The Anglo-Australian Observatory 2dF facility   总被引：1，自引：0，他引：1  

I. J. Lewis  R. D. Cannon  K. Taylor  K. Glazebrook  J. A. Bailey  I. K. Baldry  J. R. Barton  T. J. Bridges  G. B. Dalton  T. J. Farrell  P. M. Gray  A. Lankshear  C. McCowage  I. R. Parry  R. M. Sharples  K. Shortridge  G. A. Smith  J. Stevenson  J. O. Straede  L. G. Waller  J. D. Whittard  J. K. Wilcox  K. C. Willis 《Monthly notices of the Royal Astronomical Society》2002,333(2):279-299

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On the diurnal period variation of midlatitude ULF pulsations     

E.M. Poulter  W. Allan  G.J. Bailey  R.J. Moffett 《Planetary and Space Science》1984,32(6):727-734

Magnetometer studies of the periods of mid-latitude ULF pulsations have produced conflicting results on the variation of the pulsation periods with both latitude and local time. Since the mid-latitude geomagnetic field is not expected to be significantly distorted by the solar wind, the observed diurnal period variations should be determined by changes in the ambient plasma density. We have applied a physically realistic plasmasphere model to the determination of pulsation eigenperiods over a 24-h interval at L=2.3 (appropriate to Wellington, New Zealand). The resulting model pulsation eigenperiods are largest during the day, with minimum and maximum values at 05.00 and 18.00 L.T. respectively. The model predicts a general increase in the eigenperiods during the replenishment of the protonosphere after a period of geomagnetic activity.  相似文献   

The topside ionosphere above Arecibo at equinox during sunspot maximum     

G.J. Bailey 《Planetary and Space Science》1980,28(1):47-59

The coupled time-dependent O⁺ and H⁺ continuity and momentum equations and O⁺, H⁺ and electron heat balance equations are solved simultaneously within the L = 1.4 (Arecibo) magnetic flux tube between an altitude of 120 km and the equatorial plane. The results of the calculations are used in a study of the topside ionosphere above Arecibo at equinox during sunspot maximum. Magnetically quiet conditions are assumed.The results of the calculations show that the L = 1.4 magnetic flux tube becomes saturated from an arbitrary state within 2–3 days. During the day the ion content of the magnetic flux tube consists mainly of O⁺ whereas O⁺ and H⁺ are both important during the night. There is an altitude region in the topside ionosphere during the day where ion-counterstreaming occurs with H⁺ flowing downward and O⁺ flowing upward. The conditions causing this ion-counterstreaming are discussed. There is a net chemical gain of H⁺ at the higher altitudes. This H⁺ diffuses both upwards and downwards whilst O⁺ diffuses upwards from its solar e.u.v. production source which is most important at the lower altitudes. During the night the calculated O⁺ and H⁺ temperatures are very nearly equal whereas during the day there are occasions when the H⁺ temperature exceeds the O⁺ temperature by about 300 K.  相似文献   

The influence of vertical motions on the diurnal variations of temperature and density in the thermosphere     

G.J. Bailey 《Planetary and Space Science》1972

The heat balance equation for the thermosphere is examined in detail so that results and suggestions of different workers may be easily compared. Vertical motions have not been completely included in previous calculations and thus the claims by some authors are premature. Results, obtained by solving the heat balance equation with model vertical and east-west winds included, are presented. They show that east-west winds and the ‘breathing’ vertical motion of the isobars have little influence on the phases of the diurnal variations of temperature and density and affect the amplitudes of the variations by less than 20 per cent. On the other hand, vertical motion additional to the breathing motion affects significantly the phases of temperature and density. Support is given to the suggestion, made by Moffett on theoretical grounds and by Bauer et al. and Swartz and Nisbet on experimental grounds, that the diurnal variations of temperature gradient in the lower thermosphere may give temperature and density out of phase at greater heights, even with fixed temperature and density at the lower boundary.  相似文献   

The Effect of Source Field Polarization on Geomagnetic Variation Anomalies in the British Isles     

R. C. Bailey  R. N. Edwards 《Geophysical Journal International》1976,45(1):97-104

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The Human Orrery: Ground-based astronomy for all     

Mark Bailey    David Asher Astronomers  Apostolos Christou Astronomers 《Astronomy& Geophysics》2005,46(3):3.31-3.35

Mark Bailey, David Asher and Apostolos Christou describe an interactive, open-air model for explaining the motions of the planets and the position of the Earth in space, which was formally opened at the Armagh Observatory on 26 November 2004.  相似文献   

Mineralization and deformation of the Malanjkhand terrane (2,490–2,440 Ma) along the southern margin of the Central Indian Tectonic Zone     

Holly Stein  Judith Hannah  Aaron Zimmerman  Richard Markey 《Mineralium Deposita》2006,40(6-7):755-765

The Malanjkhand Cu–Mo–Au deposit, located near the northwest margin of the Malanjkhand batholith (terrane), is a strategic and significant porphyry-style deposit that experienced a protracted 50 m.y. deformational history shortly after its formation at 2,490±8 Ma (Stein et al. 2004). In a recent study, Panigrahi et al. (2004) averaged U–Pb SHRIMP zircon data from a pooled set of samples from the Malanjkhand batholith to advocate a meaningless intermediate age of ~2,476 Ma for the Malanjkhand granitoid and its Cu–Mo–Au deposit. In the northwest part of the Malanjkhand batholith, Re–Os dating of occurrence-specific molybdenite captures not only the age of porphyry-style mineralization and associated magmatism, but also elucidates a complex deformational history that extends to ~2,450 Ma. In the central part of the Malanjkhand batholith, Re–Os dating of delicate spindles of accessory molybdenite occurring with pristine muscovite in miarolitic cavities within the undeformed microgranitoid at the Devgaon Mo prospect unequivocally shows that deformation ceased at this location no later than 2,470–2,465 Ma. The deformational history recorded at the Malanjkhand deposit in the northwest most likely reflects prolonged transpressive convergence and docking of the Malanjkhand terrane with units in the poorly understood (proto) Central Indian Tectonic Zone (CITZ) along its southern margin, the Central Indian shear zone. The timing for this convergence is Late Archean–Early Paleoproterozoic.Comment on “Age of granitic activity associated with copper–molybdenum mineralization at Malanjkhand, Central India” by Panigrahi MK et al. (Mineralium Deposita 39:670–677)  相似文献   

Geochemistry of boron in the Ilímaussaq alkaline complex, South Greenland     

J.C. Bailey   《Lithos》2006,91(1-4):319-330

The distribution of boron has been studied in rocks and minerals of the Ilímaussaq complex, South Greenland, using optical emission spectrometry. In the silica-undersaturated rocks of intrusive phases 1 and 3, average B contents increased from 5.6 ppm in augite syenite to a maximum of 8.9 ppm in sodalite-rich agpaitic nepheline syenite (naujaite roof cumulate) and then decreased to 5.4 ppm in the final lujavrites. Boron only behaved as an incompatible element during certain stages of the fractionation history. Starting at the naujaite stage, sodalite crystals (60–45 ppm B) were fractionated by flotation and were also trapped among the heavy cumulus phases of the bottom cumulates. This prevented the significant build-up of B in late derivatives as seen in other nepheline syenites. Nevertheless, in late pegmatites and veins associated with the agpaitic rocks, B was locally concentrated in certain Be minerals and metamict/reworked minerals. In the silica-oversaturated rocks of intrusive phase 2, average B contents increased from 8.6 ppm in quartz syenite to 13 ppm in alkali granite.  相似文献   

Broadening participation,creating community,and learning that it never goes as planned     

James  Autumn C.  Alyasiri  Elaf  Howe  Matthew  James  Ryan D.  Jin  Yiwei  Lwanga  Kyagaba  McClain  Bailey  Moore  Andrea  Shao  Yaxiong  Valdez  Felipe 《GeoJournal》2021,87(2):281-292

This paper presents the experience of a service-learning course which used community geography to study a proposed research and community center in DeKalb, IL. The center was proposed as a jointly-developed project by the Northern Illinois University and local governmental entities. The original goal of the course was to explore the viability of the proposed project and solicit feedback from the community through traditional engaged planning and public participation. As students began interacting with university and residential communities, it became clear that both communities had input for the center, and found similarities in their experiences and perceptions. While noted divisions in interest groups are known in DeKalb, both communities found themselves surprisingly interested in meaningful discussion to better understand each other through their shared experiences. In response, our theoretical approach shifted to community geography. Students, university employees, and local residents introduced and analyzed questions together as researchers and participants, and developed recommendations to address shared concern. Students then prepared a report advocating for those concerns to submit to university and community leaders. Following the evolution of this project, this paper presents lessons learned and areas for application of community geography as a pedagogical technique, as an important component of geography curriculum, and as a research framework for town-gown relationship inquiry.

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Would you like to know more? The effect of personalized wildfire risk information and social comparisons on information-seeking behavior in the wildland–urban interface     

Meldrum  James R.  Brenkert-Smith  Hannah  Champ  Patricia A.  Gomez  Jamie  Byerly  Hilary  Falk  Lilia  Barth  Christopher M. 《Natural Hazards》2021,106(3):2139-2161

Natural Hazards - Private landowners are important actors in landscape-level wildfire risk management. Accordingly, wildfire programs and policy encourage wildland–urban interface homeowners...  相似文献