Escape of atmospheric helium by nonthermal processes

Patterson, T. N. L.

doi:10.1029/rg006i004p00553

Cited by 12 publications

(6 citation statements)

References 20 publications

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“…Previously, it was difficult to understand how a balance could be achieved between losses and gains of SHe in the ter-restrial atmosphere [e.g., MacDonald, 1963;Patterson, 1968]. The suggestion by Johnson and Axford [1969] that auroral precipitation of SHe originating in the solar wind is a significant source at least partially resolved the problem, and it is supported by the observations reported here.…”

Section: This Value Is Very Close To the Value Predicted By Johnson Asupporting

confidence: 78%

“…The average SHe thermal escape flux has been estimated to be •3-6 cm -• s -x [Kockarts and Nicolet, 1962;Johnson and Axford, 1969;Kockarts, 1973]. There should also be a nonthermal escape flux which is at least •1 cm -• s -x, since such a process is required to provide a balance in the atmospheric budget of 4He [Axford, 1968;Patterson, 1968]. In fact, the thermal escape flux may be underestimated because the effects of locally high thermospheric temperatures (such as might be associated with the auroral zones) have not been taken into account.…”

Section: This Value Is Very Close To the Value Predicted By Johnson Amentioning

confidence: 99%

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Helium isotopes in an aurora

Bühler¹,

Axford²,

Chivers³

et al. 1976

J. Geophys. Res.

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Aluminum and platinum foils were flown into two bright auroras and subsequently recovered. They were then analyzed for traces of trapped noble gases in a sensitive high‐resolution mass spectrometer. In this paper we report the detection of ³He and confirm measurements of the 4He flux reported in a previous paper. The 4He∶³He ratio in the first (brighter) aurora was 2950 ± 250. This ratio is only slightly higher than the average solar wind ratio of 2350 and since the atmospheric ratio is grossly different (250 times larger), establishes the solar wind as the principal source of auroral helium, at least in the aurora concerned. The result supports earlier suggestions that auroral precipitation is one of the main sources of the ³He in the terrestrial atmosphere. Current estimates of ³He sources and loss rates are found to be consistent with a balanced atmospheric ³He budget.

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Section: This Value Is Very Close To the Value Predicted By Johnson Asupporting

confidence: 78%

Section: This Value Is Very Close To the Value Predicted By Johnson Amentioning

confidence: 99%

Helium isotopes in an aurora

Bühler¹,

Axford²,

Chivers³

et al. 1976

J. Geophys. Res.

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“…This hydrothermal activity also injects significant amounts of the primordial isotope 3 He into the deep water (Clarke et al, 1969;Jenkins et al, 1978). Because of its inertness, paucity in the atmosphere due to ongoing loss to outer space (Stoney, 1905;Turekian, 1959;Axford, 1968;Patterson, 1968), and its low intrinsic solubility in seawater (Weiss, 1971), hydrothermal 3 He anomalies are observed throughout the deep oceans. As importantly, the distribution of the 3 He can be combined with tracer-calibrated ocean models to infer the global flux of hydrothermal 3 He to be ~550 mol/y (we obtain a weighted mean of 550 ± 90 mol/y from the estimates made by Bianchi et al, 2010;Schlitzer, 2016;Holzer et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

The deep distributions of helium isotopes, radiocarbon, and noble gases along the U.S. GEOTRACES East Pacific Zonal Transect (GP16)

et al. 2018

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We report the deep distributions of noble gases, helium isotopes, and radiocarbon measured during the U.S. GEOTRACES GP16 East Pacific Zonal Transect between 152 and 77°W at 12-15°S in the South Pacific. The dominant feature is an intense tongue of hydrothermal effluent that extends more than 4,000 km westward from the East Pacific Rise (EPR) at ~2500m depth. The patterns reveal significant "downstream" variations in water mass structure, advection, and mixing that belie the simple perception of a continuous plume extending westward from the EPR. For example, one feature observed at 120°W, 14°S has tracer signatures that are consistent with a water mass originating from an area as much as 2,000 km south of this section, suggesting a quasi-permanent northward flow on the western flank of the EPR. Helium isotope variations in the plume show a uniquely high In the western end of the section, incoming bottom waters have relatively less hydrothermal hydrothermal helium, more radiocarbon, and more oxygen, as well as negative saturation anomalies for the heavy noble gases (Ar, Kr, and Xe). During the basin-scale upwelling of this water, diapycnal mixing serves to erase these negative anomalies. The relative magnitudes of the increases for the heavy noble gases (Ar, Kr, and Xe) are quantitatively consistent with this process. This leads us to estimate the relatively smaller effects on He and Ne saturations, which range from near zero to 0.2% and 0.3% respectively. With this information, we are able to refine our estimates of the magnitude of He ratio of non-atmospheric helium introduced into deep Pacific waters.pg. 2

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“…The problem of accounting for the low terrestrial helium concentration may have at last been solved. Considering the production and loss of terrestrial helium, 4 He concentrations (the principal helium iso tope) and the ratio 4 He/ 3 He are both considerably lower than have been predicted by thermal escape processes [Patterson, 1968]. Axford has proposed a possible solution.…”

Section: Oilier Variationsmentioning

confidence: 98%

Venus: An Upper Limit on Intrinsic Magnetic Dipole Moment Based on Absence of a Radiation Belt

Allen

Krimgis

Frank

et al. 1967

Science

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On the basis of the absence of energetic electrons (E(e) 45 kiloelectron volts) and protons (E(p) 320 kiloelectron volts) associated with Venus to within a radial distance of 10,150 kilometers from the center of the planet and using a physical similitude argument and the observational and theoretical knowledge of the magnetosphere of Earth, we conclude that the intrinsic magnetic dipole moment of Venus is almost certainly less than 0.01 and probably less than 0.001 of that of Earth. Corresponding upper limits on the magnetic field at the equatorial surface of Venus are about 350 and 35 x 10(-5) gauss, respectively.

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Escape of atmospheric helium by nonthermal processes

Cited by 12 publications

References 20 publications

Helium isotopes in an aurora

Helium isotopes in an aurora

The deep distributions of helium isotopes, radiocarbon, and noble gases along the U.S. GEOTRACES East Pacific Zonal Transect (GP16)

Venus: An Upper Limit on Intrinsic Magnetic Dipole Moment Based on Absence of a Radiation Belt

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