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41.
This chapter mainly deals with magnetic reconnection and particle acceleration in relativistic astrophysical plasmas, where the temperature of the current sheet exceeds the rest mass energy and the Alfvén velocity is close to the speed of light. Magnetic reconnection now receives a great deal of interest for its role in many astrophysical systems such as pulsars, magnetars, galaxy clusters, and active galactic nucleus jets. We review recent advances that emphasize the roles of reconnection in high-energy astrophysical phenomena. 相似文献
42.
C. Fang Y. X. Zhang M. D. Ding W. C. Livingston 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2002,29(12):1947-1950
The Ca
K line has been measured regularly nearly every month since 1974 at Kitt Peak. It is well known that the K1 component of the Ca
K line is formed in the temperature minimum region (TMR) of the solar atmosphere. Our study of the data of CaII K profiles over two solar cycles indicates that both in full disc integrated spectra and in center disc spectra, the distance between the red K1 and the blue K1 of the profiles and its average intensity show periodic variations. But the variation for the full disc integrated spectra fluctuates in the same way as the sunspot number does, while that for the center disc spectra has a time delay with respect to sunspot number. Non-LTE computations yield a cyclic temperature variation of about 17 K of the TMR in the quiet-Sun atmosphere and a cyclic variation of about 15–20 km in the height position of the TMR. 相似文献
43.
H. Fuke Y. Tasaki K. Abe S. Haino Y. Makida S. Matsuda J.W. Mitchell A.A. Moiseev J. Nishimura M. Nozaki S. Orito J.F. Ormes M. Sasaki E.S. Seo Y. Shikaze R.E. Streitmatter J. Suzuki K. Tanaka T. Yamagami A. Yamamoto T. Yoshida K. Yoshimura 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008,41(12):2050-2055
44.
M. Ishiguro Y. Sarugaku S. Nishihara Y. Nakada S. Nishiura T. Soyano K. Tarusawa T. Mukai S.M. Kwon S. Hasegawa F. Usui M. Ueno 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
Cometary dust trails were first observed by IRAS; they are widely known to be the origins of meteoric showers. A new window has been opened for the study of dust trails, using ground-based observations. We succeeded in obtaining direct images of the 22P/Kopff dust trail with the Kiso 1.05-m Schmidt telescope. Following this initial success, we have continued to perform a dust trail survey at Kiso. As a result of this survey, we have detected dust trails along the orbit of six periodic comets, between February 2002 and March 2004. The optical depth of these dust trails are 10−9 to 10−8, which is consistent with IRAS measurements. In this paper, we describe the observations and data reduction procedures, and report the brief result obtained between February 2002 and March 2004. 相似文献
45.
F. M. Ipavich G. Gloeckler C. Y. Fan L. A. Fisk D. Hovestadt B. Klecker J. J. O'Gallagher M. Scholer 《Space Science Reviews》1979,23(1):93-101
We report initial measurements from the ULECA sensor of the Max-Planck-Institut/University of Maryland experiment on ISEE-1. ULECA is an electrostatic deflection — total energy sensor consisting of a collimator, deflection analyzer and an array of solid state detectors. The position of a given detector, which determines the energy per charge of an incident particle, together with the measured energy determine the particle's charge state. We find that a rich variety of phenomena are operative in the transthermal energy regime (10 keV/Q to 100 keV/Q) covered by ULECA. Specifically, we present observations of locally accelerated protons, alpha particles, and heavier ions in the magnetosheath and upstream of the Earth's bow shock. Preliminary analysis indicates that the behavior of these locally accelerated particles is most similar at the same energy per charge. 相似文献
46.
With a precise geoid, GOCE will allow an estimation of absolute dynamic topography from altimetry. The projected benefits
to operational oceanography and its applications are analyzed herein. After a brief overview of operational oceanography,
we explain how the new geoids will be used in the future to improve real time altimeter products and to better constrain modelling
and data assimilation systems. A significant impact is expected both for mesoscale (e.g. better estimations and forecasts of currents for pollution monitoring, marine safety, offshore industry) and climate (better
initialization of coupled ocean/atmosphere models) applications.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
47.
Kamide Y. Kihn E.A. Ridley A.J. Cliver E.W. Kadowaki Y. 《Space Science Reviews》2003,107(1-2):307-316
We report the recent progress in our joint program of real-time mapping of ionospheric electric fields and currents and field-aligned
currents through the Geospace Environment Data Analysis System (GEDAS) at the Solar-Terrestrial Environment Laboratory and
similar computer systems in the world. Data from individual ground magnetometers as well as from the solar wind are collected
by these systems and are used as input for the KRM and AMIE magnetogram-inversion algorithms, which calculate the two-dimensional
distribution of the ionospheric parameters. One of the goals of this program is to specify the solar-terrestrial environment
in terms of ionospheric processes, providing the scientific community with more than what geomagnetic activity indices and
statistical models provide.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
48.
R. H. Brown K. H. Baines G. Bellucci J.-P. Bibring B. J. Buratti F. Capaccioni P. Cerroni R. N. Clark A. Coradini D. P. Cruikshank P. Drossart V. Formisano R. Jaumann Y. Langevin D. L. Matson T. B. Mccord V. Mennella E. Miller R. M. Nelson P. D. Nicholson B. Sicardy C. Sotin 《Space Science Reviews》2004,115(1-4):111-168
The Cassini visual and infrared mapping spectrometer (VIMS) investigation is a multidisciplinary study of the Saturnian system. Visual and near-infrared imaging spectroscopy and high-speed spectrophotometry are the observational techniques. The scope of the investigation includes the rings, the surfaces of the icy satellites and Titan, and the atmospheres of Saturn and Titan. In this paper, we will elucidate the major scientific and measurement goals of the investigation, the major characteristics of the Cassini VIMS instrument, the instrument calibration, and operation, and the results of the recent Cassini flybys of Venus and the Earth–Moon system.This revised version was published online in July 2005 with a corrected cover date. 相似文献
49.
Improved strapdown coning algorithms 总被引:2,自引:0,他引:2
Three improved algorithms for strapdown attitude computation utilizing accumulated gyro increments from the previous and current update are developed and evaluated analytically under classical coning motion. The error criterion of Miller is derived directly from the rotation vector concept. The accuracy of updating rotation vector estimation can be improved at least two orders of magnitude as compared with those of conventional algorithms. The proposed algorithm is equivalent to increasing the number of gyro samples used in the conventional method and it requires less computer loading 相似文献
50.
Y. I. Yermolaev I. G. Lodkina N. S. Nikolaeva M. Y. Yermolaev M. O. Riazantseva 《Cosmic Research》2017,55(3):178-189
This paper discusses the errors in analyzing solar-terrestrial relationships, which result from either disregarding the types of interplanetary drivers in studying the magnetosphere response on their effect or from the incorrect identification of the type of these drivers. In particular, it has been shown that the absence of selection between the Sheath and ICME (the study of so-called CME-induced storms, i.e., magnetic storms generated by CME) leads to errors in the studies of interplanetary conditions of magnetic storm generation, because the statistical analysis has shown that, in the Sheath + ICME sequences, the largest number of storm onsets fell on the Sheath, and the largest number of storms maxima fell at the end of the Sheath and the beginning of the ICME. That is, the situation is observed most frequently when at least the larger part of the main phase of storm generation falls on the Sheath and, in reality, Sheath-induced storms are observed. In addition, we consider several cases in which magnetic storms were generated by corotating interaction regions, whereas the authors attribute them to CME. 相似文献