid phase at these cold temperatures. A possible explanation for the observations is that the wave-clouds are composed of solution droplets. Impurities in the cloud droplets could decrease the homogeneous freezing rate for these droplets, permitting them to exist for a longer time in the liquid phase, at the cold temperatures found.

Description: When a global atmospheric basic state has constant angular velocity and its temperature varies with altitude only, there exist normal mode solutions to the linearized global primitive equations. The use of these normal modes, which have known behavior in time, is superior to the use of the Rossby-Haurwitz wave as initial conditions for detecting errors in the dynamics part of primitive equation global models. With these initial conditions, integration through only one time step is sufficient to detect many formulation and coding errors. Other tests are still required for detecting problems of nonlinear instability and conservation of integral properties, however.

Description: Advances in satellite tracking data accuracy and coverage over the past 15 years have led to major improvements in global geopotential models. But the spacial resolution of the gravity field obtained solely from satellite dynamics sensed by tracking data is still of the order of 1000 km. Attention is given to an approach which will provide information regarding the fine structure of the gravity field on the basis of an application of local corrections to the global field. According to this approach, a basic satellite to satellite tracked (SST) range-rate measurement is constructed from the link between a ground station, a geosynchronous satellite (ATS 6), and a near-earth satellite (Apollo or GEOS 3). Attention is given to a mathematical model, the simulation of SST gravity anomaly estimation accuracies, a gravity anomaly estimation from GEOS 3/ATS 6 and Apollo/ATS 6 SST observations, and an evaluation of the mean gravity anomalies determined from SST.

Description: Global magnetic component anomaly field maps have been derived from the Magsat vector magnetometer data obtained from November 1979 through May 1980. The amplitude of variations of the components over the maps are between 10 and 15 nT, well above the noise in the data. Averaged data, in 2-by-2 deg blocks, exhibit standard errors of the mean of about 1 nT over most of the X and Z maps, and about 2 nT over most of the Y maps. Errors rise to about twice these amounts near the auroral belts. Most of the anomalies in the component data are consistent with a crustal magnetization model which incorporates dipoles aligned only in the direction of the main field. However, there appear to be some regions which require dipoles aligned in some other direction i.e., remanent magnetization.

Description: Initial results of the Magsat mission are presented, in keeping with the categories of earth core field, the crustal or anomaly field of the earth, and external fields. It is noted that one major advantage of orbital magnetic field surveys is their ability to obtain a global set of magnetic field measurements of uniform precision and accuracy at a single epoch, aiding the derivation of the core field models that are a prerequisite for further data analysis. The ability to isolate fields from crustal sources was unexpected, because of the low amplitudes of such fields by comparison with those of the core and those external to the earth. The most significant external-field finding has been an east-west component variation near the dip equator.

Description: Studies of Birkeland current systems have been conducted primarily with low altitude satellite magnetometer data whereas electrojet current signatures have been usually analyzed with data from ground-based magnetometer chains. However, the Magsat magnetometer data set allows magnetic disturbances due to both field-aligned and electrojet currents to be examined simultaneously. This is mainly due to Magsat's approximately 400 km altitude, thus providing data closer to the electrojet current system than has been previously available from satellite measurements. Of additional importance are the superior accuracy, both in sensitivity and altitude, of the magnetic field measurements obtained by Magsat and last, but not least, the availability of an accurate magnetic field model of the concurrent epoch (based on the Magsat data set) that allows one to obtain a better baseline than previous models. The aforementioned points are emphasized and both Birkeland and electrojet currents have been analyzed in a case study for November 13, 1979.

Description: Transverse magnetic disturbances associated with Birkeland currents have been measured by the Magsat and TRIAD spacecraft, whose orbits were nearly coplanar from November to mid-December, 1979. A comparison of data received when the satellites were over the TRIAD/Chatanika receiving station shows that 75% of magnetic disturbance measurements are similar in shape and magnitude, with TRIAD peak disturbances being on average 7% larger than those of Magsat. This discrepancy is lower than measurement uncertainties due to baselines and calibration. During periods of higher Kp, despite time separations of as much as 45 min, better agreement is found in the large-scale and well-defined field-aligned current signatures.

Description: An analytical method for the analysis of absorption spectra obtained from the interferograms of an interferometer operated in the solar occultation mode, in which an interferogram is smeared with individual interferogram components generated by the passage of rays at different tangent altitudes, is described. The creation of strong sidelobes on absorption lines by the interferogram smearing leads to the recommendation of a strong apodization on the interferogram for the solar occultation experiment. The application of these concepts to the simultaneous retrieval of temperature and pressure from CO2 4.3-micron band stratospheric absorption spectra includes the analysis of the continuum absorptions by the pressure-induced N2 fundamental bands and by far wings of the CO2 v3 band. Agreement is reported between observed and simulated spectra.

Description: The effect of attenuation in precipitation regions of the sea, which must be considered in order to measure the radar backscatter from the ocean with sufficient accuracy to allow determination of the wind vector, can be ascertained from a knowledge of the brightness temperature observed by a microwave radiometer such as the Seasat multifrequency scanning radiometer. Two algorithms relating radiometric measurements and attenuation, and thereby correcting measured scattering coefficient values, were compared with wind vectors reported by surface observers and those determined by the Seasat scatterometer measurements with and without correction for atmospheric attenuation. Although the attenuation correction yields some improvements, it is constrained by both radiometer footprint differences and different scan patterns.

Description: It is found that the difference between the wet tropospheric corrections obtained with the Seasat Multichannel Microwave Radiometer (SMMR) algorithm and corrections based on near-coincident radiosonde meteorological measurements has a standard deviation of 2.79 cm, which is consistent with the independent value for water vapor determination accuracy reported by the SMMR Evaluation Team. Because the difference between the radiosonde corrections and those obtained by means of interpolated surface meteorological data has a standard deviation of 5.73 cm, the SMMR wet tropospheric correction is recommended for investigations sensitive to the wet tropospheric height correction accuracy.

Description: Rapid intensity fluctuations in the optical emission, N2/+/ (4278 A), H-beta (4861 A), and OI (5577 A) have been observed with rocket-borne photometers during a passage through a homogeneous auroral arc. The measurements indicate that relatively weak (2-5%) intensity fluctuations of random nature, with dominant frequencies in the 2-20 Hz range, do exist in the optical emissions of quiet-form auroras. These variations have well-defined averaged spectral characteristics and apparently differ from the strong quasi-periodic type of variations seen during pulsing auroras. It is argued that the observed fluctuations, which are usually composed of weak short-lived microbursts, reflect the temporal and spatial microstructure which apparently exists always within auroral arcs.

Description: Meteorological satellites and their capabilities are described. Future satellite configurations and instrumentation are discussed in the light of future user needs. In addition to the continuation of existing baseline products and services, the goals for improvement of the geosynchronous system through the 1990's will be: increasing spacial resolution in the visible and infrared channels; increasing vertical mean layer temperature resolution; adding the ability to image the solar disk; and upgrading the ground systems. Other improvements are discussed.

Description: The meteorological satellite had its substantive origin in the analytical process that helped initiate America's military satellite program. Its impetus lay in the desire to acquire current meteorological information in large areas for which normal meteorological observational data were not available on a day-to-day basis. Serious consideration was given to the feasibility of reconnaissance from meteorological satellites. The conceptualization of a meteorological satellite is discussed along with the early research which gave substance to that concept.

Description: Measurements were made of the aerosol size, height and geographical distribution, their composition and optical properties, and their temporal variation with season and following large volcanic eruptions. Sulfur-bearing gases were measured in situ in the stratosphere, and studied of the chemical and physical processes which control gas-to-particle conversion were carried out in the laboratory.

Description: The Instruments are divided into two groups, ground based instruments and satellite-borne instruments. The ground based instruments include a Dobson ozone spectrophotometer, a filter ozonometer, and ozonesondes. The satellite-borne instruments include: a backscatter ultraviolet spectrometer, a high resolution infrared radiation sounder, a infrared interferometer spectrometer, a limb radiance inversion radiometer, and multichannel filter radiometer. A list of investigations using stratospheric satellite data is presented.

Description: The present state of knowledge concerning the absolute magnitude and temporal variability of the solar spectral irradiance is outlined with emphasis on wavelengths relevant to the mesosphere and stratosphere. Reference spectra for the wavelength region 175 to 850 nm are presented including estimates for solar maximum and solar minimum conditions. Values for the Lyman alpha emission are given separately.

Description: A compilation of rate constant data for use in stratospheric modeling is presented. The tabulations are divided into two categories: bimolecular and termolecular. Explanations are given for anomalous pressure and temperature dependences.

Description: Tropospheric and stratospheric source gases and their distribution are reported. A comparison of measurements and model calculations for stratospheric gases is presented.

Description: The capability for obtaining four-dimensional data on stratospheric structure, dynamics, and zone is discussed. Progress in the development of multidimensional models of the stratosphere is reported. The discussion of multidimensional aspects of the stratosphere is divided into four major sections: observations, analysis and interpretation, modeling, and transport of trace species.

Description: Originally conceived to be the future operational weather satellite, the Nimbus series of seven satellites became the work horse and experimental backbone of the NASA/NOAA space research program. Early problems in developing the attitude control system and proving its operational characteristics in the simulated space environment are discussed. The program proved itself many times over; contributing substantially to the scientific knowledge of atmospherics and weather. As application/research vehicles, the seven Nimbus spacecraft were used for the development, test and application of a variety of new and advanced meteorological and geophysical remote sensing instruments and associated data transmission and processing techniques.

Description: One of the most important objectives of the International Satellite Cloud Climatology Project (ISCCP) is the quantification of cloud cover and associated radiation parameters for climate research. The time-varying nature of cloud cover requires a measurement system that obtains cloud radiance at sufficient time intervals for determining accurate values of cloudiness for the appropriate averaging period. Current plans for the ISCCP call for such day to be acquired every 3 hours during both data and night to ensure that the diurnal cycle of cloud cover is adequately sampled. The satellite system proposed is an array of geostationary and polar-orbiting satellites. The error in mean cloud cover estimates for observation systems which do not include geostationary satellites are quantified. Candidates for such a system include two NOAA Sun-synchronous satellites with daylight equatorial-crossing times of 0730 and 1430, and a USSR satellite in an 81 deg. inclination, 900-km altitude orbit.

Description: A steady state analysis has been made of the sources and sinks of sulfur in the remote marine atmosphere and of the steady state exhanges of SO2 and sulfate between the sea, boundary layer, and free troposphere. Two situations were examined: an area of high biological productivity (Gulf of Guinea) and an area of low productivity (tropical Atlantic). The results of the analysis suggest that about one-third of the background concentrations of SO2 and excess sulfate observed in the remote marine atmosphere mixes in from the free troposphere, with the balance, about 100 micrograms S/sq m per day, attributed to the local oxidation of reduced sulfur-bearing precursors in the boundary layer.

Description: (Previously announced in STAR as N81-31721)

Description: A large-amplitude traveling ionospheric disturbance (TID) was detected over Owens Valley, California, on May 18, 1980, by a highly sensitive very long baseline interferometry (VLBI) radio astronomy experiment. This TID is interpreted as the response of the ionosphere to a gravity wave excited in the neutral atmosphere by the explosion of Mount St. Helens that took place at 1532 UT on that day. A model, invoking the point-excitation of internal gravity waves in an isothermal atmosphere, which fits observations of the TID at several other stations, leads to identification of the features observed in the VLBI data. Small-amplitude higher-frequency changes in the ionosphere were detected for several hours after the passage of the large-amplitude Mount St. Helens TID, but it is not clear whether these were excited by the passage of the gravity wave or were background fluctuations.

Description: (Previously announced in STAR as N82-20718)

Description: The degree of multiple scattering encountered by nadir-directed lidar in clear atmosphere conditions was assessed by the Monte Carlo method based on a model of the vertical distribution of aerosol scattering in the atmosphere. The lowest 3 km of the atmosphere were regarded as containing 90% of the aerosol optical thickness, with the unity normalized value for the forward peak of the aerosol phase function being 4.38 at a 694.3 nm laser wavelength. Results were obtained for two lidar receiver heights for three receiver field of view (FOV) angular halfwidths. An increase in receiver height was determined to cause a significant increase in the amount of angular scattering of the lidar signal. A factor of 20 change in receiver height produced an order of magnitude change in the single to multiple scattering ratio.

Description: Approximately six years of global ozone monthly mean data from the Nimbus 4 BUV instrument are compared with monthly values of solar activity using 10.7-cm flux, F(10.7), as a parameter. Several techniques are explored in calculating the correlation between the two data sets, and all are found to yield relatively high correlations, ranging from R = 0.68 for 'raw' monthly means to 0.94 using a six-month running mean for each data set. It is shown, however, that the bulk of the correlation derives from the long-term decreasing trends in both data sets. When the long-term trends are removed, a cross-correlation analysis produces a maximum with no phase shift or with the ozone variations leading the solar variations by one month, thereby reducing the likelihood of a cause and effect relationship on time scales of this order. In view of the current uncertainty in the long-term stability of the BUV instrument and the resulting uncertainty in any long-term trend derived from its data, it is considered unrealistic to draw firm conclusions about a solar cycle influence on total ozone from this satellite data set.

Description: A zonally averaged time-dependent primitive equation model is used to simulate the dispersion of both a carbon 14 injection and the volcanic aerosol from the 1974 Fuego eruption. It is noted that both injections occurred at low latitudes to midlatitudes in the Northern Hemisphere. The eddy flux terms, which account for the major portion of the transport in the lower stratosphere of this model, are specified in a manner similar to that of Harwood and Pyle (1975). Comparisons with data underline the ability of the model to simulate the vertical character of the tracer while maintaining reasonable meridional transport times. For the aerosol study, the simulated 1/e decay time at 37 deg N and for the 16- to 21-km altitude region is 9 months, whereas lidar measurements at the same latitude give a decay time of 8 months. The simulated vertical width at half-maximum for the aerosol tracer at 37 deg N and 19 deg N and for 6 months after the event possesses values of 5.0 km and 3.6 km, respectively, whereas the observed lidar values are 4.4 km and 3.0 km, respectively. The tracer transport to the Southern Hemisphere also is in qualitative agreement with the limited data that are available.

Description: Magnetic perturbations observed by the TRIAD magnetometer within two hours of an AE-C spacecraft pass provide field-aligned current data, from the same local time in the northern hemisphere, for a study of the polar cusp. The AE-C spinning mode has allowed the use of the Z-axis magnetometer for Birkeland current observations, in conjunction with particle and drift measurements. The average B(z) were found to be 1.9 nT and -1.1 nT during the first two hourly intervals on January 15, 1977. Measurements from the low energy electron experiment revealed intense fluxes of soft, cusp-like 100 eV Maxwellian electrons throughout the prenoon polar cap. The upward directed current can be identified as the dominant cusp current appropriate for B(y) values lower than zero, while the downward directed current, which has the appropriate sign of a dayside region 1 current, is observed to lie entirely within a westerly, antisunward-convecting plasma.

Description: The odd nitrogen (NOx) abundance of the high latitude mesosphere exhibits a large variability in response to energetic particle precipitation. Model calculations for a very large particle event predict increases in the NOx mixing ratio that can exceed a factor of ten over time periods of the order of one week in the summer hemisphere. A more typical sized event can still lead to an enhancement of a factor of three in summer. Relative changes in the winter hemisphere are less dramatic due to a larger ambient NOx mixing ratio predicted here. However, a factor of two increase in NOx is possible during a very large event. Owing to the large variability, it is difficult to define a physically meaningful mean state profile in the high latitude mesosphere. Rather, the NOx abundance likely displays an erratic behavior which is correlated with the level of solar activity.

Description: Applications of Doppler radar to detection of storm hazards are reviewed. Normal radar sweeps reveal data on reflectivity fields of rain drops, ionized lightning paths, and irregularities in humidity and temperature. Doppler radar permits identification of the targets' speed toward or away from the transmitter through interpretation of the shifts in the microwave frequency. Wind velocity fields can be characterized in three dimensions by the use of two radar units, with a Nyquist limit on the highest wind speeds that may be recorded. Comparisons with models numerically derived from Doppler radar data show substantial agreement in storm formation predictions based on information gathered before the storm. Examples are provided of tornado observations with expanded Nyquist limits, gust fronts, turbulence, lightning and storm structures. Obtaining vertical velocities from reflectivity spectra is discussed.

Description: Geometric characteristics of the spherical earth are shown to be responsible for the increase of variance with latitude of zonally averaged meteorological statistics. An analytic model is constructed to display the effect of a spherical geometry on zonal averages, employing a sphere labeled with radial unit vectors in a real, stochastic field expanded in complex spherical harmonics. The variance of a zonally averaged field is found to be expressible in terms of the spectrum of the vector field of the spherical harmonics. A maximum variance is then located at the poles, and the ratio of the variance to the zonally averaged grid-point variance, weighted by the cosine of the latitude, yields the zonal correlation typical of the latitude. An example is provided for the 500 mb level in the Northern Hemisphere compared to 15 years of data. Variance is determined to increase north of 60 deg latitude.

Description: The size distributions of fine particles measured at tropospheric altitudes in the periphery of the eruption plume formed during the April 17, 1979 eruption of Soufriere Volcano and in the low-level effluents on May 15, 1979 were found to be bimodal, having peak concentrations at geometric mean diameters of 1.1 and 0.23 micrometers. Scanning electron microscopy and energy-dispersive X-ray analysis of the samples revealed an abundance of aluminum and silicon and traces of sodium, magnesium, chlorine, potassium, calcium, and iron in the large-particle mode. The submicrometer-sized particles were covered with liquid containing sulfur, assumed to be in the form of liquid sulfuric acid.

Description: Definitions of the data acquisition and interpretation goals which were sought in the Florida Area Cumulus Experiment (FACE) phase-II experiment as confirmation of results from FACE-I are presented. The FACE-1 trials in cloud seeding to increase rainfall were conducted in 1970, '71, '73, '75, and '76 and phase II proceeded from June 1978-August 1980. The data from the second set were to be treated with a block randomization scheme using the mean vector wind speed and direction and superposition of rainfall data, considering fixed and floating target clouds. A first level of probability was configured to eliminate cells from further investigation, and then two other levels are included in the analyses, each of continually increasing levels of likelihood. The instances of rainfall with seeding cover periods of either 60 or more or 60 or less seeding flares being ignited.

Description: Observations of cloud top height, backscattering, and signal depolarization have been obtained by a lidar system operating onboard a high-altitude research aircraft. The transmitter for the cloud lidar system is a doubled Nd:YAG laser operating at 5 Hz. The system functions as a fully automated sensor under microprocessor control and operates from a nominal 19-km altitude. Measurements have been acquired over a wide variety of cloud cover in conjunction with passive visible and infrared measurements. Initial observation results are reported

Description: The details of an iterative radiative transfer code for computing the intensity and degree of polarization of diffuse radiation in models of the ocean-atmosphere system are described. The present code neglects the upwelling radiation from below the ocean surface and as such can be applied to the part of the spectrum where the absorption by water is strong. To establish the reliability of the numerical scheme and the computer code, the results are compared with those of Fraser and Walker (1968), Dave (1972), and Mullamaa (1964); they are found to be in excellent agreement. The computations also show that both the intensity and the degree of polarization of the upwelling diffuse radiation at the top of the atmosphere vary significantly when the rough ocean at the base of the atmosphere is replaced by a Lambertian surface that reflects the same energy as the rough ocean.

Description: It is shown by a study of ethane and ethylene photochemistry that the loss of ethane is controlled by OH in the troposphere and Cl in the stratosphere. Ethane observations indicating free Cl concentrations below 30 km that are only 10% of the value predicted by the present model calculations cannot be explained by heterogeneous aerosol concentration processes, and contradict current stratospheric photochemistry. The chemical destruction of ethane and ethylene leads to the generation of such compounds as carbon monoxide and formaldehyde, and it is found that the tropospheric concentrations of the latter are enhanced by nearly a factor of three for an ethylene mixing ratio of 2 ppb.

Description: The rate at which ammonia would have been destroyed in the earth's atmosphere under assumed NH3 mixing ratio conditions of 10 to the -8th to 0.0001 is calculated by a one-dimensional photochemical model, and the destruction rates are compared with possible biotic and abiotic ammonia sources. It is found that, while the mixing ratio of 10 to the -8th needed for the evolution of life could have been maintained by abiotic sources, the value of 0.00001 needed for the production of significant greenhouse warming could not have been sustained abiotically. The increase of atmospheric ammonia due to biological activities during the Archean is also considered lower than the level required for the generation of measurable thermal effects.

Description: The rate constant for the reaction of hydroxyl radicals with nitric acid in the 225-443 K temperature range has been measured by means of the flash photolysis resonance fluorescence technique. Above 300 K, the rate constant levels off in a way that can only be explained by the occurrence of two reaction channels, of which one, operative at low temperatures, proceeds through the formation of an adduct intermediate. The implications of these rate constant values for stratospheric reaction constants is discussed.

Description: The distribution of Magsat scalar anomalies is compared with locations of major tectonic boundaries in Asia. Foldbelts separate large-scale positive and negative anomalies inside and outside the Siberian Platform, and sediment-filled aulacogens within the Platform separate the anomalies into two parts which overlie the Anabar and Aldan Shields. Tectonic boundaries appear to exercise some control over the extent and distribution of the satellite-observed crustal anomalies.

Description: Magsat data acquired during the November 1979-June 1980 mission was used to derive a scalar magnetic anomaly map covering +50 to -50 deg geographic latitude, and the separation of anomaly fields from core and external fields was accomplished by techniques developed for POGO satellite data. Except in the Atlantic and Pacific at latitudes south of -15 deg, comparison of the Magsat map with its POGO data-derived counterpart shows basic anomaly patterns to be reproducible, and higher resolution due to Magsat's lower measurement altitude. Color-coded scalar anomaly maps are presented for both satellites.

Description: A set of solar irradiance observations is analyzed that were performed from the third Solar Absorption Balloon Experiment (SABE-3) as the payload ascended through the stratosphere from 32 to 39 km. Comparison of these data with calculations of the attenuated irradiance based on simultaneous ozone and pressure measurements made from the payload suggests a refinement of the cross section values used in photochemical models. More ultraviolet radiation in the 200-210 nm spectral region reaches the middle stratosphere than is predicted by the absorption data presently available. It is suggested that significantly smaller values for the Herzberg continuum of O2 be used in future models.

Description: It is established that geographic coincidences exist between high-altitude Magsat scalar anomalies and major geologic and tectonic structures, with oceanic abyssal plains overlain by negative anomalies agreeing well in spatial extent and position and submarine platforms lying beneath positive scalar anomalies. In addition, geographic coincidence is found in the continents between many high-latitude positive anomalies and shields and cratons in North America, Eurasia and Australia. While these correlations are qualitative, they serve to identify regions for detailed study. The global distribution of anomalies provides a basis for comparative study which will be enhanced when reduced-to-pole versions of the Magsat data become available.

Description: A spherical harmonic model of the earth's internal magnetic field of degree and order 23 is derived from selected Magsat data, and its power spectrum, computed with terms developed by Mauersberger (1956) and Lowes (1974), is found to exhibit a change of a slope at n = 14 which is interpreted as an indication that the core field dominates at values lower than 13 while the crust field dominates above a value of 15. The representations of the two portions of the spectrum obtained can be used to establish order-of-magnitude inaccuracies due to both crustal fields and the inability to observe core field wavelengths beyond n = 13, at which point they are obscured by the crustal field, in core field models.

Description: Samples of various clays and minerals were ground or fractured and monitored with a liquid scintillation spectrometer in order to obtain triboluminescent decay curves. Kaolinite samples displayed several million counts/min after grinding, with a surface area emission estimated at tens of billions of photons/sq cm of surface. The photon production rates varied with the origin of the sample, and kaolinite continually yielded higher production rates than bentonite. The addition of water to the samples slightly increased the count rate of emitted light, while the addition of the fluorescent molecule substance tryptofan significantly enhanced the count rate. Freezing smears of kaolinite and montmorillonite in liquid nitrogen and in a salt ice mixture also induced triboluminescence in the montmorillonite. A possible connection between powdery triboluminescent materials formed in mining industries and respiratory disorders among miners is suggested.

Description: A description is given of the algorithm used to convert Seasat-A satellite microwave scatterometer measurements of ocean normalized radar cross section to the neutral stability vector wind at 19.5 m height, as well as to compare these winds with high-quality surface observations. The wind vector algorithm used an empirical normalized radar cross section model function to describe the ocean normalized radar cross section's dependence on the 19.5-m neutral stability wind vector. In addition, two model functions were evaluated by means of an independent set of in situ surface wind observations from the Joint Air Sea Interaction experiment (JASIN). Better results were produced by these comparisons than the stipulated Seasat wind speed and direction accuracy specifications of + or - 2 m/sec and + or - 20 deg, respectively, over the 0-16 m/sec range of winds observed during JASIN.

Description: The goals and methods for global precipitation measurements from space are examined. Records currently exist only for visible and IR scans of cloud properties, and are applied from GEO for detecting diurnal variations in precipitation. Microwave radiometry is noted to be a suitable method for supplementing the visible and IR data for measuring stratiform oceanic precipitation, and when used at up to 3 microns can detect areas, if not amounts, of precipitation from GEO. Applications of radar altimeters are proposed in terms of modifications to the Seasat-type 2.2 cm radar, the use of surface target attentuation radar, of frequency agile rain radar, or of adaptive pointing radar. Soil moisture sensing is available with passive microwave radiometry in the 20-50 cm bands, or active sensing in the 5-8 cm bands. The utilization of GARP ground truth data is explored, along with statistical methods for treating the data samples.

Description: Fluorescent emissions from nitric oxide appear imposed upon the Rayleigh backscattered spectrum of the earth's atmosphere between 250 and 300 nm in wavelength. Satellite instruments designed to monitor the global ozone distribution can routinely observe these signals although techniques for exploiting the data are not yet available. Application of a radiative transfer equation developed for an atmosphere including absorption by ozone, molecular scattering, and nitric oxide fluorescence shows the three most prominent NO emissions relative to the 250-300 nm backscattered sunlight to be the (1,4), (1,6), and (0,3) gamma bands. Analysis of the contribution function for each emission band indicates that the fluorescent signals can provide useful information on the magnitude and variability of nitric oxide between 40 and 140 km in altitude.

Description: The absorption cross sections of molecular oxygen are calculated in the wavelength range from 187 to 230 nm from solar flux measurements obtained within the stratosphere. Within the Herzberg continuum wavelength region the molecular oxygen cross sections are found to be about 30% smaller than the laboratory results of Shardanand and Rao (1977) from 200 to 210 nm and about 50% smaller than those of Hasson and Nicholls (1971). At wavelengths longer than 210 nm the cross sections agree with those of Shardanand and Rao. The effective absorption cross sections of O2 in the Schumann-Runge band region from 187 to 200 nm are calculated and compared to the empirical fit given by Allen and Frederick (1982). The calculated cross sections indicate that the transmissivity of the atmosphere may be underestimated by the use of the Allen and Frederic cross sections between 195 and 200 nm. The ozone column content between 30 and 40 km and the relative ozone cross sections are determined from the same solar flux data set.

Description: The balance of potential enstrophy and its relationship to vacillation cycles and the sudden warming is studied for a beta-channel model of the stratosphere. It is shown that the mean flow cannot be steady in the presence of large-amplitude quasi-geostrophic waves (approximately 1-0.25 geopotential kilometers /gpkm/) when any dissipation is present, and the maximum wave amplitude allowed is approximately 2 gpkm. If wave forcing (transience plus dissipation) is artificially maintained, the mean flow decelerates slowly at first then explosively as the potential vorticity gradient of the basic state is wiped out over the channel. This process is called wave saturation. The initial phase of the explosive deceleration resembles both the observed and modeled mean flow evolution during a sudden stratospheric warming. A simple vacillation model based upon these ideas shows remarkable similarity to the results of Holton and Mass (1976) and Davies (1981).

Description: Characteristics of an earthward movement of the magnetopause caused by the arrival of an interplanetary shockwave are derived from data acquired by the GEOS 1 spacecraft on July 29, 1977. Data were taken on electric field, plasma, magnetic field, energetic particles, and composition before, during, and after leaving the magnetopause. Correlative examinations were made with information gathered by the IMP 7, IMP 8, and ATS 6 satellites. The magnetopause was found to move earthward at 95 km/sec and had a thickness of 500 km. The existence of three different regions is postulated, one with field lines connected directly to the earth, the magnetosphere, a second, the magnetosheath, with no magnetic field line connection to the earth, and a thir; with one end of the field lines connected to the earth and the other to the interplanetary medium, called the transition region.

Description: Multisatellite particle and magnetic field data for the substorms of July 29, 1977, show auroral-like activity above 80 deg invariant latitude during the recovery period. The movement of auroral zone activity to high latitudes followed the substorm sequence, at which time the inferred interplanetary magnetic field (IMF) was strongly northward. Electron energy spectra indicative of a field-aligned potential drop, and the absence of supporting precipitating ions, are found at latitudes greater than 80 deg. The north-south symmetry of these observations suggests that the events are on closed field lines. It is noted the very strong northward IMF connected to the sunward tilted geomagnetic dipole field plays a role in the driving of strong Birkeland and ionospheric current systems in the northern polar regions, while eliminating them from the southern polar regions.