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Observations of interplanetary magnetic field polarity, solar wind speed, and geomagnetic disturbance index (C9) during the years 1962–1975 are compared in a 27-day pictorial format that emphasizes their associated variations during the sunspot cycle. This display accentuates graphically several recently reported features of solar wind streams including the fact that the streams were faster, wider, and longer-lived during 1962–1964 and 1973–1975 in the declining phase of the sunspot cycle than during intervening years (Bame et al., 1976; Gosling et al., 1976). The display reveals strikingly that these high-speed streams were associated with the major, recurrent patterns of geomagnetic activity that are characteristic of the declining phase of the sunspot cycle. Finally, the display shows that during 1962–1975 the association between long-lived solar wind streams and recurrent geomagnetic disturbances was modulated by the annual variation (Burch, 1973) of the response of the geomagnetic field to solar wind conditions. The phase of this annual variation depends on the polarity of the interplanetary magnetic field in the sense that negative sectors of the interplanetary field have their greatest geomagnetic effect in northern hemisphere spring, and positive sectors have their greatest effect in the fall. During 1965–1972 when the solar wind streams were relatively slow (500 km s-1), the annual variation strongly influenced the visibility of the corresponding geomagnetic disturbance patterns.Visiting Scientist, Kitt Peak National Observatory, Tucson, Arizona.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. 相似文献
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S. J. Bame J. R. Asbridge W. C. Feldman E. E. Fenimore J. T. Gosling 《Solar physics》1979,62(1):179-201
Information concerning the coronal expansion is carried by solar wind heavy ions. Distinctly different energy-per-charge ion spectra are found in two classes of solar wind having the low kinetic temperatures necessary for E/q resolution of the ion species. Heavy ion spectra which can be resolved are most frequently observed in the low-speed interstream (IS) plasma found between high speed streams; the streams are thought to be coming from coronal holes. Although the sources of the IS plasma are uncertain, the heavy ion spectra found there contain identifiable peaks of O, Si, and Fe ions. Such spectra indicate that the IS ionization state of O is established in coronal gas at T 2.1 × 106 K while that of Fe is frozen in farther out at 1.5 × 106 K. On occasion anomalous spectra are found outside IS flows in solar wind with abnormally depressed local kinetic temperatures. The anomalous spectra contain Fe16+ ions, not usually found in IS flows, and the derived coronal freezing in temperatures are significantly higher; for two of the best cases values of 3.4 × 106 K were found for the O ions and 2.9 × 106 K for Fe ions. The coronal sources of some of these ionizationally hot flows are identified as solar flares. The appearance of abnormally depressed kinetic temperatures in solar wind coming from flare-heated coronal gas lends support to earlier speculation that flares can expel plasma enclosed in magnetic bottles or bubbles. In transit to 1 AU the gas is sufficiently isolated from the hot corona that it cools anomalously.The Los Alamos Scientific Laboratory requests that the publisher identify this article as work performed under the auspices of the Department of Energy.By acceptance of this article, the publisher recognizes that the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or to allow others to do so, for U.S. Government purposes. 相似文献
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This paper describes the solar wind plasma ejected by the proton flares of August/September, 1966, in McMath Region 8461. The discussion will serve a dual purpose. First it will help complete the record on the events of August/September 1966. Secondly we will discuss the helium enrichment of the interplanetary plasma associated with the flares. This is the fifth case reported in which major flares produce helium enriched interplanetary plasma. Relative helium abundances of greater than 15% are typical. These findings are interpreted in terms of a solar atmosphere that contains helium enriched regions. 相似文献
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S. J. Bame J. R. Asbridge W. C. Feldman M. D. Montgomery P. D. Kearney 《Solar physics》1975,43(2):463-473
During periods in 1969–1971 when interplanetary flow conditions were quiet, 17 determinations of the solar wind Fe and Si abundances and 7 of the O abundance were made. On the average 〈N(Fe)/N(H)〉 = 5.3 × 10-5, 〈N(Si)/N(H)〉 = 7.6 × 10-5 and 〈N(O)/N(H)〉 = 5.2 × 10-4. Variations from the averages over a total range of factors of ～4 for O, ～4 for Si, and ～ 10 for Fe have have observed. Although Fe and Si abundance variations appear to be correlated, no other element correlation pairs are unambiguously discernible from the present data set. 相似文献
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Solar Physics - A study of the lower corona thermal properties was made using the best examples of solar wind heavy ion spectra obtained with Vela 5 and 6 plasma analyzers at times of quiet solar... 相似文献
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Asbridge E. F. Low Choy D. Mackey B. Serrao-Neumann S. Taygfeld P. Rogers K. 《Natural Hazards》2021,109(1):999-1026
Natural Hazards - The peri-urban interface (PUI) exhibits characteristic qualities of both urban and rural regions, and this complexity has meant that risk assessments and long-term planning for... 相似文献
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