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E. A. Martell

Abstract

Analysis of radioisotope production data for the 1958 HARDTACK nuclear tests at 11N indicates a main source near 20 km altitude and another source of different radiochemical composition near 30 km altitude. Aircraft and balloon sample measurements confirm this distribution of sources and show features in the poleward and downward transport of the upper source. Radioactive tracers give evidence for mean motion downward into the lower tropical stratosphere accompanying the downward propagation of westerlies in July 1959 and again in September 1963. The apparent equatorward drift of the W185 concentration maximum is explained not by mean motion but by selective erosion of the northern part of the source due to a rapid increase in the intensity of meridional eddy-mixing with latitude in the tropical stratosphere. Evidence is presented suggesting that the poleward transport of the upper source near 30 km proceeds along mixing surfaces sloping downward toward higher latitudes. Other details of the redistribution and transport of the radiotungsten tracers in the stratosphere and lower atmosphere are considered.

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E. A. Martell

Abstract

A rocketborne cryogenic sampler, capable of collecting large, unmodified and uncontaminated high altitude air samples, has been successfully developed, tested and flown. The sampler employs a simple normal shock diffuser inlet and collects a column of air at supersonic speeds during rocket ascent. The sampled air condenses on stainless steel coils cooled with pressurized liquid hydrogen. Some of the experimental applications of this versatile sampling system are discussed. The sampling system, its operation, and its experimental evaluation are described. Preliminary results of the first rocket sampler flight at White Sands Missile Range on 4 September 1968 testify to the fully successful performance of the sampling system.

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D. H. Ehhalt, L. E. Heidt, R. H. Lueb, and E. A. Martell

Abstract

On 23 May 1973 a cryogenic air sampler was flown on an Aerobee rocket from White Sands Missile Range. A large air sample was collected between 40 and 50 km altitude and successfully recovered for water vapor and trace gas analysis. The results were as follows: water vapor, 4.0+1.3 −0.9 ppmV; methane, 0.37±0.01 ppmV; molecular hydrogen, 0.47±0.02 ppmV; carbon monoxide, 0.05±0.01ppmV; carbon dioxide, 316.2±2.8 ppmV; and nitrous oxide, 3±7ppb.

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