Analytic Magnetic Reconnection Solutions in Cylindrical Geometry     

Watson  P.G.  Craig  I.J.D. 《Solar physics》2002,207(2):337-354

In this paper we present a new class of exact reconnection solutions in cylindrical geometry. We point out that in the case of planar reconnection there is a natural cylindrical analog to the Cartesian Dawson function model for the magnetic field. Although the resistive energy release scalings of these solutions mimic the Cartesian models an important new feature is the presence of curvature in the current sheet. We go on to show that these solutions can be generalized to three dimensions.  相似文献   

Thermal and non-thermal radio variations in WR 147     

S. K. Watson  R. J. Davis  P. M. Williams  M. F. Bode 《Monthly notices of the Royal Astronomical Society》2002,334(3):631-636

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The 13th and 14th Workshops on Antarctic Meteorology and Climate     

Matthew A.LAZZARA  Sophie A.ORENDORF  Taylor P.NORTON  Jordan G.POWERS  David H.BROMWICH  Scott CARPENTIER  John J.CASSANO  Steven R.COLWELL  Arthur M.CAYETTE  Kirstin WERNER 《大气科学进展》2020,37(5):423-430

1.Overview In July 2018,the Antarctic community came together to meet at the 13th Workshop on Antarctic Meteorology and Climate(WAMC)in Madison,Wisconsin,USA(Fig.1);and in the following year in June 2019,the 14th WAMC was held in Charleston,South Carolina,USA(Fig.2).With a growing history,the WAMC addresses the topics of Antarctic meteorology and climate(Kameda et al.,2008;Colwell et al.,2016;Lazzara et al.,2018)as well as weather-related issues of scientific and operational support.The workshops bring together researchers,operational forecasters,numerical modelers,observational specialists,and students.The themes of both workshops included Antarctic meteorological observations,Antarctic atmospheric numerical modeling,Antarctic meteorological and climate research,and Antarctic weather forecasting and operational services.The 2018 and 2019 WAMC were both followed by a one-day focus on the Year of Polar Prediction-Southern Hemisphere(YOPP-SH),when preparations and follow-up discussions were made with regard to the YOPP Special Observing Period from 16 November 2018 to 15 February 2019.  相似文献   

Relative sea‐level observations in western Scotland since the Last Glacial Maximum for testing models of glacial isostatic land movements and ice‐sheet reconstructions     

Ian Shennan  Sarah Hamilton  Caroline Hillier  Amanda Hunter  Ruth Woodall  Sarah Bradley  Glenn Milne  Anthony Brooks  Sophie Bassett 《第四纪科学杂志》2006,21(6):601-613

Observations of relative sea‐level change and local deglaciation in western Scotland provide critical constraints for modelling glacio‐isostatic rebound in northern Britain over the last 18 000 years. The longest records come from Skye, Arisaig and Knapdale with a shorter, Holocene, record from Kintail. Biostratigraphic (diatom, pollen, dinoflagellate, foraminifera and thecamoebian), lithological and radiocarbon analyses provide age and elevation parameters for each sea‐level index point. All four sites reveal relative sea‐level change that is highly non‐monotonic in time as the local vertical component of glacio‐isostatic rebound and eustasy (or global meltwater influx) dominate at different periods. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Discovery of the 'missing' mode in HR 1217 by the Whole Earth Telescope     

D. W.Kurtz  S. D.Kawaler  R. L.Riddle  M. D.Reed †  M. S.Cunha  M.Wood  N.Silvestri  T. K.Watson  N.Dolez  P.Moskalik  S.Zola  E.Pallier  J. A.Guzik  T. S.Metcalfe  A. S.Mukadam  R. E.Nather  D. E.Winget  D. J.Sullivan  T.Sullivan  K.Sekiguchi  X.Jiang  R.Shobbrook  B. N.Ashoka  S.Seetha  S.Joshi  D.O'Donoghue  G.Handler  M.Mueller  J. M.Gonzalez Perez  J.-E.Solheim  F.Johannessen  A.Ulla  S. O.Kepler  A.Kanaan  A.da Costa  L.Fraga  O.Giovannini  J. M.Matthews 《Monthly notices of the Royal Astronomical Society》2002,330(3):57-61

HR 1217 is a prototypical rapidly oscillating Ap star that has presented a test to the theory of non-radial stellar pulsation. Prior observations showed a clear pattern of five modes with alternating frequency spacings of 33.3 and 34.6 μHz, with a sixth mode at a problematic spacing of 50.0 μHz (which equals  1.5×33.3 μHz)  to the high-frequency side. Asymptotic pulsation theory allowed for a frequency spacing of 34 μHz, but Hipparcos observations rule out such a spacing. Theoretical calculations of magnetoacoustic modes in Ap stars by Cunha predicted that there should be a previously undetected mode 34 μHz higher than the main group, with a smaller spacing between it and the highest one. In this Letter, we present preliminary results from a multisite photometric campaign on the rapidly oscillating Ap star HR 1217 using the 'Whole Earth Telescope'. While a complete analysis of the data will appear in a later paper, one outstanding result from this run is the discovery of a newly detected frequency in the pulsation spectrum of this star, at the frequency predicted by Cunha.  相似文献   

The component masses of the cataclysmic variable V347 Puppis     

T. D. Thoroughgood  V. S. Dhillon  D. Steeghs  C. A. Watson  D. A. H. Buckley  S. P. Littlefair  D. A. Smith  M. Still †  K. J. van der Heyden  B. Warner 《Monthly notices of the Royal Astronomical Society》2005,357(3):881-894

We present time-resolved spectroscopy and photometry of the double-lined eclipsing cataclysmic variable V347 Pup (=LB 1800). There is evidence of irradiation on the inner hemisphere of the secondary star, which we correct for using a model to give a secondary-star radial velocity of   K _R= 198 ± 5 km s⁻¹  . The rotational velocity of the secondary star in V347 Pup is found to be   v sin  i = 131 ± 5 km s⁻¹  and the system inclination is   i = 840 ± 23  . From these parameters we obtain masses of   M ₁= 0.63 ± 0.04 M_⊙  for the white dwarf primary and   M ₂= 0.52 ± 0.06 M_⊙  for the M0.5V secondary star, giving a mass ratio of   q = 0.83 ± 0.05  . On the basis of the component masses, and the spectral type and radius of the secondary star in V347 Pup, we find tentative evidence for an evolved companion. V347 Pup shows many of the characteristics of the SW Sex stars, exhibiting single-peaked emission lines, high-velocity S-wave components and phase-offsets in the radial velocity curve. We find spiral arms in the accretion disc of V347 Pup and measure the disc radius to be close to the maximum allowed in a pressureless disc.  相似文献   

Stokes imaging, Doppler mapping and Roche tomography of the AM Herculis system V834 Cen   总被引：1，自引：0，他引：1  

Stephen B. Potter  E. Romero-Colmenero  C. A. Watson  D. A. H. Buckley  A. Phillips 《Monthly notices of the Royal Astronomical Society》2004,348(1):316-324

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Relative sea‐level changes,glacial isostatic modelling and ice‐sheet reconstructions from the British Isles since the Last Glacial Maximum     

Ian Shennan  Sarah Bradley  Glenn Milne  Anthony Brooks  Sophie Bassett  Sarah Hamilton 《第四纪科学杂志》2006,21(6):585-599

While contributing <1 m equivalent eustatic sea‐level rise the British Isles ice sheet produced glacio‐isostatic rebound in northern Britain of similar magnitude to eustatic sea‐level change, or global meltwater influx, over the last 18 000 years. The resulting spatially variable relative sea‐level changes combine with observations from far‐field locations to produce a rigorous test for quantitative models of glacial isostatic adjustment, local ice‐sheet history and global meltwater influx. After a review of the attributes of relative sea‐level observations significant for constraining large‐scale models of the isostatic adjustment process we summarise long records of relative sea‐level change from the British Isles and far‐field locations. We give an overview of different global theoretical models of the isostatic adjustment process before presenting intercomparisons of observed and predicted relative sea levels at sites in the British Isles and far‐field for a range of Earth and ice model parameters in order to demonstrate model sensitivity and the resolving power available from using evidence from the British Isles. For the first time we show a good degree of fit between relative sea‐level observations and predictions that are based upon global Earth and ice model parameters, independently derived from analysis of far‐field data, with a terrain‐corrected model of the British Isles ice sheet that includes extensive glaciation of the North Sea and western continental shelf, that does not assume isostatic equilibrium at the Last Glacial Maximum and keeps to trimline constraints of ice surface elevation. We do not attempt to identify a unique solution for the model lithosphere thickness parameter or the local‐scale detail of the ice model in order to provide a fit for all sites, but argue that the next stage should be to incorporate an ice‐sheet model that is based on quantitative, glaciological model simulations. We hope that this paper will stimulate this debate and help to integrate research in glacial geomorphology, glaciology, sea‐level change, Earth rheology and quantitative modelling. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

A Very Small Array search for the extended Sunyaev–Zel''dovich effect in the Corona Borealis supercluster     

Ricardo Génova-Santos  José Alberto Rubiño-Martín  Rafael Rebolo †  Kieran Cleary ‡  Rod D. Davies  Richard J. Davis  Clive Dickinson §  Nelson Falcón ‡‡  Keith Grainge  Carlos M. Gutiérrez  Michael P. Hobson  Michael E. Jones ¶  Rüdiger Kneissl &#;  Katy Lancaster  Carmen P. Padilla-Torres  Richard D. E. Saunders  Paul F. Scott  Angela C. Taylor ¶  Robert A. Watson †† 《Monthly notices of the Royal Astronomical Society》2005,363(1):79-92

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Spectroscopic follow-up of a cluster candidate at z= 1.45     

Caroline van Breukelen  Garret Cotter  Steve Rawlings  Tony Readhead  David Bonfield  Lee Clewley  Rob Ivison  Matt Jarvis  Chris Simpson  Mike Watson 《Monthly notices of the Royal Astronomical Society》2007,382(3):971-984

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