Polar magnetic fields of the Sun: 1960–1971     

Robert Howard 《Solar physics》1972,25(1):5-13

Observations of the magnetic fields in the polar regions of the Sun are presented for the period 1960–1971. At the start of this interval the fields at the two poles were consistently of opposite sign and averaged around 1 G. Early in 1961 the field in the south decreased suddenly and the field in the north decreased in strength slowly over the next few years. By the mid-1960's the fields at both poles were quite weak and irregular. Throughout the period of these observations the fields at both poles often showed a remarkable tendency to vary in unison. About the middle of 1971 the north polar field became significantly positive, first at lower latitudes, then above 70 °. An autocorrelation analysis of the polar fields in the north shows a weak rotation peak, indicating significant features in these regions. A comparison of field strengths in the east and west quadrants in the north suggests that even at the extreme polar latitudes the following polarity fields are inclined slightly toward the rotation and the preceding polarity field lines are inclined slightly to trail the rotation.  相似文献   

A large-scale pattern in the solar magnetic field     

John M. Wilcox  Robert Howard 《Solar physics》1968,5(4):564-574

A clearly evident large-scale pattern in the interplanetary magnetic field during 1964 is used to search for a similar large-scale pattern in the solar magnetic field. It is found that such a pattern did exist in the photospheric field observations on both sides of the equator over a range of at least 40°N to 35°S. The pattern is basically similar at all these latitudes, and differs from that to be expected from solar differential rotation in three important respects. It is found that the solar magnetic pattern changed at all latitudes investigated within an interval of a few solar rotations.  相似文献   

The Systematic Error in Seismic Location     

Robert Underwood  Roy C. Lilwall 《Geophysical Journal International》1969,17(5):521-526

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Energy losses of low-energy photoelectrons to thermal electrons     

Robert W. Schunk  Paul B. Hays 《Planetary and Space Science》1971

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Spectroscopic determinations of solar rotation   总被引：2，自引：0，他引：2  

Robert Howard  J. Harvey 《Solar physics》1970,12(1):23-51

Spectral line shift data obtained from full-disk magnetograms recorded at Mt. Wilson are analyzed for differential rotation. The method of analysis is discussed and the results from the data for 1966 through 1968 are presented. The average equatorial velocity over this period is found to be 1.93 km/sec or 13.76 deg/day (sidereal). This corresponds to a sidereal period of 26.16 days. The average results are = 2.78 × 10^-6 - 3.51 × 10^-7 sin² B - 4.43 × 10^-7 sin⁴ B rad/sec, whereB is the solar latitude. This indicates a smaller decrease of angular velocity with latitude than found by earlier investigators. Variations from day to day are caused by large-scale short-lived velocity fields on the solar surface. There also appear to be secular variations.Currently at the Kitt Peak National Observatory, Tucson, Arizona.  相似文献   

    

W. A. Heiskanen  J. Lamar Worzel  G. Lynn Shurbert  Paul Herget  Clair E. Ewing  Carl I. Aslakson  Simo Laurila  John R. Williams  David T. Williams  Bertil Hallert  Robert C. Fitzpatrick  W. M. Markowitz  S. P. Worden  Henry Wild Jr  W. Kneissl 《Journal of Geodesy》1955,29(2):55-78

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Diagenetic sulfate reduction in marine sediments     

Robert E. Sweeney  I.R. Kaplan 《Marine Chemistry》1980,9(3):165-174

The importance of interstitial pore water as a vehicle for transport of dissolved ions between sediment at depth and the overlying ocean reservoir may be overestimated. The major cause of this overestimation is the assumption that the rate of ionic diffusion through the sediment is of a similar magnitude to the rate of reaction occurring within the sediment column. Examples are given to indicate that the above assumption may not be correct, at least for diagenetic sulfate reduction. Closed-system modeling, although approximate, is shown to be consistent, both qualitatively and isotopically, with measured changes that are observed for several sedimentary environments.  相似文献   

Methods of foundation engineering.—Developments in geotechnical Engineering, 24 | Z. Bazˇant. Elsevier,Amsterdam, 1979, 616 pp., U.S. $ 90.25, Dfl. 185.00     

Robert L. Lytton 《Engineering Geology》1981,17(4):284-285

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The acoustic transient recording buoy (ATRB): system descriptionand initial measurement results     

Tattersall  J.M. King  P.C. Mingrone  J.A. Herstein  P.D. 《Oceanic Engineering, IEEE Journal of》1992,17(3):227-238

An acoustic transient recording buoy (ATRB) developed to provide improved dynamic range and recording capacity in a reconfigurable manner is described. This digital system can acquire and record up to 16 h of broadband wide dynamic range (≈80 dB) acoustic data from eight hydrophones. A unique feature is the use of two inexpensive video cassette recorders to obtain up to 10 Gb of data storage capacity. The system is self-contained and capable of unattended bottom-moored operation. An experiment designed and conducted using a single ship and this system to obtain simultaneous measurements of sea surface forward scatter, propagation loss, and sea floor interaction is reported. Data obtained demonstrate the utility of this system for ocean acoustic experiments. Explosive charge source levels using direct path measurements agreed with previous measurements. Surface reflected data exhibited a frequency dependence attributed to sea surface swell and roughness  相似文献   

The palaeobiogeography of Permian anomodonts     

Gillian M. King 《地学学报》1992,4(6):633-640

It is generally considered that the oldest anomodont mammal-like reptiles are known from Late Permian sediments of the USSR and that during the rest of the Late Permian distribution of these fossils widens to encompass nearly all geographical areas by the end of the Period.
This study reviews the occurrence of anomodont genera in Permian sediments and reassesses the conventionally accepted distribution pattern. A broad correlation of terrestrial Permian rocks from different continents is attempted. Using recent reconstructions of Permian continental positions the effect of latitude on anomodont distribution is investigated. Some explanations for the restrictions operating on anomodont distribution are suggested.  相似文献