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. Analysis tech niques and application to trajectory determination. J. Atmos. Sci., 37, 846-854.Carte, A. E., and G. N. Mader, 1977: Hailstorms in the Transvaal on 29 November 1972. Quart. J. Roy. Meteor. Soc., 103, 731 749.Dansgaard, W., 1964: Stable isotopes in precipitation. Tellus, 14, 436-468.Facy, L., L. Merlivat, G. Nief and E. Roth, 1962: Etude de la formation d'un gr~lon par une m6thode d'analyse isotopique. J. M~c. Phys. Atmos., 2, No. 14, 67-77.Federer, B., and A. Wald~ogel, 1978
. Analysis tech niques and application to trajectory determination. J. Atmos. Sci., 37, 846-854.Carte, A. E., and G. N. Mader, 1977: Hailstorms in the Transvaal on 29 November 1972. Quart. J. Roy. Meteor. Soc., 103, 731 749.Dansgaard, W., 1964: Stable isotopes in precipitation. Tellus, 14, 436-468.Facy, L., L. Merlivat, G. Nief and E. Roth, 1962: Etude de la formation d'un gr~lon par une m6thode d'analyse isotopique. J. M~c. Phys. Atmos., 2, No. 14, 67-77.Federer, B., and A. Wald~ogel, 1978
spatial distribution of solid particles in hailstones shouldbe supplemented by isotopic analysis.1. Introduction List (1965) has pointed out many times that "a hailstone can be regarded as a sonde, fallen through athunderstorm cloud, its life history imprinted in itsstructure." Attempts have been made to decipher themechanism of hailstone formation by studying entrapped water-insoluble particles (Rosinski, 1966). Byapplying similar studies to rain it should be possible tolearn more about the
spatial distribution of solid particles in hailstones shouldbe supplemented by isotopic analysis.1. Introduction List (1965) has pointed out many times that "a hailstone can be regarded as a sonde, fallen through athunderstorm cloud, its life history imprinted in itsstructure." Attempts have been made to decipher themechanism of hailstone formation by studying entrapped water-insoluble particles (Rosinski, 1966). Byapplying similar studies to rain it should be possible tolearn more about the
keptin sealed containers and forwarded to the mass spectrometer laboratories for analysis. In the Sierra Nevadaprogram, all isotopic analyses were conducted in theDesert Research Institute laboratories in Las Vegas,while in the Australian program the mass spectrometeranalyses were conducted in the Commonwealth Scientific and Industrial Research Organization (CSIRO)Division of Water Resources in Canberra, Australia.For the latter program it became necessary, because ofthe particular mass spectrometer
keptin sealed containers and forwarded to the mass spectrometer laboratories for analysis. In the Sierra Nevadaprogram, all isotopic analyses were conducted in theDesert Research Institute laboratories in Las Vegas,while in the Australian program the mass spectrometeranalyses were conducted in the Commonwealth Scientific and Industrial Research Organization (CSIRO)Division of Water Resources in Canberra, Australia.For the latter program it became necessary, because ofthe particular mass spectrometer
analysis. However, in view of the likelihood of a considerably highernatural background of iodine than of silver, it seemedwiser to choose silver as the better analysis element.3. Choices of method for neutron activation analysis of silver The natural isotopes of silver and their abundancesare Ag~-7 (51.35%) and Ag~-9 (48.65%), neither of whichis radioactive. When placed in a nuclear reactor and subjected tofluxes of neutrons both of thermal energy (~0.025eV) and higher (up to 10 MeV), many
analysis. However, in view of the likelihood of a considerably highernatural background of iodine than of silver, it seemedwiser to choose silver as the better analysis element.3. Choices of method for neutron activation analysis of silver The natural isotopes of silver and their abundancesare Ag~-7 (51.35%) and Ag~-9 (48.65%), neither of whichis radioactive. When placed in a nuclear reactor and subjected tofluxes of neutrons both of thermal energy (~0.025eV) and higher (up to 10 MeV), many
to 80 ~ra range aswell as in the 1 to 30/am range. The concentration of dust 2 to 5 km above the ground, measured byboth the filtering and impactor methods, ranged from 0.1 to 0.4 mg m-~ for four intense dust storms inTexas during April of 1972 and 1973. The vertical flux for dust storms over the four-year period rangedfrom 0.25X10-? to 2.2x10-a g c..m-s s-z. Oxygen isotopic ratio values of 1 to 10/am quartz isolated from 17 dusts collected by ground-basedsamplers ranged from 16.4 to 19.5Y
to 80 ~ra range aswell as in the 1 to 30/am range. The concentration of dust 2 to 5 km above the ground, measured byboth the filtering and impactor methods, ranged from 0.1 to 0.4 mg m-~ for four intense dust storms inTexas during April of 1972 and 1973. The vertical flux for dust storms over the four-year period rangedfrom 0.25X10-? to 2.2x10-a g c..m-s s-z. Oxygen isotopic ratio values of 1 to 10/am quartz isolated from 17 dusts collected by ground-basedsamplers ranged from 16.4 to 19.5Y
condensation during ascent before arriving over the New York area we must alsocalculate the isotopic composition of the parent vaporitself. This is also assumed to result from a Rayleighcondensation process starting from initial conditionsthat are detexmined from the local sounding and fromtrajectory analysis based on the synoptic-scale winds. The initial charging of the air with vapor in thesource region is assumed to take place under quasiequilibrium conditions although at a temperaturebelow that of
condensation during ascent before arriving over the New York area we must alsocalculate the isotopic composition of the parent vaporitself. This is also assumed to result from a Rayleighcondensation process starting from initial conditionsthat are detexmined from the local sounding and fromtrajectory analysis based on the synoptic-scale winds. The initial charging of the air with vapor in thesource region is assumed to take place under quasiequilibrium conditions although at a temperaturebelow that of
beenneglected. Some justification for the neglect of scavenging of theradon and thoron daughters by falling raindrops canbe derived from the results of Greenfield (1957). Sincethe isotopes of interest here are largely associated withparticles having diameters < 1 ~m (Jacobi et al., 1959),the amount of radioactivity collected by impactionduring the descent of the rain should be sufficientlysmall to be disregarded in the present analysis. Consequently, the data'have been corrected for radioactivedecay
beenneglected. Some justification for the neglect of scavenging of theradon and thoron daughters by falling raindrops canbe derived from the results of Greenfield (1957). Sincethe isotopes of interest here are largely associated withparticles having diameters < 1 ~m (Jacobi et al., 1959),the amount of radioactivity collected by impactionduring the descent of the rain should be sufficientlysmall to be disregarded in the present analysis. Consequently, the data'have been corrected for radioactivedecay
. Frey, Eds.,Int. Assoc. Quat. Res., 7th Cong. Rev. Vol., 433-451.Mehringer, P. J., Jr., 1967: Pollen analysis of the Tule Springsarea, Nevada. Nevada State Anthropol. Pap., No. 13, pt. 3,130-200.Monteverdi, J. P., 1976: The single air mass disturbance andprecipitation characteristics at San Francisco. Mon. Wee.Rev., 104, 1289-1296.Mook, W. G., D. J. Groeneveld, A. E. Brown and A. J. VanGanswijk, 1974: Analysis of a run-off hydrograph by meansof natural 180: Isotope Techniques in Groundwater
. Frey, Eds.,Int. Assoc. Quat. Res., 7th Cong. Rev. Vol., 433-451.Mehringer, P. J., Jr., 1967: Pollen analysis of the Tule Springsarea, Nevada. Nevada State Anthropol. Pap., No. 13, pt. 3,130-200.Monteverdi, J. P., 1976: The single air mass disturbance andprecipitation characteristics at San Francisco. Mon. Wee.Rev., 104, 1289-1296.Mook, W. G., D. J. Groeneveld, A. E. Brown and A. J. VanGanswijk, 1974: Analysis of a run-off hydrograph by meansof natural 180: Isotope Techniques in Groundwater
material from the conminer walls. The leachate is then added to the mainfraction of the rain sample, followed by evaporationin concentrated nitric acid. Particulate samples arestored dry and ashed prior to acidic digestion. Sampleswere stored under acidic conditions to achieve secularequilibrium of bismuth with lead. The analysis of 2~-Pbwas accomplished by beta counting of the ~-Bi daughter to achieve lower detection limits required for analysis of the liquid fraction. All samples were taken at
material from the conminer walls. The leachate is then added to the mainfraction of the rain sample, followed by evaporationin concentrated nitric acid. Particulate samples arestored dry and ashed prior to acidic digestion. Sampleswere stored under acidic conditions to achieve secularequilibrium of bismuth with lead. The analysis of 2~-Pbwas accomplished by beta counting of the ~-Bi daughter to achieve lower detection limits required for analysis of the liquid fraction. All samples were taken at
thermal neutron activation analysis ['seecompanion paper in this Jo~va~A~. (Warburton andYoung, 1968)]. With the silver concentrated out of solution by theseion-exchange extraction procedures, it is, of course,possible to use a number of other physical or chemicaltechniques which are sufficiently sensitive to detect thesmall concentrations of this element in reasonable-sizedsamples of precipitation. Neutron activation analysis has been chosen as beingone of the more sensitive and positive
thermal neutron activation analysis ['seecompanion paper in this Jo~va~A~. (Warburton andYoung, 1968)]. With the silver concentrated out of solution by theseion-exchange extraction procedures, it is, of course,possible to use a number of other physical or chemicaltechniques which are sufficiently sensitive to detect thesmall concentrations of this element in reasonable-sizedsamples of precipitation. Neutron activation analysis has been chosen as beingone of the more sensitive and positive
