Volcanic Dust Research Articles

Atmospheric turbidity after the agung eruption of 1963 and size distribution of the volcanic aerosol

Data on atmospheric transmission related to the stratospheric layer of aerosol from the explosion of the Agung volcano in March 1963 at Bali Island are discussed. In midlatitudes of the southern hemisphere the abnormal aerosol optical thickness at λ500 nm reached a peak of 0.3 during September 1963 but became very small after mid-1965. Some pyrheliometric data require consideration of the λ dependency of attenuation on the volcanic dust to conform to spectral data. Over the northern hemisphere, the decrease of transmission due to Agung aerosol was marginal, and a strong seasonal variation that had been derived from pyrheliometric data seems questionable. Observations of the brightness of the eclipsed moon and analysis of brightness of the umbra are in good agreement with the above data if referred to the proper hemisphere. Indications on the size distribution of the volcanic dust from λ dependence of dust attenuation and sky light observations are discussed.

Stratospheric Temperature Change from the Mt. Agung Volcanic Eruption of 1963

The volcanic dust from the Mt. Agung eruption on 17 March 1963 strongly influenced the solar radiation reaching the ground, so much so that surface solar radiation measurements could be used to track the spread of the cloud over the globe. This paper outlines fairly strong circumstantial evidence that the presence of the aerosol caused increases of the stratospheric temperature of approximately 5C.

Volcanic dust in the atmosphere; with a chronology and assessment of its meteorological significance

After defining the terms commonly used in reporting volcanic eruptions and noting previous approaches to assessment of their magnitudes, this study proceeds to examine aspects of importance, or possible importance, to meteorology―principally the dust veils created in the atmosphere, particle sizes and distribution, heights, fall speeds and atmospheric residence times. Later sections deal with spread of the dust by the atmospheric circulation and the direct effects apparent upon radiation, surface temperature and extent of ice in the polar regions. These effects, as well as various crude measures of the total quantity of solid matter thrown up, are used to arrive at numerical assessments of volcanic eruptions in terms of a dust veil index (d. v. i.). The latitude of origin of the dust (latitude of the volcano) receives some attention, and apparently affects the course of development of the atmospheric circulation over the three or four years following, at least in the case of great eruptions (d. v. i. > 100 over one hemisphere). Effects upon the extent of ice on the polar seas may be of somewhat longer duration, and thereby influence the atmospheric circulation over a longer period of years, since there seems to be some association with the cumulative d.v.i. values when successive great eruptions occur with only few years between. The time distribution of volcanic dust since the last Ice Age, and since a. d. 1500, are indicated in as much detail as the evidence permits. Some associations with changes of climate are suggested, but it is clear that volcanic dust is not the only, and probably not the main, influence in this. The appendices give a chronology of eruptions (including those which it seems possible to dismiss as regards any effect on world weather or climate) and a chronology of d. v. i. values. A third appendix displays by means of graphs the variation of some circulation parameters in January and July in the region of northwest Europe over the years immediately following forty of the greatest eruptions since 1680.

Anisotropic diffusion coefficients and the global spread of volcanic dust

The global spread of volcanic dust from the Mt. Agung eruption of March 17, 1963, is assessed on the basis of the decrement in direct solar radiation. The data suggest the establishment of an equatorial reservoir at height of about 22 km, followed by poleward transport into each hemisphere during winter. The poleward-moving waves of dust appeared to have constant amplitude in any one season, with a poleward progression rate of 40 cm sec−1 between 30° and 90° latitude. Analytic solutions are found for the diffusion coefficients Kyy and Kyz for the following cases: (1) 〈ν〉 = 0, i.e., no mean motion. (2) 〈ν〉 = 20 sin 6ϕ, corresponding to a three-cell pattern for the meridional circulation. (3) Same as (2) but with assumption of also latitude attenuation, in an attempt to allow for a stratospheric source of dust particles from gaseous products of the volcano. The results for Kyy are in general agreement with findings of other workers, but the values of Kyz appear to be too high, particularly in the region 30°–60° latitude. It is speculated that better agreement could be found if the diffusion coefficients were chosen to vary seasonally.

Global spread of volcanic dust from the Bali eruption of 1963

Quarterly Journal of the Royal Meteorological SocietyVolume 96, Issue 408 p. 341-341 Discussion Global spread of volcanic dust from the Bali eruption of 1963 A. J. Dyer, A. J. DyerSearch for more papers by this authorB. B. Hicks, B. B. HicksSearch for more papers by this author A. J. Dyer, A. J. DyerSearch for more papers by this authorB. B. Hicks, B. B. HicksSearch for more papers by this author First published: April 1970 https://doi.org/10.1002/qj.49709640820Citations: 8AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume96, Issue408April 1970Pages 341-341 RelatedInformation

Response of The Growth and production sweet Corn on the Composition of Planting Media

Corn is one of the indicator plants that can give response to volcanic dust sinabung. The purpose of this study was to determine the respons of sweet corn plant growth to the composition of planting media (top soil, Sinabung volcanic dust and EFBOP). This research was done at experimental field of Agriculture Faculty of University of Sumatra Utara, Medan at height about 25 mals in August until November2016. The research was using a non-factorial randomized block design which was consisting of 6 treatments of top soil : volcanic dust : EFBOP ratio that is 10 kg : 0 kg : 0 kg (M0), 8 kg : 0 kg : 2 kg (M1), 8 kg : 0,5 kg : 1,5 kg (M2), 8 kg : 1 kg : 1 kg (M3), 8 kg : 1,5 kg : 0,5 kg (M4), and 8 kg : 2 kg : 0 kg (M5). Parameters observed were plant height, flowering age, length and width of leaves, fresh weights, length of cob, diameter of cob, seed line in cob, and number of seeds of cob. The result showed that the ratio of top soil, Sinabung volcanic dust and EFBOP had significanly effect on plant height, long and width of the leaves, fresh weights, length of cob, diameter of cob, seed line in cob, and number of seeds of cob, and had no significant effect on age flowering. The best composition of planting media was M2 with composition 8 kg top soil, 0,5 kg sinabung volcanic dust, and 1,5 kg EFBOP.

Sculpturing of moldavites and the problem of micromoldavites

Nininger and Huss stated in 1967 that the sculpturing of the surfaces of two very rare indoehinites from South Vietnam occurred in the atmosphere and was not due to etching by soil agencies. However, very important and convincing features observed in moldavites and reported in this paper support the opinion that moldavite sculpturing is due to chemical corrosion in soils and gravels. It is concluded that when moldavites fell on the earth's surface they were already cool solid bodies. Many of the falling moldavites, however, were fragmented on landing. All of them, emplaced in the soil, were strongly corroded. Pure (hyaline) and translucent glassy drops, a few tenths of a millimeter in diameter, have been separated by washing the material encountered by an 80-m-deep bore through Pannonian sediments in southern Moravia. These glassy drops may have been produced as slag spherules from steam engines; they may have been in the volcanic dust from Slovakian rhyolites; or they may be micromoldavites. To solve this problem, a more detailed investigation would be necessary.

Twilights and Stratospheric Dust Before and After the Agung Eruption

Many absolute measurements of twilight sky radiance were made in six spectral ranges from lambda377 nm to lambda970 nm at 20 degrees elevation in the solar vertical, and mostly from sunset to 6 degrees -10 degrees sun depression (sd) in southern Germany, from fall 1962 to summer 1967, and at Bedford, Massachusetts, during winter 1967-1968. A strong change of twilight radiance, especially a large increase in the amplitude of the red/green color ratio between 4.5 degrees (main purple light) and 1 degrees sd, was observed in January 1964 following the explosive eruption of the Agung volcano in March 1963, but twilights were still abnormal and variable in early 1968. Dust mixing profiles of some typical twilight groups were derived, and the volcanic twilights show, as do other optical and direct soundings of the same period, a strong maximum near 20 km. A strong secondary red/green maximum (visually observed as secondary purple light) developed at sun depressions greater than 6 degrees of the volcanic twilights. This seems to have been caused by multiple scattering and not by mesospheric dust. A few twilight observations in 1964 from Australia indicate considerably more volcanic dust in accordance with transmission data, while no stratospheric dust is indicated in Arctic twilights of spring 1966. In order to verify the persistence of abnormal twilight conditions for more than five years, the dependence on red wavelength of the red/green color ratio is investigated, and some earlier twilight measurements are discussed. This persistence may have to be related to even higher amounts of dust in the tropical stratosphere.

A Discussion on recent research in air pollution - The application of air pollution research to power station design

The aim of this contribution to the Meeting is to describe how the results of research work have been applied to the design of power stations in Britain. Before doing so, however, it is perhaps worth while giving an outline of the fundamental principles involved in the selection of air pollution control measures as they are seen by the engineers who must make practical decisions on plant design, and in this way define the specific objectives for the research work being undertaken. First, it must be appreciated that unless one accepts an exceedingly narrow definition of what constitutes air pollution, then clean air must be regarded as a matter of degree and not of kind. All sorts of naturally occurring gases and particulates pollute the atmosphere, even in places remote from mankind’s industrial and domestic activities. Volcanic dust and ashes, sulphur dioxide and other gases of geophysical origin, wind-blown dust, residues of sea-spray, pollen, spores, ozone, ammonia and many other substances exist quite naturally in the air we breathe. What constitutes an air pollution problem is the occurrence of pollutants in unduly high concentrations in a particular place or at a particular time. As a corollary of this, the aim of air pollution control measures is to prevent such high concentrations from occurring. This principle is fundamental to the whole concept of air pollution control, since once it is accepted then practical control measures need not necessarily be restricted to the prevention of the emission of pollutants, but can include also the manner of emission, in so far as this can influence subsequent concentrations of pollutants in the atmosphere

Features of Tropospheric and Stratospheric Dust

A series of 119 profiles obtained over New Mexico comprise aerosol attenuation coefficients vs altitude to about 35 km. These profiles show the existence of several features. A surface convective dust layer extending up to about 5 km is seasonally dependent. Also, a turbidity maximum exists below the tropopause. The altitude of an aerosol maximum in the lower stratosphere is located just below that of the minimum temperature. The colder the minimum temperature, the greater is the aerosol content of the layer. This relationship suggests that the 20-km dust layer is due to convection in tropical air and advection to higher latitudes. Computed averages of optical thickness show that abatement of stratospheric dust from the Mt. Agung eruption became evident in April 1964. Results based on seventy-nine profiles characterizing volcanic dust abatement indicate that above 26 km, the aerosol scale height averages 3.75 km. Extrapolating with this scale height, tabulations are developed for uv, visible, and ir attenuation to 50 km. Optical mixing ratios are used to examine the aerosol concentrations at various altitudes, including a layer at 26 km having an optical thickness 10(-3) for 0.55-micro wavelength.

Global spread of volcanic dust from the Bali eruption of 1963

AbstractThe global spread of volcanic dust from the Mt. Agung eruption of 17 March 1963 is assessed on the basis of the decrement of direct solar radiation. The initial injection at 8°S lodged an equatorial reservoir in the stratosphere at a height of 22–23 km. Most of the dust remained in the Southern Hemisphere, but a significant fraction entered the lower Northern Hemisphere stratosphere. Seasonal effects appeared in both hemispheres, the apparent dust amounts showing a ‘winter’ maximum of constant amplitude in any one season with a poleward progression of 40 cm sec−1 between 30° and 90° latitude. At 15°N, seasonal effects were also evident but significantly out of phase with the sequence at higher latitudes, suggesting a hand‐over in the horizontal transport process at 20°–30° latitude.Whilst the ‘winter’ maxima in the Northern Hemisphere were almost identical in amplitude for 1963 and 1964, the Southern Hemisphere data showed a significant reduction in dust amount over these years. The latter effect can be shown to imply an updraught in the lowest 2 km of the equatorial stratosphere of about 0·02 cm sec−1. By continuity, the poleward outflow from this circulation would be consistent with the observed rate of poleward progression. It is speculated that the seasonal effects could arise from an annual oscillation of the axis of this meridional circulation.Attempts to relate the observations by a diffusion model are less convincing, but in the absence of more direct information, no firm conclusion can be drawn. The paucity of suitable radiation data for equatorial regions severely limits the extent to which inferences can be made.

Volcanic dust, melting of ice caps, and sea levels: A reply

Volcanic dust, melting of ice caps, and sea levels: A reply

Volcanic dust, melting of ice caps, and sea levels

Volcanic dust, melting of ice caps, and sea levels

Comments on the recent decrease in solar radiation at the South Pole

A study has been made of the decrease in intensity of the direct solar radiation at the South Pole which occurred in late 1963. The decrease has been ascribed to an influx of volcanic dust in the stratosphere from the eruption of Mt. Agung, Bali. Following the decrease in 1963, the direct solar radiation values gradually approached their normal value by February 1966. Measurements of the total solar radiation received at the surface show a much smaller decrease. The solar radiation budget during this period is discussed and the influence of the dust on the radiation examined. Air trajectories at several stratospheric levels were used to indicate the height of the influx over the South Pole and the probable source region of the aerosol outside the Antarctic continental limits. DOI: 10.1111/j.2153-3490.1968.tb00380.x

ATMOSPHERIC EXTINCTION: CZECH LUNAR PHOTOMETRY OF THE JUNE 25, 1964 ECLIPSE

eclipses for the purpose of determining the excess of atmospheric extinction due to an apparently large amount of volcanic dust spread over the upper atmosphere after the eruption of Mount Agung, Bali, on March 17, 1963. The total eclipse of June 25, 1964 was not observable from Iowa, but Bouska and Mayer (1965) published the results of their photoelectric observations in the visual region which provide useful data for further comparison with the above calculations. Figure 1, which has been redrawn from Figure 3 of Paper I to include their observations, suggests that 25 km is a better assumption for the maximum height of the dust layers. The values of s, the fraction of dust extinction in terms of the usual extinction coefficient, estimated for the three eclipses are 0.20, 0.15, and 0.11 mag. per air mass for the December 1963, June 1964, and December 1964 eclipses, respectively. The corresponding value for the normal atmosphere ranges from about 0.065 at A 5500 ( Allen 1963 ) to 0.045 mag. per air mass ( Moreno, Sanduleak, and Stock 1965 ) . Hence, the excess in the extinction coefficients due to additional dust may be estimated as 0.145, 0.095, and 0.055 mag. per air mass for the three dates. We can then obtain the total extinction for each

Cross Sections of Ice Nucleus Concentrations at Altitude over Long Paths

Abstract Measurements of ice nucleus concentrations using Millipore filters at altitudes of about 4 and 11 km over lengthy paths are described. Bands of ice nuclei between latitudes 23S and 30S were frequently found at both altitudes, narrower and of higher concentration than those observed at the ground. Broad regions at 10–12 km markedly deficient in ice nuclei were found near the equator on each of two flights. There was no conspicuous difference in ice nucleus concentrations in the two hemispheres and no obvious change was found at the northern boundary of the pall of volcanic dust then present.

Palynology of late Cretaceous mammal beds, Scollard, Alberta (Canada)

Fossil mammal bones have been located in Upper Cretaceous (Lance or Maastrichtian) Upper Edmonton Beds above the Kneehills Tuff in the Scollard area, Alberta (Canada). Samples from the mammal-bearing beds and from above and below, have been analysed for their palynological contents. Abundant microflora representing pteridophytes, gymnosperms and angiosperms have been recorded with an abundance of Aquilapollenites in varied morphological diversity. The microflora showed five paleoecological stages. The lowest Microfloral Assemblage I, representing mid-Middle Edmonton vegetation, indicates swampy, tropical and humid climate which was replaced by stages of a sere of cooler climate shown by Microfloral Assemblage II. Cooling increased still more, possibly due to descrease in the total solar radiation reaching the earth's surface, caused by the volcanic dust in the atmosphere as the bentonitic content is high. Microfloral Assemblage III from the bentonitic beds associated with the Kneehills Tuff shows little preservation of spores and pollen although comminuted fragments are present. Microfloral Assemblage IV (including the mammal beds) shows warming up and restoration of vegetation but of a cooler climate. Climate became warmer during the deposition of Microfloral Assemblage V and a rich woodland vegetation was established representing warm subtropical climate with warm temperate aspect during mid-Upper Edmonton deposition.

Hemispherical transport of volcanic dust inferred from diffuse radiation measurements

Volcanic dust has been used in the past as a tracer or' atmospheric motions. The volcanic dust resulting from the eruption of Mt. Agung, Bali (8° S, 115°E) w March 1963 produced some spectacular effects in the southern hemisphere as seen from the radiation observations made at Aspendale (38° S, 145°E). The diffuse radiation mesurements made at Poona, however, do not show such effects to any appreciable extent. It is, therefore, concluded that the transport from the southern to the northern hemisphere of stratospheric dust is of a much smaller magnitude than the transport within the southern hemisphere itself.

Artificial radio-activity, ozone and volcanic dust as atmospheric tracers in the Southern Hemisphere

Artificial radio-activity, ozone and volcanic dust as atmospheric tracers in the Southern Hemisphere

SONIC VELOCITY AND PENETRABILITY OF SIMULATED LUNAR ROCK DUST

Theoretical considerations are given for the design of an ultrasonic pulsing system for noncohesive dusts. In addition, measurements of less than one percent error of sonic velocity were made in volcanic rocks of different textures. Pumice containing elongate vesicles exhibits marked sonic anisotropy. In contrast, basaltic scoria with approximately equidimensional vesicles exhibits sonic isotropy. These anisotropy contrasts may be significant in interpreting Surveyor return data and in evaluating lunar base requirements. Sonic velocity with a simultaneous recording of porosity in rock dusts under ambient conditions ranges from 150 m/sec (500 ft/sec) to 700 m/sec (2,100 ft/sec). Absolute measurements of shear strength, using the vane‐type shear tester, were made at critical density obtained by vibrating the simulated lunar dust samples for specified time periods. Relative shear strengths were also compared at maximum density obtained by long‐period vibration of dust samples. Comparson of stress curves of dusts of different grain shapes indicates that relatively little strain occurs before the plastic zone of the stress curve is reached for volcanic dust consisting of angular glass shards. For purpose of shear strength analysis, grain shapes may be grouped as spherical, prismatic, and vesiculate. Shearing resistance curves are analyzed for each of these groups, and the vesiculate shapes have the highest shear strengths at critical density. Moreover, the sliding habit during shear appears to reflect the shape of the grains. Grain shape is apparently a first‐order parameter affecting shear strength of dust particles >0.1 mm in diameter. Adhesion effects due to hard vacuum ([Formula: see text] to [Formula: see text] torr) are small but measurable for the grain sizes considered. At equivalent porosities, vacuum at [Formula: see text] torr apparently does not markedly influence the peak shear strength of dust composed of vesiculate particles greater than 0.1 mm in diameter. Once sonic velocity and shear strength data are obtained by a lunar probe or astronaut, practical studies can be made on bearing capacity, trafficability, and lunar base construction.