Showing papers in "Tellus A in 1966"
TL;DR: Weakness and temporary elimination of the equatorial easterly winds over the eastern and central Pacific in late 1957 and early 1958 brought about a brief cessation of equatorial upwelling which in turn caused the occurrence of above-normal surface water temperatures in the tropical Pacific from the American coast westward to the dateline as discussed by the authors.
Abstract: Weakness and temporary elimination of the equatorial easterly winds over the eastern and central Pacific in late 1957 and early 1958 brought about a brief cessation of equatorial upwelling which in turn caused the occurrence of above-normal surface water temperatures in the tropical Pacific from the American coast westward to the dateline. This sudden introduction of a large anomalous heat source for the atmosphere intensified its thermodynamic circulation, especially in the wintertime (northern) hemisphere. Record intensity of the westerlies resulted in the eastern North Pacific. The anomalous depth of the Low in the Gulf of Alaska had the downwind effect of weakening the Iceland Low and setting the stage for a cold winter in northern Europe. DOI: 10.1111/j.2153-3490.1966.tb00303.x
854 citations
TL;DR: In this article, an electrical particle counter and size analyzer system has been described, with a filter located at the aft end of the current collector, which allows the use of collector voltages up to 30 KV while maintaining background currents below 10 −14 amp.
Abstract: An electrical particle counter and size analyzer system having the following characteristics has been described. 1 Sizing range from 0.015 to 1.2 μ. 2 Classification range from 0.015 to 0.6 μ at 28 1/m aerosol sampling rate. 3 A unique unipolar diffusion charger that is stable, controllable and capable of near optimum charging performance. 4 A versatile mobility analyzer capable of discrete classification of particles with mobilities from 0.01 to 0.0002 (cm/sec)/(volt/cm) at aerosol flow rates up to 57 1/m. This analyzer is unique in using a filter located at the aft end of the current collector. This separation of the collecting electrode and the current collector permits the use of collector voltages up to 30 KV while maintaining background currents below 10 −14 amp. 5 Although the instrument described here is only semi-automatic, a completely automatic version of the EPC is entirely practical. An automatic EPC used together with an automatic CN and optical counter would permit continuous automatic size distribution measurement over the size range from 0.01 to 10 μ. DOI: 10.1111/j.2153-3490.1966.tb00272.x
146 citations
TL;DR: The concentration of Pb-210 has been measured at several altitudes in the atmosphere over the United Kingdom during 1958 as discussed by the authors, and the gradient into the lower stratosphere was less steep than observed by Burton & Stewart (1960) and conformed to the diffusion models of Jacobi & Andre (1963) for the case of short washout times, and Machta (1960).
Abstract: The concentration of Pb-210 has been measured at several altitudes in the atmosphere over the United Kingdom during 1958. The gradient into the lower stratosphere was less steep than observed by Burton & Stewart (1960) and conformed to the diffusion models of Jacobi & Andre (1963) for the case of short washout times, and Machta (1960). The concentrations of Pb-210 and Po-210 in surface air and Pb-210 in rainwater have been measured continuously since 1961. The ratio of Po-210/Pb-210 exhibits a seasonal variation during 1962 and 1963: this might be attributed to artificial production of Pb-210 during the weapon tests of 1961-2. An estimate has been obtained of the global deposition of Pb-210. DOI: 10.1111/j.2153-3490.1966.tb00254.x
109 citations
TL;DR: In this article, the structure of a cumulonimbus cloud subjected to vertical shear is interpreted in light of the horizontal forces acting upon it, and of the varying thermodynamic influences in its different parts.
Abstract: The structure of a cumulonimbus cloud subjected to vertical shear is interpreted in light of the horizontal forces acting upon it, and of the varying thermodynamic influences in its different parts. In-cloud horizontal velocities depart greatly from those in the environment, and the forms assumed by draft columns (updrafts typically leaning in a sense opposing the vertical shear) vary with the shear, vertical motion, and speed of storm movement. The cumulonimbus is viewed as an ensemble of air elements which have undergone varying degrees of mixing with the environment, penetrating upward to different heights. Some of the air in the updraft rises into stratospheric towers, then descends as a vigorous downdraft which, because of mixing-in of heat and of air having no initial vertical momentum, dies out in the upper troposphere. This air, together with air reaching the upper troposphere in the less buoyant outskirts of the updraft, feeds the expanding anvil plume. A separate downdraft in the lower part of the cloud, originating from middle levels where the wet-bulb potential temperature is low, continually regenerates the updraft though mechanical lifting. Estimates of the air and water budgets of squall-line thunderstorms are given. DOI: 10.1111/j.2153-3490.1966.tb00291.x
92 citations
TL;DR: In this paper, the yearly mean of the pH has remained constant since 1958 at four mountain summit stations and one coastal station fog water was sampled and analysed at the Meteorological Observatory of Dresden-Wahnsdorf (51,1° N, 13,7° E).
Abstract: Since 1957 more than 200 samples of rain water have been analysed at the Meteorological Observatory of Dresden-Wahnsdorf (51,1° N, 13,7° E). At four mountain summit stations and one coastal station fog water was sampled and analysed. The yearly mean of the pH has remained constant since 1958, while i***n western Europe Jessel found a decrease in the pH. There are no differences of the pH between summer and winter and between shower and rain. There are no differences in the concentration of chemical traces between shower and rain, the seasonal difference is unimportant. The concentration of traces including the artifical ? radioactivity in fog water is larger about one order of magnitude. It is possible to estimate approximately the trace content of one cubicmeter of air from the trace concentration of the fog water and the water content of the fog, if the fog persists for a long time. DOI: 10.1111/j.2153-3490.1966.tb00236.x
82 citations
TL;DR: In this paper, the authors studied the nature of large scale stratospheric circulation using the cosmic ray produced isotopes P 32, Be 7, S 35 and Na 22 as tracers.
Abstract: The nature of large scale stratospheric circulation is studied using the cosmic ray produced isotopes P 32 , Be 7 , S 35 and Na 22 as tracers. Supplementary information obtained from observations of the distribution of the bomb-produced Na22 and radongenic Pb 210 is taken into account. The activities of these tracer elements have been measured in the stratospheric air, up to altitudes of 20 km, during 1960-64. Data are fairly extensive for studying the characteristics of the mean circulation in the stratosphere as well as seasonal changes in patterns of mixing/transport of air in certain regions of the stratosphere. The interpretation of the data on cosmic ray tracers is based on a comparison of their observed activities with the expected production rates due to cosmic rays. For this purpose, the work of Lal & Peters is extended to evaluate the variations in the relative production rates of the isotopes P 32 , Be 7 , S 35 and Na 22 in the atmosphere. These have to be taken into account when isotope data are compared for different altitudes and latitudes in the stratosphere where relative isotope production rates are different because of the markedly different prevailing energy spectrum of nucleons. The analysis allows us to distinguish three zones in the lower stratosphere (below 20 km), well separated from the tropopause, having distinct circulation patterns. These regions are separately well mixed either vertically or horizontally; the mean time of residence of aerosols in these regions differs appreciably too. The most stable region in the stratosphere is found to be 18–20 km region at 0–30° latitude, where apparent residence times are of the order of twenty months. Polar regions are observed to exhibit an enhanced vertical mixing during November-February. Combining these results with the observations of dispersion of bomb-produced Na 22 , which appeared in significant amounts from early 1962 onwards all over the stratosphere, we deduce that in the polar regions, vertical mixing occurs rapidly during November-February so that any activity injected in this region at 20 km or so mixes downwards at the rate of about 1.5 km month −1 . It is concluded that the observed spring peaks in the troposphere are merely the consequence of this phenomena which is triggered in upper levels (above 20 km) of the stratosphere during October-November. The observations of concentrations of Pb 210 in the stratosphere are discussed. The analysis reveals that an appreciable gravitational settling of Pb 210 seems to have occurred, at least during the period over which data were collected, from the stratospheric air between 55°-75° latitude. These observations imply that the residence time of air in this region of the atmosphere is appreciably higher than that deduced from tracers which attach themselves to aerosols. Lastly, the Pb 210 data indicate that appreciable amounts of tropospheric radon presumably enter the equatorial stratosphere; this conelusion rests on the observation that Pb 210 concentrations are higher in this region compared to that in the surrounding air. DOI: 10.1111/j.2153-3490.1966.tb00250.x
71 citations
TL;DR: In this paper, the average particle size distribution function was found to approximate a log-normal distribution over the range of radius 0.1 to 1.0 microns and the number concentrations were variable but generally of the order of 0.05 cm −3 at 18 km altitude.
Abstract: Studies of the chemical composition, size distributions and concentrations of stratospheric aerosol particles have shown that the particles consist of ammonium sulfate and ammonium persulfate, and may have liquid associated with them in the stratosphere. The average particle size distribution function was found to approximate a log-normal distribution over the range of radius 0.1 to 1.0 microns. The number concentrations found were variable but generally of the order of 0.05 cm −3 at 18 km altitude. The corresponding mass concentrations are of the order of 10 −2 pg cm −3 . Combination of the presently determined size distribution with estimates of the size distribution of Aitken nuclei in the stratosphere indicates that the overall distribution of partculate matter in the lower stratosphere may be bimodal. This bimodality indicates that other processes in addition to coagulation must occur if the particles with radius 0.1 micron. DOI: 10.1111/j.2153-3490.1966.tb00259.x
70 citations
TL;DR: In this article, three methods have been used to measure the velocity of deposition of gaseous elemental iodine to grassland: field experiments, 1 cm/sec; analysis of fallout data, v g = 0.5 cm /sec; and analysis of stable iodine measurements v g /sec = 1.16 cm/ sec. The varying physicalchemical state of the iodine accounts for the variation.
Abstract: Three methods have been used to measure the velocity of deposition of iodine to grassland. For average conditions the results are: field experiments, v g = 1 cm/sec; analysis of fallout data, v g = 0.5 cm/sec; analysis of stable iodine measurements v g = 0.16 cm/ sec. The varying physical-chemical state of the iodine accounts for the variation. An analysis is made of the contributions of various parts of the boundary layer to the resistance to transport of gaseous elemental iodine to grass. DOI: 10.1111/j.2153-3490.1966.tb00231.x
66 citations
TL;DR: The number of Aitken condensation nuclei in the air is strongly influenced by human activities which increase the natural number manifold through release of combustion products from fires and combustion engines as discussed by the authors.
Abstract: The number of Aitken condensation nuclei in the air is strongly influenced by human activities which increase the natural number manifold through release of combustion products from fires and combustion engines. The natural condensation nuclei near ground level increase during day and decrease during night; there is a general decrease with increasing altitude in the atmosphere. These natural Aitken nuclei are produced in light from volatile products released by the vegetation (mainly terpenes) and therefore are organic macromolecules. They disappear again mainly by agglomeration, or or near the inversion layers, and are then removed by precipitation. DOI: 10.1111/j.2153-3490.1966.tb00268.x
60 citations
TL;DR: In this article, the chemical composition of cloud water collected in different regions of the USSR is considered and the main characteristics of chemical content have been obtained on the basis of their analysis and generalization.
Abstract: In the article the chemical composition of the cloud water collected in the different regions of the USSR is considered. On the basis of their analysis and generalization the main characteristics of chemical content have been obtained. The total ion amount of cloud water slightly differs from that of precipitation, its chemical composition being different. A great influence of industrial pollution on the chemical composition of cloud water is to be noticed. DOI: 10.1111/j.2153-3490.1966.tb00238.x
56 citations
TL;DR: In this paper, data on diurnal variations of radon and thoron decay product concentrations in the surface layer of the atmosphere in the Moscow region were given, and the maximum radon exhalation from the soil occurred at night and the strongest upset of radioactive equilibrium between radon daughter products was observed in the first half of night and in the day time.
Abstract: Data on diurnal variations of radon and thoron decay product concentrations in the surface layer of the atmosphere in the Moscow region are given. It is noted that the maximum of radon exhalation from the soil occurred at night. (Measurements were carried out in summer in dry weather.) The strongest upset of radioactive equilibrium between radon daughter products was observed in the first half of night and in the day-time. DOI: 10.1111/j.2153-3490.1966.tb00281.x
TL;DR: In this paper, two profiles of air samples have been collected over Southern U.S.A. (3° N latitude) between ground level and 23 km and analysed for methane.
Abstract: Two profiles of air samples have been collected over Southern U.S.A. (3° N latitude) between ground level and 23 km and analysed for methane. The results show, with increasing altitude, a mixing ratio nearly constant to the tropopause and decreasing rapidly in the lower stratosphere. The results suggest that the troposphere is the major region of destruction of methane. DOI: 10.1111/j.2153-3490.1966.tb00230.x
TL;DR: In this paper, the emanation rate of radon-226 from soils into the atmosphere varied 1000-fold among geographical regions but was shown to be uniform in Champaign County, averaging (140 ± 73) × 10 −18 curies per square centimeter per second.
Abstract: The emanation of radon-222 from soils has been studied Factors investigated which affect the rate of emanation include wind speeds across the surface, atmospheric turbulence, soil moisture, soil type and location Values of emanation and concomitant variation in these factors are reported An investigation of radon-222 release from leaf surfaces has been initiated; preliminary results of this study are reported Measured values of radium-226 in the soil capable of giving rise to diffusing radon were found to vary 70-fold in different geological regions but were uniform in Champaign County, Illinois, the content being (064 ± 009) × 10 −12 grams of “emanating radium-226” per gram of soil The emanation rate of radon-222 from soils into the atmosphere varied 1000-fold among geographical regions but was shown to be uniform in Champaign County, averaging (140 ± 73) × 10 −18 curies per square centimeter per second The findings of the research indicate that radon-222 may be used successfully as a cost-free tracer in studies of vertical diffusion in Champaign County, Illinois DOI: 101111/j2153-34901966tb00282x
TL;DR: The average stratospheric residence half-time of particulate radioactive debris, as represented by strontium-90 and manganese-54, was approximately 10 months during the two years following the last atmospheric tests of high yield nuclear weapons as discussed by the authors.
Abstract: The average stratospheric residence half-time of particulate radioactive debris, as represented by strontium-90 and manganese-54, was approximately 10 months during the two years following the last atmospheric tests of high yield nuclear weapons. During this interval, the carbon-14 which was produced artificially by nuclear weapons tests showed a stratospheric residence half-time which increased with time, but averaged about 18 months. It is suggested that the stratospheric residence half-time of particulate debris did not increase significantly during 1963 until early 1965 because in the upper stratosphere, above 20 km, the rate of particle settling of the debris exceeded the rate of upward diffusion, and as a result, this debris remained highly concentrated in the lower stratosphere throughout this period. It is also suggested that the relatively more rapid meridional movement of particulate debris, compared to the movement of carbon-14, into the stratosphere of the Southern Hemisphere during the second half of 1963 resulted to some extent from the partial separation of the particulate debris from the carbon-14 in the equatorial stratosphere as a result of particle settling. DOI: 10.1111/j.2153-3490.1966.tb00243.x
TL;DR: In this article, measurements of the CO 2 content in the troposphere and lower stratosphere are presented, at the last to levels both in tropospheric and stratospheric air.
Abstract: Measurements of the CO 2 content in the troposphere and lower stratosphere are presented. The seasonal variations at 5 km, 7 km, 9 km and 11 km at 60° are shown, at the last to levels both in tropospheric and stratospheric air. A comparison with previous data confirms that an annual increase of the CO 2 content of the atmosphere by 0.7 ppm occurs. Data from the Indian Ocean and the Atlantic Ocean (30° N) are presented. DOI: 10.1111/j.2153-3490.1966.tb00221.x
TL;DR: In this paper, the seasonal and latitudinal variations of THO fallout, the fallout history of tropospheric and stratospheric THO, and the effects of the continental environment upon many of the reported measurements were discussed.
Abstract: THO deposition in the Southern Hemisphere is discussed in the light of currently available tritium measurements of Southern Hemisphere precipitation. Many new results from the New Zealand laboratory are presented. Topics discussed include the seasonal and latitudinal variations of THO fallout, the fallout history of tropospheric and stratospheric thermonuclear THO, and the effects of the continental environment upon many of the reported measurements. DOI: 10.1111/j.2153-3490.1966.tb01449.x
TL;DR: In this paper, it is proposed that certain characteristic stratifications accompany cumulus and cumulonimbus, and on the basis of a thermal theory characteristic magnitudes are estimated for the properties of their updraughts, and the size which must be attained by cumulus before showers form and their transformation into cumULONIMBUS occurs.
Abstract: It is proposed that certain characteristic stratifications accompany cumulus and cumulonimbus, and on the basis of a thermal theory characteristic magnitudes are estimated for the properties of their updraughts, and the size which must be attained by cumulus before showers form and their transformation into cumulonimbus occurs. DOI: 10.1111/j.2153-3490.1966.tb00290.x
TL;DR: A systematic program to measure vertical ozone distribution was established by the Air Force Cambridge Research Laboratories in January 1963 and high resolution measurements with the Regener chemiluminescent ozonesonde have been obtained from a network of twelve stations in North America, which extends from the Canal Zone to the Arctic region as discussed by the authors.
Abstract: A systematic program to measure vertical ozone distribution was established by the Air Force Cambridge Research Laboratories in January 1963. High resolution measurements with the Regener chemiluminescent ozonesonde have been obtained from a network of twelve stations in North America, which extends from the Canal Zone to the Arctic region. Processed data from the first two years of network operation were used to analyze the broad-scale characteristics of the ozone distribution. Detailed meridional cross sections of ozone mixing ratio were constructed and compared with simultaneous distributions of other atmospheric tracers including potential vorticity and radioactive debris. The striking consistency in the behavior of these tracers, each having quite different sources and sinks, suggests that the extratropical lower stratosphere is strongly stratified but on the average remains well mixed along surfaces which have a significant slope downward toward higher latitudes. To a good first approximation in all seasons, trace substances in this region of the atmosphere tend toward a uniform distribution along surfaces of constant potential vorticity. Direct computations of the temporal eddy ozone flux indicate that the northward transport across middle latitudes over North America occurs predominately at the base of the stratosphere near the tropopause. The average flux strength observed in the summer and fall seasons is less than one-third of the average winter and spring transport. DOI: 10.1111/j.2153-3490.1966.tb00244.x
TL;DR: The chemical analysis of aerosols collected at 19-21 km altitude on a polystyrene filter was reported in this paper, where the mixing ratio of sulfur containing particulates at this altitude is ≤ 2.9 times 10−9 g S/g dry air.
Abstract: The chemical analysis of aerosols collected at 19–21 km altitude on a polystyrene filter is reported. S and/or CI, Fe, Na and Cr were detected. The mixing ratio of sulfur containing particulates at this altitude is ≤ 2.9 times 10−9 g S/g dry air. The Fe/Na ratio is 1.2 ± 1.2 similar to that of crustal rocks. The chondritic meteorite component of the collected Fe and Na is < 10%, and the annual influx of submicron chondritic material to the earth is estimated to be < 9 times 104 metric tons. DOI: 10.1111/j.2153-3490.1966.tb00262.x
TL;DR: The real system (air + sea + sediments) is compared with an equilibrium model, an imaginary system containing the same components at equilibrium as mentioned in this paper, and the behavior of the equilibrium model system on reduction is described; it may resemble earlier states of our real system.
Abstract: The real system (air + sea + sediments) is compared with an equilibrium model, an imaginary system containing the same components at equilibrium. In the model, the presence of five aluminosilicate phases (six, if Fe is included) SiO 2 and CaCO 3 will fix the concentrations of the major ions, pH, and p (CO 2 ), if temperature and [Cl-] are given. It is suggested that the real system behaves similarly to the model. The T-dependence of p (CO 2 ) may be a more important factor than industrial activity. The behavior of the equilibrium model system on reduction is described; it may resemble earlier states of our real system. The present p (O 2 ) is probably regulated by a steady state, even if some data might seem to indicate the equilibrium (3) to be nearly fulfilled. Nitrogen exists as N 2 instead of the equilibrium form, NO 3 ? . There is a nitrate sink close to the surface of the ocean, but the explanation still seems to be unknown. DOI: 10.1111/j.2153-3490.1966.tb00226.x 1966 Blackwell Munksgaard
TL;DR: In this article, some features of atmospheric atomic oxygen chemistry that have received little attention, that need to be re-evaluated in the light of recent data, that have been studied in the author's laboratory, or that encompass some combination of these three are discussed.
Abstract: Some features of atmospheric atomic oxygen chemistry that have received little attention, that need to be re-evaluated in the light of recent data, that have been studied in the author's laboratory, or that encompass some combination of these three are discussed. Newly-calculated values for the concentrations of excited atomic oxygen below 100 km are so low that it is unlikely that its reactions contribute appreciably to the concentration of any atmospheric component in that region with the possible exception of excited molecular oxygen. Reactions of ground state atomic oxygen may constitute a sink for methane and a source of sulfate in this atmospheric region. Many chemionization reactions probably occur in the atmosphere, and three possible types are considered in detail. DOI: 10.1111/j.2153-3490.1966.tb00223.x
TL;DR: In this paper, it is tentatively concluded that Aitken nuclei in the upper troposphere account for most of the sulfate in the atmosphere and that there is no stratospheric sulfate layer but only a stratosphere “large particle” layer.
Abstract: Artificial radioactivity which persists in the stratosphere on a time scale of years is shown to be associated with particles below 0.02 μ radius above 27 km and with particles very nearly 0.1 μ radius between 21 km and the tropopause. Assuming the artificial radioactivity to be associated with natural aerosols at each level, the radioactive particle size data provide insight on the size distribution of micrometeorites and other particulates in the upper stratosphere and their interaction with sulfate particles in the lower stratosphere. The decrease in specific radioactivity with increased sulfate particle radius near 20 km suggests that the photochemical oxidation of SO2 may not be the important mechanism for large particle formation at this level. Chemical factors and residence time considerations support the view that Aitken nuclei in the upper troposphere are sulfate particles of sufficient size and population to account for the production of large sulfate particles near and above the tropopause by Aitken nuclei coagulation. Approximate estimation of the total sulfate mixing ratio with altitude above 5 km indicates a broad maximum in the upper troposphere. Photochemical and radiochemical evidence for the rapid oxidation of SO2 in the stratosphere reinforces these views. It is tentatively concluded that Aitken particles in the troposphere account for most of the sulfate in the atmosphere and that there is no stratospheric sulfate layer but only a stratospheric “large particle” layer. DOI: 10.1111/j.2153-3490.1966.tb00261.x
TL;DR: In this article, the diffusion of radon, thoron and their radioactive daughter products in the lower strata of the atmosphere in relation to the variations of certain meteorological parameters, with the object of a possible future application to the measurement of the pollution and diffusion of the air.
Abstract: We undertook the study of the diffusion of radon, thoron and their radioactive daughter products in the lower strata of the atmosphere in relation to the variations of certain meteorological parameters, with the object of a possible future application to the measurement of the pollution and the diffusion of the air. We give the results of measurements which we have taken between 0 and 30 metres in altitude for the study of the vertical distribution of natural radioactivity, and in different regions in order to define the influence of certain local parameters. The study of vertical distribution is carried out at the National Meteorological Observatory in Magny-les-Hameaux (Seine-et-Oise). A tower 30 metres high permitted us to take air samples continuously at several heights above the ground. We measured simultaneously the concentrations of radon, thoron and the daughter products of these gases. The variations in the concentrations and in the radioactive equilibrium between gas and daughter products are related to the variations of meteorological parameters and, in particular, to the diffusitivity of the air. DOI: 10.1111/j.2153-3490.1966.tb00278.x
TL;DR: In this article, the influence of aperture and atmospheric turbidity on the readings of pyrheliometers, used within the meteorological network, has been considered on the basis of measurements and observations concerning the radiation intensity within the solar aureole now available.
Abstract: In the present article the influence of aperture and atmospheric turbidity on the readings of pyrheliometers, used within the meteorological network, has been considered on the basis of measurements and observations concerning the radiation intensity within the solar aureole now available. We have emphasized the fact that the constants of secondary pyrheliometers, as these constants generally are determined, are dependent on apertures of involved instruments and on the atmospheric turbidity at the occasion when the standardization is made, and also that secondary instruments generally, if the derived constants are applied to the readings, must show differences from one another which are dependent upon turbidity and aperture conditions. As the effect of these factors is of systematic character, they must be seriously considered if an accuracy surpassing about ± 1.5 per cent shall be reached. Observations made in connection with the International Comparisons of Pyrheliometers at Davos 1964 are found to confirm the ideas expressed here and in previous notes by the present authors. Applications are suggested as regards (1) the difference found to exist between the old pyrheliometric standard scales, as regards (2) the future organization of Intenational Pyrheliometer Comparisons and (3) concerning the desirability of standardizing, to a greater extent than has been made up to now, the aperture conditions of pyrheliometers within the meteorological network. DOI: 10.1111/j.2153-3490.1966.tb01440.x
TL;DR: By means of an established regression between monthly global solar radiation and monthly number of sunshine hours for eight stations in Sweden, the distribution of total potential evapotranspiration has been mapped for April-September and the year as mentioned in this paper.
Abstract: By means of an established regression between monthly global solar radiation and monthly number of sunshine hours for eight stations in Sweden the global solar radiation has been calculated from values of sunshine hours for 35 Swedish stations for the period 1931-60. The distribution of global solar radiation in Sweden then has been mapped for the months April-September and the year. Potential evapotranspiration from a grass-covered surface has been calculated for 27 stations in Sweden for 1931-60 making use of the Penman formula and applying the values obtained for the global solar radiation. The distribution of total potential evapotranspiration has been mapped for April-September and the year. Comparisons are made with values earlier obtained in Sweden for actual evapotranspiration and diagrams showing the annual development of the potential water balance conditions are given for some typical Swedish stations. DOI: 10.1111/j.2153-3490.1966.tb00299.x
TL;DR: Iodine, bromine, and chlorine have been determined in atmospheric aerosols and in snow collected in Barrow, Alaska, during January, 1965, by means of neutron activation analysis as discussed by the authors.
Abstract: Iodine, bromine, and chlorine have been determined in atmospheric aerosols and in snow collected in Barrow, Alaska, during January, 1965, by means of neutron activation analysis Aerosols collected using both an aircraft collector by impaction and a ground-based 10 ? Type EA Millipore filter collector show concentrations of Cl to be much more variable than either Br or I, and I/Br points cluster at 01-02 gI/gBr for the filter samples Cl varies from <002 to 4 ?g Cl/m 3 STP in the filter samples, and the aircraft concentrations agree with those taken by filter on the same days Filter Br is 1–30 ngBr/m 3 STP and I is 03–10 ngI/m 3 STP, and the ratios I/Cl and Br/Cl increase sharply with decreasing Cl Snow samples from the ground have Br/Cl somewhat greater than in sea water, although all halogen concentrations decrease with increasing distance from the sea up to 10 km Assuming a mixture of undifferentiated sea salt and a more permanent atmospheric component, we estimate for the atmospheric component in the snows I/Br?02 Sea water, sea ice, and related samples were analyzed, and I/Cl = 4 times 10 ?6 gI/gCl is normal for sea water, although Br/Cl = 38 times 10 ?3 gBr/gCl stands a little high DOI: 101111/j2153-34901966tb00232x
TL;DR: In this paper, a numerical model in two dimensions capable of simulating diffusion, transport, particle fall velocity and tropospheric rainout is described; the model incorporates a general anisotropic diffusion process and is simulated by fractional removal of debris at selected rain "formation" levels; the fraction removed at any latitude is proportional to the observed rainfall at that latitude.
Abstract: A numerical model in two dimensions capable of simulating diffusion, transport, particle fall velocity and tropospheric rainout is described. The model incorporates a general anisotropic diffusion process. Rainout is simulated by fractional removal of debris at selected rain “formation” levels; the fraction removed at any latitude is proportional to the observed rainfall at that latitude. In the present paper the transport terms are neglected and an attempt is made to reproduce available data with a diffusion—rainout—settling velocity model. The parameters of the model are varied in an attempt to reproduce quantitatively the known behavior of tungsten-185 injections in equatorial regions and, at least qualitatively, the behavior of high latitude stratospheric injections. Three types of models are described; they are characterized respectively by the principal diffusion axis being (a) along a horizontal surface, (b) along surfaces of constant potential temperature, and (c) along surfaces of constant potential vorticity. All three types can reproduce the latitudinal variation of rainout in a satisfactory manner, but only the third can reproduce the observed pattern of concentration in the stratosphere. The third type yields satisfactory results using lines of constant potential vorticity (only tentatively established by Hering and Borden) or using lines parallel to the tropopause as the principal axis of diffusion. DOI: 10.1111/j.2153-3490.1966.tb00242.x
TL;DR: In this article, optical radar observations were carried out at high latitudes simultaneously from two stations at widely separated longitudes, and some measurements related to the optical thickness of noctilucent clouds were reported.
Abstract: Optical radar observations were carried out at high latitudes simultaneously from two stations at widely separated longitudes. Some measurements related to the optical thickness of noctilucent clouds are reported. DOI: 10.1111/j.2153-3490.1966.tb01441.x
TL;DR: In this paper, the radon content of the atmosphere at different levels above ground between 0.5 and 4 m was recorded at Aachen, Germany with a stepwise progressive filter (Schrittfilter).
Abstract: With a new continuous measurement method, the radon content of the atmosphere at different levels above ground between 0.5 and 4 m was recorded at Aachen, Germany. Evaluation of simultaneous measurements of the radon daughters with a stepwise progressive filter (Schrittfilter) showed a close relation between radon and its daughters and the meteorological factors at the measuring place. Questions discussed in the paper include the daily variations of the radon concentration in relation to the exchange (Austausch), the radioactive equilibrium of radon and its daughters at different heights, and influences of the wind direction. It was found that during temperature inversions the concentration of radon and its daughters was enlarged whilst on overcast days the mean daily variation of both the radon and the radon daughter concentration was smaller. Moreover, the radon and thoron daughters were correlated with the dust content of the air. DOI: 10.1111/j.2153-3490.1966.tb00280.x
TL;DR: In this paper, the authors have made a study of natural radioactivity of the atmosphere above a plateau and, secondly, they have taken measurements at different latitudes and longitudes over the continents and the oceans, to obtain the general distribution of the radioactivity in the lower atmosphere.
Abstract: The study of natural radioactivity in the lower atmosphere will provide information on turbulent diffusion and transport of air masses in the lower atmosphere. We have, therefore, undertaken a two-part research program. Firstly, we have made a study of natural radioactivity of the atmosphere above a plateau and, secondly, we have taken measurements at different latitudes and longitudes over the continents and the oceans, to obtain the general distribution of the radioactivity in the lower atmosphere. We have found that the radioactivity of the air is much more important over the plateau than over the oceans (100 and 6 times 10 −12 Ci m −2 , respectively) and more important over the oceans in the Northern Hemisphere than in the Southern Hemisphere (6 and 1.5 times 10 −12 Ci m −3 , respectively). From these results, we can suppose that it will be possible, with the aid of natural radioactivity, to identify air masses and to follow the vertical and horizontal diffusions in a given mass of air. DOI: 10.1111/j.2153-3490.1966.tb00283.x