An original theory of the universe: Thomas Wright. American Elsevier Inc. xxxvii + 178 pp. Price $32.00     

Owen Gingerich 《Icarus》1974,22(1):119-121

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The UBV orbital phase curves of Rhea,Dione, and Tethys     

Guy N. Blair  Frazer N. Owen 《Icarus》1974,22(2):224-229

Orbital phase curves are reported for Rhea (SV), Dione (SIV), and Tethys (SIII). Variations of 0.2 mag. and 0.8 mag. were found for Rhea and Dione respectively, while no variation of Tethys was detected. Some color variations are also reported.  相似文献   

Infrared observations of the surface and atmosphere of Titan     

R.F. Knacke  T. Owen  R.R. Joyce 《Icarus》1975,24(4):460-464

Infrared photometry of Titan, Saturn, and Saturn's Rings at 3.5, 4.9, 17.8, and 18.4 μm is reported. Comparison of the albedo of Titan in the 4.9 μm “window” with the albedo of the rings and with laboratory spectra suggests that frost, possibly water ice, could be a major constituent. If thick clouds are present they must be very dark at 4.9 μm. The 17.8 and 18.4 μm data are not consistent with a clear, dense molecular hydrogen atmosphere.  相似文献   

A physical model of Titan's clouds     

Owen B. Toon  R.P. Turco  James B. Pollack 《Icarus》1980,43(3):260-282

We have constructed a model of the physical processes controlling Titan's clouds. Our model produces clouds that qualitatively match the present observational constraints in a wide variety of model atmospheres, including those with low atmospheric pressures (25 mbar) and high atmospheric pressures. We find the following: (1) high atmospheric temperatures (160°K) are important so that there is a large scale height in the first few optical depths of cloud; (2) the aerosol mass production occurs at very low aerosol optical depth so that the cloud particles do not directly affect the photochemistry producing them; (3) the production rate of aerosol mass by chemical processes is probably greater than 3.5 × 10^?14 g cm^?2 sec^?1; (4) and the eddy diffusion coefficient is less than 5 × 10⁶ cm² sec^?1 except perhaps in the top optical depth of the cloud. Our model is not extremely sensitive to particle shape, but it is sensitive to particle density. Higher particle densities require larger aerosol mass production rates to produce satisfactory clouds. Particle densities of unity require a mass production rate on the order of 3.5 × 10^?13 g cm^?2 sec^?1. We also show that an increase in mass input causes a decrease in the mean particle size, as required by J. B. Pollack et al. (1980, Geophys. Res. Lett. 7, 829–832), to explain the observed correlation between the solar cycle and Titan's albedo; that coagulation need not be extremely inefficient in order to obtain realistic clouds as proposed by M. Podolak and E. Podolak (1980, Icarus43, 73–83); that coagulation could be inefficient due to photoelectric charging of the particles; and, that the lifetime of particles near the altitude of unit optical depth is a few months, as required to explain the temporal variability observed by S. T. Suess and G. W. Lockwood and D. P. Cruikshank and J. S. Morgan (1979, Bull. Amer. Astron. Soc.11, 564). Although Titan's aerosols are ottically thick in the vertical direction, the atmosphere is so extended that the horizontal visibility is greater than that found anywhere at Earth's surface.  相似文献   

Visit to the British Museum: South African Reptilian Remains April 14th, 1877     

Owen C.B.  J. Foulerton 《Proceedings of the Geologists' Association. Geologists' Association》1877,5(3):122-125

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Improving acoustic estimates of krill: experience from repeat sampling of northern krill (Meganyctiphanes norvegica) in Gullmarsfjord, Sweden     

Everson  Inigo; Tarling  Geraint A.; Bergstrom  Bo 《ICES Journal of Marine Science》2007,64(1):39-48

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The effect of particles on light scattering in the sea     

Robert W. Owen Jr. 《Journal of Oceanography》1973,29(5):171-184

Relationships of light scattering to particle concentration and size distribution were experimentally determined to follow theoretical findings, both in laboratory suspensions and in a variety of conditions in the natural marine environment. Confirmation was obtained by electronic particle counts paired with scattering measurements that light scattering provides a measure of concentration of particle cross-section in the sea. The use of light scattering as a measure of particle bulk concentration is shown to require constancy of the distribution of particle size, which is met under prescribed circumstances in the upper part of the sea. A simple test can indicate the constancy of the size distribution. A tentative estimate is made of the effect particles have on the inherent properties of open ocean water.  相似文献   

Geomorphology,sedimentology and minimum exposure ages of streamlined subglacial landforms in the NW Himalaya,India          下载免费PDF全文

Sourav Saha  Milap C. Sharma  Madhav K. Murari  Lewis A. Owen  Marc W. Caffee 《Boreas: An International Journal of Quaternary Research》2016,45(2):284-303

Streamlined subglacial landforms that include drumlins in three study areas, the upper Chandra valley around Chandra Tal, the upper Spiti Valley and the middle Yunam Valley of the NW Himalaya of India were mapped and studied using geomorphic, sedimentological and geochronological methods. These streamlined subglacial landforms include a variety of morphological types, including: (i) half egg‐shaped forms; (ii) complex superimposed forms; (iii) dome‐shaped forms; (iv) inverse forms; and (v) flat‐topped symmetrical forms. Sedimentological data indicate that subglacial deformational processes are responsible for the formation of the streamlined subglacial landforms in the Chandra Tal and upper Spiti Valley study areas. In contrast, streamlined landforms in the middle Yunam Valley are the result of melt‐out and subglacial erosional processes. In the Yunam Valley study area, 11 new cosmogenic ¹⁰Be surface exposure ages were obtained for boulders inset into the crests of streamlined subglacial landforms and moraines, and also for a bedrock surface. The streamlined landforms date to 8–7 ka, providing evidence of an early Holocene valley glaciation, and older moraines date to ～17–15 and 79–52 ka, representing other significant valley glacial advances in the middle Yunam Valley. The subglacial landforms in the Chandra Valley provide evidence for a ≥300‐m‐thick Lateglacial glacier that advanced southeast, overtopping the Kunzum Range, and advancing into the upper Spiti Valley. The streamlined subglacial landforms in these study areas of the NW Himalaya highlight the usefulness of such landforms in developing glacial chronostratigraphy and for understanding the dynamics of Himalayan glaciation.  相似文献   

The carboniferous rocks of the north Cornish Coast and their structures     

David E. Owen 《Proceedings of the Geologists' Association. Geologists' Association》1934,45(4):451-IN9

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Nature and timing of large landslides in the Himalaya and Transhimalaya of northern India     

Jason M. Dortch  Lewis A. Owen  William C. Haneberg  Marc W. Caffee  Craig Dietsch  Ulrich Kamp 《Quaternary Science Reviews》2009,28(11-12):1037-1054

Four large landslides, each with a debris volume >10⁶ m³, in the Himalaya and Transhimalaya of northern India were examined, mapped, and dated using ¹⁰Be terrestrial cosmogenic radionuclide surface exposure dating. The landslides date to 7.7±1.0 ka (Darcha), 7.9±0.8 ka (Patseo), 6.6±0.4 ka (Kelang Serai), and 8.5±0.5 ka (Chilam). Comparison of slip surface dips and physically reasonable angles of internal friction suggests that the landslides may have been triggered by increased pore water pressure, seismic shaking, or a combination of these two processes. However, the steepness of discontinuities in the Darcha rock-slope, suggests that it was more likely to have started as a consequence of gravitationally-induced buckling of planar slabs. Deglaciation of the region occurred more than 2000 years before the Darcha, Patseo, and Kelang Serai landslides; it is unlikely that glacial debuttressing was responsible for triggering the landslides. The four landslides, their causes, potential triggers and mechanisms, and their ages are compared to 12 previously dated large landslides in the region. Fourteen of the 16 dated landslides occurred during periods of intensified monsoons. Seismic shaking, however, cannot be ruled out as a mechanism for landslide initiation, because the Himalaya has experienced great earthquakes on centennial to millennial timescales. The average Holocene landscape lowering due to large landslides for the Lahul region, which contains the Darcha, Patseo, and Kelang Serai landslides, is ～0.12 mm/yr. Previously published large-landslide landscape-lowering rates for the Himalaya differ significantly. Furthermore, regional glacial and fluvial denudation rates for the Himalaya are more than an order of magnitude greater. This difference highlights the lack of large-landslide data, lack of chronology, problems associated with single catchment/large landslide-based calculations, and the need for regional landscape-lowering determinations over a standardized time period.  相似文献